|
Capstar Flea Medication (active ingredient: Nitenpyram) - Information about Capstar Flea Control Pills For Dogs and Cats.
Important note: I have researched and written this page to provide information on Nitenpyram from a veterinary perspective. I am not paid to promote Capstar flea control (the trading name of Nitenpyram in Australia) as a flea treatment, although I have used the product in practice and have found that it acts well as a speedy flea killer for cats and dogs (the function for which it was designed). 
Capstar Flea Control (Nitenpyram) - Contents: 1) What is the active ingredient of Capstar flea medication? 2) What does Capstar do to fleas? How does the Nitenpyram work? 3) Does Capstar Nitenpyram kill adult fleas? 4) Capstar for cats and dogs - how to use Capstar flea control pills (includes information on storage and dosing). 5) How long does Capstar work for once it has been given? 6) What age can dogs and cats start taking Capstar flea medication? 7) Can Capstar flea control pills be used on other species besides the dog and cat? 8) Can Capstar flea control pills containing Nitenpyram be used on pregnant or lactating animals? 9) Nitenpyram safety and side effects - How safe is Capstar? 10) Is Capstar flea treatment useful in dogs and cats suffering Flea Allergy Dermatitis (FAD)? 11) Capstar also kills the maggots of blowflies and screw-worm flies, helping to treat cutaneous myiasis (flystrike). Note - This is off-label use.
1) What is the active ingredient of Capstar flea medication? The active ingredient in Capstar flea medication is a chemical compound called Nitenpyram. The drug belongs to a newer class of chemical insecticides called neonicotinoids. Nitenpyram is closely related to other neonicotinoid insecticidal compounds including: imidacloprid, acetamiprid, clothianidin, dinotefuran, thiacloprid and thiamethoxam, which are used in the control of fleas (imidacloprid, nitenpyram) and other garden and crop pests (generally pests that feed by piercing or sucking juices and saps from the plants). These chemicals bind to the post-synaptic nicotinic acetylcholine receptors (nAChR) of insect motoneurones (see next section for details), causing paralysis of the insects and then death. The product is adulticidal, meaning that it works to kill adult fleas rather than their eggs, larvae or cocoons. Nitenpyram as it occurs in Capstar flea control pills is white to yellow in colour. Capstar is not quite odorless, however, the smell is mild and in no-way noxious. Nitenpyram is non-flammable, non-corrosive and non-explosive, however it is potentially combustible. Capstar flea control pills are immiscible in water, meaning that they will not dissolve to form a homogenous solution or suspension with water. Nitenpyram is chemically stable under normal conditions of storage. Nitenpyram generally appears on its own in products (e.g. Capstar flea medication), however, sometimes it is used concurrently with Lufenuron flea control to achieve both an insect growth inhibition effect (the Lufenuron) and an adult-flea killing effect (the Nitenpyram). For information on the concurrent use of Capstar flea medication (Nitenpyram) and Program flea control (Lufenuron), refer to the following information sheet by Novartis: http://www.capstarpet.com/pdf/Product_Info.pdf Links to the Capstar flea medication MSDS are found at the end of this page.
2) What does Capstar do to fleas? How does the Nitenpyram work? The following information on the effect of Capstar flea medication pertains mainly to cat and dog flea species (Ctenocephalides felis and Ctenocephalides canis). Most of the studies into Nitenpyram that I could find were performed on Ctenocephalides fleas (probably because these are a common nuisance flea species and probably because they are found on the types of animal hosts that Novartis has targeted with this particular flea control product range). Consequently, I can not say for sure whether or not the product will have the same effect on rabbit stickfast fleas, poultry fleas or other kinds of fleas. I imagine that it might (after all, other fleas drink blood too), but can give no guarantees. Capstar flea control pills are administered to dogs and cats orally. The Nitenpyram present in the Capstar flea medication product enters the treated animal's bloodstream and circulates with the blood. Adult fleas ingest the Nitenpyram medication when they drink the blood of the medicated dog or cat. The Nitenpyram kills the adult flea. How Nitenpyram works: Nitenpyram is a neonicotinoid chemical, which, loosely translated, means: "new or novel nicotine-related" chemical. Neonicotinoid insecticides are synthetic variations of nicotine: a natural alkaloid compound that exists within the leaves of a variety of plant species of the Genus Nicotiana, including those trees responsible for producing tobacco (as in cigarettes). Nitenpyram and other drugs of the neonicotinoid family (e.g. imidacloprid as found in the flea control product: Advantage) act on the same bodily receptors as the drug nicotine does. These receptors are called nicotinic acetylcholine receptors (nAChR). Nicotinic acetylcholine receptors in animals: Nicotinic acetylcholine receptors (nAChR) are found in many locations within the animal nervous system. They are present in the synapses of the nerve bundles (called ganglions) supplying the parasympathetic and sympathetic nervous systems and they are also present on the surface of the animal's muscle cells where the nerves supplying the muscles make close contact (another form of synapse connection whereby the nerve end plate sends a chemical signal (a chemical called acetylcholine or ACh) to the muscle cells over a synaptic gap). Explanatory author's note: Nerves are not continuous. For example, one nerve doesn't go straight from the brain to a toe. When the brain wants to tell a toe to move, it sends electrical nerve signals to the toe along of chain of interlinking nerves. These nerves communicate by relaying signals to one other in order along the chain. When one nerve wants to relay a signal (say, to the next nerve along the chain or to the muscle it wants to activate, like a toe muscle), it must do so by secreting a chemical called a neurotransmitter. Acetylcholine (abbreviated to ACh) is but one type of neurotransmitter. This neurotransmitter crosses a small gap between the nerve that secreted it (the nerve 'sending the message') and the next nerve or muscle intended for activation. This gap is called a "synapse". The neurotransmitter binds to a receptor on the nerve or muscle intended for activation, causing activation to occur. The receptor that receives ACh and becomes activated is called the acetylcholine receptor (AChR). There are a couple of types of AChR and one type is called a 'nicotinic' AChR because scientists found that the drug "nicotine" also activated this particular acetylcholine receptor in much the same way as true acetylcholine did (i.e. nicotine worked by binding to and activating those particular acetylcholine receptors of the body thereby mimicking the AChR activation effects of the body's own natural ACh). When nicotine or the body's own acetylcholine activates the 'nicotinic' acetylcholine receptors in the body, it causes activation of the sympathetic and parasympathetic nerves (via activation of the nerve synapse bundles or ganglia supplying them) and also activation/stimulation of the body's muscles. Concurrent activation of the sympathetic and parasympathetic nervous systems through activation of the nicotinic AChR in the neural ganglions produces a wide range of effects, some of which are typical of parasympathetic nerve stimulation and some of which are more typical of sympathetic (flight or fight) nerve stimulation. These include: peripheral blood vessel constriction, effects on the heart rate (sometimes the heart will race, in keeping with sympathetic stimulation, and sometimes it will slow, in keeping with parasympathetic nerve effects), effects on blood pressure (often an increase), pupil dilation, increased mental stimulation and alertness, increased saliva production and increased gastrointestinal activity among other effects. Activation of the body muscles is needed to create muscle contraction and movement. When taken to extremes (e.g. if someone took excessive and toxic quantities of nicotine or if they took a poison like a carbamate-based snail bait that increased their levels of acetylcholine excessively), the effects of excessive acetylcholine receptor stimulation can be severe and life-threatening, producing extreme blood vessel constriction (with pallor); massive increases in blood pressure; increases in heart rate (to the point of heart palpitations or even life-threatening arrhythmias) or, alternatively, critical heart slowing; profound drooling; excessive gut contractions (to the point of vomiting or diarrhea); hyperactivity (or sometimes depression/lethargy) and extreme muscle activation and contraction, to the extent that the muscles are so over-stimulated they start to tremor uncontrollably (similar in appearance to seizuring), eventually becoming rigidly stiff and immobile and, in essence, completely paralyzed (incapable of moving from the rigid state). Such rigidity in the muscles responsible for moving the rib cage in and out causes the animal to breathe shallowly (some animals become completely incapable of drawing breath in and out and thus the animal dies from a lack of oxygen). Excessive muscle stimulation and rigidity also causes the animal to produce excessive body heat (muscle activity produces heat - which is why we shiver when we are cold - to warm up), causing extreme hyperthermia and often death from excessive body heat. So where does the flea and the Nitenpyram fit in? Nitenpyram is a neonicotinoid, meaning that it is related to and resembles nicotine in effect. Similar to the situation described above for nicotine poisoning, Nitenpyram causes excessive stimulation and swamping of the nicotinic acetylcholine receptors, producing rigidity, paralysis and death. The fantastic thing about nitenpyram, however, is that, due to its chemical structure, it is specific for the nicotinic acetylcholine receptors present on the nerves of insects like fleas. It binds strongly to insect nAChR causing intense activation of these receptors and resultant rigidity and paralysis of the insects (thus killing the fleas). Nitenpyram binds very poorly to the nicotinic acetylcholine receptors of vertebrate animals (e.g. dogs and cats and even birds and fish) and thus it does not have an effect on these species. This is the reason why side effects and toxicity effects are very uncommon in animals given Nitenpyram-containing Capstar flea control pills. Author's note: insect nicotinic acetylcholine receptors are only found in the central nervous system of the insects, not directly on the muscles as seen in vertebrates. The ultimate effect is still very similar, however. Neonicotinoid insecticides bind to the nicotinic receptors, causing them to become activated and overstimulated. The insect develops rigidity and twitching as a result. Following this period of nerve activation, the neonicotinoid drug does not unbind from the nicotinic receptor in the way that acetylcholine does (in animals, acetylcholine bound to the nAChR degrades, allowing the effect to cease). This results in the nicotinic receptors being swamped and overstimulated to the extent that the nerves become exhausted. The exhausted nerves can not send any signals at all then, (particularly since the receptors are all clogged up with neonicotinoid compounds) and, as a result, the insect becomes fully paralysed. A 2003 article in the Annual Review of Entomology confirmed the different effect of neonicotinoids on vertebrates versus insects. It showed that neonicotinoid chemicals like Nitenpyram and Imidacloprid were toxic to insects and not to vertebrates (the study focussed on mammals) because of differences in the structure of insect and mammalian nicotinic acetylcholine receptors (nAChR). The neonicotinoid drugs were capable of binding to insect nAChR and causing toxicity signs, but they were not as capable of binding to mammalian nAChR. The active 'binding site' of mammalian nAChR is negatively charged (anionic), whereas the active 'binding site' of insect nAChR (the site on the nicotinic receptor where the neonicotinoid drugs bind to exert their activation effect) is positively charged (cationic). Being positively charged, the insect nAChR is ideally suited to binding with the neonicotinoid chemicals which are negatively charged, whereas, the negatively charged mammalian nAChR would only repel these chemicals, stopping them from exerting an effect. Nitenpyram is considered to be a "full agonist" at the insect nAChR, meaning that it binds strongly to and exerts a full stimulatory effect on the insect's nicotinic acetylcholine receptor. Thus, it works quickly and aggressively to swamp the nAChR receptors on the flea's nerves causing complete over-stimulation and rapid obstruction of nerve signals and resultant paralysis. The affected flea can't move and falls off the pet, its body and legs stiffly rigid. This extreme degree of paralysis persists (the nitenpyram does not unbind from the nAChR) and the immobilised flea dies in the environment. Imidacloprid, another related flea control product, is considered to be a "partial agonist" at the insect nAChR, meaning that it binds less strongly to the receptor and does not exert as extreme or rapid a stimulatory effect (though the effect it has is still irreversible, such that it eventually causes the death of the flea, particularly at high doses). A 2007 study, published in Neurotoxicology, looked into the effect of various neonicotinoids on cockroach neurons and found imidacloprid to produce only about 20-25% of the effect of acetylcholine when applied to cockroach nAChR. Nitenpyram, in contrast, produced an effect that was 60-100% of the effect of acetylcholine (i.e. full effect and much more rapid and powerful). The result was different poisoning symptoms in the cockroaches, with depression and full paralysis observed for the full agonist compounds (e.g. Nitenpyram) and excitation responses predominating before death for the partial agonist compounds like imidacloprid (e.g. reference 15 described roaches poisoned with imidacloprid as showing: reduced leg strength, "then leg tremors, then body shaking and then death"). The reason for the different symptoms is likely to be related to the full/partial agonist difference. The full agonist completely and rapidly binds to and swamps the system, producing extreme spasms and rigidity and immobile, stiff paralysis, whereas the partial agonist binds poorly and exerts a slower, less-complete activation effect on the receptors, resulting in a more gradual onset of effect, characterised by an obvious excitation phase. Another 2008 study, published in the journal of Veterinary Parasitology, examined the effect of various flea control products, including Capstar flea medication, on flea feeding times and blood consumption quantities. The first thing noticed in the study was that 38% of fleas were dead within 1 hour of nitenpyram (Capstar flea pill) dosing and that 100% had died or were dying within 4 hours of dosing (fast acting). Capstar flea control pills (along with topical selamectin) also caused significant reduction in blood consumption by fleas. Nitenpyram-affected fleas only fed for about 15 minutes before starting to die.
3) Does Capstar Nitenpyram kill adult fleas? Yes. Capstar flea medication is designed to kill adult fleas feeding directly on the blood of the dog or cat. Capstar flea medication works very rapidly: Capstar flea control pills are almost completely absorbed from the dog or cat intestinal tract after dosing. Little is lost to the feces. Following oral dosing, peak drug levels are reached in the animal's blood after about 40 minutes in cats and 80 minutes in dogs. Adult fleas stop feeding after about fifteen minutes of consuming Nitenpyram-treated blood and dead fleas start to fall off the treated pet within about 30 minutes of dosing. It is a fast-action effect. Depending on the textbooks or journal articles you read, the time taken to achieve maximum effect and the maximum effect achieved (% of fleas killed) varies a little, however, pretty much all Nitenpyram articles state that >90-95% of fleas will be killed within 6 hours of dosing. The Novartis site (Capstar flea medication site) states that >90% of fleas on dogs will be killed within 4 hours of dosing and >90% of fleas on cats will be killed within 6 hours of dosing. Another references states that, in dogs there will be 98.6% efficacy of flea kill in 6 hours and, in cats, 98.4% efficacy over the same timespan. A 2008 study, published in the journal of Veterinary Parasitology, examined the effect of various flea control products, including Capstar flea medication, on flea survival. 38% of fleas were dead within 1 hour of nitenpyram (Capstar flea pill) dosing and 100% had died or were dying within 4 hours of dosing (fast acting). How fast is Capstar compared to other flea control products: A 2003 article published in Veterinary Parasitology compared the speed of kill and percentage of flea kill between five of the major flea control products on the market at that time (Nitenpyram, Fipronil, Imidacloprid, Selamectin and Cythioate). The results for Nitenpyram were very impressive. Within 3 hours, "nitenpyram was 100% effective in cats and 99.1% effective in dogs" and 100% effective in both species at 8 hours. Cythioate (used on cats only in the study) showed a 62.4% and 97.4% flea kill at 3 and 8 hours, respectively. Selamectin (used on dogs only in the study) showed a 39.7% and 74.4% flea kill at 3 and 8 hours, respectively. In dogs, Fipronil showed a 35.9% and 46.5% flea kill at 3 and 8 hours, respectively, whereas, in cats, the respective percentage kills were 24.3% and 62.6%. Imidacloprid in cats showed only a 26.9% flea kill at 3 hours, but then a rapid recovery response and an 82.8% flea kill at 8 hours. In dogs, a similar pattern was seen with a lower % kill (22.2%) at 3 hours, but a high % kill (95.7%) at 8 hours. Capstar flea medication doesn't maintain its effect for a very long period: Capstar flea medication is rapidly excreted via the urine and does not last in the animal's body very long (the effect is lost within 2 days, as indicated in the 2003 Journal of Medical Entomology article, below). For this reason, Capstar flea medication needs to be given daily to maintain an ongoing effect, otherwise the fleas developing and hatching out of the environment will soon invade the pet once again. The drug is not cumulative and does not build-up excessively in the body with repeated dosing. A 2003 article published in the Journal of Medical Entomology showed 100% kill of all fleas on the host animal at the time of Capstar treatment and throughout the first 24 hours immediately following dosing (i.e. new fleas that jumped onto the animal died also). Between 1 and 2 days after a single treatment, adult flea numbers were decreased by 98.6%. After day 2, however, flea control with Capstar flea medication was greatly reduced with only a 5% reduction of flea numbers recorded. What does Capstar flea medication do to immature flea stages (eggs, larvae, cocoons) and other parasite insects: Capstar flea control pills have no effect on fleas in the pet's environment. The drug only kills the fleas that drink directly from the medicated host animal. Capstar flea medication does not inhibit or destroy flea eggs, flea larvae or flea cocoons (flea pupae). It should be noted, however, that Capstar flea medication works so quickly, adult fleas rarely get a chance to lay their eggs before they die. Thus, the quantity of fertile flea eggs falling from the coat (and into the environment) of a Capstar-treated animal is greatly reduced. Thus, environmental contamination with flea eggs is also minimized. A 2003 article published in the Journal of Medical Entomology showed that there was a 97% reduction in the number of flea eggs collected from Capstar treated animals in the first 2 days after treatment. Between 2-3 days after treatment, the flea egg quantities collected from the coats of host animals were reduced by around 95.2%. Capstar flea medication does not kill ticks. Capstar flea medication will kill blow fly maggots (flystrike or myiasis). For more information, see section 11.
4) Capstar for cats and dogs - how to use Capstar flea control pills (includes information on storage and dosing). Capstar flea control pills are given to dogs and cats over 4 weeks of age, so long as the animal is over 2 lb (2 pounds or 900g in weight). Dogs and cats are dosed with Capstar flea medication at a dosage of 1mg/kg orally. A 25 pound dog is approximately 11.4kg and receives an 11.4mg dose of Capstar. CAPSTAR for cats and small dogs - each Capstar flea pill contains 11.4 mg of nitenpyram for animals 2-25 pounds (0.9-11.36kg) in weight. CAPSTAR for dogs (bigger dogs) - each Capstar flea pill contains 57.0 mg of nitenpyram for dogs 25.1-125 pounds (11.4-56.8kg) in weight. The Capstar flea control pills are available in packs of 6. Capstar is non-prescription and can be purchased over the counter. You must purchase tablets that are correct for the weight of your dog or cat. Do not split big-dog tablets to give them to smaller dogs. Capstar flea medication tablets can be given daily. They should never be given more frequently than this (only once in 24 hours). The drug is not cumulative and will not build up to toxic levels in the animal's system so long as the flea control pills are used as directed. Capstar flea medication is absorbed very well into the cat or dog's system (little is lost in the feces). Tablets may be given with or without food. Capstar flea medication begins to kill fleas within 30 minutes of dosing. Within 6-7 hours of dosing, 100% of adult, blood sucking fleas present on the animal's body will be dead. New fleas will of course jump onto your pet's body from the environment and the Capstar flea medication will get rid of these fleas very well for 24 hours after dosing (a 2003 study in the Journal of Medical Entomology showed that Nitenpyram actually maintained high effectiveness for up to 48 hours, though pills are generally administered daily). Capstar is excreted rapidly from the body via the urine and once-daily dosing is required if one is to maintain nitenpyram's excellent flea killing effect (should Capstar flea medication be the only treatment elected for that animal). Be aware that animals may show signs of agitation for up to 7 hours after treatment. This agitation is characterised by such signs as scratching, biting at the fur, licking at the fur and skin twitching. Vocalization, panting and hyperactivity may also be seen. This reaction is not a result of the drug, but a response to the rapid death of the fleas. The fleas become transiently 'excited' and twitch as the poison sets in, creating weird, possibly ticklish sensations on the dog or cat's skin. A 2003 study in the Journal of Medical Entomology describes these side effects. All canine and feline pets in the household should be treated at the same time with Capstar flea control products. This is because untreated pets can act as reservoirs for the flea life cycle. Treatment should begin in Late Winter or Early Spring at the start of the flea season. Treatment can, however, start anytime fleas are noticed on our canine and feline friends. If flea numbers are very high in the environment, you will either have to give the Capstar flea medication daily to maintain a flea killing effect (killing new fleas jumping onto the dog or cat from the environment) or you may elect to treat your pet with Capstar flea control pills as a once-off to achieve rapid flea knock-down and follow this up with another, long-lasting (monthly) flea control product. Adding in a flea treatment that controls flea larvae and eggs in the environment (e.g. Lufenuron) can also be helpful at speeding up the elimination of fleas from the environment. Treating the environment for fleas (flea bombs, vacuuming, steaming) is also beneficial. Capstar flea medication (Nitenpyram) and Program flea control (Lufenuron) are often given concurrently, as separate tablets, to the one animal. For information on the concurrent use of Capstar flea medication (Nitenpyram) and Program flea control (Lufenuron), refer to the following information sheet by Novartis: http://www.capstarpet.com/pdf/Product_Info.pdf Capstar tablets should be stored at room temp (15-25C), in a cool, dry place, well away from direct sunlight. The product comes with a long expiration time - 3 years shelf life for the Capstar flea control pills in dogs and cats. For safety, all animal pills should be kept out of reach of children. Capstar flea control pills are unaffected by grooming or bathing of the pet (the product can not be washed away or groomed off the fur like some spot-ons can). The product does not leave odorous, oily residues on the coat like some spot-on treatments can. Capstar flea medication can be used with other commonly used products and medications including: heartworm preventatives, all-wormers, vaccines, antibiotics, shampoos and most other flea control products (e.g. monthly spot-ons). Important note: The Capstar flea control packet and information sheets state that Capstar flea control pills are safe for pregnant and nursing dogs and cats. Over years of Capstar use, reports by owners of adverse effects have shown that this may no longer be the case and Novartis, as a responsible company, has since issued an update (2010 update) on the safety of Capstar flea control pills in such breeding animals. The information can be found at: http://www.capstarpet.com/pdf/Dear_Doctor.pdf Information sheets: http://www.ah.novartis.com/products/en/capstar_dog.shtml http://www.capstarpet.com/pdf/Product_Info.pdf http://ah.novartis.com.au/verve/_resources/Capstar_for_Cats_and_Small_Dogs_MSDS.pdf http://ah.novartis.com.au/verve/_resources/Capstar_for_Large_Dogs_MSDS.pdf
5) How long does Capstar work for once it has been given? Capstar flea medication is rapidly excreted via the urine and does not last for very long in the animal's body (Nitenpyram is non-cumulative and has no long term, residual activity). Capstar flea medication needs to be given daily to maintain an ongoing 100% flea-kill effect, otherwise the fleas developing and hatching out of the environment will soon invade the pet once again. A 2003 article published in the Journal of Medical Entomology showed that Nitenpyram killed 100% of all adult fleas on the host animal at the time of treatment and that it maintained this 100% kill effect throughout the first 24 hours immediately following dosing (i.e. new fleas that jumped onto the animal within the first 24 hours died also). Between days 1 and 2 following a single Nitenpyram dose, adult flea numbers were still found to be decreased by 98.6% (i.e. the Capstar flea medication was still highly effective up to 48 hours after dosing). Following day 2, however, flea control with Capstar flea treatment was greatly reduced, with only a 5% reduction in flea numbers recorded. Thus, it can be said that Capstar flea medication is massively effective at killing fleas in the first 24 hours after dosing and that its effectiveness is probably still quite high even 48 hours after dosing. Capstar flea treatment is often given as a once-off dose to achieve a high-level, rapid knock-down effect on adult fleas crawling on the dog or cat. Although the Capstar product could quite easily be given daily to maintain this flea killing effect, most owners generally follow the initial dose of Capstar up with another, long-lasting (monthly) flea control product. This is because of convenience (daily tableting is inconvenient and often quite tricky in small dogs and cats) and cost (with daily dosing, you'd be mowing through just over a packet of Capstar per week and that's if you only had one animal).
6) What age can dogs and cats start taking Capstar flea medication? Dogs and cats over 4 weeks of age can be treated with Capstar flea medication pills. Animals must be over 2 pounds (900g) in body-weight, even if they are greater than 4 weeks of age. To give you an example, most kittens do not achieve 2-pounds in bodyweight until they are at least 8-9 weeks of age, so you couldn't dose them with Capstar flea control pills before this age. Basically, make sure you weigh any small dog or cat (particularly puppies and kittens) to ensure that it is over 2 pounds or 900g in bodyweight before giving it Capstar. Super important note: The Capstar flea control packet and information sheets state that Capstar flea control pills are "safe for use in dogs and cats, puppies and kittens 2 pounds of body weight or greater and 4 weeks of age and older." Over the years, reports by owners of adverse effects have shown that this may no longer be quite the case and Novartis, as a responsible company, has since issued an update on the safety of Capstar flea control pills. The information can be found at: http://www.capstarpet.com/pdf/Dear_Doctor.pdf I would advise you to read it before giving your pet Capstar flea medication. The adverse effects information contained in the above link states that serious side effects, including seizures, neurological signs and even death, are most commonly seen in animals below 2 pounds of weight and in those animals less than 8 weeks old and/or those in poor condition (e.g. thin, sickly animals). Many of the adverse effects reported in dogs and cats following the administration of Capstar flea medication are excitatory effects including: hyperactivity, panting, nervousness, fever, vocalisation and an increased heart rate. In extreme cases, these excitatory effects have tipped over into marked gastrointestinal effects (vomiting, decreased appetite, diarrhea, salivation) and moderate to severe neurological signs (difficulty breathing, incoordination, seizures, trembling, pupil dilation), some of which have the potential to result in death (e.g. seizures). Allergic reactions have also been described, manifesting as: hypersalivation, fever, hives, swollen or puffy eyes, itching and redness. In seeming contrast, some animals have shown signs of depression and lethargy, rather than excitation, when given Capstar flea medication. Birth defects and the loss of unborn puppies and kittens have been reported following the administration of Capstar flea medication to pregnant animals. Newborn puppies and kittens (neonates) have also been reported to die following the administration of Capstar flea medication to lactating animals. Although these effects are not guaranteed to have been caused by Capstar (many factors can cause pregnancy loss and the death of delicate neonatal animals), the company recommends exercising caution with the product in pregnant and lactating animals. Here again is the updated Capstar adverse reactions link - http://www.capstarpet.com/pdf/Dear_Doctor.pdf Novartis, like all responsible drug companies, wants to know about any observed side effects. Pet owners are encouraged to report suspected side effects (most drug side effects are never known about because most pet owners never report them). If you suspect a Capstar related side effect or adverse drug event, you can call Novartis Animal Health on 1-800-637-0281 or the FDA on 1-800-FDA-VETS. You can also report issues with Capstar flea medication online at http://www.fda.gov/AnimalVeterinary/SafetyHealth/ReportaProblem/ucm055305.htm
7) Can Capstar flea control pills be used on other species besides the dog and cat? No. Even though Capstar flea medication (Nitenpyram) has been studied extensively in such mammals as rabbits, guinea pigs and rats (in addition to dogs and cats) and found to have minimal side effects in these other mammalian species, Capstar flea control pills are only registered for use in dogs and cats. They should, therefore, only be used in dogs and cats. Capstar flea medication is not recommended for other species, particularly since most other species of 'pet animal' are likely to weigh under 2 pounds (the weight below which Capstar must not be given) or well over 500 pounds (making flea control pills impractical). Toxicity studies have found Capstar flea medication to be "practically non-toxic to fish, birds and aquatic arthropods." See MSDS. Being a neonicotinoid, Nitenpyram is probably quite toxic to a broad range of insect species. It should not be allowed to contaminate outdoor environments as it may kill beneficial insect species.
8) Can Capstar flea control pills containing Nitenpyram be used on pregnant or lactating animals? The Capstar flea control packet and information sheets have always stated that Capstar flea control pills are "safe for pregnant and nursing dogs and cats." Over years of Capstar use, however, reports by owners of adverse effects have shown that this may no longer be the case and Novartis, as a responsible company, has since issued an update (2010 update) on the safety of Capstar flea control pills in such breeding and lactating animals. The information can be found at: http://www.capstarpet.com/pdf/Dear_Doctor.pdf The information states that birth defects and the loss of unborn puppies and kittens have been reported following the administration of Capstar flea medication to pregnant animals. Newborn puppies and kittens (neonates) have also been reported to die following the administration of Capstar flea medication to lactating animals. Although these effects are not guaranteed to have been caused by Capstar (many factors can cause pregnancy loss and the death of delicate neonatal animals), the company recommends exercising caution with the product in pregnant and lactating animals. Novartis, like all responsible drug companies, wants to know about any observed side effects. Pet owners are encouraged to report suspected side effects (most drug side effects are never known about because most pet owners never report them). If you suspect a Capstar related side effect or adverse drug event, you can call Novartis Animal Health on 1-800-637-0281 or the FDA on 1-800-FDA-VETS. You can also report issues with Capstar flea medication online at http://www.fda.gov/AnimalVeterinary/SafetyHealth/ReportaProblem/ucm055305.htm Additional note - The importance of pet owners reporting side effects following a drug's approval for sale is particularly important to note when you take into consideration that even the MSDS determined Nitenpyram to be safe in pregnant and lactating animals. According to the MSDS, tests on laboratory animals and cell cultures have determined that the chemical, Nitenpyram (Capstar flea medication) does not cause mutations, cancer, fetal malformations (teratogenic effects) or any other reproductive effects. http://ah.novartis.com.au/verve/_resources/Capstar_for_Large_Dogs_MSDS.pdf
9) Nitenpyram safety and side effects - How safe is Capstar Flea Treatment? Nitenpyram is a neonicotinoid, meaning that it is related to and resembles nicotine in effect. Thus, it causes stimulation of the nicotinic acetylcholine receptors (nAChR), producing excessive muscle activity, rigidity, paralysis and death. The fantastic thing about nitenpyram, however, is that, due to its chemical structure, it is specific for the nicotinic acetylcholine receptors present on the muscles and nerves of insects like fleas. It binds strongly to insect nAChR causing intense activation of these receptors and resultant rigidity and paralysis of insects (thus killing the fleas). Nitenpyram binds very poorly to the nicotinic acetylcholine receptors of vertebrate animals (e.g. dogs and cats and even birds and fish) and thus it does not have anywhere near as much of an effect on these species. This is the reason why side effects and toxicity effects are very uncommon in animals given Nitenpyram-containing Capstar flea pills. A 2003 article in the Annual Review of Entomology confirmed this. It showed that neonicotinoid chemicals like Nitenpyram and Imidacloprid were toxic to insects and not to vertebrates (the study focussed on mammals) because of differences in the structure of insect and mammalian nicotinic acetylcholine receptors (nAChR). The neonicotinoid drugs were capable of binding to insect nAChR and causing toxicity signs, but they were not as capable of binding to mammalian nAChR. The active 'binding site' of mammalian nAChR is negatively charged (anionic), whereas the active 'binding site' of insect nAChR (the site on the nicotinic receptor where the neonicotinoid drugs bind to exert their activation effect) is positively charged (cationic). Being positively charged, the insect nAChR is ideally suited to binding with the neonicotinoid chemicals which are negatively charged, whereas, the negatively charged mammalian nAChR would repel these chemicals, stopping them from exerting much of an effect. The Capstar flea treatment packet and information sheets state that Capstar flea control pills are "safe for use in dogs and cats, puppies and kittens 2 pounds of body weight or greater and 4 weeks of age and older." Over the years, reports by owners of adverse effects have shown that this may no longer be quite the case and Novartis, as a responsible company, has since issued an update on the safety of Capstar flea control pills. The information can be found at: http://www.capstarpet.com/pdf/Dear_Doctor.pdf I would advise you to read it before giving your pet Capstar flea medication. The adverse effects information contained in the above link states that serious side effects including seizures, neurological signs and even death, whilst very rare overall, are most commonly seen in animals below 2 pounds of weight and in those animals less than 8 weeks old and/or those in poor condition (e.g. thin, sickly animals). Many of the adverse effects reported in dogs and cats following the administration of Capstar flea medication are excitatory effects including: hyperactivity, panting, nervousness, fever, vocalisation and an increased heart rate. In extreme cases, these excitatory effects have tipped over into marked gastrointestinal effects (vomiting, decreased appetite, diarrhea, salivation) and moderate to severe neurological signs (difficulty breathing, incoordination, seizures, trembling, pupil dilation), some of which have the potential to result in death (e.g. seizures). Allergic reactions have also been described, manifesting as: hypersalivation, fever, hives, swollen or puffy eyes, itching and redness. In seeming contrast, some animals have shown signs of depression and lethargy, rather than excitation, when given Capstar flea medication. Birth defects and the loss of unborn puppies and kittens have been reported following the administration of Capstar flea medication to pregnant animals. Newborn puppies and kittens (neonates) have also been reported to die following the administration of Capstar flea medication to lactating animals. Although these effects are not guaranteed to have been caused by Capstar (many factors can cause pregnancy loss and the death of delicate neonatal animals), the company recommends exercising caution with the product in pregnant and lactating animals. Here again is the updated Capstar adverse reactions link - http://www.capstarpet.com/pdf/Dear_Doctor.pdf Important note: It is important to mention that, although this 'side effects' section mentions many nasty adverse reactions that might be attributed to Capstar flea medication, in reality, such side effects are exceedingly rare. I have never personally seen a reaction from Capstar and have used a lot of it. The only reaction I have typically seen is the irritation and itching reaction described in the next paragraph. Just looking at the dose range for Capstar flea control pills should give you an idea of the drug's safety. A whole 11.4mg tablet will treat an animal from 1kg to 11.36kg. The 1kg animal is receiving a dose that is 11.4x that of the 11.36kg animal and yet it is not poisoned. It shows that Capstar flea medication has a broad safety range. Be aware, readers, that animals will often show signs of agitation for up to 7 hours after Capstar treatment is given and that these signs are not usually adverse reactions of the severe kind described in the "Dear Doctor" letter contained in the link above. This particular and common form of 'agitation' is characterised by such signs as scratching, biting at the fur, licking at the fur and skin twitching. Vocalisation, panting and hyperactivity may also be seen. This form of reaction is not generally a result of the drug (i.e. it is not a toxicity or drug-intolerance effect), but a response to the rapid death of the fleas in the fur. The fleas become transiently 'excited' and twitch as the Nitenpyram poison sets in, creating weird, possibly ticklish sensations against the dog or cat's skin. A 2003 study in the Journal of Medical Entomology confirms and describes these effects. It found an increase in "scratching, biting, licking and twitching" symptoms in the first 5 hours after Capstar administration, with biting and licking continuing to 7 hours after the drug was first dosed. Novartis says that Capstar flea medication can be used with many other commonly used products and medications including: heartworm preventatives, all-wormers, vaccines, antibiotics, shampoos and most other flea control products (e.g. monthly spot-ons). Corticosteroids are also included in the list of drugs that Capstar flea medication is safe to give with. Novartis, like all responsible drug companies, wants to know about any observed side effects. Pet owners are encouraged to report suspected side effects (most drug side effects are never known about because most pet owners never report them). If you suspect a Capstar related side effect or adverse drug event, you can call Novartis Animal Health on 1-800-637-0281 or the FDA on 1-800-FDA-VETS. You can also report issues with Capstar flea medication online at http://www.fda.gov/AnimalVeterinary/SafetyHealth/ReportaProblem/ucm055305.htm Toxicity studies have found Capstar flea medication to be "practically non-toxic to fish, birds and aquatic arthropods." See MSDS. Important: Being a neonicotinoid, Nitenpyram is probably quite toxic to a broad range of insect species. It should not be allowed to contaminate outdoor environments as it may kill beneficial insect species.
10) Is Capstar flea treatment useful in dogs and cats suffering Flea Allergy Dermatitis (FAD)? Animals with flea allergy dermatitis are allergically sensitized to fleas such that they have a severe skin reaction (itching, scratching, rashing) each time a flea bites them. In such animals, the immune system is reacting inappropriately and extremely to elements (antigens) that are present in the flea's saliva and/or feces. It can take a single flea bite to set a flea allergic animal off on a path of scratching (you might not even see any fleas on the animal - the flea has simply jumped on, bitten and then jumped off again, leaving the animal to itch away). The best flea control products for helping flea allergic dogs and cats are those that kill all adult fleas (i.e. high effectiveness) in a very short period of time (fast-acting), whilst at the same time limiting adult flea feeding times (which is where allergic sensitization occurs - when the animal is exposed to the flea's saliva and droppings). On all of these points, Capstar flea medication ticks all the required boxes (if it only lasted longer in the animal's system, Capstar would probably be the number 1 flea control product for flea allergy dermatitis because it does everything else right). Capstar is super-fast-acting and highly-effective (high % flea kills within 6 hours): Capstar flea control pills are almost completely absorbed from the dog or cat intestinal tract after oral dosing and, following dosing, peak drug levels are reached in the animal's blood-stream after only about 40 minutes in the cat and 80 minutes in the dog. The adult fleas stop feeding after about fifteen minutes of consuming Nitenpyram-treated blood and dead fleas start to fall off the treated pet within about 30 minutes of dosing. It is a fast-action effect. Depending on the textbooks or journal articles you read, the time taken to achieve maximum effect and the maximum effect achieved (% of fleas killed) varies a little, however, pretty much all Nitenpyram articles I've read state that >90-95% of fleas will be killed within 6 hours of dosing (most journal articles seem to record a 100% kill of all adult fleas within 6 hours). The Novartis site (Capstar flea medication site) states that >90% of fleas on dogs will be killed within 4 hours of dosing and >90% of fleas on cats will be killed within 6 hours of dosing. Their site is probably being conservative (not wanting to overstate their claims) because most of the studies I have read record >95% flea kills and often 100% kills at 6-8 hours post-dosing. How fast is Capstar compared to other flea control products: A 2003 article published in Veterinary Parasitology compared the speed of kill and percentage of flea kill between five of the major flea control products on the market at that time (Nitenpyram, Fipronil, Imidacloprid, Selamectin and Cythioate). The results for Nitenpyram were very impressive. Within 3 hours, "nitenpyram was 100% effective in cats and 99.1% effective in dogs" and 100% effective in both species at 8 hours. Cythioate (used on cats only in the study) showed a 62.4% and 97.4% flea kill at 3 and 8 hours, respectively. Selamectin (used on dogs only in the study) showed a 39.7% and 74.4% flea kill at 3 and 8 hours, respectively. In dogs, Fipronil showed a 35.9% and 46.5% flea kill at 3 and 8 hours, respectively, whereas, in cats, the respective percentage kills were 24.3% and 62.6%. Imidacloprid in cats showed only a 26.9% flea kill at 3 hours, but then a rapid recovery response and an 82.8% flea kill at 8 hours. In dogs, a similar pattern was seen with a lower % kill (22.2%) at 3 hours, but a high % kill (95.7%) at 8 hours. Capstar flea medication greatly reduces flea feeding times and blood consumed: A 2008 study, published in the journal of Veterinary Parasitology, examined the effect of various flea control products, including Capstar flea medication, on flea feeding times and blood consumption quantities. The first thing noticed in the study was that 38% of fleas were dead within 1 hour of nitenpyram (Capstar flea pills) dosing and that 100% had died or were dying within 4 hours of dosing (again - fast acting). Capstar flea control pills also caused significant reduction in blood consumption by fleas. Nitenpyram-affected fleas only fed for about 15 minutes before starting to die. Only topical selamectin (Revolution) was found to be similar in its ability to greatly limit flea feeding times and blood consumption. Note that Spinosad (Comfortis) was not around when this study was conducted so wasn't compared at this time. The abstract ends by stating: "In this study systemically acting insecticides such as nitenpyram, and the topically applied but systemically active insecticide selamectin, were more effective in interfering with flea blood feeding than were imidacloprid and fipronil." Additionally, Capstar flea medication is compatible with corticosteroid administration (prednisolone, dexamethasone and so on). Corticosteroids are commonly given to flea allergy dogs and cats to reduce the severity of the allergic skin reaction and lessen the signs of skin irritation associated with the flea allergy dermatitis condition. Overall, it would seem that Capstar flea medication is one of the better flea control products to give to pets suffering from flea allergy dermatitis. The main issue with Capstar flea medication is that it is rapidly excreted via the urine and does not last for very long in the animal's body (Nitenpyram is non-cumulative and has no long term, residual activity). Capstar flea medication needs to be given daily to maintain an ongoing 100% flea-kill effect, otherwise the fleas developing and hatching out of the environment will soon invade and bite the sensitised pet once again. Capstar is often given as a once-off dose to achieve a high-level, rapid knock-down effect on adult fleas crawling on the dog or cat. Although the Capstar product could quite easily be given daily to maintain this flea killing effect, most owners generally follow the initial dose of Capstar up with another, long-lasting (monthly) flea control product. This is because of convenience (daily tableting is inconvenient and often quite tricky in small dogs and cats) and cost (with daily dosing, you'd be mowing through just over a packet of Capstar per week and that's if you only had one animal). Following up with selamectin (which also greatly inhibits flea feeding times) would seem to be a good choice in flea allergy dermatitis dogs and cats (selamectin is typically more expensive than fipronil or imidacloprid, though). Be aware too that Capstar flea medication does not have any effect on fleas in the pet's environment. The drug only kills the fleas that drink directly from the medicated host animal. Capstar flea treatment does not inhibit or destroy flea eggs, flea larvae or flea cocoons (flea pupae), which is not ideal with flea allergy conditions. With flea allergy dermatitis, you do want to aim for rapid and complete destruction and removal of the flea life stages (flea eggs, larvae and cocoons) present in the pet's environment. Adult fleas only come from the immature flea stages present in the environment and if these are nullified, adult fleas will stop hatching out of the environment and thus flea control will be achieved. With no adult fleas about, the animal with flea allergic dermatitis will improve and most likely its condition will resolve significantly. For this reason, Capstar flea treatment is often coupled with Program flea control (Lufenuron - an insect growth inhibitor that renders fertilised flea eggs and flea larvae non-viable) to achieve an aggressive flea killing effect and reduced flea feeding times (Nitenpyram) along with control of the environmental immature flea stages (Lufenuron). It should be noted, however, that Capstar flea medication works so quickly, adult fleas rarely get a chance to lay their eggs before they die. Thus, the quantity of fertile flea eggs falling from the coat (and into the environment) of a Capstar-treated animal is greatly reduced. Thus, environmental contamination with flea eggs is also minimised. A 2003 article published in the Journal of Medical Entomology showed that there was a 97% reduction in the number of flea eggs collected from Capstar treated animals in the first 2 days after treatment. Between 2-3 days after treatment, the flea egg quantities collected from the coats of host animals were reduced by around 95.2%.
11) Capstar also kills the maggots of blowflies and screw-worm flies, helping to treat cutaneous myiasis (flystrike). To go from this Capstar flea treatment page to my detailed Flea Control Page, click here.
1) Arthropods. In Bowman DD, Lynn RC, Eberhard ML editors: Parasitology for Veterinarians, USA, 2003, Elsevier Science.
|
