![]() Of the more than 700 calls received from 2003 to 2010, 59 were single-agent exposures that had been assessed as having clinical signs and exposure histories that were highly consistent with an atomoxetine exposure. With the exception of repetitive head movements reported at 16 mg/kg/day, the abstract (the full study was not published) does not provide doses at which specific clinical signs were seen.6Ī rodent study showed that when 25 mg/kg of atomoxetine was fed to female rats for two weeks before conception and continued throughout lactation, decreased pup survival rates were observed.2 A decrease in pup survival was also noted when male rats were fed the same dose starting 10 weeks before mating. In a study involving 8-week-old beagle puppies receiving oral doses of atomoxetine at 4, 8, or 16 mg/kg/day for four weeks, dose-related clinical signs of vomiting, retching, tremors, mydriasis, and decreased pupillary light reflex were noted. Other noradrenergic effects such as urinary sphincter contractions, transient hyperglycemia, and mydriasis may also be seen with excessive accumulation of norepinephrine.5Īdditionally, since the drug's release, there have been some documented cases of severe hepatic injury in people receiving this medication.2 This has not been noted in any ASPCA APCC cases. Because atomoxetine selectively inhibits the presynaptic norepinephrine transporter while having minimal affinity and effect on other neurotransmitter receptors, it may cause an increase in autonomic tone.4Īs with the body's natural fight-or-flight response, a pharmacologically induced increase in norepinephrine may result in clinical signs that are consistent with cardiovascular stimulation: vasoconstriction, hypertension, or tachycardia followed by possible reflex bradycardia. The terminal half-life in dogs after oral administration of atomoxetine at a dose of 2 mg/kg is about 3.7 (+/- 0.5) hours.3Ĭlinical research involving acute atomoxetine toxicosis in dogs and cats is minimal, and there is no LD50 established for either species. The reported elimination half-life in people is 5.3 hours in extensive metabolizers and 24 hours in poor metabolizers.2ĭogs do not express CYP2D6 they metabolize the drug by aromatic ring hydroxylation and N-demethylation, but atomoxetine is ultimately metabolized to the same primary oxidative metabolite as in humans, 4-hydroxyatomoxetine.3 In dogs, 48% of the drug is excreted through the kidneys and 42% in the feces. About 7% of Caucasian populations are poor metabolizers. Those that metabolize CYP2D6 poorly experience plasma concentrations that are five times greater than the concentrations that extensive metabolizers experience. There is a genetic polymorphism of CYP2D6 in people. In people, atomoxetine is well-absorbed orally with a peak plasma concentration occurring one or two hours after administration.2 It is highly protein bound in both dogs (97%) and people (98%).3 In people, atomoxetine is metabolized primarily through the cytochrome P-450 enzymatic pathway CYP2D6 to an oxidative metabolite (4-hydroxyatomoxetine). The mechanism of action by which this medication improves clinical signs associated with ADHD is not yet known, but it is thought to be due to the selective inhibition of the presynaptic norepinephrine transporter.1 Since the release of atomoxetine in 2003, the American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Poison Control Center (APCC) has received more than 700 calls involving a possible exposure to atomoxetine (ASPCA APCC Database, Urbana, Ill: Unpublished data, 2003-2011). However, you should be aware of its toxic potential because of its availability in households that have pets or animal visitors. ![]() This drug is not used in veterinary medicine. Atomoxetine, a selective norepinephrine reuptake inhibitor with minimal affinity for other noradrenergic receptors, is used to treat attention deficit hyperactivity disorder (ADHD) in children and adults.1 It is available by prescription under the brand name Strattera (Eli Lilly) in 10-, 18-, 25-, 40-, 60-, 80-, and 100-mg capsules.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |