(for veterinary information only)
BRAND NAMES: ADEKIN, AMANTA, AMANTAGAMMA, AMANTAN, AMANTREL, AMIXX, ANTADINE, ANTIFLU-DES, ATARIN, ATENEGINE, CEREBRAMED, ENDANTADINE, INFECTOFLU, INFLU-A, LYSOVIR, MANTADINE, MANTADIX, MANTIDAN, PADIKEN, SYMADINE, SYMMETREL, VIROIFRAL AND VIRUCID
When the NMDA receptor is antagonized or blocked by a medication such as amantadine chronic pain may be alleviated. Amantadine alone is not an effective analgesic but when combined with other pain relievers, it adds an extra dimension of pain relief. At this time veterinary experience with this drug is rather limited but it seems to be emerging as helpful addition to pain relief regimens for dogs and cats.
HOW THIS MEDICATION IS USED
Typical situations where amantadine might be used:
Diarrhea, flatulence, and agitation have been described. Humans have reported hallucinations, dizziness, and other forms of mental side effects. Overdose (in humans) has resulted in heart problems (abnormal rhythm and high blood pressure) as well as seizures and respiratory distress.
INTERACTIONS WITH OTHER DRUGS
Trimethoprim/Sulfa (an antibiotic), quinidine (a heart medication), thiazide diuretics may decrease the excretion of amantadine, yielding higher blood levels, making amantadine stronger.
Other anticholinergic drugs, such as antihistamines, may enhance the anticholinergic effects of amantadine. These effects include dry mouth (possibly showing as more lip-licking or water consumption), difficulty urinating, increased heart rate.
Other drugs that increase activity/general stimulation may exacerbate the agitation side effect sometimes seen with amantadine. Selegiline, which is frequently used to treat senile cognitive dysfunction might be an unexpected member of this category of drugs.
CONCERNS AND CAUTIONS
Probably the biggest concern is that this medication is fairly new to veterinary use and a full catalog of what to expect with its use is not yet available. Right now amantadine is growing in popularity for pets and may prove to be an excellent complement to many pain relief regimens.
In human medicine it is recommended to have caution when considering its use in patients with kidney disease, seizure disorders, active psychoses, liver disease, or congestive heart failure. This means that side effects are more likely in these situations.
Amantadine is best used in conjunction with other pain relievers and requires at least a week of use before its effectiveness can be judged.
Amantadine has a narrow therapeutic range which means accurate dosing is important to avoid toxicity. Use of oral liquid formulations allow for more accurate dosing.
Page posted: 4/16/08