Also Known As: Amantadine, Symmetrel
Amantadine is the organic compound known formally as 1-adamantylamine or 1-aminoadamantane. The molecule consists of adamantane backbone that has an amino group substituted at one of the four methyne positions. This pharmaceutical is sold under the name Symmetrel for use both as an antiviral and an antiparkinsonian drug. Rimantadine is a closely related derivative of adamantane with similar biological properties.
Apart from medical uses, this compound is useful as a building block, allowing the insertion of an adamantyl group.
According to the US Centers for Disease Control and Prevention, 100% of seasonal H3N2 and 2009 pandemic flu samples tested have shown resistance to adamantanes, and amantadine is no longer recommended for treatment of influenza. Additionally, its effectiveness as an antiparkinsonian drug is controversial, with a 2003 Cochrane Review concluding that it was ineffective for this purpose.
Amantadine is a weak antagonist of the NMDA type glutamate receptor, increases dopamine release and blocks dopamine reuptake. This makes it a weak therapy for Parkinson's disease. Although, as an antiparkinsonian it can be used as monotherapy; or together with L-DOPA to treat L-DOPA-related motor fluctuations (i.e., shortening of L-DOPA duration of clinical effect, probably related to progressive neuronal loss) and L-DOPA-related dyskinesias (choreiform movements associated with long-term L-DOPA use, probably related to chronic pulsatile stimulation of dopamine receptors).
Contrary to its continued use, a 2003 Cochrane review of the scientific literature concluded that there is inadequate evidence to support the use of amantadine for Parkinson's.
Amantadine is no longer recommended for treatment of influenza A infection.
For the 2008/2009 flu season, the United States' Centers for Disease Control and Prevention (CDC) found that 100% of seasonal H3N2 and 2009 pandemic flu samples tested have shown resistance to adamantanes. The CDC issued an alert to doctors to prescribe the neuraminidase inhibitors oseltamivir and zanamivir instead of amantadine and rimantadine for treatment of current circulating flu.
Amantadine is frequently used to treat the chronic fatigue often experienced by patients with multiple sclerosis. Additionally, there have been anecdotal reports that low-dose amantadine has been successfully used to treat ADHD. Limited data has shown that amantadine may help to relieve SSRI-induced sexual dysfunction.