Amantadine (Symmetrel) is a drug that has US Food and Drug Administration approval for use both as an antiviral and an antiparkinsonian drug.Amantadine is a weak antagonist of the NMDA type glutamate receptor, increases dopamine release, and blocks dopamine reuptake.Amantadine has been associated with several central nervous system (CNS) side effects, likely due to amantadine's dopaminergic and adrenergic activity, and to a lesser extent, its activity as an anticholinergic.
Ketamine is a drug used in human and veterinary medicine, primarily for the induction and maintenance of general anesthesia, usually in combination with a sedative. Pharmacologically, ketamine is classified as an NMDA receptor antagonist.
NMDA receptor antagonists are a class of anesthetics that work to antagonize, or inhibit the action of, the N-methyl d-aspartate receptor (NMDAR). They are used as anesthesia for animals and, less commonly, for humans; the state of anesthesia they induce is referred to as dissociative anesthesia. Memantine is an uncompetitive NMDA channel blocker. Memantine is the first in a novel class of Alzheimer's disease medications acting on the glutamatergic system by blocking NMDA glutamate receptors.
Naltrexone (Vivitrol) is an opioid receptor antagonist for alcohol dependence and opioid dependence. It is marketed in generic form as its hydrochloride salt, naltrexone hydrochloride, and under the trade names Revia & Depade. In some countries including the United States, a once-monthly extended-release injectable formulation is the trade name Vivitrol. Also in the US, Methylnaltrexone Bromide, a closely related drug, is Relistor, for the treatment of opioid induced constipation.
Bupropion (Wellbutrin, Zyban) is an atypical antidepressant and smoking cessation aid. Its chemical name is β-keto-3-chloro-N-tert-butylamphetamine, a substituted cathinone (β-ketoamphetamine), as well as substituted amphetamine. Its primary action is thought to be NE-DA reuptake inhibition. It binds selectively to the dopamine transporter, but its behavioural effects have often been attributed to its inhibition of NE reuptake. It also acts as a nicotinic ACh receptor antagonist.