One effective medication used in smoking cessation is Zyban, generically known as bupropion. This medication produces higher dopamine levels to avoid the precipitous drop a smoker experiences when he or she stops smoking.
A newer medication for smoking cessation is Chantix, generically known as varenicline. It activates the nicotinic receptors that cause the release of dopamine, but it does so only partially. It provides a small, steady release of dopamine while blocking the usual rush of dopamine that smoking typically provides. Therefore, there is no positive reinforcement.
Vivitrol and Revia, generically known as naltrexone, are medications for treating alcohol that block alcohol from binding to the opioid receptors that activate dopamine. These medications block the positive reinforcement of alcohol.
A new medication Acamprosate is being used to treat alcohol addiction. Its molecular structure is similar to that of glutamate. Acamprosate slows the release of glutamate. (Glutamate can be too stimulating and overwhelming for the brain.) By slowing its release, one may feel less inclined to calm the brain with alcohol.
Baclofen, a muscle relaxant, stimulates production of the inhibitor gamma-aminobutyric acid (GABA). GABA's role is the opposite to that of glutamate. Baclofen appears to reduce the cravings for several different addictive substances.
Topiramate is an antiseizure medication that appears to increase GABA levels and reduce cravings for addictive substances. In one (manufacturer-supported) research study, 370 adults with alcohol dependence were randomized to Topiramate (up to 300 milligrams daily) or a placebo for 14 weeks and Topiramate significantly reduced alcohol consumption.
Rimonabant is a medication that blocks cannabinoid receptors (the same receptors stimulated by marijuana). Our bodies naturally produce a marijuana-like chemical known as endocannabinoid. Blockage of this receptor appears to decrease cravings for food, nicotine, and alcohol. When it came up for FDA review in 2007, it was not approved for use in the United States because of psychiatric side effects.