(Reuters) - Scientists researching drugs to treat alcoholism are building on an established range of treatments which target known areas of brain activity.
The following overview outlines treatments already available, and those more recently launched or in clinical trials, and the brain activity they target.
The three main drugs with regulator approval for treating alcohol dependence are naltrexone, acamprosate, and disulfiram. A fourth, topiramate, which is used in epilepsy, is showing some encouraging results in clinical trials for alcoholism.
* Naltrexone blocks opioid receptors that are involved in the rewarding effects of drinking and in the craving for alcohol. It reduces relapse to heavy drinking and is highly effective in some but not all patients.
* Acamprosate is an NMDA agonist and is thought to reduce symptoms of protracted withdrawal, such as insomnia, anxiety, restlessness, and dysphoria (an unpleasant or uncomfortable emotional state, such as depression, anxiety, or irritability). It may be more effective in patients with severe dependence.
* Disulfiram interferes with the degradation of alcohol, resulting in the accumulation of acetaldehyde, which, if the patient drinks alcohol produces an unpleasant reaction that includes flushing, nausea, and palpitations. Compliance can be a problem, but among patients who are highly motivated, disulfiram can be very effective.
Launched or Clinical trials phase of development for the treatment of alcoholism
ALKS-33 Alkermes Phase II Opioid receptor
ALKS-29 Alkermes Phase II Opioid receptor
naltrexone Launched US/Russia (slow release) Alkermes Preregistration UK,
and Germany Opioid receptor
nalmefene IVAX/Lundbeck/ Phase III
BioTie/Whanln EU, US, Korea Opioid receptor
Quetiapine AstraZeneca Phase II 5-HT2 receptor/
fumerate Dopamine receptors
neramexane Merz Phase II NMDA receptor
OpRA II Eli Lilly Phase II Opioid receptor
MK-0594 Merck & Co Phase II undisclosed
SCH-900435 Merck & Co Phase II Glycine transporter-1
LY-2196044 Eli Lilly Phase II undisclosed
KRL-901 Krele Pharma Clinical undisclosed
TO-2060 Transcept Pharma Clinical 5-HT2/3 receptor/
Sources: Thomson Pharma and the National Institute on Alcohol Abuse and Alcoholism in the United States.
Reporting by Kate Kelland; editing by Ben Hirschler and Sara Ledwith