Question

Psychoactive drugs are often used in the treatment of addiction to other psychoactive drugs.

a. Name one drug that is used as an agonist in the treatment of heroin dependence. In a few sentences, describe the pharmacodynamic effect of this drug, to show your understanding of the use of agonistic drugs in therapy.      

b. Now name a drug that is anantagonist to heroin. How does it differ in both use and biochemical action from the agonist you just discussed?

c. In your opinion, is it appropriate to use psychoactive drugs as therapy in treating addiction to psychoactive drugs?

Answer 1

A. Methadone (Dolophine or Methadose) is a slow-acting opioid agonist. Methadone is taken orally so that it reaches the brain slowly, dampening the high that occurs with other routes of administration while preventing withdrawal symptoms. Methadone is an opioid agonist acting by binding to ?, ? and ? opioid receptors (MOR, KOR and DOR, respectively). Its pharmacodynamic properties, such as analgesia, respiratory depression, dependence and tolerance are primarily triggered by MOR activation.

B. Naltrexone (Vivitrol) is an opioid antagonist. It is used for heroine dependence. Naltrexone blocks the action of opioids, is not addictive or sedating, and does not result in physical dependence; however, patients often have trouble complying with the treatment, and this has limited its effectiveness.

C. Psychoactive therapies are also used to treat psychoactive drug dependence. Motivational and cognitive therapies are designed to work on the same motivational processes in the brain that are affected by psychoactive substances. These therapies try to replace the motivation to use substances with the motivation to engage in other behaviours.