4.4.6 Controlled substances
Controlled Substances
Controlled substances are drugs that are regulated by government agencies due to their potential for abuse and harm. They are classified into schedules based on their accepted medical use, the potential for abuse, and safety. Examples include marijuana, cocaine, heroin, methamphetamine, and prescription drugs such as opioids and benzodiazepines. The possession, distribution, and use of these substances are subject to legal restrictions and penalties.
In the United Kingdom, controlled substances are classified into five schedules, known as Schedules 1 to 5, based on their medical use and potential for abuse.
Drugs used in the Management of Addictions
There are several medications used in the management of addictions, including:
| Drug: | Drug class: | Summary: |
| Methadone | Synthetic opioid | Used to treat addiction to heroin and other opioids |
| Buprenorphine | Partial opioid agonist | Used to treat addiction to opioids. |
| Naltrexone | Opioid antagonist | Used to treat addiction to opioids and alcohol |
| Acamprosate | GABA (gamma-Aminobutyric acid) modulator | A medication used to treat alcohol dependence by reducing cravings and the risk of relapse. |
| Disulfiram | Antabuse (alcohol deterrent) – blocks this oxidation by inhibiting aldehyde dehydrogenase, causing a rapid rise of acetaldehyde in the blood when alcohol is consumed | A medication used to treat alcohol dependence by causing a negative reaction to alcohol consumption, such as nausea and flushing. |
| Varenicline | Nicotinic receptor agonist | A medication used to treat nicotine addiction by reducing the craving for nicotine and blocking the effects of nicotine if the individual smokes. |
Putative Modes of Action and Safety/Tolerability Issues
Here is a brief overview of the putative modes of action and safety/tolerability issues for each of the six medications used in the management of addictions:
- Methadone: Methadone works by binding to the same receptors in the brain as opioids, reducing withdrawal symptoms and cravings. The safety and tolerability of methadone can vary between individuals, but it can cause side effects such as drowsiness, dizziness, and nausea. Methadone can also interact with other medications and has a potential for overdose, especially when not taken as prescribed.
- Buprenorphine: Buprenorphine works by binding to the same receptors in the brain as opioids, reducing withdrawal symptoms and cravings. It is a partial agonist, meaning it has a lower potential for overdose compared to full agonists like methadone. However, buprenorphine can still cause side effects such as dizziness, nausea, and headache, and it can interact with other medications.
- Naltrexone: Naltrexone works by blocking the effects of opioids in the brain, reducing the risk of relapse. It is a safe and well-tolerated medication for most individuals, but it can cause side effects such as nausea, headache, and fatigue. It is important to note that naltrexone is not suitable for individuals who are currently using opioids, as it can cause rapid opioid withdrawal.
- Acamprosate: Acamprosate works by modulating the levels of the neurotransmitter GABA in the brain, reducing cravings and the risk of relapse in individuals with alcohol addiction. It is a well-tolerated medication with few side effects, but it can cause diarrhoea, nausea, and headache in some individuals.
- Disulfiram: Disulfiram works by causing a negative reaction to alcohol consumption, making it an effective deterrent for individuals with alcohol addiction. It is a safe and well-tolerated medication for most individuals, but it can cause side effects such as headache, nausea, and fatigue. Disulfiram can also interact with other medications, so it’s important to inform your healthcare provider of all medications you are taking.
- Varenicline: Varenicline works by binding to the nicotinic receptors in the brain, reducing cravings and the effects of nicotine. It is a safe and well-tolerated medication for most individuals, but it can cause side effects such as nausea, headache, and insomnia. Varenicline can also interact with other medications, so it’s important to inform your healthcare provider of all medications you are taking.
(Meyer, 2018)
References:
(1) Meyer, J.S., Quenzer, L.F., Rice, S.A. and Yates, J.R. (2018). Psychopharmacology : drugs, the brain, and behavior. Sunderland, Massachusetts, Usa: Sinauer Associates, Inc. ; New York, Ny, United States Of America.