Codeine

Codeine is an opiate analgesic originally derived from the opium poppy, Papaver somniferum. The history of opium use dates back to ancient Mesopotamian times, circa 3400 BCE, where it was known as “joy plant”. However, codeine itself wasn’t isolated until the early 19th century. A French chemist, Pierre Jean Robiquet, is credited with discovering codeine in 1832 during his investigations into opium alkaloids.¹

Appearance

Codeine tablets are typically small, round or oval-shaped, and white. However, the exact appearance can vary depending on the manufacturer and any other medications that may be combined with it. Codeine-containing cough syrups may be clear to light pink or purple, depending on the brand and formulation.⁵

Tastе

Codeine has a bitter taste, but it is often masked by sweeteners or other flavours when it is included in cough syrups or other liquid formulations. Tablets do not generally have a strong taste as they are intended to be swallowed whole, not chewed.

Smell

Codeine tablets and syrup do not have a distinctive smell. Any odour would likely come from other ingredients in the formulation.

Codeine can be administered in several ways, depending on the medical requirement. It is most commonly available in oral formulations, including tablets and liquids. When prescribed, it’s crucial to follow the healthcare provider’s instructions regarding dosage and frequency of administration.

For adult patients, the following dosages are typical, although the exact dosage may vary depending on the individual’s health condition, body weight, and previous exposure to opioids⁶:

• Minimum to feel something: A dose as low as 15mg may be sufficient to produce noticeable pain relief in some individuals.
• Low dose: Codeine is typically prescribed at a dose of 15-30mg every four to six hours as needed for pain, up to a maximum of 120mg per day.
• Common dose: The common dosage for moderate pain is 30-60mg every four to six hours as needed, not exceeding 240mg daily.
• High dose: Doses higher than 60mg every four to six hours are rarely more effective at managing pain and increase the risk of side effects. Higher doses may be used in specific cases under careful medical supervision.

Exceeding the high dose of codeine can lead to dangerous and potentially life-threatening effects, such as extreme drowsiness, slowed breathing, loss of consciousness, and even overdose, which can be fatal. This is especially risky for people who are ‘ultra-rapid metabolisers’ of codeine into morphine.³

Users commonly report feelings of relaxation, euphoria, and drowsiness. It also relieves pain and suppresses cough. However, it can cause side effects such as nausea, constipation, and itching.¹

Codeine can cause nausea, constipation, and itching. Prolonged use can lead to addiction and physical dependence.

The effects of codeine are typically felt within 30 minutes to an hour after oral administration.⁶

The effects of codeine can last for around four to six hours.⁶

The risks associated with codeine use include dependence and addiction, respiratory depression, constipation, and, in severe cases, overdose and death. Misuse can also lead to serious health problems. ^{4, 7}

Codeine is addictive. Prolonged use, even as prescribed by a doctor, can lead to physical dependence and withdrawal symptoms when discontinued. Problematic use or misuse, such as using higher doses or using it for longer periods than prescribed, can lead to addiction.⁷

In the UK, codeine is a Class B, Schedule 2 drug. This means having for yourself, giving away, or selling is illegal. Possession can get you up to 5 years in prison, an unlimited fine, or both. Supplying someone else, including your friends, can get you up to 14 years in prison, an unlimited fine, or both.⁸

Mixing codeine with alcohol or with other sedatives can lead to an increased risk of respiratory depression and potentially fatal overdose. It should also not be combined with certain antidepressants or other medications that depress the central nervous system.⁶

1. Smith, H.S. 2009. Opioid Metabolism. Mayo Clinic Proceedings, 84(7), 613-624. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2704133/
2. Kalso, E., Edwards, J.E., Moore, R.A. & McQuay, H.J. 2004. Opioids in Chronic Non-cancer Pain: Systematic Review of Efficacy and Safety. Pain, 112(3), 372-380. Available at: https://pubmed.ncbi.nlm.nih.gov/15561393
3. Gasche, Y., Zhou, H. & Kafka, M.S. 2004. Codeine intoxication associated with ultrarapid CYP2D6 metabolism. The New England Journal of Medicine, 351(27), 2827-2831. Available at: https://www.nejm.org/doi/full/10.1056/NEJMoa041888
4. Frei, M.Y., Nielsen, S. & Dobbin, M.D. 2010. Serious morbidity associated with misuse of over-the-counter codeine-ibuprofen analgesics: A series of 27 cases. Medical Journal of Australia, 193(5), 294-296. Available at: https://www.mja.com.au/journal/2010/193/5/serious-morbidity-associated-misuse-over-counter-codeine-ibuprofen-analgesics
5. National Institute on Drug Abuse. (n.d.). Prescription opioids drug facts. Retrieved from https://www.drugabuse.gov/publications/drugfacts/prescription-opioids
6. National Health Service. (2018). Codeine. Retrieved from https://www.nhs.uk/medicines/codeine/
7. Dart, R.C. et al., 2015. Trends in opioid analgesic abuse and mortality in the United States. The New England Journal of Medicine, 372(3), 241-248. Available at: https://www.nejm.org/doi/full/10.1056/NEJMsa1406143
8. UK Government. (2020). Drugs penalties. Retrieved from https://www.gov.uk/penalties-drug-possession-dealing