Dihydrocodeine

Dihydrocodeine is a semi-synthetic opioid analgesic medication derived from codeine. It was first synthesised in Germany in the early 20th century for moderate to severe pain management. The compound is closely related to codeine and has similar analgesic and antitussive effects.

Dihydrocodeine was discovered in Germany in the early 1900s as part of ongoing research to produce opioid analgesics that would have the efficacy of morphine and codeine but with a lower potential for addiction. It is a derivative of codeine, differing from it by the presence of an additional hydrogen atom on the 7,8-double bond.²

Dihydrocodeine undergoes hepatic metabolism via the cytochrome P450 enzyme system to produce active metabolites such as dihydromorphine. These metabolites are responsible for the drug’s analgesic effects.1 It works by binding to opioid receptors in the central nervous system, modulating the perception of pain and eliciting effects that include analgesia, sedation, and euphoria.

The drug is effective for the treatment of various types of pain, including postoperative pain and chronic pain conditions. Like other opioids, it comes with a range of side effects, including nausea, constipation, and drowsiness. There is also a risk of dependence, and it is a controlled substance in many countries, including the UK.³

Safety concerns associated with dihydrocodeine usage include the risk of respiratory depression and the potential for abuse and addiction. Regulatory bodies like the UK Medicines and Healthcare Products Regulatory Agency (MHRA) have advised the cautious use of over-the-counter painkillers containing codeine or dihydrocodeine.⁴

Appearance

Dihydrocodeine is commonly found in tablet form, though it also exists in other formulations like oral solutions and injections. The tablets are typically round and may be white or off-white. The appearance can vary depending on the manufacturer, and the tablets are available in different strengths, such as 30 mg, 60 mg, 90 mg, and 120 mg.³

Tastе

Dihydrocodeine tablets generally have a bitter taste, which is a characteristic common to many opioid analgesics.⁵

Smell

The tablets are usually odourless. If the drug is in an oral solution form, it may be flavoured to mask any bitterness, but the actual medication itself is typically without a distinct smell.⁵

The dosage of dihydrocodeine can vary based on several factors, including the severity of pain, individual tolerance, and other medications being taken. It’s crucial to follow healthcare provider recommendations for dosage.

• Minimum to Feel Something (mg): The minimum effective dose for experiencing analgesic effects is generally considered to be around 15-30 mg.
• Low Dose: A low dose usually ranges from 30 mg to 60 mg and is often used for moderate pain relief.³
• Common Dose: A common dose for managing moderate to severe pain is typically 60 mg, although this can be adjusted depending on the patient’s medical condition and response to treatment.
• High Dose: High doses, usually above 90 mg up to 120 mg, are generally reserved for severe pain and are usually administered under strict medical supervision due to the risk of respiratory depression and other severe side effects. ³

It’s essential to note that dihydrocodeine has a potential for dependency and misuse. Exceeding prescribed doses can lead to serious health complications, including respiratory depression, which can be fatal.

What May Happen When Exceeding the High Dose:
Exceeding the high dose of dihydrocodeine can lead to severe adverse effects, including respiratory depression, which can be life-threatening. Other risks include extreme drowsiness, confusion, and decreased consciousness. Overdose can also lead to a potentially fatal condition called opioid toxicity.³

Users report feeling pain relief, sedation, and sometimes a sense of euphoria when taking dihydrocodeine. Like other opioids, it works by binding to opioid receptors in the brain, altering the perception of pain.¹

The onset of action for dihydrocodeine is typically between 30 minutes to an hour when taken orally. The timing can vary depending on individual metabolism and whether the drug is taken with food.¹

The analgesic effects can last up to 4 to 6 hours, depending on the dose and individual metabolic factors.

Reported risks include but are not limited to respiratory depression, gastrointestinal issues such as constipation and nausea, and neurological effects like dizziness and confusion. Dependency and addiction are also significant concerns.⁴

Dihydrocodeine has a moderate to high potential for addiction, especially with prolonged use or misuse. Dependency can develop, leading to withdrawal symptoms when the drug is not taken.⁴

In the United Kingdom, dihydrocodeine is classified as a Class B controlled substance. This means that it is illegal to possess, distribute, or produce the drug without proper authorisation. Generally, dihydrocodeine is available only through a prescription from a qualified healthcare provider. Unauthorised possession can result in up to five years in prison, an unlimited fine, or both. Unauthorised supply (including giving it to friends) could result in up to 14 years in prison, an unlimited fine, or both.⁴

Combining dihydrocodeine with other CNS depressants like alcohol, benzodiazepines, or other opioids can lead to severe respiratory depression. It can also interact with medications that influence the cytochrome P450 enzyme system, affecting its metabolism.⁶

1. Ammon, S., Hofmann, U., Griese, E. U., Gugeler, N., Mikus, G. (1999). Pharmacokinetics of dihydrocodeine and its active metabolite after single and multiple oral dosing. Br J Clin Pharmacol, 48(3), 317-22. https://go.drugbank.com/articles/A14408)
2. Schmidt, H., Vormfelde, S. V., Walchner-Bonjean, M., Klinder, K., Freudenthaler, S., Gleiter, C. H., Gundert-Remy, U., Skopp, G., Aderjan, R., Fuhr, U. (2003). The role of active metabolites is dihydrocodeine effects. Int J Clin Pharmacol Ther, 41(3), 95-106. https://go.drugbank.com/articles/A14410)
3. NHS. (n.d.). Dihydrocodeine. Retrieved from https://www.nhs.uk/medicines/dihydrocodeine/)
4. Gov. uk. (n.d.). Over-the-counter painkillers containing codeine or dihydrocodeine. https://www.gov.uk/drug-safety-update/over-the-counter-painkillers-containing-codeine-or-dihydrocodeine)
5. Mayo Clinic. (n.d.). Acetaminophen, Caffeine, and Dihydrocodeine (Oral Route). Retrieved from https://www.mayoclinic.org/drugs-supplements/acetaminophen-caffeine-and-dihydrocodeine-oral-route/description/drg-20406132)
6. DrugBank. (n.d.). Dihydrocodeine. Retrieved from https://go.drugbank.com/drugs/DB01551 )