Loading page
Loading page
Loading substance route
A ceiling effect limits analgesic and recreational benefit beyond 300–500 mg for most users, with individual variation sometimes extending to 600 mg; further dose escalation increases adverse effects without proportional gains in desired effects.
Effects vary widely by individual, dose, and context.
The physical effects of codeine can be broken down into several components which progressively intensify proportional to dosage. The general head space of codeine is described by many as one of intense euphoria, relaxation, anxiety suppression and pain relief.
These combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.
There is considerable risk of physical harm when taking these combinations, they should be avoided where possible.
These combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.
Codeine exhibits abuse potential similar to other opioid medications, though it is considered less reinforcing than stronger opioids like morphine or heroin. There is a tendency to underestimate its harm potential, particularly with codeine-promethazine cough syrup formulations where at least two deaths in the hip-hop community have been attributed to chronic use.
Chronic use causes physical dependence with potentially severe withdrawal symptoms including drug craving, runny nose, yawning, sweating, insomnia, weakness, stomach cramps, nausea, vomiting, diarrhea, muscle spasms, chills, irritability, and pain. Withdrawal can be as painful and long-lasting as heroin withdrawal, with symptom onset typically within 4-48 hours and duration of 4-5 days.
Human lethal dose has been estimated at 291 to 518 mg in non-tolerant individuals, though recovery from larger amounts has been reported. Lethal dose varies significantly based on CYP2D6 metabolizer status; ultrarapid metabolizers can experience fatal respiratory depression at medical doses due to rapid conversion to morphine. Approximately 30% of the Ethiopian population are ultrarapid metabolizers, leading to a nationwide ban. Blood concentrations of 1,000-10,000 μg/L are associated with acute fatal overdose. Deaths have occurred in pediatric patients at normal therapeutic doses, particularly after tonsillectomy.
| Species | Route | Value |
|---|---|---|
| rat | oral | 427 mg/kg |
Respiratory depression is the primary mechanism of fatal overdose and can occur even at near-medical doses in susceptible individuals, particularly ultrarapid CYP2D6 metabolizers, young children, or when combined with other respiratory depressants.
Reduced intestinal motility and constipation are common with regular use; chronic opioid use may lead to obstructive bowel disease, particularly in patients with underlying intestinal motility disorders.
Cardiovascular effects including orthostatic hypotension and bradycardia may occur during use, with compromised ability to maintain blood pressure due to peripheral vasodilation.
Long-term use may cause reduced sexual desire in both sexes; women may experience absent or irregular menstruation.
Chronic long-term use may contribute to apathy and memory loss; sedation, drowsiness, and cognitive impairment occur during acute intoxication.
Seizures are listed as a rare adverse effect. Seizures have also been observed in neonates experiencing narcotic withdrawal from maternal codeine use during pregnancy.
Codeine derives its name from the Greek word "kodeia," meaning "poppy head," reflecting its natural occurrence as an alkaloid in the opium poppy (Papaver somniferum). The compound comprises approximately 2% of raw opium, which has been used by humans for millennia. The poppy may have been…
Single Convention on Narcotic Drugs 1961 (Schedule II and III, concentration-dependent)
WHO List of Essential Medicines
Since February 1, 2018, all codeine-containing preparations require a prescription. Pure codeine products are classified as Schedule 8 (Controlled Drug), meaning possession without authority is illegal and subject to the strictest regulation. Prior to this date, lower-dose preparations were available over-the-counter.
Codeine is a Schedule I controlled substance. However, low-concentration combination products remain available over-the-counter, including formulations containing 8 mg codeine combined with caffeine and paracetamol.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
Codeine can be purchased over-the-counter under pharmacist supervision without prescription. However, no mechanism exists to track patients visiting multiple pharmacies, leading to concerns about potential misuse and addiction.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
Regulated under national narcotic control legislation. Specific scheduling varies by formulation and concentration.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
Regulated under national narcotic control laws. Prescription required for codeine-containing products.
Pure codeine is Schedule II under the Controlled Substances Act. Certain combination formulations are classified as Schedule III or V depending on concentration. Some low-dose polysubstance products are available over-the-counter.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
As of 2015, over-the-counter sale of codeine solid dosage forms is permitted under European Union member state regulations.
Controlled under the Misuse of Drugs Act. Prescription required for most products, though combination preparations containing less than 12.8 mg codeine per dose are available over-the-counter from pharmacies.
12 sources cited
