Stilpane syrup is a combination medication available in South Africa that contains three active ingredients in every 5 ml (one teaspoon): 120 mg paracetamol (a pain and fever reducer), 5 mg codeine phosphate (an opioid that suppresses cough and relieves pain), and 6.5 mg promethazine hydrochloride (an antihistamine that reduces allergies and causes sedation). It is used to treat mild to moderate pain, cough, and symptoms associated with upper respiratory conditions.
How the Three Ingredients Work Together
Each ingredient in Stilpane targets a different part of the problem. Paracetamol lowers fever and blocks pain signals at a basic level. Codeine works on opioid receptors in the brain to suppress the cough reflex and provide additional pain relief. Promethazine is an antihistamine that reduces itching, sneezing, and runny nose while also having a calming, sedative effect that can help when symptoms are keeping you awake.
The combination means a single dose addresses pain, cough, and congestion-related discomfort at the same time. However, it also means you’re taking three drugs at once, each with its own side effects and risks.
Dosage for Adults
The standard adult dose is 5 ml (one teaspoon) every 4 to 6 hours as needed. You should not take more than 30 ml in a 24-hour period. That ceiling matters especially because of the paracetamol component: exceeding the daily limit puts serious strain on the liver and can cause irreversible damage.
Common Side Effects
The most noticeable side effect is drowsiness, driven by both the promethazine and the codeine. This can impair your ability to drive or operate machinery, and the effect intensifies if you drink alcohol or take other sedating medications at the same time. Constipation is another frequent issue with any codeine-containing product, especially with regular use over several days.
Other side effects include nausea, dizziness, dry mouth, and blurred vision. Most of these are mild and fade as the dose wears off, but persistent or worsening symptoms deserve medical attention.
Who Should Not Take Stilpane
Stilpane is contraindicated in children under 2 years of age. Beyond that age cutoff, codeine carries particular risks for all children and teenagers (up to 18) who have had their tonsils or adenoids removed for obstructive sleep apnoea. There have been rare but life-threatening reactions, including deaths, in children who received standard doses of codeine after these surgeries. The problem relates to genetic differences in how the body converts codeine into morphine: some people (called ultra-rapid metabolisers) produce dangerously high levels of morphine from a normal dose, and there is no simple way to know in advance who these individuals are.
Codeine is also not recommended for children with compromised breathing, including those with neuromuscular disorders, severe heart or lung conditions, upper respiratory infections, or those recovering from major surgery or trauma.
Adults with liver disease should be cautious because of the paracetamol content. People with asthma or other chronic respiratory conditions face added risk because codeine can slow breathing. If you have a history of substance use disorder, the opioid component makes Stilpane a potential concern for dependence.
Interactions With Alcohol and Other Sedatives
Mixing Stilpane with alcohol is dangerous. Alcohol amplifies the sedating effects of both codeine and promethazine, which can slow your breathing to a hazardous degree. The same applies to other central nervous system depressants: sleeping pills, anxiety medications, muscle relaxants, and other opioid painkillers. Taking Stilpane alongside any of these increases the risk of excessive sedation and respiratory depression.
The paracetamol in Stilpane also interacts poorly with alcohol. Regular or heavy drinking combined with paracetamol raises the likelihood of liver toxicity, even at doses that would otherwise be safe.
Overdose Risks
Because Stilpane contains three active drugs, an overdose can be complicated. The codeine component can cause slow, shallow, or completely stopped breathing. This is the most immediately life-threatening effect. The paracetamol component creates a second, slower danger: liver failure, which may not produce obvious symptoms for 24 to 72 hours after the overdose but can be fatal without treatment. Promethazine overdose adds severe drowsiness, seizures, and heart rhythm disturbances to the picture.
If you suspect someone has taken too much Stilpane, treat it as a medical emergency. The combination of an opioid and a high dose of paracetamol means both the immediate breathing risk and the delayed liver damage need to be addressed quickly.
Dependence and Misuse
Codeine is an opioid, and even at the relatively low dose found in Stilpane, regular use over days to weeks can lead to physical dependence. You may notice that you need more to get the same effect (tolerance) or that you feel unwell when you stop taking it (withdrawal). Stilpane has become a commonly misused medication in South Africa, sometimes consumed in large quantities for its sedative and euphoric effects. Using it beyond short-term symptom relief significantly raises the risks of addiction, liver damage from cumulative paracetamol, and respiratory complications.