Alcohol and Drug Interactions

Alcohol interacts with many drugs, including prescribed and over-the-counter medicines, herbal medicines and illegal drugs. Alcohol can react with different medicines and drugs in different ways, such as increasing the sedating effect of sleeping tablets and opiate-based pain relief, increasing the potential for aspirin to irritate the stomach or increasing the potential of paracetamol to damage the liver. Also, chronic and/or heavy episodic drinking activates the liver enzymes that are involved in breaking down prescription medicines, which can lead to these medicines being metabolised faster than usual and being less effective.[7]

Prescription drugs that interact with alcohol include benzodiazepines, opiates, paracetamol, antidepressants, antibiotics, antihistamines, anti-inflammatory drugs, hypoglycaemic agents, warfarin, barbiturates and some heart medicines. Anyone starting or using one of these medicines should seek advice from their health professional about how alcohol may interact with the drug and whether reduction or temporary stopping of alcohol is necessary. People who are driving a motor vehicle or operating heavy machinery must take particular care when starting a new medicine that has a potential interaction with alcohol.[2, 14]

When combined with illegal drugs, alcohol can have various effects depending on the type of illegal drug. It may increase the risk of sedation when mixed with other sedating drugs, or counteract the effect of stimulant drugs. When alcohol is taken with cannabis, driving ability is significantly impaired, even more than when alcohol is drunk alone.[76]