Drug-drug interaction: A drug-drug interaction happens when one medicine changes the effect, level or safety profile of another.
Critical for patients taking epilepsy medicines, sedatives, hormonal contraception or other centrally acting drugs.
NICE tells prescribers to consider interactions, including with CNS depressants, antiepileptics and hormonal contraceptives; NHS also warns CBD and THC can affect other medicines.
Interactions can increase side effects, alter liver metabolism or change efficacy.