Pharmacists in Ireland are urging people to steer clear of mixing alcohol with medication, stressing the fact that it can have "unpredictable" effects.
According to the Irish Pharmacy Union, drinking alcohol while taking medication can reduce the effectiveness of the medicine.
It can also make side-effects associated with the medication worse.
Catriona O'Riordan, a pharmacist and member of the IPU, said that many different types of medication can react negatively with alcohol.
She said: "Although most medicines are safe and effective when used as directed, mixing alcohol and medicines can put you at risk of a dangerous reaction as alcohol can interact negatively with many medicines."
She also said that prescribed medication is not the only type that can react badly to alcohol.
"Many over-the-counter medicines, such as cough and cold remedies, pain relievers, antihistamines and travel sickness pills, have the potential to interact negatively with alcohol."
They also warned that a lot of medications can make patients sleepy, drowsy or lightheaded, and that drinking alcohol alongside taking this kind of medication can lead to a risk to personal safety.
Ms O'Riordan has advised anyone taking medication to contact their pharmacist before attempting to drink alcohol with it.