When not to drink:

Even if you can legally drink, there are times when adults should avoid alcohol altogether because, even in small amounts, it affects judgement, co-ordination, and motor control, e.g if driving, operating machinery, working at a height, or doing sports or swimming or looking after a baby or young child. Drinking alcohol when taking certain drugs and medicines, or if you're pregnant, should also be avoided. Consult your doctor for advice.