Is it OK to drink while on medication?

We asked him why doctors sometimes tell us not to drink when we take prescription drugs, and what happens if we do. Professor Wallace says it depends what medication you have been prescribed. For most, it is fine to drink within the recommended guidelines (women should not regularly exceed 2-3 units daily and  men should not regularly exceed 3-4 units daily – a large glass (250ml) of wine or a pint of 5% lager is around 3 units). However, for some, alcohol should be completely avoided.

Professor Wallace says that:

• People taking sedative drugs (like Valium) or antidepressants (like Prozac) should avoid alcohol altogether
• People  taking long term medications should be careful about drinking, as alcohol can make some drugs less effective, meaning long term conditions get worse. Examples include  people taking drugs for epilepsy or diabetes, or dugs like warfarin to thin the blood.
• There are some antibiotics which simply do not mix with alcohol - drinking with these will make you sick. But for most commonly prescribed antibiotics, drinking is unlikely to cause problems so long as it is within the recommended guidelines  
• There’s no real evidence about the effects of alcohol on your immune system – the benefits of a hot toddy are probably all in our head.

Read on to find out more about all of the above.

How alcohol can interfere with medication

Professor Wallace says there are two main reasons why doctors advise patients not to drink with some drugs.

“Firstly, because alcohol is a depressant, it affects the way your brain works, numbing your senses so they don’t operate properly,” he says.

“Some types of medication also affect the way your brain works, and if you’re drinking alcohol there will be a conflict. Alcohol will increase the sedative effects of both, causing sleepiness and dizziness. It could also change the way the brain responds to the medication, making it less effective.”

If you’re taking a sedative drug such as Valium, or any other drug that can make you drowsy, and you drink alcohol, your reaction times could decrease and you’ll get tired faster. If you’re driving or operating machinery, this can be extremely dangerous.

“Secondly, alcohol can affect the way drugs are absorbed by the body and broken down in the liver,” says Professor Wallace.

“If you drink alcohol regularly and in excessive amounts, your liver produces more enzymes so that it can get rid of the alcohol more quickly. Those same enzymes might break down the medication you are taking so it no longer has the same effect. An example of this is medications for epilepsy".

Alcohol and antibiotics

When it comes to antibiotics, Professor Wallace says that the message is slightly different than it is with sedative drugs. The NHS advises that people who choose to drink alcohol when taking antibiotics do so within the recommended limits.

There are antibiotics, like Metronidazole and Tinidazole, which you should not drink alcohol with.  Mixing them with alcohol can lead to nausea, vomiting, flushing of the skin, accelerated heart rate or shortness of breath. This is probably because  they can interfere with the breakdown of alcohol, leading to the production of nasty side effects.

Can alcohol  make you better?

So, can alcohol itself ever be a good medicine? Historically it was once a very important medication, says Professor Wallace.

“Before the advent of modern anaesthetics, when surgeons were performing operations, they would use alcohol as an anaesthetic, getting their patients drunk before they operated,” he explains. Professor Wallace says the reason for this is because alcohol numbs the brain.

He explains that many people also feel better after having a hot toddy when they have a cold because alcohol also numbs your senses; a hot toddy can make you feel better but there’s no evidence to suggest that it actually improves your health.

“Nobody should kid themselves that it is going to help you actually get better,” says Professor Wallace. “You may experience an immediate gain because if you are feeling rotten alcohol might make you feel less bad for a short time. But the term ‘medicinal brandy’ is an oxymoron.”

Alcohol and the immune system

There’s no firm evidence about the effects of alcohol on the immune system, but Professor Wallace thinks it’s probably not a good idea to drink alcohol when you are feeling ill because it is likely to make you feel worse.

“Our state of mind can affect the way we respond to illnesses and alcohol is, after all, a depressant,” says Professor Wallace.

Finding out if you can drink on your medication

If you’re taking prescription drugs and are unsure whether it is safe to drink alcohol, the best advice is to check with your doctor and the pharmacist. Also check the leaflet that comes with the medication.

“If it doesn’t say don’t drink it’s probably okay to drink within the recommended limits. But if you are in any doubt, don’t drink alcohol at all because you could put your health at risk.”

Page last updated by

Stephen Sanchez, 21 May 2010.

Page checked on

18 May 2010