Alcohol
It may be possible to drink some alcohol while taking mirtazapine but having the two together might make you very sleepy and unsteady on your feet.
During the first few weeks of treatment, it is recommended that you don’t drink alcohol until you know how the medicine affects you.
Drinking alcohol every day, or in large amounts, can make your symptoms worse and may mean you won’t get the maximum benefit from your medication.
Street drugs
Cannabis can make drowsiness worse with mirtazapine and give you a fast heartbeat.
Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis.
Methadone or heroin can make drowsiness worse with mirtazapine.
Mirtazapine could raise the level of cocaine in your body, giving you a bigger reaction.
Taking mirtazapine with cocaine or ecstasy is likely to dampen the stimulant effects. Ecstasy may also increase your levels of mirtazapine as it interferes with its breakdown in the liver.
You should not mix mirtazapine and amfetamines unless you are under close medical supervision, as an increased amfetamine response may be dangerous.
There are many other street drugs, but we don’t know what effect taking them with mirtazapine will have, so it’s best to be cautious. There is no regulation of street drugs or ‘legal highs’, so even if there are no known issues with the medication you take, the supply you receive might be mixed with other substances that could be dangerous.
Smoking
Cigarette smoke affects the amount of mirtazapine in your body.
If you smoke, you may need a higher dose of mirtazapine than someone who does not smoke.
Tell your doctor if you smoke, so that you get the right dose for you.
If you stop smoking, the body’s mirtazapine level rises, and you might need to reduce your dose of mirtazapine slowly over one week.
If you start or restart smoking, you will probably need to increase your dose of mirtazapine again.
Go to your doctor for advice if you stop or start smoking, or if you switch to vaping or a nicotine replacement product instead of smoking.
Get more advice on our drugs and alcohol guide.