Taking mirtazapine with other medicines and herbal supplements

Cautions with other medicines

Some medicines and mirtazapine can affect each other and increase the chances of you having side effects.

Tell your doctor or pharmacist if you're taking:

• any other medicines for depression, or if you've taken them recently – some antidepressants can affect mirtazapine to cause very high blood pressure even after you've stopped taking them
• medicines that make you feel sleepy, including strong painkillers like morphine or muscle relaxants like diazepam
• warfarin – mirtazapine can affect warfarin so your doctor may need to change your warfarin dose
• epilepsy medicines such as carbamazepine or phenytoin – these medicines can reduce the effects of mirtazapine, so your doctor may prescribe a higher dose
• rifampicin – this antibiotic can reduce the effects of mirtazapine, so your doctor may prescribe a higher dose

Mixing mirtazapine with herbal remedies and supplements

Do not take the herbal remedy St John's wort while you're being treated with mirtazapine, as this will increase your risk of side effects.

There's not enough information to say that other herbal remedies or supplements are safe to take with mirtazapine. They're not tested in the same way as pharmacy and prescription medicines.