This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Cautions with other medicines
Many medicines and amitriptyline can affect each other and increase the chances of side effects.
Always check with your doctor or a pharmacist before starting any new medicine while you're taking amitriptyline.
Taking opioid-based medicines, like codeine, morphine or oxycodone, together with amitriptyline can increase your risk of becoming very drowsy and having breathing problems.
Tell your doctor if you've ever taken any medicines for depression. Some antidepressants can affect the way amitriptyline works and can cause very high blood pressure. This can happen even after you stop taking them.
Mixing amitriptyline with herbal remedies and supplementsDo not take St John's wort, a herbal remedy often taken for depression, while you're taking amitriptyline. It will increase your risk of side effects.
There's not enough information to say that other complementary medicines and herbal remedies are safe to take with amitriptyline. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
Meds New IA (H2) - Cautions with other medicines alert
Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.
View the original NHS website page ↗. Refreshed 19 August 2026.
Licensed under the Open Government Licence v3.0 ↗. MyPHU is independent and is not endorsed by the NHS.