Lithium does not mix well with some other medicines, including herbal remedies. It may affect how they work, could cause more side effects or may change the lithium level in your body. If the level of lithium becomes too high this could be dangerous.
Before you start taking lithium, tell your doctor if you are taking any other medications including things you have bought from a pharmacy (or other shop) for common illnesses like colds and flu. This includes medications that you put on your skin. You can also show them the lithium treatment card you were given when you started lithium.
Do not take anti-inflammatory painkillers such as ibuprofen while you are taking lithium. This is because ibuprofen and related medicines (e.g. naproxen, diclofenac) can make the lithium level become too high.
Diuretics (‘water tablets’) and certain types of blood-pressure medicine can also make the lithium level become too high.
A few people who take lithium will, on their doctor’s advice, need to take one of these interacting medicines at the same time. If this is the case, then the lithium dose will be adjusted to take the interacting medicine into account, and you may need more frequent blood tests to check your lithium level.
Sometimes lithium is combined with antidepressant medicine if the antidepressant hasn’t worked as well as expected on its own. When these medicines are combined there have been some reports of serotonin syndrome occurring. This is rare, but you need to be aware of the symptoms so you know what to do if you get them. Symptoms include high temperature (fever), shivering, excessive sweating, agitation, confusion, trembling, and weird muscle movements. If you get these symptoms, you must seek medical attention straight away.
There is also a risk of serotonin syndrome if you take a type of anti-migraine medicine called a ‘triptan’ while taking lithium.
Some people will need to take an antipsychotic medicine while they are taking lithium.
When these medicines are combined, there have been some reports of neuroleptic malignant syndrome (NMS) occurring. This is rare, but you need to be aware of the symptoms so you know what to do if you get them. Symptoms include confusion, disorientation, agitation, tiredness, shaking, excessive sweating, rigid muscles, muscle cramps, weird muscle movements, and high temperature (fever). If you get these symptoms, then you must seek medical attention straight away.
Antipsychotic medicines and some other medicines may affect your heart rhythm if taken with lithium, and you may need to have a test called an electrocardiogram (ECG) to check on your heart.
Look at the leaflet inside your medicine box for more information about other medicines that can interact with lithium. With some medicines your doctor may need to adjust the dose of your medicines if you take them together. Ask a doctor or pharmacist for more information if you have any questions.