Taking some other medicines at the same time as lithium can make the level of lithium in your body become too high. This is because they affect the way your kidneys deal with lithium.
When you see a doctor or any other healthcare professional, you should tell or remind them that you are taking lithium.
Whenever you are prescribed a new medicine, or the dose of one of your medicines is changed, always ask whether this will affect your lithium.
If you buy medicines from a pharmacy or from another shop, you should check with a pharmacist whether they are safe with your lithium before you take them.
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.
Some people will need to take antidepressant medicine while they are taking lithium. This is usually safe, but there is a chance of a rare reaction called serotonin syndrome. 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. This is usually safe, but there is a chance of a rare reaction called neuroleptic malignant syndrome (NMS). Symptoms of this 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.