Losartan and other medicines
Losartan is a drug used to treat high blood pressure. It's important that your doctor or pharmacist knows what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start taking losartan.
Also, always check with your pharmacist before taking any other medicines while you're on losartan, to make sure that the combination is safe.
Can you take other medicines with losartan?
If you take other medicines that lower blood pressure with losartan, either to treat high blood pressure (antihypertensives), or medicines that can lower blood pressure as a side effect (for example tricyclic antidepressants like amitriptyline), the combination might lower your blood pressure too much.
This could make you feel dizzy or faint, particularly when getting up from a lying or sitting position. If this happens to you, you should sit or lie down until the symptoms pass. Tell your doctor if you frequently feel dizzy while taking any other medicine with losartan, as your doses may need adjusting.
If you're already taking a medicine to lower your blood pressure, particularly if you're taking a diuretic medicine such as furosemide, your first dose of losartan may cause a large drop in blood pressure. If you're taking a diuretic medicine, your doctor may reduce your dose for a few days before you start taking losartan, to avoid your blood pressure dropping too low.
The blood pressure lowering effect of losartan may be opposed by medicines that have the potential to increase your blood pressure, such as the following:
corticosteroids, such as dexamethasone or prednisolone
oestrogens, such as those in the contraceptive pill
regular use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, diclofenac or indometacin. These may also increase the risk of getting kidney problems. You should avoid taking this type of painkiller while you're taking losartan, unless it's recommended by your doctor. If you need a painkiller it's fine to take paracetamol with losartan.
The level of potassium in your blood could rise too high (hyperkalaemia) if you take any of the following medicines with losartan, so these are not normally recommended. If you take any of the following with losartan, you should have regular blood tests to monitor the amount of potassium in your blood:
aliskiren or ACE inhibitors, eg ramipril (these medicines should not be used with losartan, particularly in people with reduced kidney function or diabetes)
ciclosporin
drospirenone
epoetin (this may also oppose the blood pressure lowering effect of losartan)
heparin
potassium-containing salt substitutes (eg Lo-Salt)
potassium salts, eg potassium citrate for cystitis
potassium-sparing diuretics (eg spironolactone, triamterene, amiloride, eplerenone)
potassium supplements
tacrolimus
trimethoprim.
The following medicines may reduce the blood level of losartan and could make it less effective:
fluconazole (although taking a single-dose of fluconazole to treat thrush is unlikely to have a significant effect)
rifampicin.
Losartan may increase the blood level of the medicine lithium. If you're taking lithium and start treatment with losartan, you should let your doctor know if you experience any signs that your lithium level is increasing, for example: loss of appetite, diarrhoea, vomiting, blurred vision, muscle weakness, lack of co-ordination, drowsiness, tremor, unsteadiness, muscle twitching, ringing in the ears or confusion. Your doctor will need to check your lithium level.
In general other medicines are not expected to significantly affect losartan, however it's always important to get advice from your pharmacist before taking other medicines while you're on it, because they not be suitable for you due to your condition.
Last updated: 5.07.2020
You Might Also Like
