I am a 61 year old woman on losartan 50mg (Cozaar),once a day. This medication does a good job controlling my blood pressure however I am experiencing peripheral neuropathy on my fingers and muscle aches in my legs and wondering if this could be attributed to the drug? It seems worse at night, causing me insomnia and anxiety. In your experience, does this sound like something that could be related to the drug? I am in otherwise good health, exercise regularly, am not overweight, don't have diabetes or smoke and take no other meds.
The short answer to your question is 'yes'. These certainly are side effects that have been reported with the use of losartan and other drugs within its class (angiotensin receptor antagonists). These side effects were first identified during early clinical trials, and were regarded as 'clinically significant' during the drug's post-marketing surveillance. Studies have not demonstrated that these side effects are dose-related, ie, that symptoms worsen with dose increases. Nor have they provided conclusive evidence of how quickly these side effects can develop after commencing treatment. The exact mechanism by which these effects occur is unknown. However, there has been suggestion that losartan's ability to raise potassium (and/or lower sodium levels) in the blood may be the cause of these side effects you mention.
Maria, my advice to you is to return to your doctor, mention these side effects, and request to have a blood test. It is important for your doctor to assess your kidney function and electrolyte levels (which invariably include potassium and sodium in a standard 'urea and electrolyte' blood test). These drugs are well known to affect potassium levels, which can be particularly problematic in renal failure (even mild cases) because the kidneys play an important role in clearing potassium from the blood. Abnormalities in serum electrolytes will be reason enough to either lower the dose of losartan or stop it entirely (particularly if side effects are a significant concern to you). Rest assured that there are alternative agents to effectively control blood pressure, so do not feel obligated to 'stick it out' if you're finding these side effects intolerable. But please do not stop taking this medication abruptly of your own accord. Do so only under your doctor's supervision.
Naturally, there is always a possibility that these are symptoms of some other condition, but if you noticed tingling and muscle aches around the time losartan was commenced, then there is a strong chance that they are associated with the drug.
I hope this information has been useful to you, Maria. Take care.