Losartan-Associated Adverse Effects
Losartan can cause nausea and fatigue (asthenia/fatigue) in some patients. [1], [2] Losartan can also cause muscle cramps or muscle-related symptoms such as myalgia or muscle pain. [1], [2]
Nausea and Fatigue
Nausea is listed among adverse reactions reported in patients taking losartan (at a frequency at least comparable to placebo in trials). [2] Fatigue (asthenia/fatigue) is listed among adverse reactions reported in patients taking losartan. [2]
Leg/Toe Muscle Cramps
Muscle cramps or muscle weakness are listed as possible side effects of losartan. [1] Myalgia and other musculoskeletal pain syndromes are also listed among reported adverse reactions with losartan. [2]
Clinical Clarifications
Muscle cramps can occur for reasons other than losartan, including electrolyte abnormalities and other medication effects, so persistence or worsening should prompt reassessment. [1], [2] Losartan can alter laboratory parameters, so evaluation of kidney function and potassium may be warranted when muscle symptoms occur. [1], [2]
When Urgent Evaluation Is Indicated
Urgent medical evaluation is recommended for severe or rapidly worsening muscle weakness or cramps, or for symptoms suggesting serious electrolyte disturbance or kidney injury. [1], [2]
Medication Safety Steps
If adverse effects occur after starting or dose changes, contacting the prescriber for guidance on continuation or adjustment is recommended. [1], [2]