Losartan Therapy

Introduction to Losartan

The European Society of Cardiology recommends monitoring of renal function when starting losartan, similar to ACE inhibitors, particularly in patients with pre-existing kidney disease, bilateral renal artery stenosis, or severe heart failure 1

Losartan may cause cough, but significantly less common than with ACE inhibitors, with only 17-29% of patients who previously experienced ACE inhibitor-induced cough developing cough on losartan 1, 2
The American College of Cardiology notes that angioedema, though rare, can occur with losartan, even in patients who previously experienced angioedema with ACE inhibitors 3
Potassium supplements or salt substitutes containing potassium may increase serum potassium, and diuretics, lithium, NSAIDs (including COX-2 inhibitors) may interact with losartan, while no clinically significant interactions with hydrochlorothiazide, warfarin, or digoxin have been observed 4

It is recommended to check renal function and potassium within 1-2 weeks of initiation, and follow closely after dose changes, particularly in patients with systolic blood pressure below 80 mmHg, low serum sodium, diabetes mellitus, or impaired renal function 4

Losartan is contraindicated in pregnancy (Category D) and should be discontinued as soon as pregnancy is detected, as it can cause fetal injury and death when used in the second and third trimesters 4
Dual RAS blockade with ACE inhibitors or other ARBs should be avoided, as it increases adverse effects without significant clinical benefit 4