What is the best hypertension drug for patients with low gfr (17)? I am taking Losartan-hctz 100/12.5mg currently. The site says in rare cases it can cause kidney failure: In rare cases, hydrochlorothiazide and losartan can cause a condition that results in the breakdown of skeletal muscle tissue, leading to kidney failure. Call your doctor right away if you have unexplained muscle pain, tenderness, or weakness especially if you also have fever, unusual tiredness, and dark colored urine. http://www.rxlist.com/hyzaar-drug/patient-images-side-effects.htm