Tell your doctor immediately if any of these unlikely but serious side effects occur: unusual thirst, weakness, confusion, fast heartbeat, fainting, decreased sexual ability. Should be subsequently evaluated, and if blood pressure remains uncontrolled after about weeks of therapy, the dose may be increased to two tablets of HYZAAR 50-12. With regards to my blood pressure, despite taking atenolol 100 and lifezar 50 losartan for the past two years, my pressure is still always in the region of 140 90 which is the reason why my new buy losartan with mastercard doctor added clonidine catapres. About 14 of an orally-administered dose of losartan is converted to the active metabolite.