<p>Rifampicin and fluconazole reduce levels of active metabolite of Losartan Potassium. Concomitant use of Losartan Potassium and hydrochlorothiazide may lead to potentiation of the antihypertensive effects. Concomitant use of potassium-sparing diuretics (eg, spironolactone, triamterene, amiloride), potassium supplements or salt substitutes containing potassium may lead to increases in serum potassium. The antihypertensive effect of losartan may be attenuated by the non-steroidal anti-inflammatory drug indomethacin. The use of ACE-inhibitor, angiotensin receptor antagonist, an anti-inflammatory drug and a thiazide diuretic at the same time increases the risk of renal impairment.</p>