<p><strong>Losartan Potassium</strong>: No significant drug-drug pharmacokinetic interactions have been found in interaction studies with Hydrochlorothiazide, Digoxin, Warfarin, Cimetidine and Phenobarbital. As with other drugs that block angiotensin II or its effects, concomitant use of potassium-sparing diuretics (e.g. Spironolactone, Triamterene, Amiloride), potassium supplements, or salt substitutes containing potassium may lead to increase in serum potassium. As with other antihypertensive agents, the antihypertensive effect of Losartan may be blunted by the non-steroidal anti-inflammatory drug Indomethacin.<br />
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<strong>Hydrochlorothiazide</strong>: When administered concurrently, the following drugs may interact with Thiazide diuretics: alcohol, barbiturates, or narcotics-potentiation of orthostatic hypotension may occur.<br />
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<strong>Antidiabetic drugs (oral agents and Insulin)</strong>: dosage adjustment of the antidiabetic drug may be required.<br />
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<strong>Other antihypertensive drugs</strong>: additive effect or potentiation.<br />
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<strong>Cholestyramine and colestipol resins</strong>: absorption of Hydrochlorothiazide is impaired in the presence of anionic exchange resins</p>