<p><strong>Diuretics and other antihypertensive&nbsp;agents</strong>: prior treatment with high dose diuretics may result in volume depletion and&nbsp;a risk of hypotension when initiating therapy with Irbesartan.<br />
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<strong>Potassium&nbsp;supplements and potassium-sparing diuretics</strong>: based on experience with the use of&nbsp;other drugs that affect the renin-angiotensin system, concomitant use of potassiumsparing&nbsp;diuretics, potassium supplements, salt substitutes containing potassium or&nbsp;other drugs that may increase serum potassium levels (e.g. heparin) may lead to&nbsp;increases in serum potassium and is, therefore, not recommended.<br />
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<strong>Lithium</strong>:&nbsp;reversible increases in serum lithium concentrations and toxicity have been reported&nbsp;during concomitant administration of lithium with angiotensin converting enzyme&nbsp;inhibitors. Similar effects have been very rarely reported with irbesartan so far.&nbsp;Therefore, this combination is not recommended. If the combination proves&nbsp;necessary, careful monitoring of serum lithium levels is recommended.<br />
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<strong>Non-steroidal&nbsp;anti-inflammatory drugs</strong>: When angiotensin II antagonists are administered&nbsp;simultaneously with non-steroidal anti- inflammatory drugs (i.e. selective COX-2&nbsp;inhibitors, acetylsalicylic acid &gt; 3 g/day and non-selective NSAIDs), attenuation of&nbsp;the antihypertensive effect may occur. Additional information on irbesartan&nbsp;interactions: In clinical studies, the pharmacokinetic of irbesartan is not affected by&nbsp;hydrochlorothiazide. Irbesartan is mainly metabolised by CYP2C9 and to a lesser&nbsp;extent by glucuronidation. No significant pharmacokinetic or pharmacodynamic&nbsp;interactions were observed when irbesartan was coadministered with warfarin, a&nbsp;drug metabolised by CYP2C9. The effects of CYP2C9 inducers such as rifampicin&nbsp;on the pharmacokinetic of irbesartan have not been evaluated. The pharmacokinetic&nbsp;of digoxin was not altered by coadministration of irbesartan.</p>