Hydrochlorothiazideinteractions

NSAIDs and selective COX-2 inhibitors: Can reduce diuretic, natriuretic of diuretic, may lead to increased risk of renal impairment and reduced antihypertensive effect. Monitor renal function periodically. Dual blockade of the renin-angiotensin system: Increased risk of renal impairment, hypotension, and hyperkalemia.

Antidiabetic drugs: Dosage adjustment of antidiabetic may be required.

Cholestyramine and colestipol: Reduced absorption of thiazides.

Lithium: Increases in serum lithium concentrations and lithium toxicity.

Carbamazepine: Increased risk of hyponatremia.

7.1 Nonsteroidal

Anti-inflammatory Agents Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) Irbesartan In patients who are elderly, volume depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists, including irbesartan, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Therefore, monitor renal function and blood pressure periodically in patients receiving irbesartan and NSAID therapy. Hydrochlorothiazide Administration of a nonsteroidal anti-inflammatory agent, including a selective COX-2 inhibitor can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing, and thiazide diuretics. Therefore, when AVALIDE (irbesartan and hydrochlorothiazide) tablets and nonsteroidal anti-inflammatory agents are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained.

7.2 Dual Blockade of the

Renin-Angiotensin System (RAS) Dual blockade of the RAS with angiotensin-receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy. Closely monitor blood pressure, renal function, and electrolytes in patients on AVALIDE and other agents that affect the RAS. In most patients no benefit has been associated with using two RAS inhibitors concomitantly. In general, avoid combined use of RAS inhibitors. Do not coadminister aliskiren with AVALIDE in patients with diabetes. Avoid use of aliskiren with AVALIDE in patients with renal impairment (GFR <60 mL/min).

7.3 Agents Increasing

Serum Potassium Coadministration of AVALIDE with other drugs that raise serum potassium levels may result in hyperkalemia, sometimes severe. Monitor serum potassium in such patients.

7.4 Antidiabetic

Drugs (oral agents and insulin) Dosage adjustment of the antidiabetic drug may be required when coadministered with hydrochlorothiazide.

7.5 Cholestyramine and

Colestipol Resins Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins. Stagger the dosage of hydrochlorothiazide and the resin such that AVALIDE is administered at least 4 hours before or 4 to 6 hours after the administration of the resin.

7.6 Lithium

Increases in serum lithium concentrations and lithium toxicity have been reported with concomitant use of irbesartan or thiazide diuretics. Monitor lithium levels in patients receiving AVALIDE and lithium.

7.7 Carbamazepine

Concomitant use of carbamazepine and hydrochlorothiazide has been associated with the risk of symptomatic hyponatremia. Monitor electrolytes during concomitant use.