Irbesartan/hydrochlorothiazide

Black Box Warnings

Discontinue as soon as possible when pregnancy is detected; affects renin-angiotensin system causing oligohydramnios, which may result in fetal injury and/or death

Contraindications

Hypersensitivity to irbesartan, hydrochlorothiazide, or sulfonamides

Pregnancy (2nd and 3rd trimesters): Significant risk of fetal/neonatal morbidity and mortality

Anuria

Do not coadminister with aliskiren in patients with diabetes mellitus

Cautions

Acute transient myopia and acute angle-closure glaucoma has been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is a sulfonamide)

CrCl <30 mL/min: Use loop diuretic instead of hydrochlorothiazide

Hyperkalemia, particularly when coadministered with potassium-sparing diuretics, potassium supplements, or salt substitutes; concurrent therapy with hydrochlorothiazide may reduce the frequency of this effect; monitor serum potassium levels periodically

Dual blockade of the renin angiotensin system with ARBs, ACE inhibitors, or aliskiren associated with increased risk for renal function changes (including acute renal failure) compared to monotherapy

Hypotension may occur in patients who are salt or volume depleted (correct the volume depletion especially in patients receiving high dose diuretics)

Hydrochlorothiazide can cause hypokalemia and hyponatremia; hypomagnesemia can result in hypokalemia which appears difficult to treat despite potassium repletion

Drugs that inhibit the renin-angiotensin system can cause hyperkalemia; monitor serum electrolytes periodically

Hyperuricemia may occur or gout may be precipitated in certain patients receiving thiazide therapy

Hydrochlorothiazide may alter glucose tolerance and raise serum levels of cholesterol and triglycerides

Thiazides may decrease urinary calcium excretion

Caution in  aortic mitral stenosis, hepatic impairment, hypercholesterolemia, hypercalcemia, parathyroid disease, pre-existing renal insufficiency, systemic lupus erythematosus, bilateral renal artery stenosis or anuria