Hydrochlorothiazide + Irbesartan

Hydrochlorothiazide + Irbesartan is a combination medicine that helps control high blood pressure. Irbesartan is an angiotensin II receptor antagonist (ARB) that relaxes blood vessels, allowing blood to flow more smoothly and the heart to pump more efficiently. Hydrochlorothiazide is a diuretic that removes extra water and electrolytes from the body and over time also relaxes blood vessels to improve blood flow. This combination is effective for treating hypertension, which if left untreated can lead to heart attacks, strokes and kidney failure.

• Hypertension (high blood pressure) - in patients for whom combination therapy is appropriate

Adult Dose:

• Initial: 150 mg/12.5 mg once daily
• May titrate up to 300 mg/25 mg once daily after 1-2 weeks if needed
• Maximum dose: 300 mg/25 mg once daily

Special Populations:

• Renal Impairment (CrCl >30 mL/min): Follow usual regimen
• Hepatic Impairment: No dosage adjustment necessary

Common Side Effects:

• Dizziness
• Nausea
• Taste change
• Upset stomach
• Diarrhea
• Weakness
• Headache
• Decreased blood pressure
• Glucose intolerance
• Increased blood uric acid
• Electrolyte imbalance

Gastrointestinal: Anorexia, gastric irritation, vomiting, diarrhea, constipation, pancreatitis

CNS: Dizziness, vertigo, headache, yellow vision

Cardiovascular: Arrhythmia, hypotension, bradycardia, syncope

Precautions:

• Hydrochlorothiazide + Irbesartan may decrease alertness, affect vision or make you feel sleepy and dizzy; do not drive if these symptoms occur
• May cause dehydration; drink plenty of fluids; inform doctor if extreme thirst, very dry mouth or muscle weakness develops
• May cause dizziness; get up slowly when rising from a sitting or lying position
• Not safe during pregnancy and breastfeeding
• Changes in renal function may occur due to renin-angiotensin-aldosterone system inhibition; monitor renal function and potassium
• Caution in heart failure or ventricular dysfunction

Contraindications:

• Hypersensitivity
• Pregnancy
• Lactation
• Anuria
• Severe renal impairment

Drug Interactions:

• Alcohol, Barbiturates, Narcotics: May potentiate orthostatic hypotension
• Antidiabetic drugs: Dosage adjustment may be required
• Other antihypertensives: Additive effect
• Lithium: May increase lithium concentrations; monitor serum lithium
• NSAIDs: May attenuate diuretic and antihypertensive effects
• Cholestyramine & Colestipol: Reduced absorption of hydrochlorothiazide

Food Interactions: Hydrochlorothiazide + Irbesartan may cause excessive drowsiness with alcohol.

Use in Pregnancy: Unsafe during pregnancy; in the second and third trimesters, irbesartan can cause injury or death to the developing baby; contraindicated in pregnancy.

Use in Lactation: Thiazides appear in breast milk; if drug use is deemed essential, patient should stop breastfeeding.

Renal Impairment: Follow usual regimen if CrCl >30 mL/min; loop diuretics preferred in severe renal impairment; caution is advised.

Hepatic Impairment: No dosage adjustment necessary in hepatic impairment; however caution is advised in liver disease.

Overdose: Irbesartan: Hypotension and tachycardia may occur; bradycardia may occur; not removed by hemodialysis. Hydrochlorothiazide: Electrolyte depletion (hypokalemia, hypochloremia) and dehydration; hypokalemia with digitalis may accentuate cardiac arrhythmias; symptomatic treatment.