Karvezide (Hydrochlorothiazide, Irbesartan)

Karvezide combines an ARB and a thiazide diuretic to manage high blood pressure.

• Essential hypertension: lowers systolic and diastolic blood pressure, reducing cardiovascular risk.
• Primary hypertension requiring combination therapy: provides additive blood‑pressure control when monotherapy is insufficient.
• Hypertension with fluid retention: adds diuretic effect to improve volume management.

• Irbesartan selectively blocks the angiotensin II type 1 (AT1) receptor, preventing vasoconstriction and aldosterone release. Hydrochlorothiazide inhibits sodium‑chloride reabsorption in the distal convoluted tubule, promoting diuresis and decreasing plasma volume. The combined actions result in reduced peripheral resistance and lower blood pressure.

Karvezide may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Dizziness or light‑headedness
• Headache
• Increased urination or nocturia
• Fatigue or weakness
• Electrolyte disturbances (e.g., low potassium)

Serious or Rare Side Effects

• Severe allergic reaction (rash, swelling, anaphylaxis)
• Acute kidney injury or worsening renal function
• Significant hypotension (very low blood pressure)
• Pancreatitis (rare)
• Hyperkalemia when combined with potassium‑sparing agents

Before initiating therapy, certain precautions should be observed.

• Blood pressure monitoring: ensure adequate control and avoid excessive drops.
• Renal function assessment: check serum creatinine and eGFR periodically.
• Electrolyte surveillance: monitor potassium and sodium levels, especially in patients on other diuretics.
• Pregnancy: contraindicated in pregnancy (Category D) due to fetal risk.
• Elderly patients: start at lower doses and monitor for orthostatic hypotension.
• Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.

Karvezide can interact with several drug classes, requiring clinical attention.

Major Interactions (Avoid)

• Potassium‑sparing diuretics or supplements: risk of hyperkalemia.
• Lithium: increased lithium levels leading to toxicity.
• ACE inhibitors or other ARBs: additive renal effects and hyperkalemia.

Moderate Interactions (Monitor Closely)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may reduce antihypertensive efficacy and affect renal function.
• Antidiabetic agents: diuretic‑induced hypokalemia can alter glucose control.
• CYP2C9 inhibitors (e.g., fluconazole): may increase irbesartan plasma concentrations.