This combination is indicated for the treatment of hypertension.

এই কম্বিনেশন উচ্চ রক্তচাপ (হাইপারটেনশন) এর চিকিৎসায় ব্যবহৃত হয়।is an oral angiotensin II receptor blocker (ARB) that selectively acts on the AT1 receptor subtype. Angiotensin II causes vasoconstriction by binding to its receptors, leading to increased blood pressure. Valsartan blocks this action, resulting in vasodilation and reduction of blood pressure without affecting heart rate. It has a much higher affinity for AT1 receptors compared to AT2 receptors and does not significantly interact with other hormone receptors or ion channels involved in cardiovascular regulation.

Hydrochlorothiazide is a thiazide diuretic that acts on the renal tubules to inhibit sodium and chloride reabsorption, increasing their excretion in equal amounts. This leads to a reduction in plasma volume, which subsequently increases renin activity, aldosterone secretion, potassium loss in urine, and decreases serum potassium levels. The effect on the renin-angiotensin system is mediated through angiotensin II; therefore, co-administration with ACE inhibitors may reduce potassium loss associated with thiazide diuretics.

Hypertension: Patients whose blood pressure is not adequately controlled with Valsartan or Hydrochlorothiazide monotherapy should be switched to a combination of Valsartan and Hydrochlorothiazide once daily. The maximum allowed dose of Valsartan in combination therapy should not exceed 320 mg with Hydrochlorothiazide 25 mg.

Elderly: No initial dose adjustment is required in elderly patients.

Pediatric use: Safety and effectiveness in pediatric patients have not been established.

Valsartan:

• Diuretics: Patients receiving diuretics may occasionally experience an excessive reduction in blood pressure after initiation of therapy with Valsartan. No clinically significant interaction has been identified with thiazide diuretics.
• Agents increasing serum potassium: Since Valsartan reduces aldosterone production, concomitant use of potassium supplements or potassium-containing salt substitutes may lead to hyperkalemia.
• Lithium salts: As with other sodium-eliminating drugs, lithium clearance may be reduced. Therefore, serum lithium levels should be closely monitored when lithium is co-administered.
• Other interacting drugs include Warfarin and Digoxin.

Hydrochlorothiazide:

• When used concomitantly, alcohol, barbiturates, or narcotics may potentiate the antihypertensive effect and increase the risk of orthostatic hypotension.
• Antidiabetic drugs (oral agents and insulin): Dose adjustment of antidiabetic medications may be required.
• Other antihypertensive agents produce an additive blood pressure–lowering effect.
• Cholestyramine and colestipol resins: Absorption of Hydrochlorothiazide is reduced in the presence of anionic exchange resins.

The combination of Valsartan and Hydrochlorothiazide is contraindicated in patients with hypersensitivity to any component of this product. Due to the Hydrochlorothiazide component, it is also contraindicated in patients with anuria or hypersensitivity to other sulfonamide-derived drugs.

The combination is generally well tolerated and side effects are rare. Common side effects include headache, dizziness, fatigue, abdominal pain, cough, diarrhea, and nausea. Patients may also experience hyperkalemia, impotence, reduced renal function, allergic reactions, dyspnea, constipation, back pain, muscle cramps, rash, anxiety, insomnia, vertigo, and hypotension.

Pregnancy: Valsartan should not be used during pregnancy, especially in the 2nd and 3rd trimesters, as it may cause fetal injury or death. The drug should be discontinued immediately once pregnancy is detected.

Nursing mothers: It is not known whether Valsartan passes into human milk. Hydrochlorothiazide is excreted in breast milk.

Impaired hepatic function: Since Valsartan is mainly eliminated via bile, caution is required in patients with mild to moderate hepatic impairment or biliary obstruction.

Impaired renal function: Dose reduction or discontinuation may be necessary in patients with renal impairment, as thiazides may cause azotemia.

Heart failure and myocardial infarction: Caution is required when initiating therapy in these patients.

Renal impairment: Usual dosing may be followed if creatinine clearance is >30 ml/min. In severe renal impairment, loop diuretics are preferred and Hydrochlorothiazide is not recommended.

Hepatic impairment: Care should be taken in patients with liver impairment.

Valsartan: Overdose may cause hypotension and tachycardia; bradycardia may also occur. In severe hypotension, the patient should be placed in a supine position and treated with intravenous normal saline if needed.

Hydrochlorothiazide: Overdose may cause electrolyte imbalance such as hypokalemia, hypochloremia, and dehydration. If used with digitalis, hypokalemia may increase risk of arrhythmia. Dialysis effectiveness is not well established.

Combined antihypertensive preparations

Store between 15–30°C.