What is the recommended dosage of Valsartan (Angiotensin II receptor antagonist) for patients with hypertension or heart failure?

Valsartan Dosage for Hypertension and Heart Failure

For hypertension, the recommended starting dose of valsartan is 80-160 mg once daily with a maximum dose of 320 mg daily; for heart failure, start with 40 mg twice daily and titrate up to 160 mg twice daily as the target dose. 1

Dosing for Hypertension

Initial Dosing

• Starting dose: 80 mg or 160 mg once daily for patients who are not volume-depleted 1
• The antihypertensive effect is substantially present within 2 weeks, with maximal reduction generally attained after 4 weeks 1

Dose Titration

• Dose range: 80-320 mg daily, administered once daily 1
• If additional antihypertensive effect is required beyond the starting dose, the dose may be increased to a maximum of 320 mg or a diuretic may be added 1
• Addition of a diuretic has a greater effect than dose increases beyond 80 mg 1

Efficacy Considerations

• The antihypertensive efficacy of the 80-mg dose is enhanced by doubling it to 160 mg, while maintaining a tolerability profile comparable to placebo 2
• Valsartan 160 mg once daily provides more sustained AT1-receptor blockade over 24 hours compared to 80 mg, which is particularly important for maintaining blood pressure control 3
• For stage 2 hypertension, higher doses (160-320 mg) or combination with hydrochlorothiazide may be needed to achieve blood pressure goals more quickly 4

Dosing for Heart Failure

Initial Dosing

• Starting dose: 40 mg twice daily 1

Dose Titration

• Uptitrate to 80 mg and 160 mg twice daily or to the highest dose tolerated by the patient 1
• Consider reducing the dose of concomitant diuretics during uptitration 1
• Maximum daily dose administered in clinical trials: 320 mg in divided doses 1

Target Dose

• Target maintenance dose: 160 mg twice daily 1, 5
• This dose was used in the Valsartan Heart Failure Trial (Val-HeFT), which showed a 13.2% reduction in the combined endpoint of mortality and morbidity compared with placebo 5

Post-Myocardial Infarction Dosing

• Starting dose: 20 mg twice daily, initiated as early as 12 hours after MI 1
• Uptitration: Increase to 40 mg twice daily within 7 days, with subsequent titrations to target maintenance dose of 160 mg twice daily as tolerated 1
• If symptomatic hypotension or renal dysfunction occurs, consider dose reduction 1

Special Considerations

Monitoring

• Check renal function and serum electrolytes within 1-2 weeks after starting treatment 6, 7
• Monitor for hypotension, particularly in patients who are volume-depleted 1, 5
• For heart failure patients, careful individualization of therapy is necessary; rigid dose standardization may not be appropriate 2

Precautions

• Avoid in pregnancy (contraindicated) 7
• Use with caution in patients with severe bilateral renal artery stenosis or elevated potassium levels (>5.0 mEq/L) 7
• If potassium rises above 5.5 mmol/L, consider halving the dose or discontinuing valsartan 6

Comparison with Other ARBs

• Response rate to valsartan 160 mg once daily is significantly greater than losartan 100 mg once daily 8
• Valsartan has good tolerability with a side-effect profile similar to placebo and superior to that of comparable drugs 8

Common Pitfalls and Caveats

1. Underdosing: Many patients remain on suboptimal doses. For heart failure, the target dose of 160 mg twice daily provides optimal clinical benefits 5

2. Formulation differences: Valsartan tablets and oral suspension are not substitutable on a milligram-per-milligram basis. The systemic exposure to valsartan is 60% higher with the suspension compared to tablets 1

3. Combination therapy: When using valsartan with ACE inhibitors and aldosterone antagonists, monitor closely for hypotension, renal dysfunction, and hyperkalemia 7

4. Missed doses: If a dose is missed, it should be administered as soon as possible, unless it is almost time for the next dose. The dose should not be doubled to make up for a missed dose 1