Should Losartan be taken once daily or twice daily in a patient with normal renal function?

Losartan Dosing Frequency

Losartan should be taken once daily for hypertension in patients with normal renal function, with the standard dosing being 50-100 mg once daily. 1, 2

Guideline-Supported Dosing Regimen

The American College of Cardiology/American Heart Association guidelines explicitly state that losartan can be administered with a daily frequency of "1 or 2," meaning both once-daily and twice-daily dosing are acceptable, though once-daily administration is the standard recommendation. 1

• For hypertension: Start with 50 mg once daily and titrate to 100 mg once daily as needed for blood pressure control. 1
• Maximum recommended dose: 100 mg once daily for hypertension, though the total daily dose should not exceed 100 mg regardless of frequency. 1
• Pharmacokinetic support: The active metabolite E-3174 has a terminal half-life of 6-9 hours and provides antihypertensive effects that persist throughout 24 hours after once-daily administration. 3

When to Consider Twice-Daily Dosing

While once-daily dosing is standard, twice-daily administration may be appropriate in specific circumstances:

• If better blood pressure control is needed throughout the day: Split the 100 mg total daily dose into 50 mg twice daily for more consistent 24-hour coverage. 1
• The KDOQI guidelines list losartan dosing for diabetic kidney disease as 25-100 mg daily in 1-2 divided doses, not exceeding 100 mg total. 1

Practical Implementation Algorithm

1. Start with once-daily dosing: Begin at 50 mg once daily, as this is the standard approach supported by clinical trials. 1, 4
2. Titrate every 2 weeks: Adjust dose based on blood pressure response, increasing to 100 mg once daily if needed. 2
3. Consider combination therapy before splitting doses: If blood pressure remains uncontrolled on 100 mg once daily, add hydrochlorothiazide 12.5-25 mg daily rather than splitting the losartan dose. 1
4. Reserve twice-daily dosing for specific situations: Only consider 50 mg twice daily if there is documented inadequate 24-hour blood pressure control on once-daily dosing. 1

Critical Monitoring Requirements

• Check blood pressure, renal function, and potassium within 1-2 weeks after initiation or dose changes. 2
• Monitor for hyperkalemia, especially in patients with chronic kidney disease or diabetes. 1
• Avoid combining with ACE inhibitors, as this increases risk of hyperkalemia and renal dysfunction without added benefit. 1, 2

Common Pitfalls to Avoid

• Underdosing is widespread: Less than 25% of patients are titrated to target doses in clinical practice, despite evidence that higher doses provide greater cardiovascular benefits. 2
• Titrating too quickly: Adjusting more frequently than every 2 weeks doesn't allow adequate time to assess the full antihypertensive effect. 2
• Unnecessary twice-daily dosing: The pharmacokinetics support once-daily administration, and splitting doses adds complexity without clear benefit for most patients. 3