From the FDA Drug Label
The studies allowed comparisons of two doses (50 to 100 mg/day) as once-daily or twice-daily regimens, comparisons of peak and trough effects, and comparisons of response by gender, age, and race. Twice-daily dosing at 50 mg to 100 mg/day gave consistently larger trough responses than once-daily dosing at the same total dose.
- Efficacy: Losartan is efficacious when given twice daily, as twice-daily dosing at 50 mg to 100 mg/day gave consistently larger trough responses than once-daily dosing at the same total dose.
- Dosage: The appropriate dosage for twice-daily administration is 50 mg to 100 mg/day, divided into two doses. 1
From the Research
Losartan should not be given twice daily, as once-daily dosing is the standard and appropriate regimen, providing 24-hour blood pressure control with a single dose. The usual adult dosage ranges from 25-100 mg once daily, with 50 mg being a common starting dose for hypertension. According to the most recent and highest quality study, 2, there were no differences in systolic/diastolic blood pressure between twice-daily and once-daily dosing, with absolute differences in mean systolic blood pressure ranging from -1.8 to 0.7 mmHg and diastolic blood pressure ranging from -1.1 to 0.1 mmHg. This study suggests that once-daily dosing is sufficient and effective for blood pressure control.
Some key points to consider when prescribing losartan include:
- The active metabolite of losartan has a half-life of 6-9 hours, providing 24-hour blood pressure control with once-daily administration.
- While some patients might benefit from divided dosing in specific circumstances, this is not routinely recommended or necessary.
- The once-daily dosing schedule improves medication adherence and maintains consistent blood pressure control throughout the day.
- If blood pressure control is inadequate with maximum once-daily dosing (100 mg), adding a different antihypertensive medication rather than splitting the losartan dose is generally preferred.
- Patients should take losartan at the same time each day to maintain consistent blood levels and therapeutic effect.
It's also worth noting that the study 2 found no improved effectiveness or safety of twice-daily dosing compared to once-daily dosing, which further supports the use of once-daily dosing as the standard regimen.