Can a 100 mg losartan tablet be split in half?

Can Losartan 100 mg Tablets Be Split in Half?

Yes, losartan 100 mg tablets can be split in half, as the 50 mg formulation is scored specifically to facilitate splitting, and both once-daily and twice-daily dosing regimens are guideline-supported for the same total daily dose. 1

Tablet Formulation and Splitting Feasibility

• The FDA-approved losartan 50 mg tablets are scored on one side, which indicates they are designed to be split. 2
• The 100 mg tablets are not scored and are described as "plain on the other side," making them less suitable for accurate splitting. 2
• If you need to split a 100 mg dose, the practical approach is to prescribe two 50 mg tablets (which are scored) rather than attempting to split a single 100 mg tablet. 2

Guideline-Supported Dosing Flexibility

• The American College of Cardiology/American Heart Association guidelines explicitly state that losartan's usual dose range is 50-100 mg/day with a daily frequency of "1 or 2," meaning both once-daily and twice-daily administration are acceptable. 1
• Losartan 50 mg twice daily (total 100 mg/day) is guideline-supported and provides equivalent total daily exposure to 100 mg once daily. 1

Pharmacokinetic Rationale

• Losartan's active metabolite E-3174 has a terminal half-life of 6-9 hours, which supports twice-daily dosing for more consistent 24-hour coverage in some patients. 3
• The pharmacokinetics are linear and dose-proportional, so splitting the dose does not alter overall drug exposure. 3
• The maximum recommended daily dose is 100 mg, which can be given as a once-daily dose or by splitting the same total daily dose into two doses. 3

Clinical Considerations for Twice-Daily Dosing

• If twice-daily dosing is desired for more consistent 24-hour blood pressure coverage, prescribe losartan 50 mg twice daily rather than attempting to split 100 mg tablets. 1
• Twice-daily dosing may provide better control in patients with breakthrough hypertension at the end of the dosing interval. 1
• Ensure the total daily dose (100 mg) remains appropriate for the indication when prescribing 50 mg BID. 1

Practical Implementation

• Order losartan 50 mg tablets (which are scored) and instruct the patient to take one tablet twice daily if splitting the 100 mg dose is needed. 2
• Avoid attempting to split the 100 mg tablets, as they lack a score line and may not divide accurately. 2
• Monitor serum potassium and creatinine within 1-2 weeks after any dosing change, especially in patients with chronic kidney disease or diabetes. 1

Common Pitfall to Avoid

• Do not assume that splitting unscored 100 mg tablets will provide accurate 50 mg doses; the lack of a score line makes precise division difficult and may lead to inconsistent dosing. 2