Dose Optimization of Losartan
Increase losartan from 25 mg to 50 mg once daily, as this represents the standard starting dose for most patients and the current 25 mg dose is below the usual therapeutic range for blood pressure control. 1
Rationale for Dose Escalation
The FDA-approved usual starting dose of losartan for adult hypertension is 50 mg once daily, with the current 25 mg dose reserved specifically for patients with possible intravascular depletion (e.g., those on diuretic therapy) 1
The dosage can be increased to a maximum of 100 mg once daily as needed to control blood pressure, providing substantial room for dose optimization before adding additional agents 1
Clinical trials demonstrate that maximum blood pressure reductions occur after doses of approximately 50 mg, with some patients requiring 100 mg for adequate control 2
Stepwise Approach to Dose Titration
First step: Increase losartan to 50 mg once daily and reassess blood pressure within 2-4 weeks 3
Second step: If blood pressure remains uncontrolled on losartan 50 mg, increase to 100 mg once daily before adding a second agent 1
Third step: If blood pressure remains uncontrolled on losartan 100 mg monotherapy, add either a thiazide diuretic (hydrochlorothiazide 12.5-25 mg) or a calcium channel blocker (amlodipine 5-10 mg) as the second agent 4, 3
Target Blood Pressure Goals
Target blood pressure should be <140/90 mmHg for most patients, with consideration of <130/80 mmHg for higher-risk patients 3
The 2007 ESH/ESC guidelines support that losartan has demonstrated efficacy in elderly hypertensive patients with left ventricular hypertrophy, showing superiority over atenolol in reducing cardiovascular events, particularly stroke 4
Evidence Supporting Combination Therapy When Needed
If monotherapy at maximum dose (100 mg) fails to achieve target blood pressure, adding hydrochlorothiazide 12.5 mg daily provides significant additional antihypertensive response, with the option to increase to 25 mg daily based on blood pressure response 1
The combination of losartan with a calcium channel blocker or thiazide diuretic represents guideline-recommended dual therapy for uncontrolled hypertension 3
Safety and Tolerability Considerations
Losartan demonstrates excellent tolerability, with an overall withdrawal rate due to adverse experiences (2.3%) lower than placebo (3.7%) 5
The most common drug-related adverse experience is dizziness (2.4% versus 1.3% for placebo), with significantly lower incidence of cough compared to ACE inhibitors 2, 5
No dosage adjustment is required for elderly patients or those with mild-to-moderate renal dysfunction, though patients with mild-to-moderate hepatic impairment should start at 25 mg once daily 1
Common Pitfalls to Avoid
Do not add a second antihypertensive agent before optimizing losartan to at least 50 mg daily, as the current 25 mg dose is subtherapeutic for most patients 1
Do not assume treatment failure without confirming medication adherence, as non-adherence is the most common cause of apparent treatment resistance 3
Confirm elevated blood pressure readings with home blood pressure monitoring (target <135/85 mmHg) or 24-hour ambulatory monitoring (target <130/80 mmHg) to rule out white-coat hypertension 3