Losartan 50/25 HCTZ: Medication Identification
Losartan 50/25 HCTZ is a fixed-dose combination antihypertensive medication containing 50 mg of losartan (an angiotensin II receptor blocker/ARB) and 25 mg of hydrochlorothiazide (a thiazide diuretic). 1
Medication Components
Losartan 50 mg: An angiotensin II receptor antagonist (ARB) that blocks the vasoconstrictive and aldosterone-secreting effects of angiotensin II 2
Hydrochlorothiazide (HCTZ) 25 mg: A thiazide-type diuretic with the chemical name 6-Chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1-dioxide, molecular formula C7H8ClN3O4S2 3
Clinical Indications
This combination is FDA-approved for:
- Treatment of hypertension, including as initial therapy in severe hypertension 4
- Stroke risk reduction in patients with hypertension and left ventricular hypertrophy 4
Available Formulations
The standard fixed-dose combinations of losartan/HCTZ available are:
Note: The "50/25" formulation you're asking about appears to refer to losartan 50 mg with HCTZ 25 mg, which is not a standard FDA-approved fixed-dose combination. 1 The standard combinations are 50/12.5 mg or 100/25 mg. If a patient requires losartan 50 mg with HCTZ 25 mg, this would typically be prescribed as separate tablets rather than a fixed combination.
Antihypertensive Efficacy
Losartan 100 mg/HCTZ 25 mg produces mean trough blood pressure reductions of approximately 17.5/9 mmHg in patients with moderate-to-severe hypertension, with response rates of 86.7% 5
Losartan 50 mg/HCTZ 12.5 mg produces mean trough blood pressure reductions of approximately 15.2/8 mmHg, with response rates of 78.9% 5
The addition of HCTZ 12.5 mg or 25 mg to losartan 50 mg produces effective blood pressure control in 71% and 83% of patients, respectively, who only partially responded to losartan monotherapy 6
Safety Profile
The combination is well-tolerated with adverse event rates similar to placebo (34.7% for losartan 100/HCTZ 25 vs 32.6% for placebo) 5
Drug-related adverse events occur in approximately 7-11% of patients across all treatment groups 5
Common adverse events include dizziness (3%), upper respiratory infection (8%), nasal congestion (2%), and back pain (2%) 2
Unlike ACE inhibitors, losartan has a significantly lower incidence of persistent dry cough (17-29% vs 62-69% with lisinopril) 2