Dosing and uses of Hyzaar (losartan-hydrochlorothiazide)
Adult dosage forms and strengths
losartan/hydrochlorothiazide
tablet
- 50mg/12.5mg
- 100mg/12.5mg
- 100mg/25mg
Hypertension
Initial: 50 mg/12.5 mg PO qDay
If dose titrated upward, do not to exceed final titration of 100 mg/25 mg PO qDay or 50 mg/12.5 mg PO q12hr
Decrease losartan to 25 mg PO qDay initially if volume depleted
Dosing considerations
- Replacement therapy: Combination may be substituted for the individually titrated components
Dosing Modifications
Renal impairment
- CrCl ≤30 mL/min: Do not use thiazide-containing products; loop diuretic preferred
- CrCl >30 mL/min: No dosage adjustment required
Pediatric dosage forms and strengths
Safety and efficacy not established
Hyzaar (losartan-hydrochlorothiazide) adverse (side) effects
>10%
Losartan
- Fatigue (14%)
- Hypoglycemia (14%)
- Chest pain (12%)
- Cough, incidence higher in previous cough related to ACE therapy (3-11%)
1-10%
Losartan
- Diarrhea (2-10%)
- URI (8%)
- Hypotension (7%)
- Dizziness (4%)
- Nausea (2%)
Hydrochlorothiazide
- Hypotension
- Anorexia
- Epigastric distress
- Hypokalemia
- Phototoxicity
- Thrombocytopenia
Warnings
Black box warnings
Discontinue as soon as possible when pregnancy is detected; affects renin-angiotensin system, causing oligohydramnios, which may result in fetal injury and/or death (see Pregnancy and lactation)
Contraindications
Hypersensitivity to losartan, hydrochlorothiazides, or sulfonamides
Renal impairment (CrCl <30 mL/min)
Hepatic impairment
Anuria
Do not coadminister with aliskiren in patients with diabetes
Cautions
Stroke risk reduction may be less effective in African-Americans
Intravascular volume or salt depletion should be corrected prior to use
Monitor serum lithium levels in patients receiving lithium and hydrochlorothiazide
Inform female patients of childbearing age about consequences of exposure to losartan during pregnancy and importance of informing their physician about a pregnancy while on therapy; discontinue if pregnancy detected
Monitor for signs of fluid or electrolyte imbalance, including hyponatremia, hypochloremic alkalosis, and hypokalemia
If oliguria or hypotension occurs in neonate with history of in utero exposure, direct attention toward support of blood pressure and renal perfusion; exchange transfusions or dialysis may be required as a means of reversing hypotension and/or substituting for disordered renal function
Acute transient myopia and acute angle-closure glaucoma have been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is a sulfonamide)
Coadministration with corticosteroids, ACTH, or glycyrrhizin (found in liquorice) may intensify electrolyte depletion, particularly hypokalemia
Monitor renal function and potassium in susceptible patients
Exacerbation of systemic lupus erythematosus reported
Dual blockade of the renin-angiotensin-aldosterone system (ie, ARB plus an ACE inhibitor) in patients with established atherosclerotic disease, heart failure, or with diabetes with end organ damage is associated with a higher frequency of hypotension, syncope, hyperkalemia, and changes in renal function (including acute renal failure) as compared with use of a single renin-angiotensin-aldosterone system agent; closely monitor blood pressure, renal function and electrolytes in patients on losartan and other agents that affect the renin-angiotensin system (RAS)
Pregnancy and lactation
Pregnancy category: d
Use of drugs that act on the renin-angiotensin system during the 2nd and 3rd trimesters of pregnancy reduces renal function and increases fetal and neonatal morbidity and death
Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations
Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death
When pregnancy is detected, discontinue as soon as possible
Lactation: Discontinue drug or do not nurse
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
