Losartan: Side Effects, Uses & Monitoring
Hypertension Losartan potassium tablets are indicated for the treatment of hypertension.
- Data source
- FDA labeling via NIH DailyMed (label d6ba182e…)
- Label version
- current
- Last reviewed
- 2026
Reported adverse reactions
Reactions listed in current FDA labeling, with the highest frequency reported across summarized placebo-controlled trials.
| Adverse reaction (as reported in labeling) | Reported frequency* |
|---|---|
| Cough | 69% |
| Urinary tract infection | 16% |
| Diarrhea | 15% |
| Asthenia/fatigue | 14% |
| Anemia | 14% |
| Hypoglycemia | 14% |
| Chest pain | 12% |
| Back pain | 12% |
| Influenza-like disease | 10% |
| Diabetic vascular disease | 10% |
| Bronchitis | 10% |
| Infection, upper respiratory | 8% |
| Hypotension | 7% |
| Cataract | 7% |
| Hyperkalemia | 7% |
| Muscular weakness | 7% |
| Cellulitis | 7% |
| Infection | 5% |
| Gastritis | 5% |
| Leg pain | 5% |
*Highest percentage reported for the active moiety across placebo-controlled trial tables in current FDA labeling. Values reflect trial reporting, not your individual risk.
Labeled uses (from FDA prescribing information)
Hypertension Losartan potassium tablets are indicated for the treatment of hypertension. It may be used alone or in combination with other antihypertensive agents, including diuretics. Hypertensive Patients with Left Ventricular Hypertrophy Losartan potassium tablets are indicated to reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy, but there is evidence that this benefit does not apply to Black patients. (See PRECAUTIONS, Race and CLINICAL PHARMACOLOGY, Pharmacodynamics and Clinical Effects, Reduction in the Risk of Stroke, Race.) Nephropathy in Type 2 Diabetic Patients Losartan potassium tablets are indicated for the treatment of diabetic nephropathy with an elevated serum creatinine and proteinuria (urinary albumin to creatinine ratio ≥300 mg/g) in patients with type 2 diabetes and a history of hypertension. In this population, losartan potassium tablets reduce the rate of progression of nephropathy as measured by the occurrence of doubling of serum creatinine or end stage renal disease (need for dialysis or renal transplantation) (see CLINICAL PHARMACOLOGY, Pharmacodynamics and Clinical Effects).
Tests providers may use to monitor Losartan therapy
Conditions associated with Losartan in labeling
Hypertension
Chronically elevated blood pressure that puts strain on the heart, blood vessels, kidneys, and brain. Often ha...
Stroke
Sudden interruption of blood flow to the brain, causing rapid loss of brain function. Time-critical medical em...
Type 2 Diabetes
A chronic condition in which the body becomes resistant to insulin or does not produce enough insulin to maint...
Frequently Asked Questions
What is Losartan used for?
FDA labeling lists the approved uses shown above under "Labeled uses." This summary is informational; only a qualified prescriber can determine whether a medication is appropriate for you.
What are the most commonly reported side effects of Losartan?
The table above shows adverse reactions and the highest frequencies reported in placebo-controlled trials summarized in current FDA labeling for Losartan. Individual risk varies.
Does Losartan require lab monitoring?
Labeling and standard practice associate Losartan with periodic laboratory monitoring; the tests above are commonly ordered by clinicians to monitor patients on therapy. Your provider decides what is appropriate.
Where does this information come from?
All clinical facts on this page were extracted from the current FDA-registered product labeling for this ingredient, published by manufacturers through NIH DailyMed. See the source link below.
Medical disclaimer: Educational content extracted from public FDA labeling. Not medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.