· Brand: Arbli, Cozaar
Losartan Side Effects: Common, Serious & FDA Warnings
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FDA-Approved For
Quick answer
Based on 206,000+ FDA adverse event reports, the most-reported losartan reactions include fatigue, diarrhoea, and nausea. FDA reports 3 active Class II recalls of losartan, primarily for failed dissolution specifications. The FDA-approved label carries a boxed warning.
For information only. MedivaScan summarizes public FDA data and is not medical advice. Consult a healthcare professional before changing any medication. If you experience a serious reaction, contact your doctor or call 911.
FDA Boxed Warning
WARNING: FETAL TOXICITY When pregnancy is detected, discontinue losartan potassium as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus [see Warnings and Precautions (5.1) ]. WARNING: FETAL TOXICITY See full prescribing information for complete boxed warning. When pregnancy is detected, discontinue losartan potassium as soon as possible. Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. (5.1)
Common Side Effects of Losartan
The most-reported reactions in the FDA Adverse Event Reporting System (FAERS) for losartan. Percentages reflect the share of reports mentioning each reaction; a single report may include multiple reactions. Reports indicate co-occurrence, not causation.
| Reaction | Reports | % of total |
|---|---|---|
| Fatigue | 14,302 | 6.9% |
| Diarrhoea | 11,974 | 5.8% |
| Nausea | 11,753 | 5.7% |
| Dyspnoea | 10,585 | 5.1% |
| Dizziness | 10,097 | 4.9% |
| Headache | 9,701 | 4.7% |
| Pain | 9,028 | 4.4% |
| Arthralgia | 7,714 | 3.7% |
| Asthenia | 7,386 | 3.6% |
| Malaise | 7,054 | 3.4% |
Serious Outcomes and FDA Warnings
FAERS reports flagged with a serious outcome (death, hospitalization, life-threatening, disability, or congenital anomaly), plus reactions surfaced in the FDA-approved label's Warnings section. Reports indicate co-occurrence, not causation.
| Outcome flag | Reports | % of total |
|---|---|---|
| Serious reports (any flag) | — | — |
| Hospitalization | — | — |
| Death reported as outcome FAERS outcome flag, not a reaction term. The patient was on the drug when the report was filed; causation is not established. | 5,669 | 2.7% |
From the FDA-approved label, Section 5.1: Fetal Toxicity
Losartan potassium can cause fetal harm when administered to a pregnant woman. Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal 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 losartan potassium as soon as possible [see Use in Specific Populations (8.1) ].
From the FDA-approved label, Section 5.4: Hyperkalemia
Monitor serum potassium periodically and treat appropriately. Dosage reduction or discontinuation of losartan potassium may be required [see Adverse Reactions (6.1) ]. Concomitant use of other drugs that may increase serum potassium may lead to hyperkalemia [see Drug Interactions (7.1) ].
Losartan Recalls
FDA enforcement actions matched to losartan via openFDA's structured generic_name field and the NDC bridge. Ongoing recalls are listed below (verify on FDA →); closed recalls are grouped in the disclosure that follows.
| Date | Reason | Class | Quantity | Status |
|---|---|---|---|---|
| 2019-03-27 | CGMP Deviations; trace amounts of N-Nitroso N-Methyl 4-amino butyric acid (NMBA) detected in the active pharmaceutical ingredient Camber Pharmaceuticals Inc | Class II | 69712 bottles | Ongoing |
| 2019-03-27 | CGMP Deviations; trace amounts of N-Nitroso N-Methyl 4-amino butyric acid (NMBA) detected in the active pharmaceutical ingredient Camber Pharmaceuticals Inc | Class II | 683,641 bottles | Ongoing |
| 2019-03-27 | CGMP Deviations; trace amounts of N-Nitroso N-Methyl 4-amino butyric acid (NMBA) detected in the active pharmaceutical ingredient Camber Pharmaceuticals Inc | Class II | 351,732 bottles | Ongoing |
Show 16 closed recalls (2014 to 2023)
Includes resolved and terminated recalls matched to losartan. Most recent first.
| Date | Reason | Class | Quantity | Status |
|---|---|---|---|---|
| 2023-07-12 | Presence of Foreign Substance: Presence of a small piece of blue plastic embedded in the tablet. Strides Pharma Inc. | Class II | 2,700 HDPE Bottles | Terminated |
| 2022-07-06 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits PD-Rx Pharmaceuticals, Inc. | Class II | 687 bottles | Terminated |
| 2022-07-06 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits PD-Rx Pharmaceuticals, Inc. | Class II | 1320 bottles | Terminated |
| 2022-07-06 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits PD-Rx Pharmaceuticals, Inc. | Class II | 1441 bottles | Terminated |
| 2022-06-08 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Strides Pharma Inc. | Class II | 381456 bottles | Terminated |
| 2022-06-08 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Strides Pharma Inc. | Class II | 200407 bottles | Terminated |
| 2022-06-08 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Strides Pharma Inc. | Class II | 96966 bottles | Terminated |
| 2022-05-11 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Lupin Pharmaceuticals Inc. | Class II | 657,336 bottles | Terminated |
| 2022-05-11 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Macleods Pharma Usa Inc | Class II | 12,408/90 count bottles; 1670/1000 count bottles =2,786,720 tablets | Terminated |
| 2022-05-11 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Macleods Pharma Usa Inc | Class II | 3288/30 count bottles; 23,904/90 count bottles; 3364/1000 count bottles = 5,614,000 tablets | Terminated |
| 2022-05-11 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Macleods Pharma Usa Inc | Class II | 3216/30 count bottles; 47,904/90 count bottles; 4269/1000 count bottles = 8,676,840 tablets | Terminated |
| 2022-05-11 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Lupin Pharmaceuticals Inc. | Class II | 1,247,067 bottles | Terminated |
| 2022-05-11 | CGMP Deviations- AZIDO Impurity levels observed to be above acceptable limits Lupin Pharmaceuticals Inc. | Class II | 1,466,150 bottles | Terminated |
| 2019-07-17 | CGMP Deviations: impurity for N-Nitroso-N-methyl-4-aminobutyric acid (NMBA) detected in the active pharmaceutical ingredient (API) used to manufacture finished products. Macleods Pharma Usa Inc | Class II | 47520 bottles (4,276,800 tablets) | Terminated |
| 2019-07-17 | CGMP Deviations: impurity for N-Nitroso-N-methyl-4-aminobutyric acid (NMBA) detected in the active pharmaceutical ingredient (API) used to manufacture finished products. Macleods Pharma Usa Inc | Class II | 4277 bottles (4,277,000 tablets) | Terminated |
| 2014-11-26 | Failed Content Uniformity Specifications; Dry mix failed blend uniformity. Micro Labs Usa, Inc S | Class II | 144 bottles | Terminated |
Losartan Shortages
FDA-listed shortages of losartan products. Strength and dosage-form level detail.
No active or recent shortages of losartan are listed. We refresh this view daily.
Is Losartan Safe?
Losartan is FDA-approved. The label's Warnings and Precautions section covers fetal toxicity (Section 5.1), hypotension in volume- or salt-depleted (Section 5.2), renal function deterioration (Section 5.3), hyperkalemia (Section 5.4).
As with any prescription, the assessment of safety is individual; consult a clinician about your own risk profile.
FDA-Approved Indications
Losartan is FDA-approved for use in the condition categories below. The FDA-approved label’s Indications and Usage section is shown verbatim.
Losartan potassium tablets are an angiotensin II receptor blocker (ARB) indicated for: • Treatment of hypertension, to lower blood pressure in adults and children greater than 6 years old. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. (1.1) • Reduction of the risk of stroke in patients with hypertension and left ventricular hypertrophy.Show full Indications and Usage
There is evidence that this benefit does not apply to Black patients. (1.2) • Treatment of diabetic nephropathy with an elevated serum creatinine and proteinuria in patients with type 2 diabetes and a history of hypertension. (1.3) 1.1 Hypertension Losartan potassium tablets are indicated for the treatment of hypertension in adults and pediatric patients 6 years of age and older, to lower blood pressure. Lowering blood pressure lowers the risk of fatal and nonfatal cardiovascular (CV) events, primarily strokes and myocardial infarction. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including losartan. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than 1 drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program's Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in Black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Losartan potassium tablets may be administered with other antihypertensive agents. 1.2 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 Use in Specific Populations (8.6) and Clinical Pharmacology (12.3) ]. 1.3 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 reduces 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 Studies (14.3) ].
Frequently Asked Questions
What are the most-reported side effects of losartan?
Fatigue, diarrhoea, and nausea are among the most-reported reactions in FDA FAERS data for losartan. The full ranking, with reaction counts and the share of total reports, is in the Common Side Effects table above. Reports indicate co-occurrence, not causation; consult a clinician about your specific case.
Is losartan the same as Arbli?
Losartan is the generic name; Arbli is a brand name for the same active ingredient. Other brand names include Cozaar. The active ingredient is identical; formulation and inactive ingredients may vary by manufacturer.
Has losartan been recalled?
Yes. Losartan has active and closed recalls on record in the FDA enforcement database. Reasons are dominated by CGMP deviations, contamination or foreign material, and subpotent or out-of-spec content. See the recalls table on this page for current counts, firm names, dates, and lot quantities.
What are losartan's current ongoing recalls about?
Active losartan recalls are listed in the recalls table above with their class, reason, firm, and affected lots. The dominant reason across these recalls is CGMP deviations. For lot numbers, distribution patterns, and the FDA enforcement record for any individual recall, follow the verify-on-FDA link from each row.
What do FDA recall classes mean?
Class I means a reasonable probability of serious adverse health consequences or death. Class II means temporary or medically reversible adverse health consequences with remote probability of serious harm. Class III means use of the product is unlikely to cause adverse health consequences. The class assignment is the FDA's, not the manufacturer's.
Does losartan have an FDA boxed warning?
Yes. The FDA-approved label for losartan carries a boxed warning. Boxed warnings are the FDA's strongest cautions. See the "FDA Boxed Warning" section above for the verbatim warning text.
Data Sources & Methodology
How each section of this page is sourced, and how often the data is refreshed.
| Source | Endpoint | Refresh |
|---|---|---|
| FAERS reactions | openFDA /drug/event.json count API. Aggregated per drug per reaction term; we do not store individual reports. | Daily |
| Recalls | openFDA /drug/enforcement.json. Drugs matched via three confidence-tracked strategies: structured generic name (HIGH), NDC code bridge (MEDIUM), text token parse (LOW). Only HIGH and MEDIUM matches surface here. | 6 hours |
| Shortages | FDA Drug Shortages list. | Daily |
| Boxed warnings & label sections | openFDA /drug/label.json. Labels are stable; monthly cadence is sufficient. | Monthly |
| Condition categories | Synonym-mapped from drug_labels.indications. Methodology at /methodology/. | Per-drug |
What we do not do. We do not invent, paraphrase, or extrapolate drug claims. Every figure on this page comes from a query against an openFDA endpoint. If the data is unavailable, the section gracefully omits rather than filling the space with editorial guesswork.