Losartan side effects: what 173,627 FDA adverse event reports show
Drug class
Angiotensin ii receptor blocker (arb)
Brand names
Losartan Potassium
Who reports
173,627 reports · 63% serious · 12,522 with death outcome · 60% female
Used for
Losartan potassium tablet is 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.
What it is
Losartan is a biphenylyltetrazole where a 1,1'-biphenyl group is attached at the 5-position and has an additional trisubstituted imidazol-1-ylmethyl group at the 4'-position.
Boxed warning
FETAL TOXICITY When pregnancy is detected, discontinue losartan potassium tablets 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.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only (and, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,116 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Cardiospasm | 340 | 190.3 160.3–225.9ROR 190.7 · calibrated p 8e-10 ✓ | 73.2 EB05 66.9 · IC025 +5.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=340 | not reported in cached trials |
| Immunisation | 220 | 124.9 103.3–151.0ROR 125.1 · calibrated p 3e-8 ✓ | 60.9 EB05 54.4 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=220 | not reported in cached trials |
| Palmoplantar keratoderma | 334 | 104.6 90.3–121.2ROR 104.8 · calibrated p 9e-8 ✓ | 55.8 EB05 50.9 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=334 | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 185 | 24.9 21.3–29.2ROR 24.9 · calibrated p 7e-4 ✓ | 20.7 EB05 18.3 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=185 | not reported in cached trials |
| Atrial tachycardia | 349 | 23.8 21.2–26.7ROR 23.8 · calibrated p 9e-4 ✓ | 19.9 EB05 18.2 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=349 | NCT00090259: 1/1,913 (0.1%) on Losartan (serious AE) |
| Pruritus genital | 376 | 23.1 20.7–25.8ROR 23.1 · calibrated p 0.001 ✓ | 19.5 EB05 17.9 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=361 | not reported in cached trials |
| Hyperparathyroidism secondary | 364 | 20.1 18.0–22.5ROR 20.2 · calibrated p 0.002 ✓ | 17.3 EB05 15.9 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=364 | not reported in cached trials |
| Nephrogenic anaemia | 650 | 19.4 17.8–21.0ROR 19.4 · calibrated p 0.002 ✓ | 16.8 EB05 15.7 · IC025 +3.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=650 | NCT00090259: 2/1,921 (0.1%) on Losartan (serious AE) |
| Carotid artery occlusion | 406 | 15.0 13.5–16.6ROR 15.0 · calibrated p 0.007 ✓ | 13.4 EB05 12.3 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=406 | not reported in cached trials |
| Rebound acid hypersecretion | 339 | 14.9 13.3–16.7ROR 14.9 · calibrated p 0.007 ✓ | 13.3 EB05 12.2 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=339 | not reported in cached trials |
| Brash syndrome | 135 | 13.2 11.1–15.8ROR 13.3 · calibrated p 0.012 ✓ | 11.9 EB05 10.3 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=135 · 100% clinician | not reported in cached trials |
| Tension headache | 408 | 12.6 11.4–13.9ROR 12.6 · calibrated p 0.014 ✓ | 11.4 EB05 10.5 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious n=384 | not reported in cached trials |
| Sleep terror | 358 | 11.1 10.0–12.4ROR 11.2 · calibrated p 0.022 ✓ | 10.2 EB05 9.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=346 | not reported in cached trials |
| Multi-organ disorder | 141 | 9.2 7.7–10.9ROR 9.2 · calibrated p 0.045 ✓ | 8.4 EB05 7.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=139 · ♀ 100% (drug 60%) | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| End stage renal disease | 1,263 | 8.8 8.3–9.3ROR 8.9 · calibrated p 0.048 ✓ | 8.3 EB05 7.9 · IC025 +3.0 3/3 methods agree | Likely indication confounding term in indications | serious PRR 7.5 | not reported in cached trials |
| Chronic kidney disease | 4,187 | 6.9 6.7–7.1ROR 7.1 · calibrated p 0.096 | 6.6 EB05 6.4 · IC025 +2.7 3/3 methods agree | Labeled — boxed warning exact term | age-adj. PRR 6.2 · serious PRR 6.1 | not reported in cached trials |
| Dengue fever | 117 | 6.4 5.3–7.7ROR 6.4 · calibrated p 0.129 | 6.0 EB05 5.1 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=115 · ♀ 100% (drug 60%) · 100% consumer | not reported in cached trials |
| Facial pain | 451 | 6.4 5.8–7.0ROR 6.4 · calibrated p 0.128 | 6.1 EB05 5.6 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=409 | not reported in cached trials |
| Eyelid pain | 94 | 6.1 5.0–7.5ROR 6.1 · calibrated p 0.148 | 5.7 EB05 4.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | ♀ 100% (drug 60%) · 100% consumer | not reported in cached trials |
| Discouragement | 99 | 5.4 4.4–6.5ROR 5.4 · calibrated p 0.204 | 5.0 EB05 4.3 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=95 · ♀ 100% (drug 60%) · 100% consumer | not reported in cached trials |
| Subarachnoid haemorrhage | 426 | 5.2 4.7–5.7ROR 5.2 · calibrated p 0.213 | 5.0 EB05 4.6 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | NCT00546052: 1/1,714 (0.1%) on Losartan (serious AE) |
| Asthmatic crisis | 151 | 5.2 4.4–6.1ROR 5.2 · calibrated p 0.221 | 4.9 EB05 4.3 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=151 · ♀ 100% (drug 60%) | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Loss of employment | 124 | 5.1 4.2–6.1ROR 5.1 · calibrated p 0.229 | 4.8 EB05 4.2 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=121 · ♀ 100% (drug 60%) · 100% clinician | not reported in cached trials |
| Vasculitis | 456 | 4.9 4.4–5.4ROR 4.9 · calibrated p 0.248 | 4.7 EB05 4.3 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 4.8 · serious PRR 4.6 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Essential hypertension | 96 | 4.6 3.8–5.7ROR 4.6 · calibrated p 0.286 | 4.4 EB05 3.7 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious n=89 · ♀ 100% (drug 60%) · 100% clinician | not reported in cached trials |
| Blood pressure inadequately controlled | 222 | 4.5 4.0–5.2ROR 4.6 · calibrated p 0.291 | 4.4 EB05 3.9 · IC025 +1.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=170 | not reported in cached trials |
| Anosmia (loss of smell) | 517 | 4.4 4.1–4.8ROR 4.4 · calibrated p 0.306 | 4.3 EB05 4.0 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious n=451 | not reported in cached trials |
| Body height decreased | 383 | 4.4 4.0–4.9ROR 4.4 · calibrated p 0.311 | 4.3 EB05 3.9 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious n=253 | not reported in cached trials |
| Blood cholesterol abnormal | 155 | 4.2 3.5–4.9ROR 4.2 · calibrated p 0.352 | 4.0 EB05 3.5 · IC025 +1.7 3/3 methods agree | Lab value / disease marker | serious n=133 · 100% consumer | not reported in cached trials |
| Impaired gastric emptying | 420 | 4.1 3.7–4.5ROR 4.1 · calibrated p 0.363 | 4.0 EB05 3.7 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 · 84% consumer | not reported in cached trials |
| Infarction | 227 | 4.1 3.6–4.6ROR 4.1 · calibrated p 0.366 | 3.9 EB05 3.5 · IC025 +1.8 3/3 methods agree | Likely indication confounding term in indications | serious PRR 3.6 · 100% consumer | NCT00090259: 1/1,913 (0.1%) on Losartan (serious AE) |
| Renal injury | 930 | 3.8 3.6–4.1ROR 3.8 · calibrated p 0.409 | 3.7 EB05 3.5 · IC025 +1.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.4 | not reported in cached trials |
| Blood pressure abnormal | 613 | 3.8 3.5–4.1ROR 3.8 · calibrated p 0.411 | 3.7 EB05 3.5 · IC025 +1.8 3/3 methods agree | Likely indication confounding term in indications | serious PRR 3.4 | NCT00090259: 1/1,913 (0.1%) on Losartan (serious AE) |
| Acute kidney injury (sudden kidney damage) | 4,669 | 3.8 3.7–3.9ROR 3.9 · calibrated p 0.404 | 3.7 EB05 3.6 · IC025 +1.8 3/3 methods agree | Labeled — boxed warning synonym match | age-adj. PRR 2.4 · serious PRR 3.4 | not reported in cached trials |
| Arterial occlusive disease | 241 | 3.8 3.3–4.3ROR 3.8 · calibrated p 0.425 | 3.7 EB05 3.3 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 · 80% consumer | not reported in cached trials |
| Ventricular tachycardia | 502 | 3.7 3.4–4.1ROR 3.7 · calibrated p 0.429 | 3.6 EB05 3.4 · IC025 +1.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | age-adj. PRR 3.2 · serious PRR 3.4 | NCT00090259: 2/1,913 (0.1%) on Losartan (serious AE) |
| Diabetic neuropathy | 149 | 3.7 3.1–4.3ROR 3.7 · calibrated p 0.442 | 3.6 EB05 3.1 · IC025 +1.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=137 | not reported in cached trials |
| Oligohydramnios | 100 | 3.7 3.0–4.5ROR 3.7 · calibrated p 0.446 | 3.5 EB05 3.0 · IC025 +1.5 3/3 methods agree | Labeled — boxed warning exact term | serious n=100 · ♀ 100% (drug 60%) · 100% clinician | not reported in cached trials |
| Glomerular filtration rate decreased | 357 | 3.6 3.3–4.0ROR 3.6 · calibrated p 0.453 | 3.5 EB05 3.2 · IC025 +1.7 3/3 methods agree | Lab value / disease marker | serious PRR 3.2 | not reported in cached trials |
| Eye haemorrhage | 394 | 3.6 3.3–4.0ROR 3.6 · calibrated p 0.452 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
Clinical concept groups
MedDRA splits one clinical problem across several terms (e.g. "neutropenia", "neutrophil count decreased", "agranulocytosis"), which dilutes term-level signals. These rows count reports with any term in a concept group (an exact union, not a sum), compared with all other drugs. Groups are hand-built and listed in the methods.
| Concept | Reports | PRR 95% CI | Reading |
|---|---|---|---|
| Kidney injury | 9,226 | 2.52.4–2.5 | signal |
| Hyponatraemia | 1,571 | 2.42.3–2.5 | signal |
| Arrhythmia / qt | 3,315 | 2.12.0–2.2 | signal |
| Fall / fracture | 5,794 | 1.91.8–1.9 | raised |
| Hyperglycaemia / diabetes | 5,136 | 1.81.8–1.9 | raised |
| Heart failure | 2,557 | 1.71.7–1.8 | raised |
| Tendon disorder | 544 | 1.71.6–1.9 | raised |
| Hypoglycaemia | 1,362 | 1.71.6–1.8 | raised |
| Gi bleeding | 2,569 | 1.71.6–1.8 | raised |
| Myocardial infarction | 2,749 | 1.61.6–1.7 | raised |
| Serious infection | 10,094 | 1.61.6–1.6 | raised |
| Anaemia | 3,870 | 1.61.5–1.6 | raised |
| Anaphylaxis / angioedema | 1,476 | 1.41.4–1.5 | raised |
| Stroke | 2,918 | 1.41.4–1.5 | raised |
| Depression | 3,270 | 1.41.4–1.5 | raised |
| Venous thromboembolism | 2,211 | 1.21.2–1.3 | raised |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Losartan as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (10 of 40 signal terms matched).
- NCT00090259 — Study to Evaluate Potential Decrease in Hospitalization Events, Time Between Events, and Increasing Longevity (N=3834, PHASE3; 813 AE terms posted; arms: Losartan 50 mg; Losartan 150 mg)
- NCT00546052 — A 52 Week Study to Evaluate the Effects of Losartan With or Without HCTZ on Plasma Glucose, Metabolic Paramete (N=1738, PHASE3; 37 AE terms posted; arms: Overall ITT)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 12,473 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.959 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 1.9 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Diarrhoea (diarrhea) | 10,448 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.965 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 1.9 | NCT00090259: 5/1,921 (0.3%) on Losartan (serious AE) |
| Nausea | 9,692 | 1.5 1.5–1.5ROR 1.5 · calibrated p 0.653 | 1.5 EB05 1.5 · IC025 +0.5 | Labeled adverse reaction exact term | age-adj. PRR 1.4 · serious PRR 1.6 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Drug ineffective (drug did not work) | 9,635 | 0.9 0.9–0.9ROR 0.9 · calibrated p 0.228 | 0.9 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | age-adj. PRR 1.0 · serious PRR 1.0 | not reported in cached trials |
| Dyspnoea (shortness of breath) | 8,853 | 1.9 1.9–1.9ROR 2.0 · calibrated p 0.917 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.8 | NCT00090259: 2/1,921 (0.1%) on Losartan (serious AE) |
| Dizziness | 8,424 | 2.1 2.0–2.1ROR 2.1 · calibrated p 0.995 | 2.0 EB05 2.0 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 2.1 | NCT00090259: 7/1,921 (0.4%) on Losartan (serious AE) |
| Headache | 8,331 | 1.6 1.6–1.6ROR 1.6 · calibrated p 0.735 | 1.6 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.8 | NCT00090259: 1/1,913 (0.1%) on Losartan (serious AE) |
| Pain | 7,677 | 1.5 1.5–1.5ROR 1.5 · calibrated p 0.665 | 1.5 EB05 1.5 · IC025 +0.6 | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 1.5 | NCT00090259: 2/1,921 (0.1%) on Losartan (serious AE) |
| Off label use (used outside approved label) | 7,612 | 1.1 1.0–1.1ROR 1.1 · calibrated p 0.347 | 1.1 EB05 1.0 · IC025 +0.0 | Reporting / coding artifact | age-adj. PRR 1.0 · serious PRR 1.0 | not reported in cached trials |
| Arthralgia (joint pain) | 6,625 | 1.9 1.9–2.0ROR 2.0 · calibrated p 0.934 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 2.2 | NCT00090259: 3/1,921 (0.2%) on Losartan (serious AE) |
| Malaise (feeling unwell) | 6,139 | 1.7 1.7–1.7ROR 1.7 · calibrated p 0.782 | 1.7 EB05 1.7 · IC025 +0.7 | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.9 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Asthenia (weakness) | 6,097 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.948 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.8 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Cough | 5,685 | 2.5 2.4–2.5ROR 2.5 · calibrated p 0.799 | 2.5 EB05 2.4 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.0 · serious PRR 2.5 | NCT00090259: 1/1,913 (0.1%) on Losartan (serious AE) |
| Vomiting | 5,502 | 1.4 1.4–1.5ROR 1.4 · calibrated p 0.599 | 1.4 EB05 1.4 · IC025 +0.5 | Labeled adverse reaction exact term | age-adj. PRR 1.4 · serious PRR 1.4 | NCT00090259: 1/1,921 (0.1%) on Losartan (serious AE) |
| Fall | 5,459 | 2.0 1.9–2.1ROR 2.0 · calibrated p 0.961 | 2.0 EB05 1.9 · IC025 +0.9 | Not in label — unassessed | age-adj. PRR 1.4 · serious PRR 1.9 | NCT00090259: 12/1,921 (0.6%) on Losartan (serious AE) |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Immunisation — n=220, PRR 124.9
- Palmoplantar keratoderma — n=334, PRR 104.6
- Chronic kidney disease-mineral and bone disorder — n=185, PRR 24.9
- Atrial tachycardia — n=349, PRR 23.8 (also seen in trial arm)
- Pruritus genital — n=376, PRR 23.1
- Hyperparathyroidism secondary — n=364, PRR 20.1
- Carotid artery occlusion — n=406, PRR 15.0
- Rebound acid hypersecretion — n=339, PRR 14.9
- Brash syndrome — n=135, PRR 13.2
- Sleep terror — n=358, PRR 11.1
✓ A hand-written Bradford Hill causality assessment exists for this drug: Losartan ↔ Renal failure.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Losartan?
In FDA FAERS, the most frequently co-reported reaction terms for Losartan are fatigue, diarrhoea, nausea, dyspnoea, dizziness, headache. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Losartan have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: FETAL TOXICITY When pregnancy is detected, discontinue losartan potassium tablets 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.
Do FAERS signals prove that Losartan causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 9501dfaa-c8cf-46d6-8bec-936c4fd8fe03, effective 20260716; matched on
openfda.generic_name.exact:"LOSARTAN" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG") - PubChem CID 3961 description (ChEBI)
- Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 1,156 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath - ClinicalTrials.gov API v2 (query
LOSARTAN, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.