Ribavirin side effects: what 63,917 FDA adverse event reports show
Drug class
Nucleoside Analog Antiviral
Who reports
63,917 reports · 59% serious · 3,412 with death outcome · 43% female
Used for
Ribavirin capsules are a nucleoside analogue indicated in combination with interferon alfa-2b (pegylated and nonpegylated) for the treatment of Chronic Hepatitis C (CHC) in patients 3 years of age or older with compensated liver disease. ( 1.1 ) Patien.
What it is
Ribavirin, is a synthetic nucleoside analogue (purine analogue).
Boxed warning
EMBRYO-FETAL TOXICITY, HEMOLYTIC ANEMIA, and MONOTHERAPY NOT RECOMMENDED Significant teratogenic and embryocidal effects have been demonstrated in all animal species exposed to ribavirin. In addition, ribavirin has a multiple-dose half-life of 12 days and may persist in non-plasma compartments for as long as 6 months.
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 (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.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- 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). 1,146 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 |
|---|---|---|---|---|---|---|
| Anal pruritus | 819 | 212.8 194.9–232.4ROR 215.6 · calibrated p 2e-10 ✓ | 128.3 EB05 121.1 · IC025 +6.8 3/3 methods agree | Not in label — unassessed | serious n=206 · 76% consumer | not reported in cached trials |
| Vogt-koyanagi-harada syndrome | 38 | 165.7 112.1–245.0ROR 165.8 · calibrated p 7e-9 ✓ | 104.2 EB05 79.3 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=38 · 100% clinician | not reported in cached trials |
| Hepatitis c rna positive | 58 | 164.2 119.7–225.2ROR 164.3 · calibrated p 5e-9 ✓ | 105.5 EB05 84.6 · IC025 +5.4 3/3 methods agree | Lab value / disease marker | serious n=57 · 100% clinician | not reported in cached trials |
| Anorectal discomfort | 1,651 | 146.9 138.6–155.6ROR 150.7 · calibrated p 4e-9 ✓ | 101.1 EB05 97.1 · IC025 +6.5 3/3 methods agree | Not in label — unassessed | serious n=287 · 84% consumer | not reported in cached trials |
| Hepatitis c rna increased | 103 | 140.3 111.3–176.7ROR 140.5 · calibrated p 1e-8 ✓ | 96.4 EB05 81.7 · IC025 +5.7 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=78 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Hepatic hydrothorax | 21 | 116.8 70.9–192.5ROR 116.9 · calibrated p 2e-7 ✓ | 80.0 EB05 55.2 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=21 · 100% clinician | not reported in cached trials |
| Amaurosis fugax | 229 | 89.4 77.2–103.4ROR 89.7 · calibrated p 3e-7 ✓ | 69.8 EB05 62.5 · IC025 +5.7 3/3 methods agree | Not in label — unassessed | serious n=229 · 93% clinician | not reported in cached trials |
| Viral load decreased | 28 | 76.6 50.7–115.6ROR 76.6 · calibrated p 2e-6 ✓ | 59.7 EB05 43.3 · IC025 +4.3 3/3 methods agree | Lab value / disease marker | 100% consumer | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Hepatitis c | 2,237 | 73.5 70.3–76.9ROR 76.2 · calibrated p 8e-7 ✓ | 60.0 EB05 58.0 · IC025 +5.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 57.8 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Genotype drug resistance test positive | 180 | 68.7 58.5–80.7ROR 68.9 · calibrated p 2e-6 ✓ | 56.5 EB05 49.9 · IC025 +5.4 3/3 methods agree | Lab value / disease marker | serious n=179 · ♀ 14% (drug 43%) · 100% clinician | not reported in cached trials |
| Remission not achieved | 96 | 60.0 48.3–74.6ROR 60.1 · calibrated p 5e-6 ✓ | 50.3 EB05 42.4 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=95 · 100% clinician | not reported in cached trials |
| Porphyria non-acute | 68 | 60.0 46.3–77.7ROR 60.0 · calibrated p 6e-6 ✓ | 50.1 EB05 40.8 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=63 · 100% clinician | not reported in cached trials |
| Hepatic cancer recurrent | 41 | 55.1 39.6–76.8ROR 55.2 · calibrated p 1e-5 ✓ | 46.3 EB05 35.6 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=41 · ♀ 0% (drug 43%) · 100% clinician | not reported in cached trials |
| Viral load | 25 | 54.9 35.9–83.9ROR 54.9 · calibrated p 2e-5 ✓ | 45.5 EB05 32.4 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | – | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Chronic hepatitis c | 53 | 50.8 38.0–67.8ROR 50.8 · calibrated p 2e-5 ✓ | 43.4 EB05 34.4 · IC025 +4.5 3/3 methods agree | Labeled — boxed warning exact term | serious n=47 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Hepatocellular carcinoma | 966 | 47.5 44.4–50.8ROR 48.2 · calibrated p 2e-5 ✓ | 41.5 EB05 39.3 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 40.2 · 94% clinician | not reported in cached trials |
| Hepatitis e | 187 | 44.3 38.0–51.6ROR 44.4 · calibrated p 3e-5 ✓ | 38.9 EB05 34.5 · IC025 +4.9 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=187 · 100% clinician | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Painful defaecation | 80 | 42.0 33.3–53.0ROR 42.0 · calibrated p 5e-5 ✓ | 37.0 EB05 30.7 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=24 · 82% consumer | not reported in cached trials |
| Cryoglobulinaemia | 76 | 39.6 31.2–50.2ROR 39.6 · calibrated p 7e-5 ✓ | 35.1 EB05 28.9 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=74 · 100% clinician | not reported in cached trials |
| Retinal exudates | 98 | 38.3 31.1–47.2ROR 38.3 · calibrated p 8e-5 ✓ | 34.1 EB05 28.8 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=82 | not reported in cached trials |
| Anti-erythropoietin antibody positive | 25 | 35.7 23.6–54.0ROR 35.7 · calibrated p 2e-4 ✓ | 31.5 EB05 22.5 · IC025 +3.7 3/3 methods agree | Lab value / disease marker | serious n=24 · 100% clinician | not reported in cached trials |
| Viral load increased | 381 | 35.4 31.9–39.3ROR 35.6 · calibrated p 1e-4 ✓ | 32.0 EB05 29.4 · IC025 +4.8 3/3 methods agree | Lab value / disease marker | serious n=253 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Bleeding varicose vein | 45 | 29.6 21.8–40.2ROR 29.7 · calibrated p 4e-4 ✓ | 27.0 EB05 21.0 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=42 · 100% clinician | not reported in cached trials |
| Hepatitis c virus test positive | 48 | 28.9 21.5–38.8ROR 28.9 · calibrated p 4e-4 ✓ | 26.4 EB05 20.7 · IC025 +3.9 3/3 methods agree | Lab value / disease marker | serious n=34 | not reported in cached trials |
| Proctalgia | 503 | 27.8 25.4–30.5ROR 28.0 · calibrated p 4e-4 ✓ | 25.7 EB05 23.8 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=203 | not reported in cached trials |
| Cutaneous sarcoidosis | 32 | 26.8 18.7–38.4ROR 26.8 · calibrated p 7e-4 ✓ | 24.5 EB05 18.1 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious n=31 · ♀ 100% (drug 43%) · 100% clinician | not reported in cached trials |
| Oesophageal varices haemorrhage | 158 | 25.6 21.8–30.1ROR 25.7 · calibrated p 6e-4 ✓ | 23.8 EB05 20.8 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=157 · 92% clinician | NCT02106156: 4/9,620 (0.0%) on Ribavirin (serious AE) |
| Anorectal disorder | 124 | 21.5 18.0–25.8ROR 21.6 · calibrated p 0.002 ✓ | 20.2 EB05 17.4 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=92 | not reported in cached trials |
| Gastric varices haemorrhage | 20 | 21.0 13.4–33.0ROR 21.0 · calibrated p 0.003 ✓ | 19.4 EB05 13.1 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=20 | not reported in cached trials |
| Retinopathy | 219 | 20.4 17.8–23.4ROR 20.4 · calibrated p 0.002 ✓ | 19.2 EB05 17.2 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=200 · 92% clinician | not reported in cached trials |
| Hepatic encephalopathy | 507 | 18.8 17.2–20.5ROR 18.9 · calibrated p 0.003 ✓ | 17.8 EB05 16.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | age-adj. PRR 14.3 · serious PRR 17.2 · 91% clinician | NCT02106156: 3/9,620 (0.0%) on Ribavirin (serious AE) |
| Varices oesophageal | 159 | 18.2 15.5–21.3ROR 18.2 · calibrated p 0.003 ✓ | 17.2 EB05 15.1 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=159 | NCT02106156: 4/9,620 (0.0%) on Ribavirin (serious AE) |
| Haemorrhoids | 987 | 17.4 16.3–18.5ROR 17.7 · calibrated p 0.003 ✓ | 16.6 EB05 15.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.0 · 74% consumer | not reported in cached trials |
| Hyperuricaemia | 199 | 16.7 14.5–19.2ROR 16.7 · calibrated p 0.005 ✓ | 15.9 EB05 14.1 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=192 | not reported in cached trials |
| Hepatorenal syndrome | 82 | 16.6 13.3–20.8ROR 16.6 · calibrated p 0.005 ✓ | 15.8 EB05 13.1 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=82 | not reported in cached trials |
| Basedow's disease | 23 | 16.6 10.9–25.2ROR 16.6 · calibrated p 0.006 ✓ | 15.4 EB05 10.5 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=22 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Exposure via direct contact | 46 | 16.6 12.3–22.3ROR 16.6 · calibrated p 0.005 ✓ | 15.6 EB05 12.1 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | 74% consumer | not reported in cached trials |
| Liver transplant | 174 | 16.5 14.2–19.2ROR 16.6 · calibrated p 0.005 ✓ | 15.7 EB05 13.9 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=174 · ♀ 17% (drug 43%) | NCT02106156: 1/90 (1.1%) on Ribavirin (serious AE) |
| Liver transplant rejection | 86 | 16.3 13.1–20.3ROR 16.3 · calibrated p 0.005 ✓ | 15.5 EB05 12.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=86 | not reported in cached trials |
| Hyperbilirubinaemia | 489 | 16.3 14.9–17.8ROR 16.4 · calibrated p 0.005 ✓ | 15.6 EB05 14.4 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | age-adj. PRR 14.5 · serious PRR 15.1 · 91% clinician | NCT00922779: 1/6,661 (0.0%) on Ribavirin (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 |
|---|---|---|---|
| Anaemia | 11,131 | 12.612.4–12.8 | signal |
| Thrombocytopenia | 3,870 | 5.95.7–6.0 | signal |
| Depression | 2,955 | 3.53.4–3.6 | signal |
| Neutropenia / agranulocytosis | 2,244 | 3.02.9–3.1 | signal |
| Liver injury | 2,562 | 2.82.7–2.9 | signal |
| Gi bleeding | 1,233 | 2.22.1–2.3 | signal |
| Severe cutaneous reaction | 434 | 1.91.7–2.1 | raised |
| Pancreatitis | 443 | 1.81.6–2.0 | raised |
| Kidney injury | 2,224 | 1.61.5–1.7 | raised |
| Serious infection | 2,870 | 1.21.2–1.3 | raised |
| Hyponatraemia | 299 | 1.21.1–1.4 | raised |
| Suicidality | 672 | 0.90.8–1.0 | lower than other drugs |
| Interstitial lung disease | 237 | 0.80.7–0.9 | lower than other drugs |
| Rhabdomyolysis / myopathy | 197 | 0.80.7–0.9 | lower than other drugs |
| Stroke | 587 | 0.80.7–0.8 | lower than other drugs |
| Opportunistic infection | 320 | 0.80.7–0.9 | lower than other drugs |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Ribavirin 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 (13 of 40 signal terms matched).
- NCT02106156 — Observational Study Evaluating the Quality of Pegylated Interferon Alfa-2a and Ribavirin Treatment for Chronic (N=10228, phase n/a; 332 AE terms posted; arms: Main Analysis Set; Elastography Analysis Set: Treated; Elastography Analysis Set: Untreated)
- NCT00922779 — A Study of Ribavirin in Combination With PEGASYS (Peginterferon Alfa-2a (40KD))in Patients With Chronic Hepati (N=6661, PHASE4; 70 AE terms posted; arms: Ribavirin + Peginterferon Alfa-2a)
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) | 9,565 | 4.1 4.0–4.2ROR 4.6 · calibrated p 0.280 | 4.0 EB05 4.0 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 3.6 · serious PRR 2.9 · 70% consumer | NCT02106156: 5/9,620 (0.1%) on Ribavirin (serious AE) |
| Anaemia (low red blood cells) | 8,367 | 15.0 14.7–15.3ROR 17.1 · calibrated p 0.004 ✓ | 14.4 EB05 14.1 · IC025 +3.8 3/3 methods agree | Labeled — boxed warning exact term | age-adj. PRR 15.0 · serious PRR 11.2 | NCT02106156: 35/9,620 (0.4%) on Ribavirin (serious AE) |
| Nausea | 7,439 | 3.1 3.0–3.2ROR 3.4 · calibrated p 0.512 | 3.1 EB05 3.0 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.6 · serious PRR 2.5 | NCT02106156: 6/9,620 (0.1%) on Ribavirin (serious AE) |
| Rash | 5,359 | 4.1 4.0–4.2ROR 4.4 · calibrated p 0.314 | 4.1 EB05 4.0 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 3.7 · serious PRR 4.3 | NCT02106156: 2/9,620 (0.0%) on Ribavirin (serious AE) |
| Headache | 4,794 | 2.5 2.5–2.6ROR 2.6 · calibrated p 0.753 | 2.5 EB05 2.5 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 1.9 · serious PRR 2.0 | NCT02106156: 3/9,620 (0.0%) on Ribavirin (serious AE) |
| Pruritus (itching) | 4,644 | 4.1 4.0–4.2ROR 4.3 · calibrated p 0.325 | 4.0 EB05 3.9 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 3.4 · serious PRR 4.2 | NCT02106156: 2/9,620 (0.0%) on Ribavirin (serious AE) |
| Vomiting | 3,808 | 2.7 2.6–2.8ROR 2.8 · calibrated p 0.700 | 2.7 EB05 2.6 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.3 · serious PRR 2.1 | NCT02106156: 4/9,620 (0.0%) on Ribavirin (serious AE) |
| Diarrhoea (diarrhea) | 3,745 | 1.9 1.9–2.0ROR 2.0 · calibrated p 0.929 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 1.5 | NCT02106156: 2/9,620 (0.0%) on Ribavirin (serious AE) |
| Asthenia (weakness) | 3,617 | 3.2 3.1–3.3ROR 3.3 · calibrated p 0.535 | 3.2 EB05 3.1 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.9 · serious PRR 2.6 | NCT02106156: 3/9,620 (0.0%) on Ribavirin (serious AE) |
| Pyrexia (fever) | 3,582 | 3.4 3.3–3.5ROR 3.6 · calibrated p 0.469 | 3.4 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.8 · serious PRR 2.4 | NCT02106156: 8/9,620 (0.1%) on Ribavirin (serious AE) |
| White blood cell count decreased | 3,443 | 10.7 10.4–11.1ROR 11.3 · calibrated p 0.021 ✓ | 10.4 EB05 10.1 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | age-adj. PRR 9.7 · serious PRR 9.0 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Insomnia (trouble sleeping) | 3,435 | 4.3 4.1–4.4ROR 4.5 · calibrated p 0.303 | 4.2 EB05 4.1 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 3.5 · serious PRR 3.7 | NCT02106156: 857/9,620 (8.9%) on Ribavirin |
| Dyspnoea (shortness of breath) | 3,336 | 1.9 1.9–2.0ROR 2.0 · calibrated p 0.940 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.5 | NCT02106156: 5/9,620 (0.1%) on Ribavirin (serious AE) |
| Decreased appetite (loss of appetite) | 3,272 | 4.7 4.5–4.8ROR 4.9 · calibrated p 0.247 | 4.6 EB05 4.5 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 4.6 · serious PRR 3.6 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (serious AE) |
| Drug ineffective (drug did not work) | 3,217 | 0.8 0.8–0.8ROR 0.8 · calibrated p 0.178 | 0.8 EB05 0.8 · IC025 -0.4 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | age-adj. PRR 0.9 · serious PRR 1.6 | NCT02106156: 1/9,620 (0.0%) on Ribavirin (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.
- Anal pruritus — n=819, PRR 212.8
- Vogt-koyanagi-harada syndrome — n=38, PRR 165.7
- Anorectal discomfort — n=1,651, PRR 146.9
- Hepatic hydrothorax — n=21, PRR 116.8
- Amaurosis fugax — n=229, PRR 89.4
- Remission not achieved — n=96, PRR 60.0
- Porphyria non-acute — n=68, PRR 60.0
- Hepatic cancer recurrent — n=41, PRR 55.1
- Viral load — n=25, PRR 54.9 (also seen in trial arm)
- Hepatocellular carcinoma — n=966, PRR 47.5
✓ A hand-written Bradford Hill causality assessment exists for this drug: Ribavirin ↔ Haemolytic anaemia.
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 Ribavirin?
In FDA FAERS, the most frequently co-reported reaction terms for Ribavirin are fatigue, anaemia, nausea, rash, headache, pruritus. 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 Ribavirin have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: EMBRYO-FETAL TOXICITY, HEMOLYTIC ANEMIA, and MONOTHERAPY NOT RECOMMENDED Significant teratogenic and embryocidal effects have been demonstrated in all animal species exposed to ribavirin. In addition, ribavirin has a multiple-dose half-life of 12 days and may persist in non-plasma compartments for as long as 6 months.
Do FAERS signals prove that Ribavirin 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 35f99f76-f2ef-4a81-91ff-285419664be3, effective 20240206; matched on
openfda.generic_name.exact:"RIBAVIRIN") - 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, 1,186 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
RIBAVIRIN, 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.