Clindamycin side effects: what 28,215 FDA adverse event reports show
Drug class
Not stated in label
Who reports
28,215 reports · 75% serious · 2,350 with death outcome · 62% female
Used for
CLINICAL STUDIES In one 12-week multicenter, randomized, evaluator-blind, vehicle-controlled, parallel comparison clinical trial in which patients used CLINDAGEL (clindamycin phosphate topical gel, 1%) once daily or the vehicle gel once daily, in the treatment of acne vulgaris of mild to moderate severity, CLINDAGEL applied once daily was more effective than the vehicle applied once daily.
What it is
DESCRIPTION CLINDAGEL (clindamycin phosphate) topical gel, 1%, a topical antibiotic, contains clindamycin phosphate, USP, at a concentration equivalent to 10 mg clindamycin per gram in a gel v.
Boxed warning
None in the current label
Causality screen of the 40 strongest signals
What the badges mean
- 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.
- 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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 1,172 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 |
|---|---|---|---|---|---|---|
| Babesiosis | 34 | 102.4 71.6–146.6ROR 102.6 · χ² 2,908 / p <1e-300 | 85.8 EB05 64.2 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=34 · ♀ 0% (drug 62%) · 100% clinician | not reported in cached trials |
| Graft infection | 32 | 77.6 53.9–111.7ROR 77.7 · χ² 2,119 / p <1e-300 | 67.5 EB05 50.1 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=32 · 100% clinician | not reported in cached trials |
| Microsporidia infection | 29 | 65.9 45.1–96.4ROR 66.0 · χ² 1,642 / p <1e-300 | 58.4 EB05 42.6 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=29 · ♀ 0% (drug 62%) · 100% consumer | not reported in cached trials |
| Genital abscess | 29 | 57.1 39.1–83.3ROR 57.1 · χ² 1,431 / p <1e-300 | 51.3 EB05 37.5 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=29 | not reported in cached trials |
| Scrotal abscess | 26 | 54.9 36.8–81.7ROR 54.9 · χ² 1,229 / p 1e-269 | 49.4 EB05 35.4 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 0% (drug 62%) | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 64 | 47.0 36.5–60.4ROR 47.1 · χ² 2,662 / p <1e-300 | 43.7 EB05 35.4 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=64 | not reported in cached trials |
| Hyperparathyroidism secondary | 137 | 42.5 35.8–50.4ROR 42.7 · χ² 5,205 / p <1e-300 | 40.0 EB05 34.7 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=137 | not reported in cached trials |
| Type iv hypersensitivity reaction | 142 | 40.8 34.5–48.3ROR 41.0 · χ² 5,190 / p <1e-300 | 38.5 EB05 33.5 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=141 · 100% clinician | not reported in cached trials |
| Nephrogenic anaemia | 233 | 38.9 34.2–44.4ROR 39.3 · χ² 8,144 / p <1e-300 | 36.9 EB05 33.1 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=233 | not reported in cached trials |
| Aortic calcification | 26 | 34.2 23.1–50.6ROR 34.2 · χ² 769 / p 2e-169 | 32.0 EB05 23.0 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=26 | not reported in cached trials |
| Acute generalised exanthematous pustulosis | 313 | 31.3 28.0–35.0ROR 31.6 · χ² 8,777 / p <1e-300 | 30.0 EB05 27.3 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 23.0 · 100% clinician | not reported in cached trials |
| Toxic shock syndrome | 25 | 30.5 20.5–45.5ROR 30.5 · χ² 657 / p 3e-145 | 28.8 EB05 20.5 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=25 · 100% clinician | not reported in cached trials |
| Symmetrical drug-related intertriginous and flexural exanthema | 31 | 30.2 21.1–43.2ROR 30.2 · χ² 812 / p 6e-179 | 28.6 EB05 21.1 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=29 · ♀ 100% (drug 62%) · 100% clinician | not reported in cached trials |
| Primary sequestrum | 35 | 29.4 21.0–41.2ROR 29.5 · χ² 897 / p 3e-197 | 27.9 EB05 21.0 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=35 · 100% consumer | not reported in cached trials |
| Glomerulosclerosis | 22 | 26.8 17.5–40.9ROR 26.8 · χ² 502 / p 2e-111 | 25.3 EB05 17.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=22 · 100% clinician | not reported in cached trials |
| Hidradenitis | 296 | 26.2 23.3–29.4ROR 26.4 · χ² 6,896 / p <1e-300 | 25.3 EB05 22.9 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=199 | not reported in cached trials |
| Rebound acid hypersecretion | 104 | 26.1 21.4–31.7ROR 26.1 · χ² 2,395 / p <1e-300 | 25.1 EB05 21.3 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=104 | not reported in cached trials |
| Red man syndrome | 30 | 25.8 18.0–37.2ROR 25.9 · χ² 668 / p 1e-147 | 24.7 EB05 18.1 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 100% (drug 62%) · 100% clinician | not reported in cached trials |
| Intervertebral disc space narrowing | 27 | 25.8 17.6–37.8ROR 25.8 · χ² 597 / p 3e-132 | 24.6 EB05 17.7 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=27 · 100% consumer | not reported in cached trials |
| Abscess neck | 22 | 24.7 16.2–37.8ROR 24.8 · χ² 462 / p 8e-103 | 23.5 EB05 16.3 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=22 | not reported in cached trials |
| Pneumocystis jirovecii infection | 36 | 23.9 17.2–33.3ROR 23.9 · χ² 744 / p 5e-164 | 22.9 EB05 17.3 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=36 · ♀ 0% (drug 62%) | not reported in cached trials |
| Cerebral toxoplasmosis | 29 | 23.8 16.4–34.4ROR 23.8 · χ² 590 / p 1e-130 | 22.7 EB05 16.6 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=29 · 100% clinician | not reported in cached trials |
| Groin abscess | 35 | 23.0 16.4–32.1ROR 23.0 · χ² 692 / p 9e-153 | 22.1 EB05 16.6 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=35 | not reported in cached trials |
| Osteosclerosis | 47 | 22.8 17.1–30.5ROR 22.8 · χ² 929 / p 3e-204 | 22.0 EB05 17.2 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=47 · 100% consumer | not reported in cached trials |
| Clostridium test positive | 63 | 22.1 17.2–28.3ROR 22.1 · χ² 1,210 / p 2e-265 | 21.3 EB05 17.3 · IC025 +3.8 3/3 methods agree | Lab value / disease marker | serious n=59 | not reported in cached trials |
| Loss of employment | 88 | 22.1 17.9–27.3ROR 22.1 · χ² 1,698 / p <1e-300 | 21.4 EB05 17.9 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=88 · ♀ 100% (drug 62%) | not reported in cached trials |
| Abscess jaw | 30 | 21.8 15.2–31.4ROR 21.8 · χ² 558 / p 9e-124 | 21.0 EB05 15.3 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 100% (drug 62%) | NCT00729937: 1/249 (0.4%) on Clindamycin; 8/617 (1.3%) control (serious AE) |
| Pseudomembranous colitis | 55 | 18.6 14.3–24.4ROR 18.7 · χ² 878 / p 2e-193 | 18.1 EB05 14.4 · IC025 +3.5 3/3 methods agree | Labeled adverse reaction exact term | serious n=54 · 100% clinician | not reported in cached trials |
| Osteolysis | 50 | 18.5 14.0–24.5ROR 18.6 · χ² 793 / p 1e-174 | 18.0 EB05 14.1 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=50 | not reported in cached trials |
| Clostridium difficile colitis | 258 | 18.5 16.3–20.9ROR 18.6 · χ² 4,146 / p <1e-300 | 18.0 EB05 16.3 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 13.7 | NCT00729937: 1/248 (0.4%) on Clindamycin (serious AE) |
| End stage renal disease | 426 | 17.6 16.0–19.3ROR 17.8 · χ² 6,491 / p <1e-300 | 17.2 EB05 15.8 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 13.1 | not reported in cached trials |
| Megacolon | 36 | 17.5 12.6–24.3ROR 17.5 · χ² 530 / p 1e-117 | 16.9 EB05 12.7 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=36 · ♀ 0% (drug 62%) · 100% clinician | not reported in cached trials |
| Necrotising fasciitis | 79 | 17.0 13.6–21.3ROR 17.1 · χ² 1,149 / p 3e-252 | 16.6 EB05 13.7 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=79 · ♀ 40% (drug 62%) · 100% clinician | NCT00729937: 1/248 (0.4%) on Clindamycin (serious AE) |
| Exposed bone in jaw | 48 | 16.6 12.5–22.1ROR 16.7 · χ² 674 / p 6e-149 | 16.1 EB05 12.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=48 · 74% consumer | not reported in cached trials |
| Bone demineralisation | 23 | 16.4 10.9–24.8ROR 16.4 · χ² 311 / p 6e-70 | 15.7 EB05 10.7 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=22 | not reported in cached trials |
| Rash morbilliform | 60 | 16.4 12.7–21.2ROR 16.4 · χ² 834 / p 9e-184 | 16.0 EB05 12.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=59 · ♀ 40% (drug 62%) · 100% clinician | not reported in cached trials |
| Breast abscess | 22 | 16.4 10.7–25.0ROR 16.4 · χ² 296 / p 1e-66 | 15.6 EB05 10.6 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=22 | NCT00729937: 1/617 (0.2%) control (serious AE) |
| Methaemoglobinaemia | 48 | 15.8 11.9–21.0ROR 15.8 · χ² 637 / p 6e-141 | 15.3 EB05 12.0 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=47 · ♀ 0% (drug 62%) · 100% clinician | not reported in cached trials |
| Clostridial infection | 67 | 14.9 11.7–18.9ROR 14.9 · χ² 835 / p 7e-184 | 14.5 EB05 11.7 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=62 | not reported in cached trials |
| Clostridium difficile infection | 409 | 14.3 13.0–15.7ROR 14.5 · χ² 4,945 / p <1e-300 | 14.0 EB05 12.9 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 10.9 | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Clindamycin 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 (4 of 40 signal terms matched).
- NCT00729937 — Strategies Using Off-Patent Antibiotics for Methicillin Resistant S. Aureus "STOP MRSA" (N=2265, PHASE2, PHASE3; 62 AE terms posted; arms: Abscess, Placebo; Abscess, TMP/SMX; Infected Wound, TMP/SMX; Infected Wound, Clindamycin)
- NCT00689117 — A Clinical Study to Evaluate the Safety and Effectiveness of an Investigational Product Called CT Gel (N=1649, PHASE3; 7 AE terms posted; arms: CT Gel; Clindamycin Gel; Tretinoin Gel; Vehicle Gel)
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 |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 2,459 | 1.4 1.3–1.4ROR 1.4 · χ² 284 / p 5e-64 | 1.4 EB05 1.3 · IC025 +0.4 | Reporting / coding artifact | serious PRR 2.2 | not reported in cached trials |
| Drug hypersensitivity | 2,335 | 9.0 8.7–9.4ROR 9.8 · χ² 16,618 / p <1e-300 | 8.9 EB05 8.6 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.6 · ♀ 83% (drug 62%) | not reported in cached trials |
| Diarrhoea (diarrhea) | 1,916 | 2.2 2.1–2.3ROR 2.3 · χ² 1,315 / p 3e-288 | 2.2 EB05 2.1 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.3 | NCT00729937: 81/249 (32.5%) on Clindamycin; 96/617 (15.6%) control |
| Rash | 1,673 | 2.9 2.7–3.0ROR 3.0 · χ² 2,077 / p <1e-300 | 2.9 EB05 2.8 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 | NCT00729937: 4/249 (1.6%) on Clindamycin; 9/617 (1.5%) control |
| Nausea | 1,664 | 1.6 1.5–1.6ROR 1.6 · χ² 355 / p 2e-79 | 1.6 EB05 1.5 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.8 | NCT00729937: 28/249 (11.2%) on Clindamycin; 102/617 (16.5%) control |
| Pain | 1,530 | 1.8 1.8–1.9ROR 1.9 · χ² 613 / p 1e-135 | 1.8 EB05 1.8 · IC025 +0.8 | Labeled adverse reaction exact term | serious PRR 1.9 | NCT00729937: 1/630 (0.2%) on Clindamycin (serious AE) |
| Off label use (used outside approved label) | 1,342 | 1.1 1.1–1.2ROR 1.2 · χ² 27 / p 1e-7 | 1.1 EB05 1.1 · IC025 +0.1 | Reporting / coding artifact | serious PRR 1.3 | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 1,328 | 6.5 6.2–6.9ROR 6.8 · χ² 6,200 / p <1e-300 | 6.5 EB05 6.2 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.0 · 90% clinician | not reported in cached trials |
| Chronic kidney disease | 1,302 | 12.8 12.2–13.5ROR 13.4 · χ² 13,989 / p <1e-300 | 12.6 EB05 12.0 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | not reported in cached trials |
| Fatigue (tiredness) | 1,289 | 1.2 1.2–1.3ROR 1.2 · χ² 59 / p 9e-15 | 1.2 EB05 1.2 · IC025 +0.2 | Not in label — unassessed | serious PRR 1.3 | not reported in cached trials |
| Dyspnoea (shortness of breath) | 1,207 | 1.6 1.5–1.7ROR 1.6 · χ² 268 / p 2e-60 | 1.6 EB05 1.5 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.5 | not reported in cached trials |
| Pyrexia (fever) | 1,195 | 2.6 2.4–2.7ROR 2.6 · χ² 1,160 / p 2e-254 | 2.6 EB05 2.4 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 2.3 | NCT00729937: 1/630 (0.2%) on Clindamycin (serious AE) |
| Renal failure (kidney failure) | 1,074 | 6.0 5.7–6.4ROR 6.2 · χ² 4,468 / p <1e-300 | 6.0 EB05 5.7 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | NCT00729937: 1/248 (0.4%) on Clindamycin (serious AE) |
| Vomiting | 1,011 | 1.6 1.5–1.7ROR 1.6 · χ² 234 / p 5e-53 | 1.6 EB05 1.5 · IC025 +0.6 | Not in label — unassessed | serious PRR 1.5 | NCT00729937: 14/249 (5.6%) on Clindamycin; 40/617 (6.5%) control |
| Headache | 985 | 1.2 1.1–1.2ROR 1.2 · χ² 25 / p 3e-7 | 1.2 EB05 1.1 · IC025 +0.1 | Not in label — unassessed | serious PRR 1.5 | NCT00729937: 27/249 (10.8%) on Clindamycin; 76/617 (12.3%) control |
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.
- Babesiosis — n=34, PRR 102.4
- Graft infection — n=32, PRR 77.6
- Microsporidia infection — n=29, PRR 65.9
- Genital abscess — n=29, PRR 57.1
- Scrotal abscess — n=26, PRR 54.9
- Chronic kidney disease-mineral and bone disorder — n=64, PRR 47.0
- Hyperparathyroidism secondary — n=137, PRR 42.5
- Type iv hypersensitivity reaction — n=142, PRR 40.8
- Nephrogenic anaemia — n=233, PRR 38.9
- Aortic calcification — n=26, PRR 34.2
✓ A hand-written Bradford Hill causality assessment exists for this drug: Clindamycin ↔ Clostridioides difficile colitis.
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 Clindamycin?
In FDA FAERS, the most frequently co-reported reaction terms for Clindamycin are drug hypersensitivity, diarrhoea, rash, nausea, pain, acute kidney injury. 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 Clindamycin have an FDA boxed warning?
No. The FDA label retrieved for Clindamycin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Clindamycin 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 f7b4e985-719a-4547-b624-94612d520991, effective 20200101; matched on
openfda.generic_name.exact:"CLINDAMYCIN") - 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, 1,212 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
CLINDAMYCIN, results-bearing studies sorted by enrollment)
Page generated 2026-10-08. 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.