PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Drug side effects

cefdinir Side Effects

The reactions most often reported to the FDA for cefdinir (also sold as Omnicef), with demographics, serious outcomes, and reporting trends.

Data updated 2026-05-15

7,348
FAERS reports

Data from the FDA Adverse Event Reporting System (FAERS), 2003 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.

The most commonly reported side effects of cefdinir come from 7,348 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.

This page analyzes 7,348 reports to the FDA Adverse Event Reporting System (FAERS) for cefdinir (Omnicef): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.

Total Reports

7,348

Reports Mentioning Death

571

7.8% of reports — not proof the medicine caused the death

Hospitalizations

2,379

32.4% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

DIARRHOEA
508
CHRONIC KIDNEY DISEASE
485
PNEUMONIA
466
FATIGUE
442
NAUSEA
382
PAIN
367
RENAL FAILURE
360
SINUSITIS
349
ACUTE KIDNEY INJURY
324
HEADACHE
315
DYSPNOEA
314
URINARY TRACT INFECTION
288
DEATH
286
PYREXIA
279
RASH
272
COUGH
254
VOMITING
252
ANXIETY
229

Who Reports Side Effects

Gender Distribution

Female 4,235 (64%)
Male 2,427 (36%)
Unknown 5

Age Distribution

0-17 642 (15%)
18-44 750 (17%)
45-64 1,335 (31%)
65-74 874 (20%)
75+ 752 (17%)

Reporting Trend by Year

2003 2025

Reactions in Death Reports

Top reactions reported in 571 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 284
RENAL FAILURE 60
CHRONIC KIDNEY DISEASE 55
ACUTE KIDNEY INJURY 47
PNEUMONIA 45
END STAGE RENAL DISEASE 36
ANAEMIA 32
CARDIAC ARREST 27
DYSPNOEA 27
NAUSEA 27
RESPIRATORY FAILURE 24
URINARY TRACT INFECTION 23
ASTHENIA 22
PYREXIA 22
DIARRHOEA 21
FATIGUE 21
HYPOTENSION 20
WEIGHT DECREASED 20
VOMITING 19

Reactions in Hospitalization Reports

Top reactions in 2,379 reports where hospitalization was an outcome.

Reaction Reports
PNEUMONIA 342
DIARRHOEA 167
FATIGUE 163
URINARY TRACT INFECTION 159
DYSPNOEA 155
NAUSEA 155
PAIN 147
PYREXIA 143
ACUTE KIDNEY INJURY 126
RENAL FAILURE 121
CHRONIC KIDNEY DISEASE 117
ASTHENIA 115
VOMITING 114
FALL 106
ANXIETY 92
HEADACHE 91
MALAISE 85
SINUSITIS 84
SEPSIS 81

Compare cefdinir vs amikacin →

What the FAERS Data Reveals About cefdinir Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 7,348 voluntary reports linked to cefdinir and its brand equivalents (Omnicef), spanning 2003 through 2025. Of those, 571 (7.8%) listed death as an outcome and 2,379 (32.4%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 64% were female and 36% male; age distribution skews toward 45-64, with 1,335 reports in that bracket. The single most reported reaction is diarrhoea with 508 submissions, followed by chronic kidney disease and pneumonia.

How to read these numbers

FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.