What the label lists and what reports show
Cefazolin side effects
Cefazolin's FDA label lists its adverse reactions in its own words. FAERS holds 11,982 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is hypotension (702 reports).
- Generic listed
Check it at the source: the cefazolin FDA label on DailyMed (effective May 14, 2026, Hikma Pharmaceuticals USA Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe following reactions have been reported: Gastrointestinal Diarrhea, oral candidiasis (oral thrush), vomiting, nausea, stomach cramps, anorexia, and pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS ). Nausea and vomiting have been reported rarely. Allergic Anaphylaxis, eosinophilia, itching, drug fever, skin rash, Stevens-Johnson syndrome. Hematologic Neutropenia, leukopenia, thrombocytopenia, thrombocythemia. Hepatic Transient rise in SGOT, SGPT, and alkaline phosphatase levels has been observed. As with other cephalosporins, reports of hepatitis have been received. Renal As with other cephalosporins, reports of increased BUN and creatinine levels, as well as renal failure, have been received. Local Reactions Rare instances of phlebitis have been reported at site of injection. …
Source: FDA drug label, Hikma Pharmaceuticals USA Inc., effective May 14, 2026 (SPL set 1dc9de56-e259-4546-a1db-23119a8a088e), via openFDA; the full label on DailyMed
What do FAERS reports show?
11,982 reports list cefazolin among the medicines taken, each a report of something that happened, not proof the medicine caused it; 1,387 are coded as a death and 6,057 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 6 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Cefazolin: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions