Abdominal cramp/pain, anorexia, (e.g., oral thrush), CDAD and colitis, diarrhea, dyspepsia, gastritis, gastroenteritis, glossitis/stomatitis, nausea, vomiting.
Anaphylaxis, angioedema, eosinophilia, erythema multiforme, fever, genital and anal pruritus, intertrigo, pruritus, rash (maculopapular erythematous, or morbilliform), serum sickness-like reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria.
Decreased hemoglobin and/or hematocrit, hemolytic anemia, reversible leukopenia; neutropenia, decreased platelets; positive direct and indirect antiglobulin (Coombs’) test results; thrombocytopenia.
Renal and Genitourinary:
Transient increases in blood urea nitrogen (BUN) and serum creatinine concentrations; dysuria, reversible interstitial nephritis; nephrotoxicity, leukorrhea, pruritus vulvae, vaginal discharge, vulvo-vaginitis.
Transient increases in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase concentrations; increased serum bilirubin; transient hepatitis and cholestatic jaundice.
Agitation, confusion, diplopia, dizziness, fatigue, headache, hallucinations, insomnia, malaise, paresthesia, somnolence, tremor, toxic paranoid reactions (rarely in patients with renal impairment).
Vertigo, tinnitus, hearing loss and behavioral changes in young children have been reported with cefalexin use.
Other Adverse Effects (AEs):
Arthralgia, myalgia, arthritis, joint disorder, back pain, nuchal swelling, cardiac arrhythmia, vasodilatation, dyspnea, superinfection, elevated cholesterol.
The following AEs have also been reported for cephalosporin-class antibiotics:
Hypersensitivity reactions including chills, joint pain or inflammation, edema, facial edema, erythema, shock, hypotension, exfoliative dermatitis; anaphylaxis, including a few fatalities, has occurred rarely with cephalosporins; agranulocytosis, aplastic anemia, pancytopenia, thrombocythemia, prolonged prothrombin time, leukocytosis, granulocytosis, monocytosis, lymphocytopenia, basophilia, anemia, epistaxis or hemorrhage; renal dysfunction, toxic nephropathy, genital pruritus, vaginal candidiasis, menstrual irregularities; transient increases in serum γ-glutamyl transferase concentrations; increased serum concentrations of lactate dehydrogenase (LDH); decreased serum albumin and/or total protein; hepatic dysfunction, including cholestasis; epigastric pain, decreased appetite, flatulence, candidiasis, decreased salivation, taste alteration, tenesmus, heartburn; anxiety, nightmares, hyperactivity, nervousness, weakness, hot flushes, alteration in color perception, hypertonia; chest pain, pleural effusion, pulmonary infiltrate, respiratory distress, cough, rhinitis, increased or decreased serum glucose concentration.
Several cephalosporins have been implicated in triggering seizures, particularly in patients with renal impairment when the dosage was not reduced.