Hypersensitivity Reactions: Anaphylaxis [manifested by generalized pruritus, angioneurotic edema (which may affect the larynx), tachycardia, severe dyspnea, cyanosis, diaphoresis, stridor, dizziness, rigors, loss of consciousness, and peripheral circulatory failure], acute interstitial nephritis, agranulocytosis, allergic bronchial asthma, allergic vasculitis, angioedema, Arthus phenomenon, chills, drug fever, eosinophilia, erythema multiforme, erythema nodosum, exfoliative dermatitis, fixed drug eruptions, hemolytic anemia, hypotension, laryngospasm, leukopenia, urticarial, erythematous, or morbilliform (maculopapular or exanthematic) rash and pruritus, serum sickness-like reactions (characterized by fever, malaise, urticaria, arthralgia, myalgia, lymphadenopathy, splenomegaly), Stevens-Johnson syndrome, vesiculobullous eruptions.
Hematologic Effects: Transient neutropenia, thrombocytopenia, thrombocytopenic purpura.
Gastrointestinal Effects: Black hairy tongue,
Clostridium difficile-associated diarrhea and colitis, increased capillary fragility characterized by spontaneous petechial hemorrhages with positive result on the tourniquet test, diarrhea, epigastric distress, nausea, pruritus ani, sore mouth or tongue, vomiting.
Other Adverse Effects: Hepatotoxicity, nephropathy, neuropathy.