The following convention has been utilized for the classification of adverse effects: Very common (>1/10); common (>1/100 to <1/10); uncommon (>1/1,000 to <1/100); rare (>1/10,000 to <1/1,000); very rare (<1/10,000).
The majority of the adverse effects listed as follows are not unique to amoxicillin and may occur when using other penicillins.
Unless otherwise stated, the frequency of adverse events has been derived from >30 years of post-marketing reports.
Blood and Lymphatic System Disorders:
Very Rare: Reversible leukopenia (including severe neutropenia or agranulocytosis), reversible thrombocytopenia and hemolytic anemia; prolongation of bleeding time and prothrombin time.
Immune System Disorders:
Very Rare: As with other antibiotics, severe allergic reactions, including angioneurotic edema, anaphylaxis (see Precautions), serum sickness and hypersensitivity vasculitis.
If a hypersensitivity reaction is reported, the treatment must be discontinued (see also Skin and Subcutaneous Tissue Disorders as follows).
Nervous System Disorders:
Very Rare: Hyperkinesia, dizziness and convulsions. Convulsions may occur in patients with impaired renal function or in those receiving high doses.
Infections and Infestations:
Very Rare: Mucocutaneous candidiasis.
Gastrointestinal Disorders: #
Common: Diarrhea and nausea. #
Uncommon: Vomiting. Very Rare: Antibiotic-associated colitis (including pseudomembranous and hemorrhagic colitis); black hairy tongue. Superficial tooth discoloration has been reported in children. Good oral hygiene may help prevent tooth discoloration as it can usually be removed by brushing (for Amoxil 100 mg/mL oral drops, Amoxil 125 mg/5 mL and Amoxil Forte powder for oral suspension only).
Very Rare: Hepatitis and cholestatic jaundice. A moderate rise in aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT). The significance of a rise in AST and/or ALT is unclear.
Skin and Subcutaneous Tissue Disorders: #
Common: Skin rash. #
Uncommon: Urticaria and pruritus. Very Rare: Skin reactions eg, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, bullous and exfoliative dermatitis, and acute generalized exanthematous pustulosis (AGEP) (see also Immune System Disorders in previous texts).
Renal and Urinary Tract Disorders:
Very Rare: Interstitial nephritis, crystalluria (see Overdosage).
The incidence of these adverse events was derived from clinical studies involving a total of approximately 6,000 adult and pediatric patients taking amoxicillin.