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EFFECTS
Amoxicillin; clavulanate potassium is generally well tolerated.
The majority of side effects observed in clinical trials were
of a mild and transient nature and less than 3% of patients
discontinued therapy because of drug-related side effects. From
the original premarketing studies, where both pediatric and
adult patients were enrolled, the most frequently reported adverse
effects were diarrhea/loose stools (9%), nausea (3%), skin rashes
and urticaria (3%), vomiting (1%) and vaginitis (1%). The overall
incidence of side effects, and in particular diarrhea, increased
with the higher recommended dose. Other less frequently reported
reactions include: abdominal discomfort, flatulence and headache.
Oral Solution and Chewable Tablets: In pediatric patients (aged
2 months to 12 years), one U.S./Canadian clinical trial was
conducted which compared amoxicillin; clavulanate potassium
45/6.4 mg/kg/day (divided q12h) for 10 days versus amoxicillin;
clavulanate potassium 40/10 mg/kg/day (divided q8h) for 10 days
in the treatment of acute otitis media. A total of 575 patients
were enrolled, and only the suspension formulations were used
in this trial. Overall, the adverse event profile seen was comparable
to that noted above. However, there were differences in the
rates of diarrhea, skin rashes/urticaria, and diaper area rashes.
(See CLINICAL STUDIES.)
The following adverse reactions have been reported
for ampicillin class antibiotics:
Gastrointestinal: Diarrhea, nausea, vomiting, indigestion,
gastritis, stomatitis, glossitis, black “hairy”
tongue, mucocutaneous candidiasis, enterocolitis, and hemorrhagic/pseudomembranous
colitis. Onset of pseudomembranous colitis symptoms may occur
during or after antibiotic treatment. (See WARNINGS.)
Hypersensitivity Reactions: Skin rashes, pruritus, urticaria,
angioedema, serum sickness-like reactions (urticaria or skin
rash accompanied by arthritis, arthralgia, myalgia and frequently
fever), erythema multiforme (rarely Stevens-Johnson Syndrome)
and an occasional case of exfoliative dermatitis (including
toxic epidermal necrolysis) have been reported. These reactions
may be controlled with antihistamines and, if necessary, systemic
corticosteroids. Whenever such reactions occur, the drug should
be discontinued, unless the opinion of the physician dictates
otherwise. Serious and occasional fatal hypersensitivity (anaphylactic)
reactions can occur with oral penicillin. (See WARNINGS.)
Liver: A moderate rise in AST (SGOT) and/or ALT (SGPT) has
been noted in patients treated with ampicillin class antibiotics
but the significance of these findings is unknown. Hepatic dysfunction,
including increases in serum transaminases (AST and/or ALT),
serum bilirubin and/or alkaline phosphatase, has been infrequently
reported with amoxicillin; clavulanate potassium. It has been
reported more commonly in the elderly, in males, or in patients
on prolonged treatment. The histologic findings on liver biopsy
have consisted of predominantly cholestatic, hepatocellular,
or mixed cholestatic-hepatocellular changes. The onset of signs/symptoms
of hepatic dysfunction may occur during or several weeks after
therapy has been discontinued. The hepatic dysfunction, which
may be severe, is usually reversible. On rare occasions, deaths
have been reported (less than one death reported per estimated
4 million prescriptions worldwide). These have generally been
cases associated with serious underlying diseases or concomitant
medications.
Renal: Interstitial nephritis and hematuria
have been reported rarely.
Hemic and Lymphatic Systems: Anemia, including hemolytic anemia,
thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia
and agranulocytosis have been reported during therapy with penicillins.
These reactions are usually reversible on discontinuation of
therapy and are believed to be hypersensitivity phenomena. A
slight thrombocytosis was noted in less than 1% of the patients
treated with amoxicillin; clavulanate potassium. There have
been reports of increased prothrombin time in patients receiving
amoxicillin; clavulanate potassium and anticoagulant therapy
concomitantly.
Central Nervous System: Agitation, anxiety, behavioral changes,
confusion, convulsions, dizziness, insomnia, and reversible
hyperactivity have been reported rarely.
DRUG INTERACTIONS
Probenecid decreases the renal tubular secretion of amoxicillin.
Concurrent use with amoxicillin; clavulanate potassium may result
in increased and prolonged blood levels of amoxicillin. Co-administration
of probenecid cannot be recommended.
The concurrent administration of allopurinol and ampicillin
increases substantially the incidence of rashes in patients
receiving both drugs as compared to patients receiving ampicillin
alone. It is not known whether this potentiation of ampicillin
rashes is due to allopurinol or the hyperuricemia present in
these patients. There are no data with amoxicillin; clavulanate
potassium and allopurinol administered concurrently.
In common with other broad-spectrum antibiotics, amoxicillin;
clavulanate potassium may reduce the efficacy of oral contraceptives
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