UNASYN is generally well tolerated. The following adverse reactions have been reported in clinical trials.
Local Adverse Reactions
Pain at IM injection site – 16%
Pain at IV injection site – 3%
Thrombophlebitis – 3%
Phlebitis – 1.2%
Systemic Adverse Reactions
The most frequently reported adverse reactions were diarrhea in 3% of the patients and rash in less than 2% of the patients.
Additional systemic reactions reported in less than 1% of the patients were: itching, nausea, vomiting, candidiasis, fatigue, malaise, headache, chest pain, flatulence, abdominal distension, glossitis, urine retention, dysuria, edema, facial swelling, erythema, chills, tightness in throat, substernal pain, epistaxis and mucosal bleeding.
Available safety data for pediatric patients treated with UNASYN demonstrate a similar adverse events profile to those observed in adult patients. Additionally, atypical lymphocytosis has been observed in one pediatric patient receiving UNASYN.
Adverse Laboratory Changes
Adverse laboratory changes without regard to drug relationship that were reported during clinical trials were:
Hepatic: Increased AST (SGOT), ALT (SGPT), alkaline phosphatase, and LDH.
Hematologic: Decreased hemoglobin, hematocrit, RBC, WBC, neutrophils, lymphocytes, platelets and increased lymphocytes, monocytes, basophils, eosinophils, and platelets.
Blood Chemistry: Decreased serum albumin and total proteins.
Renal: Increased BUN and creatinine.
Urinalysis: Presence of RBC's and hyaline casts in urine.
The following adverse reactions have been identified in post-marketing reports. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Blood and Lymphatic System Disorders: Hemolytic anemia, thrombocytopenic purpura
General Disorders and Administration Site Conditions: Injection site reaction
Hepatobiliary Disorders: Hepatitis cholestatic, cholestasis, hyperbilirubinemia, jaundice, and hepatic function abnormal
Nervous System Disorders: Convulsion
Renal and Urinary Disorders: Tubulointerstitial nephritis
Skin and Subcutaneous Tissue Disorders: Toxic epidermal necrolysis, Stevens-Johnson syndrome, and acute generalised exanthematous pustulosis (AGEP)
The following adverse reactions have been reported with ampicillin-class antibiotics and can also occur with UNASYN.
Gastritis, stomatitis, black "hairy" tongue and enterocolitis. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment. (see
Skin and Subcutaneous Tissue Disorders
Urticaria, erythema multiforme, and an occasional case of exfoliative dermatitis 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.
Immune System Disorders
Serious and occasional fatal hypersensitivity (anaphylactic) reactions can occur with a penicillin including UNASYN. (See
Blood and Lymphatic System Disorders
In addition to the adverse laboratory changes listed above, agranulocytosis has been reported during therapy with penicillins including UNASYN. All of these reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena. Some individuals have developed positive direct Coombs Tests during treatment with UNASYN, as with other beta-lactam antibiotics.