As with other penicillins, untoward reactions of the sensitivity phenomena are likely to occur, particularly in individuals who have previously demonstrated hypersensitivity to penicillins or in those with a history of allergy, asthma, hay fever, or urticaria.
The following have been reported with parenteral penicillin G: General: Hypersensitivity reactions including the following: skin eruptions (maculopapular to exfoliative dermatitis), urticaria, laryngeal edema, fever, eosinophilia; other serum sickness-like reactions (including chills, fever, edema, arthralgia, and prostration); and anaphylaxis including shock and death. Note: Urticaria, other skin rashes, and serum sickness-like reactions may be controlled with antihistamines and, if necessary, systemic corticosteroids. Whenever such reactions occur, penicillin G should be discontinued unless, in the opinion of the physician, the condition being treated is life-threatening and amenable only to therapy with penicillin G. Serious anaphylactic reactions require immediate emergency treatment with epinephrine. Oxygen, intra-venous steroids, and airway management, including intubation, should also be administered as indicated.
Gastrointestinal: Pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibacterial treatment. (See WARNINGS section.)
Hematologic: Hemolytic anemia, leukopenia, thrombocytopenia.
Neurologic: Neuropathy.
Urogenital: Nephropathy.
The following adverse events have been temporally associated with parenteral administrations of penicillin G benzathine, although a causal relationship has not necessarily been established:
Body as a Whole: Hypersensitivity reactions including allergic vas-culitis, pruritis, fatigue, asthenia, and pain; aggravation of existing disorder; headache.
Cardiovascular: Cardiac arrest; hypotension; tachycardia; palpitations; pulmonary hypertension; pulmonary embolism; vasodilation; vasovagal reaction; cerebrovascular accident; syncope.
Gastrointestinal: Nausea, vomiting; blood in stool; intestinal necrosis.
Hemic and Lymphatic: Lymphadenopathy.
Injection Site: Injection site reactions including pain, inflammation, lump, abscess, necrosis, edema, hemorrhage, cellulitis, hypersen-sitivity, atrophy, ecchymosis, and skin ulcer. Neurovascular reactions including warmth, vasospasm, pallor, mottling, gangrene, numbness of the extremities, cyanosis of the extremities, and neurovascular damage.
Metabolic: Elevated BUN, creatinine, and SGOT.
Musculoskeletal: Joint disorder, periostitis; exacerbation of arthritis; myoglobinuria; rhabdomyolysis.
Nervous System:Nervousness; tremors; dizziness; somnolence; confusion; anxiety; euphoria; transverse myelitis; seizures; coma. A syndrome manifested by a variety of CNS symptoms such as severe agitation with confusion, visual and auditory hallucinations, and a fear of impending death (Hoigne's syndrome), has been reported after administration of penicillin G procaine and, less commonly, after injection of the combination of penicillin G benzathine and penicillin G procaine. Other symptoms associated with this syndrome, such as psychosis, seizures, dizziness, tinni-tus, cyanosis, palpitations, tachycardia, and/or abnormal perception in taste, also may occur.
Respiratory: Hypoxia; apnea; dyspnea.
Skin: Diaphoresis.
Special Senses: Blurred vision; blindness.
Urogenital: Neurogenic bladder; hematuria; proteinuria; renal failure; impotence; priapism.