Complete adverse effect profile including incidence rates and management
Important Safety Information
This is not a complete list of all possible side effects. Contact your healthcare provider if you experience any unexpected symptoms. For serious or life-threatening side effects, seek emergency medical attention immediately.
ADVERSE REACTIONS Body as a Whole The Jarisch-Herxheimer reaction is a systemic reaction, that may occur after the initiation of penicillin therapy in patients with syphilis or other spirochetal infections (i.e., Lyme disease and Relapsing fever).
The reaction begins one to two hours after initiation of therapy and disappears within 12 to 24 hours.
It is characterized by fever, chills, myalgias, headache, exacerbation of cutaneous lesions, tachycardia, hyperventiliation, vasodilation with flushing and mild hypotension.
The pathogenesis of the Herxheimer reaction may be due to the release from the spirochaete of host stable pyrogen.
Hypersensitivity Reactions The reported incidence of allergic reactions to all penicillins ranges from 0.7 to 10 percent in different studies (see WARNINGS ).
Sensitization is usually the result of previous treatment with a penicillin, but some individuals have had immediate reactions when first treated.
In such cases, it is postulated that prior exposure to penicillin may have occurred via trace amounts present in milk or vaccines.
Two types of allergic reactions to penicillin are noted clinically – Immediate and delayed.
Immediate reactions usually occur within 20 minutes of administration and range in severity from urticaria and pruritus to angloneurotic edema, laryngospasm, bronchospasm, hypotension, vascular collapse and death (see WARNINGS ).
Such immediate anaphylactic reactions are very rare and usually occur after parenteral therapy, but a few cases of anaphylaxis have been reported following oral therapy.
WARNINGS SERIOUS AND OCCASIONALLY FATAL HYPERSENSITIVITY (anaphylactic) REACTIONS HAVE BEEN REPORTED IN PATIENTS ON PENICILLIN THERAPY.
THESE REACTIONS ARE MORE LIKELY TO OCCUR IN INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY AND/OR A HISTORY OF SENSITIVITY TO MULTIPLE ALLERGENS.
THERE HAVE BEEN REPORTS OF INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY WHO HAVE EXPERIENCED SEVERE REACTIONS WHEN TREATED WITH CEPHALOSPORINS.
BEFORE INITIATING THERAPY WITH PENICILLIN G, CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, OR OTHER ALLERGENS.
IF AN ALLERGIC REACTION OCCURS, PENICILLIN G SHOULD BE DISCONTINUED AND APPROPRIATE THERAPY INSTITUTED.
Like all medications, Penicillin G Sodium can cause side effects. However, not everyone who takes this medication will experience them. Many side effects are dose-dependent and may improve as your body adjusts to the medication. Others may require dose adjustment or medical attention.
Contact your healthcare provider promptly if you experience:
Seek immediate emergency medical care if you experience signs of: