Medical Editor: John P. Cunha, DO, FACOEP
What Is Penicillin G Potassium?
Penicillin G Potassium for Injection is an antibiotic used to treat severe infections including strep and staph infections, diphtheria, meningitis, gonorrhea, and syphilis. Penicillin G potassium is available in generic form.
What Are Side Effects of Penicillin G Potassium?
Common side effects of penicillin G potassium include:
- injection site reactions (pain, redness, swelling, bruising, or irritation),
- twitching or muscle spasm,
- overactive reflexes,
- mild skin rash,
- nausea,
- vomiting,
- upset stomach,
- diarrhea,
- black or hairy tongue,
- fever,
- chills,
- muscle pain,
- headache,
- fast heart rate,
- hyperventilation,
- flushing,
- low blood pressure, and
- allergic reactions (including itching, rash, and anaphylaxis).
Penicillin G Potassium may cause serious side effects including:
- hives,
- itching,
- swelling under the skin (edema),
- fast heart rate,
- swelling of your vocal cords,
- difficulty breathing,
- low blood pressure,
- vascular collapse,
- diarrhea,
- fever,
- weakness,
- joint pain,
- abdominal pain, and
- rash
Get medical help right away, if you have any of the symptoms listed above.
Seek medical care or call 911 at once if you have the following serious side effects:
- Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
- Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
- Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.
Dosage for Penicillin G Potassium
Dosage of Penicillin G Potassium is dependent upon what it is being used to treat.
What Drugs, Substances, or Supplements Interact with Penicillin G Potassium?
Penicillin G Potassium may interact with other antibiotics, aspirin, phenylbutazone, sulfonamides, indomethacin, thiazide diuretics, furosemide and ethacrynic acid. Tell your doctor all medications and supplements you take.
Penicillin G Potassium During Pregnancy and Breastfeeding
If you are pregnant, only take Penicillin G Potassium if clearly needed. Penicillin G Potassium passes into breast milk. Consult your doctor before breastfeeding.
Additional Information
Our Penicillin G Potassium Side Effects Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
QUESTION
About how much does an adult human brain weigh? See AnswerGet emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
- the first sign of any skin rash, no matter how mild;
- red or scaly skin;
- fever, chills, swollen glands, muscle or joint pain, fast heartbeats, general ill feeling;
- a light-headed feeling, like you might pass out;
- severe stomach pain, diarrhea that is watery or bloody;
- little or no urinating;
- bruising, severe tingling, numbness, pain, muscle weakness;
- seizure (convulsions); or
- unusual changes in mood or behavior.
Common side effects may include:
- mild diarrhea;
- headache;
- black or hairy tongue; or
- pain, swelling, bruising, or irritation around the IV needle.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
SLIDESHOW
Digestive Disorders: Common Misconceptions See SlideshowSIDE EFFECTS
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 or two hours after initiation of therapy and disappears within 12 to 24 hours. Itis characterized by fever, chills, myalgias, headache, exacerbation of cutaneous lesions, tachycardia, hyperventilation, vasodilation with flushing and mild hypotension. The pathogenesis of the Herxheimer reaction may be due to the release from the spirochetes of heat-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 angioneurotic 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. Another type of immediate reaction, an accelerated reaction, may occur between 20 minutes and 48 hours after administration and may include urticaria, pruritus, fever and, occasionally, laryngeal edema.
Delayed reactions to penicillin therapy usually occur within 1–2 weeks after initiation of therapy. Manifestations include serum sickness-like symptoms, i.e., fever, malaise, urticaria, myalgia, arthralgia, abdominal pain and various skin rashes, ranging from maculopapular eruptions to exfoliative dermatitis.
Contact dermatitis has been observed in individuals who prepare penicillin solutions.
Gastrointestinal System
Pseudo membranous colitis has been reported with the onset occurring during or after penicillin G treatment. Nausea, vomiting, stomatitis, black or hairy tongue, and other symptoms of gastrointestinal irritation may occur, especially during oral therapy.
Hematologic System
Reactions include neutropenia, which resolves after penicillin therapy is discontinued; Coombs-positive hemolytic anemia, an uncommon reaction, occurs in patients treated with intravenous penicillin G in doses greater than 10 million units/day and who have previously received large doses of the drug; and with large doses of penicillin, a bleeding diathesis can occur secondary to platelet dysfunction.
Metabolic
Penicillin G Potassium, USP (1 million units contains 1.7 mEq of potassium ion) may cause serious and even fatal electrolyte disturbances, i.e.,hyperkalemia, when given intravenously in large doses.
Nervous System
Neurotoxic reactions including hyperreflexia, myoclonic twitches, seizures and coma have been reported following the administration of massive intravenous doses, and are more likely in patients with impaired renal function.
Urogenital System
Renal tubular damage and interstitial nephritis have been associated with large intravenous doses of penicillin G. Manifestations of this reaction may include fever, rash, eosinophilia, proteinuria, eosinophiluria, hematuria and a rise in serum urea nitrogen.
Discontinuation of penicillin G results in resolution in the majority of patients.
Local Reactions
Phlebitis and thrombophlebitis may occur, and pain at the injection site has been reported with intravenous administration.
To report SUSPECTED ADVERSE EVENTS, contact Pfizer, Inc. at 1-800-438-1985 or FDA at 1-800-FDA-1088 or http://www.fda.gov/ for voluntary reporting of adverse reactions.
DRUG INTERACTIONS
Bacteriostatic antibacterials (i.e ., chloramphenicol, erythromycins, sulfonamides or tetracyclines) may antagonize the bactericidal effect of penicillin, and concurrent use of these drugs should be avoided. This has been documented in vitro ; however, the clinical significance of this interaction is not well-documented.
Penicillin blood levels may be prolonged by concurrent administration of probenecid which blocks the renal tubular secretion of penicillins. Other drugsmay compete with penicillin G for renal tubular secretion and thus prolong the serum half-life of penicillin. These drugs include: aspirin, phenylbutazone, sulfonamides, indomethacin, thiazide diuretics, furosemide and ethacrynic acid.
Read the entire FDA prescribing information for Penicillin G Potassium (Penicillin G Potassium)
© Penicillin G Potassium Patient Information is supplied by Cerner Multum, Inc. and Penicillin G Potassium Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.
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