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Pronunciation
(pen i SIL in jee PROE kane)
Generic Available (U.S.)
Yes
Index Terms
Brand Names: Canada
Pharmacologic Category
Pharmacologic Category Synonyms
Use: Labeled Indications
Treatment of moderately-severe infections due to Treponema pallidum and other penicillin G-sensitive microorganisms that are susceptible to low, but prolonged serum penicillin concentrations; anthrax due to Bacillus anthracis (postexposure) to reduce the incidence or progression of disease following exposure to aerolized Bacillus anthracis
Pregnancy Risk Factor
B
Pregnancy Considerations
Adverse events have not been observed in animal studies; therefore, penicillin G is classified as pregnancy category B. Penicillin crosses the placenta and distributes into amniotic fluid. There is no evidence of adverse fetal effects after penicillin use during pregnancy in humans.
Lactation
Enters breast milk/compatible
Breast-Feeding Considerations
Penicillins are excreted in breast milk. The manufacturer recommends that caution be exercised when administering penicillin to nursing women. Nondose-related effects could include modification of bowel flora and allergic sensitization.
Contraindications
Hypersensitivity to penicillin, procaine, or any component of the formulation
Warnings/Precautions
Concerns related to adverse effects:
• Anaphylactoid/hypersensitivity reactions: Serious and occasionally severe or fatal hypersensitivity (anaphylactoid) reactions have been reported in patients on penicillin therapy, especially with a history of beta-lactam hypersensitivity, history of sensitivity to multiple allergens, or previous IgE-mediated reactions (eg, anaphylaxis, angioedema, urticaria). Use with caution in asthmatic patients.
• Neurovascular damage: Avoid I.V., intravascular, or intra-arterial administration since severe and/or permanent neurovascular damage may occur.
• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.
Disease-related concerns:
• Renal impairment: Use with caution in patients with severe renal impairment; dosage adjustment recommended.
• Seizure disorders: Use with caution in patients with a history of seizure disorder; high levels, particularly in the presence of renal impairment, may increase risk of seizures.
Other warnings/precautions:
• Prolonged use: Extended duration of therapy or use associated with high serum concentrations (eg, in renal insufficiency) may be associated with an increased risk for some adverse reactions (neutropenia, hemolytic anemia, serum sickness).
Adverse Reactions
Frequency not defined.
Cardiovascular: Conduction disturbances, myocardial depression, vasodilation
Central nervous system: CNS stimulation, confusion, drowsiness, myoclonus, seizure
Hematologic: Hemolytic anemia, neutropenia, positive Coombs' reaction
Local: Pain at injection site, sterile abscess at injection site, thrombophlebitis
Renal: Interstitial nephritis
Miscellaneous: Hypersensitivity reactions, Jarisch-Herxheimer reaction, pseudoanaphylactic reactions, serum sickness
Metabolism/Transport Effects
None known.
Drug Interactions
BCG: Antibiotics may diminish the therapeutic effect of BCG. Risk X: Avoid combination
Fusidic Acid: May diminish the therapeutic effect of Penicillins. Risk D: Consider therapy modification
Methotrexate: Penicillins may decrease the excretion of Methotrexate. Risk C: Monitor therapy
Mycophenolate: Penicillins may decrease serum concentrations of the active metabolite(s) of Mycophenolate. This effect appears to be the result of impaired enterohepatic recirculation. Risk C: Monitor therapy
Probenecid: May increase the serum concentration of Penicillins. Risk C: Monitor therapy
Tetracycline Derivatives: May diminish the therapeutic effect of Penicillins. Risk D: Consider therapy modification
Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 24 hours after cessation of antibacterial agents. Risk D: Consider therapy modification
Vitamin K Antagonists (eg, warfarin): Penicillins may enhance the anticoagulant effect of Vitamin K Antagonists. Risk C: Monitor therapy
Storage
Refrigerate
Mechanism of Action
Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs); which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.
Pharmacodynamics/Kinetics
Duration: Therapeutic: 15-24 hours
Absorption: I.M.: Slow
Distribution: Penetration across the blood-brain barrier is poor, despite inflamed meninges
Protein binding: 65%
Metabolism: ~30% hepatically inactivated
Time to peak, serum: 1-4 hours
Excretion: Urine (60% to 90% as unchanged drug)
Clearance: Renal: Delayed in neonates, young infants, and with impaired renal function
Dosage
Usual dosage range:
Infants and Children: I.M.: 25,000-50,000 units/kg/day in divided doses 1-2 times/day (maximum: 4.8 million units/day)
Adults: I.M.: 0.6-4.8 million units/day in divided doses every 12-24 hours
Indication-specific dosing:
Children: I.M.:
Anthrax, inhalational (postexposure prophylaxis): 25,000 units/kg every 12 hours (maximum: 1,200,000 units every 12 hours); see "Note" in adult dosing
Syphilis (congenital): 50,000 units/kg/day for 10 days; if more than 1 day of therapy is missed, the entire course should be restarted
Adults: I.M.:
Anthrax:
Inhalational (postexposure prophylaxis): 1,200,000 units every 12 hours
Note: Overall treatment duration should be 60 days. Available safety data suggest continued administration of penicillin G procaine for longer than 2 weeks may incur additional risk for adverse reactions. Clinicians may consider switching to effective alternative treatment for completion of therapy beyond 2 weeks.
Cutaneous (treatment): 600,000-1,200,000 units/day; alternative therapy is recommended in severe cutaneous or other forms of anthrax infection
Endocarditis caused by susceptible viridans
Streptococcus
(when used in conjunction with an aminoglycoside): 1.2 million units every 6 hours for 2-4 weeks
Gonorrhea (uncomplicated): 4.8 million units as a single dose divided in 2 sites given 30 minutes after probenecid 1 g orally
Neurosyphilis: 2.4 million units/day with 500 mg probenecid by mouth 4 times/day for 10-14 days; Note: Penicillin G aqueous I.V. is the preferred agent
Whipple's disease: 1.2 million units/day (with streptomycin) for 10-14 days, followed by oral trimethoprim/sulfamethoxazole or doxycycline for 1 year
Hemodialysis: Moderately dialyzable (20% to 50%)
Administration: I.M.
Procaine suspension is for deep I.M. injection only. Rotate the injection site. Do not inject in gluteal muscle in children <2 years of age. Avoid I.V., intravascular, or intra-arterial administration of penicillin G procaine since severe and/or permanent neurovascular damage may occur.
Monitoring Parameters
Periodic renal and hematologic function tests with prolonged therapy; fever, mental status, WBC count
Test Interactions
Positive Coombs' [direct], false-positive urinary and/or serum proteins
Patient Education
This drug can only be given by injection. Report immediately any redness, swelling, burning, or pain at injection site or any signs of allergic reaction (eg, respiratory or swallowing difficulty, chest tightness, rash, hives, swelling of lips or mouth). Maintain adequate hydration unless instructed to restrict fluid intake. If being treated for sexually-transmitted disease, partner will also need to be treated. May cause confusion or drowsiness. Report signs of opportunistic infection (eg, fever, chills, diarrhea, unhealed sores, white plaques in mouth or vagina, purulent vaginal discharge).
Geriatric Considerations
Dosage does not usually need to be adjusted in the elderly, however, if multiple doses are to be given, adjust dose for renal function.
Dental Health: Effects on Dental Treatment
No significant effects or complications reported
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
May rarely cause drowsiness, confusion, or CNS stimulation
Mental Health: Effects on Psychiatric Treatment
None reported
Nursing: Physical Assessment/Monitoring
Assess results of culture and sensitivity tests and patient's allergy history prior to starting therapy. Use with caution and monitor closely in presence of renal impairment or seizure disorder. Avoid intravascular or intra-arterial administration or injection into or near major peripheral nerves or blood vessels; may cause severe and/or permanent neurovascular damage. Monitor for hypersensitivity reactions and opportunistic infection (fever, chills, unhealed sores, white plaques in mouth or vagina, purulent vaginal discharge, fatigue), CNS changes, and thrombophlebitis.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Injection, suspension: 600,000 units/mL (1 mL, 2 mL)
References
Centers for Disease Control and Prevention (CDC), "Sexually Transmitted Diseases Treatment Guidelines, 2010," MMWR Recomm Rep, 2010, 59(RR-12):1-110.
Donowitz GR and Mandell GL, “Beta-Lactam Antibiotics,” N Engl J Med, 1988, 318(7):419-26 and 318(8):490-500.
Paryani SG, Vaughn AJ, Crosby M, et al, “Treatment of Asymptomatic Congenital Syphilis: Benzathine Versus Procaine Penicillin G Therapy,” J Pediatr, 1994, 125(3):471-5.
Wright AJ, “The Penicillins,” Mayo Clin Proc, 1999, 74(3):290-307.
Yoshikawa TT, “Antimicrobial Therapy for the Elderly Patient,” J Am Geriatr Soc, 1990, 38(12):1353-72.
International Brand Names
Lexi-Comp.com
Last full review/revision October 2011
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