Adult Dosing

Serious infections due to susceptible strains of streptococci and staphylococci septicemia, empyema, pneumonia, pericarditis, endocarditis and meningitis

• 5-24 million units/day IM/IV depending on the infection and its severity; administer in equally divided doses q4-6 hrs

Anthrax

• 8 million units/day IM/IV in divided doses q6 hrs; higher doses may be required depending on susceptibility of organism

Actinomycosis

• Cervicofacial disease: 1-6 million units/day IM/IV; administer in divided doses q4-6 hrs
• Thoracic and abdominal disease: 10-20 million units/day IM/IV; administer in divided doses q4-6 hrs

Clostridial infections

• 20 million units/day IM/IV; administer in divided doses q4-6 hrs

Diphtheria (adjunctive therapy to antitoxin and for the prevention of the carrier state)

• 2-3 million units/day IM/IV in divided doses x 10-12 days; administer in equally divided doses q4-6 hrs

Erysipelothrix endocarditis

• 12-20 million units/day IM/IV x 4-6 wks; administer in equally divided doses q4-6 hrs

Fusospirochetosis

• 5-10 million units/day IM/IV; administer in equally divided doses q4-6 hrs

Listeria infections

• Meningitis: 15-20 million units/day IM/IV x 2 wks; administer in equally divided doses q4-6 hrs
• Endocarditis: 15-20 million units/day IM/IV x 4 wks; administer in equally divided doses q4-6 hrs

Pasteurella infections including bacteremia and meningitis

• 4-6 million units/day IM/IV x 2 wks; administer in equally divided doses q4-6 hrs

Haverhill fever, Rat-bite fever

• 12-20 million units/day IM/IV x 3-4 wks; administer in equally divided doses q4-6 hrs

Disseminated gonococcal infections

• 10 million units/day IM/IV; administer in equally divided doses q4-6 hrs; duration depends on the type of infection

Syphilis (neurosyphilis)

• 12-24 million units/day, as 2-4 MU IM/IV q4 hrs x10-14 days; additional therapy with Benzathine PCN G 2.4 MU IM weekly x 3 doses after completion of IV therapy may be required

Meningococcal meningitis and/or septicemia

• 24 million units/day IM/IV as 2 million units q2 hrs

Pediatric Dosing

Serious infections, such as pneumonia and endocarditis

• 150,000 units/kg/day IM/IV divided in equal doses q4-6 hrs; duration depends on infecting organism and type of infection

Meningitis

• 250,000 units/kg/day IM/IV divided in equal doses q4 hrs x 7-14 days depending on the infecting organism
• Max: 12-20 million units/day

Disseminated gonococcal infections

• Arthritis
• <45 kg: 100,000 units/kg/day IM/IV in 4 equally divided doses x 7-10 days
• 45 kg: 10 million units/day IM/IV in 4 equally divided doses; duration depends on the type of infection

• Meningitis
• <45 kg: 250,000 units/kg/day IM/IV in equal doses q4 hrs x 10-14 days
• 45 kg: 10 million units/day IM/IV in 4 equally divided doses; duration depends on the type of infection

• Endocarditis
• <45 kg: 250,000 units/kg/day IM/IV in equal doses q4 hrs x 4 wks
• 45 kg: 10 million units/day IM/IV in 4 equally divided doses; duration depends on the type of infection

Syphilis (congenital and neurosyphilis) after the newborn period

• 200,000-300,000 units/kg/day IM/IV (administered as 50,000 units/kg q4-6 hrs) x 10-14 days

Diphtheria (adjunctive therapy to antitoxin and for prevention of the carrier state)

• 150,000-250,000 units/kg/day IM/IV in equal doses q6 hrs x7-10 days

Rat-bite fever, Haverhill fever

• 150,000-250,000 units/kg/day IM/IV in equal doses q4 hrs x 4 wks

Note:

• Avoid administering this drug to patients requiring <1 million units per dose

Tetanus [Non-FDA Approved]

• 100,000 units/kg/day IV divided into q6hr doses

[Outline]

• Adult Dosing
• Pediatric Dosing

• Treatment of serious infections caused by susceptible strains of the designated organisms in the following conditions
• Septicemia, empyema, pneumonia, pericarditis, endocarditis, meningitis
• Anthrax
• Actinomycosis (cervicofacial disease, thoracic and abdominal disease)
• Clostridial infections: Botulism (adjunctive to antitoxin), gas gangrene, and tetanus (adjunctive to human tetanus immune globulin)
• Diphtheria (adjunctive to antitoxin and prevention of the carrier state)
• Erysipelothrix endocarditis
• Fusospirochetosis (severe infections of the oropharynx [Vincents], lower respiratory tract and genital area)
• Listeria infections including meningitis and endocarditis
• Pasteurella infections including bacteremia and meningitis
• Haverhill fever
• Rat-bite fever
• Disseminated gonococcal infections
• Syphilis (congenital and neurosyphilis)
• Meningococcal meningitis and/or septicemia
• Gram-negative bacillary infections (bacteremias)

• Hypersensitivity to any of the ingredients of the product
• Anaphylactic reaction to beta-lactams

• N/A

Renal Dose Adjustment (Based on CrCl)

• CrCl <10 mL/min/1.73 m²: Administer usual dose x1; then 50% of the usual dose q8-10 hrs
• Uremic patients with CrCl >10 mL/min/1.73 m²: Administer usual dose x1; then 50% of the usual dose q4-5 hrs
• Hemodialysis: Administer dose after dialysis

Note:

• Further modification of dose is required in patients with both renal and hepatic impairment

Hepatic Dose Adjustment

• Hepatic impairment: Dose adjustments not defined

See Supplemental Patient Information

• Serious and occasionally fatal hypersensitivity or anaphylactic reactions have been reported in patients on penicillin therapy that are more likely to occur in individuals with a hx of penicillin hypersensitivity and/or a hx of sensitivity to multiple allergens. Cases of severe reactions have been reported in patients with a hx of penicillin hypersensitivity when treated with cephalosporins
• Carefully inquire regarding previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens prior to initiating penicillin therapy. Discontinue therapy on occurrence of any allergic reactions and initiate appropriate medical therapy. Manage serious anaphylactic reactions using immediate treatment with epinephrine, oxygen, intravenous steroids, and airway management, including intubation, as indicated
• Therapy may cause Clostridium difficile associated diarrhea (CDAD) that may range from mild diarrhea to fatal colitis; may occur during therapy or >2mo after therapy discontinuation. Consider this diagnosis in patients presenting with diarrhea following administration of antibacterial agents and initiate therapeutic measures on confirmation of diagnosis
• Reserve use for serious infections where less toxic agents are inappropriate; avoid use in nonbacterial infections such as most URTIs
• Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridium. C. difficile produces toxins A and B which contribute to CDAD. Hypertoxin producing strains cause increased morbidity and mortality since these infections can be refractory to antibiotic therapy and may require colectomy
• Discontinue therapy if CDAD is suspected/confirmed; in moderate to severe cases, consider management of fluids and electrolytes, protein supplementation and antibacterial drug clinically effective against C. difficile colitis
• Withdraw penicillin on occurrence of allergic reactions unless, in the opinion of the physician, the condition being treated is life-threatening and amenable only to penicillin therapy
• Intravenous doses (>10 million units) should be administered slowly because of the potential adverse effects of electrolyte imbalance from the sodium content of the penicillin
• Antibiotic use may result in overgrowth of nonsusceptible organisms; monitor continuously. Discontinue therapy on occurrence of new infections due to bacteria or fungi and institute appropriate measures
• When required, perform incision and drainage or other surgical procedures in conjunction with antibiotic therapy
• To reduce the development of drug-resistant bacteria, use therapy only to treat infections proven or strongly suspected to be caused by susceptible bacteria. Obtain susceptibility tests before starting therapy
• Evaluate electrolyte balance, renal, hepatic, and hematopoietic systems periodically in case of prolonged therapy with penicillin and particularly with high-dose regimen. Consider a reduction in the total dosage if any impairment of function is suspected or confirmed
• Perform appropriate laboratory examination (including susceptibility tests) in suspected staphylococcal infections
• Perform serological tests for syphilis before starting penicillin therapy in patients being treated for gonococcal infection; institute adequate follow-up including clinical and serological examinations in all cases of penicillin-treated syphilis
• Treatment should be provided for at least 10 days in all group A beta-hemolytic streptococci infections

Cautions: Use cautiously in

• Renal impairment
• Non-anaphylactic hypersensitivity to beta-lactams
• Active or history of asthma
• Hypersensitivity to multiple allergens
• Seizure disorder
• Sodium restriction
• Recent history of antibiotic-associated colitis

Supplemental Patient Information

• Advise patients to promptly report their physician if they develop watery and bloody stools during therapy or even as late as 2 or more months after therapy discontinuation

Pregnancy Category:B

Breastfeeding: Use of penicillin G is acceptable during breastfeeding. Single maternal doses of 4 million units intramuscularly produce low levels in milk that are not expected to cause adverse effects in breastfed infants. Disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush, has been reported occasionally, but has not been adequately evaluated. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/ht mlgen?LACT last accessed 8 Sept 2011). Manufacturer advises caution.

• CNS: Hyperreflexia, myoclonic twitches, seizures, coma
• NEURO: Neurotoxicity (high-dose use)
• CV: Hypotension, vascular collapse, congestive heart failure
• GI: Pseudomembranous colitis, abdominal pain, nausea, vomiting, diarrhea, stomatitis, black or hairy tongue, Clostridium difficile associated diarrhea
• MUSC: Myalgia, arthralgia
• HEMA: Neutropenia, Coombs-positive hemolytic anemia, bleeding (high-dose use)
• METABOLIC: Fatal electrolyte disturbances (high-dose use)
• GU: Renal tubular necrosis, interstitial nephritis, eosinophilia, proteinuria, eosinophiluria, hematuria, rise in serum urea nitrogen
• HYPERSENSITIVITY: Anaphylaxis, immediate or delayed hypersensitivity reactions, urticaria, pruritus, angioneurotic edema, Stevens-Johnson sydrome, laryngospasm, bronchospasm, death, serum sickness-like reaction (fever, malaise, urticaria, myalgia, arthralgia, abdominal pain and various skin rashes, ranging from maculopapular eruptions to exfoliative dermatitis), laryngeal edema
• DERM: Exfoliative dermatitis
• LOCAL: Phlebitis, thrombophlebitis, injection site pain
• MISC: Jarisch-Herxheimer reaction (fever, chills, myalgias, headache, exacerbation of cutaneous lesions, tachycardia, hyperventilation, vasodilation with flushing), superinfection

• Natural penicillin antibiotic; exhibits a bactericidal action against penicillin-susceptible microorganisms during the active multiplication stage by inhibiting mucopeptide synthesis of bacterial cell wall
• Metabolized in the liver
• Excretion: Renal (58-85%)
• Half-life: 42 minutes (31-50 minutes)

US Trade Name(s)

• Only generic available

US Availability

penicillin g sodium (generic)

• PWDR for INJ: 5,000,000 units/vial

Canadian Trade Name(s)

• Crystapen

Canadian Availability

penicillin g sodium (generic)

• PWDR for INJ: 1000000 units/vial
• PWDR for INJ: 10000000 units/vial
• PWDR for INJ: 5000000 units/vial

Crystapen

• PWDR for INJ: 1000000 units/vial
• PWDR for INJ: 10000000 units/vial
• PWDR for INJ: 5000000 units/vial

UK Trade Name(s)

• Crystapen

UK Availability

Crystapen

• PWDR for INJ: 600 mg/vial
• PWDR for INJ: 1200 mg/vial

Australian Trade Name(s)

• Benpen

Australian Availability

Benpen

• PWDR for INJ: 600 mg/vial
• PWDR for INJ: 1200 mg/vial
• PWDR for INJ: 3000 mg/vial

[Outline]

Antimicrobials

Penicillins/Other Combinations