|
|
Penicillin
G, Parenteral, Aqueous |
| |
|
Pronunciation |
|
(pen
i SIL in jee, pa REN ter al, AYE
kwee us) |
|
|
U.S. Brand
Names |
|
Pfizerpen® |
|
|
Generic
Available |
|
No |
|
|
Synonyms |
|
Benzylpenicillin Potassium; Benzylpenicillin Sodium; Crystalline Penicillin;
Penicillin G Potassium; Penicillin G Sodium |
|
|
Pharmacological Index |
|
Antibiotic, Penicillin |
|
|
Use |
|
Active against some gram-positive organisms, generally not Staphylococcus
aureus; some gram-negative organisms such as Neisseria gonorrhoeae,
and some anaerobes and spirochetes |
|
|
Pregnancy Risk
Factor |
|
B |
|
|
Contraindications |
|
Known hypersensitivity to penicillin or any component |
|
|
Warnings/Precautions |
|
Avoid intra-arterial administration or injection into or near major
peripheral nerves or blood vessels since such injections may cause severe and/or
permanent neurovascular damage; use with caution in patients with renal
impairment (dosage reduction required), pre-existing seizure disorders, or with
a history of hypersensitivity to cephalosporins |
|
|
Adverse
Reactions |
|
<1%: Convulsions, confusion, drowsiness, fever, rash, electrolyte
imbalance, hemolytic anemia, positive Coombs' reaction, thrombophlebitis,
myoclonus, acute interstitial nephritis, Jarisch-Herxheimer reaction,
hypersensitivity reactions, anaphylaxis |
|
|
Overdosage/Toxicology |
|
Symptoms of penicillin overdose include neuromuscular hypersensitivity
(agitation, hallucinations, asterixis, encephalopathy, confusion, and seizures)
and electrolyte imbalance with potassium or sodium salts, especially in renal
failure
Hemodialysis may be helpful to aid in the removal of the drug from the blood,
otherwise most treatment is supportive or symptom directed |
|
|
Drug
Interactions |
|
Decreased effect: Tetracyclines may decrease penicillin effectiveness;
decreased oral contraceptive effect is possible
Increased effect:
Probenecid may increase penicillin levels
Aminoglycosides may result in synergistic efficacy; heparin and parenteral
penicillins may result in increased bleeding |
|
|
Stability |
|
Penicillin G potassium is stable at room temperature
Reconstituted parenteral solution is stable for 7 days when refrigerated
(2°C to 15°C)
Penicillin G potassium for I.V. infusion in NS or D5W, solution is
stable for 24 hours at room temperature
Incompatible with aminoglycosides; inactivated in acidic or alkaline
solutions |
|
|
Mechanism of
Action |
|
Interferes with bacterial cell wall synthesis during active multiplication,
causing cell wall death and resultant bactericidal activity against susceptible
bacteria |
|
|
Pharmacodynamics/Kinetics |
|
Distribution: Crosses the placenta; appears in breast milk; penetration
across the blood-brain barrier is poor, despite inflamed meninges
Relative diffusion of antimicrobial agents from blood into cerebrospinal
fluid (CSF): Good only with inflammation (exceeds usual MICs)
Ratio of CSF to blood level (%): Normal meninges: <1; Inflamed meninges:
3-5
Protein binding: 65%
Metabolism: In the liver (30%) to penicilloic acid
Half-life:
Neonates: <6 days: 3.2-3.4 hours; 7-13 days: 1.2-2.2 hours; >14 days:
0.9-1.9 hours
Children and adults with normal renal function: 20-50 minutes
End-stage renal disease: 3.3-5.1 hours
Time to peak serum concentration: I.M.: Within 30 minutes; I.V. Within 1 hour
Elimination: In urine |
|
|
Usual Dosage |
|
I.M., I.V.:
>7 days, >2000 g: 100,000 units/kg/day in divided doses every 6 hours
>7 days, <2000 g: 75,000 units/kg/day in divided doses every 8 hours
<7 days, >2000 g: 50,000 units/kg/day in divided doses every 8 hours
<7 days, <2000 g: 50,000 units/kg/day in divided doses every 12 hours
Infants and Children (sodium salt is preferred in children): 100,000-250,000
units/kg/day in divided doses every 4 hours
Severe infections: Up to 400,000 units/kg/day in divided doses every 4 hours;
maximum dose: 24 million units/day
Adults: 2-24 million units/day in divided doses every 4 hours depending on
sensitivity of the organism and severity of the infection
Congenital syphilis:
Newborns: 50,000 units/kg/day I.V. every 8-12 hours for 10-14 days
Infants: 50,000 units/kg every 4-6 hours for 10-14 days
Disseminated gonococcal infections or gonococcus ophthalmia (if organism
proven sensitive): 100,000 units/kg/day in 2 equal doses (4 equal doses/day for
infants >1 week)
Gonococcal meningitis: 150,000 units/kg in 2 equal doses (4 doses/day for
infants >1 week)
Dosing interval in renal impairment:
Clcr 30-50 mL/minute: Administer every 6 hours
Clcr 10-30 mL/minute: Administer every 8 hours
Clcr <10 mL/minute: Administer every 12 hours
Hemodialysis: Moderately dialyzable (20% to 50%)
Continuous arteriovenous or venovenous hemodiafiltration (CAVH) effects: Dose
as for Clcr 10-50 mL/minute |
|
|
Monitoring
Parameters |
|
Observe for signs and symptoms of anaphylaxis during first
dose |
|
|
Test
Interactions |
|
False-positive or negative urinary glucose determination using
Clinitest®; positive Coombs' [direct]; false-positive
urinary and/or serum proteins |
|
|
Dental Health: Local
Anesthetic/Vasoconstrictor
Precautions |
|
No information available to require special precautions |
|
|
Dental Health:
Effects on Dental Treatment |
|
No effects or complications reported |
|
|
Patient
Information |
|
This medication will be administered I.V. or I.M. Maintain adequate hydration
(2-3 L/day of fluids unless instructed to restrict fluid intake). If being
treated for sexually transmitted disease, partner will also need to be treated.
Small frequent meals, frequent mouth care, sucking lozenges, or chewing gum may
reduce nausea or dry mouth. Important to maintain good oral and vaginal hygiene
to reduce incidence of opportunistic infection. If diabetic, drug may cause
false tests with Clinitest® urine glucose monitoring; use
of glucose oxidase methods (Clinistix®) or serum glucose
monitoring is preferable. This drug may interfere with oral contraceptives; an
alternate form of birth control should be used. Report persistent diarrhea,
fever, chills, unhealed sores, bloody urine or stool, muscle pain, mouth sores,
or difficulty breathing. |
|
|
Nursing
Implications |
|
Dosage modification required in patients with renal
insufficiency |
|
|
Dosage Forms |
|
Penicillin g potassium:
Injection, as sodium: 5 million units
Injection:
Frozen premixed, as potassium: 1 million units, 2 million units, 3 million
units
Powder, as potassium: 1 million units, 5 million units, 10 million units, 20
million units |
|
|
References |
|
American Academy of Pediatrics Committee on Infectious Diseases,
"Treatment of Bacterial Meningitis," Pediatrics, 1988, 81(6):904-7.
Donowitz GR and Mandell GL, "Beta-Lactam Antibiotics," N Engl J Med,
1988, 318(7):419-26 and 318(8):490-500.
Hansen JM, Kampmann J, and Laursen H,
"Renal Excretion of Drugs in the Elderly," Lancet, 1970, 1(657):1170.
Prober CG, Stevenson DK, and Benitz WE,
"The Use of Antibiotics in Neonates Weighing Less Than 1200 Grams," Pediatr
Infect Dis J, 1990, 9(2):111-21.
Wickerts CJ, Asaba H, Gunnarsson B, et al,
"Combined Carbon Haemoperfusion and Haemodialysis in the Treatment of Penicillin Intoxication,"
Br Med J, 1980, 280(6226):1254-5.
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.
|
|
Copyright © 1978-2000 Lexi-Comp Inc. All Rights Reserved
| |