penicillin G procaine(redirected from Wycillin)
penicillin G procaine
Pharmacologic class: Penicillin
Therapeutic class: Anti-infective
Pregnancy risk category B
Inhibits biosynthesis of cell-wall mucopeptide; bactericidal against penicillin-susceptible microorganisms during active multiplication stage
Suspension for I.M. injection: 600,000 units/ml vial, 1.2 million units/2-ml vial, 2.4 million units/4-ml vial, 3 million units/10-ml vial
Indications and dosages
➣ Anthrax; bacterial endocarditis; erysipeloid and fusospirochetal infections; group A streptococcal infections; moderately severe, uncomplicated pneumococcal pneumonia and staphylococcal infections; rat-bite fever
Adults: 600,000 to 1 million units/day I.M.
Adults: 300,000 to 600,000 units/day I.M. given with antitoxin for 14 days. For carrier state, 300,000 units/day I.M. for 10 days.
➣ Syphilis, yaws, bejel, pinta
Adults and children older than age 12: 600,000 units/day I.M. for 8 days; for late infections, continue for 10 to 15 days. For neurosyphilis, 2.4 million units/day I.M. for 10 to 14 days, given with probenecid.
➣ Congenital syphilis
Children: 50,000 units/kg I.M. daily for at least 10 days
➣ Uncomplicated gonorrhea
Adults: 4.8 million units/day I.M., divided into at least two doses and two sites at one visit, with P.O. probenecid given 30 minutes before injection
• Lyme disease
• Predental prophylaxis against bacterial endocarditis
• Hypersensitivity to penicillins, beta-lactamase inhibitors (piperacillin/tazobactam), or procaine
Use cautiously in:
• severe renal insufficiency, significant allergies, asthma
• pregnant or breastfeeding patients
• Before giving, ask patient about allergy to penicillin, beta-lactamase inhibitors, or benzathine. Know that cross-sensitivity to imipenem and cephalosporins may occur.
☞ Keep epinephrine and emergency equipment at hand in case anaphylaxis occurs.
• In adults, inject I.M. deep into upper outer aspect of buttock.
• In infants and small children, inject at a slow, steady rate into midlateral aspect of thigh.
• Be aware that Hoigne's syndrome (transient bizarre behavior and neurologic reactions) may immediately follow I.M. injection.
• Know that in syphilis treatment, Jarisch-Hersheimer reaction (fever, chills, headache, sweating, malaise, hypotension or hypertension) may occur 2 to 12 hours after therapy starts and usually subsides within 24 hours.
CNS: lethargy, hallucinations, anxiety, depression, twitching, Hoigne's syndrome, seizures, coma
EENT: laryngeal edema
GI: nausea, vomiting, diarrhea, epigastric distress, abdominal pain, colitis, blood in stool, glossitis, pseudomembranous colitis
GU: interstitial nephritis
Hematologic: increased bleeding, hemolytic anemia, bone marrow depression, leukopenia, thrombocytopenia, granulocytopenia
Skin: rash, urticaria
Other: pain at I.M. injection site, fever, superinfection, Jarisch-Hersheimer reaction, sterile abscess, procaine toxicity, anaphylaxis, serum sickness
Drug-drug. Aspirin, probenecid: increased penicillin blood level
Erythromycins, tetracyclines: decreased antimicrobial activity of penicillin
Hormonal contraceptives: decreased contraceptive efficacy
Drug-diagnostic tests. Alanine aminotransferase, eosinophils, granulocytes, hemoglobin, platelets, potassium, white blood cells: increased levels
Direct Coombs' test: positive result
Sodium: decreased level
Urine glucose, urine protein: false-positive results
☞ Watch closely for signs and symptoms of anaphylaxis and serum sickness.
• In long-term therapy, monitor electrolyte levels and CBC with white cell differential. Watch for electrolyte imbalances and blood dyscrasias.
• Assess neurologic status, especially for seizures and decreasing level of consciousness.
☞ Monitor patient for signs and symptoms of superinfection and pseudomembranous colitis.
☞ Teach patient to recognize signs and symptoms of anaphylaxis. Tell him to contact emergency medical services immediately if these occur.
☞ Tell patient drug may cause diarrhea. Instruct him to immediately report severe, persistent diarrhea and fever.
• Stress importance of completing entire course of therapy as prescribed, even after symptoms improve.
• Advise patient to contact prescriber if infection symptoms worsen.
• Tell female patient that drug may make hormonal contraceptives ineffective. Encourage her to use barrier birth-control method if she wishes to avoid pregnancy.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.