|PENICILLIN G PROCAINE
Classifications: beta-lactam antibiotic; natural penicillin; Therapeutic: antibiotic; beta-lactam
Prototype: Penicillin G potassium
Pregnancy Category: B
600,000 units/mL, 300,000 units/mL
Long-acting form of penicillin G. The procaine salt has low solubility and thus creates a tissue depot from which penicillin
is slowly absorbed. Onset of action is slower and produces lower serum concentrations than penicillin G potassium, but has
longer duration of action. It inhibits the final stage of bacterial cell wall synthesis by binding to specific penicillin-binding
proteins (PBPs) located in the bacterial cell wall. This results in cell death of bacteria.
Same actions and antibacterial activity as for penicillin G potassium and is similarly inactivated by penicillinase and
Moderately severe infections due to penicillin G-sensitive microorganisms that are susceptible to low but prolonged serum
penicillin concentrations. Commonly, uncomplicated pneumococcal pneumonia, uncomplicated gonorrheal infections, and all
stages of syphilis. May be used concomitantly with penicillin G or probenecid when more rapid action and higher blood levels
History of hypersensitivity to any of the penicillins, or to procaine or any other "caine-type" local anesthetic;
History of or suspected allergy, hypersensitivity to cephalosporins, carbapenem; asthmatics; GI disease, renal disease;
renal impairment; pregnancy (category B); infants, neonates.
Route & Dosage
|Moderate to Severe Infections
Adult: IM 600,0001,200,000 U once/d
Child: IM 300,000 U once/d
Adult: IM 600,000 U q12h
Adult: IM 4,800,000 U divided between 2 different injection sites at one visit preceded by 1 g of probenecid 30 min before injections
Adult: IM Primary, secondary, latent: 600,000 U/d for 8 d; late latent, tertiary, neurosyphilis: 600,000 U/d for 1015 d
Child: IM 500,0001,000,000 U/m2 once/d
- Shake multiple-dose vial thoroughly before withdrawing medication to ensure uniform suspension of drug.
- Use 20-gauge needle to avoid clogging.
- Give IM deep into upper outer quadrant of gluteus muscle; in infants and small children midlateral aspect of thigh is generally
preferred. Select IM site carefully. Accidental injection into or near major peripheral nerves and blood vessels can cause
- Aspirate carefully before injecting drug to avoid entry into a blood vessel. Inadvertent IV administration reportedly has
resulted in pulmonary infarcts and death.
- Inject drug at a slow, but steady rate to prevent needle blockage. Give in two sites if the dose is very large. Rotate injection
Adverse Effects (≥1%)Body as a Whole:
[e.g., mental disturbances (anxiety, confusion, depression
, combativeness, hallucinations), expressed
fear of impending death, weakness, dizziness, headache, tinnitus, unusual tastes, palpitation, changes in pulse rate and
BP, seizures]. Also see PENICILLIN G POTASSIUM
elimination; may decrease efficacy
of oral contraceptives
Slowly from IM site. Peak:
13 h. Duration:
1520 h. Distribution:
Crosses placenta; distributed into breast milk. Metabolism:
Hydrolyzed to penicillin in body. Elimination:
By kidneys within 2436 h.
Assessment & Drug Effects
- Obtain an exact history of patient's previous exposure and sensitivity to penicillins, cephalosporins, and to procaine,
and other allergic reactions of any kind prior to treatment.
- Test patient by injecting 0.1 mL of 12% procaine hydrochloride intradermally if sensitivity is suspected. Appearance
of a wheal, flare, or eruption indicates procaine sensitivity.
- Be alert to the possibility of a transient toxic reaction to procaine, particularly when large single doses are administered.
The reaction manifested by mental disturbance and other symptoms (see ADVERSE EFFECTS) occurs almost immediately and usually subsides after 1530 min.
Patient & Family Education
- Report any skin reaction at the site of injection.
- Report onset of rash, itching, fever, chills or other symptoms of an allergic reaction to physician.