Indications
Procaine Benzylpenicillin (procaine penicillin G) is a long-acting penicillin injection used for infections caused by bacteria sensitive to penicillin, such as some throat, chest, skin and soft tissue infections, syphilis, and certain infections in newborns. It is also widely used in veterinary medicine, sometimes combined with Streptomycin, for infections in cattle, sheep, goats and poultry; veterinary products are for animal use only.
How It Works
Benzylpenicillin kills bacteria by stopping them from building their cell wall, so they burst and die. Combining it with procaine makes the injection dissolve slowly from the muscle, so the antibiotic is released over about 12 to 24 hours and fewer injections are needed.
Dosage and Administration
Given only by deep injection into a muscle by a doctor or nurse. It must never be injected into a vein. The dose and length of treatment depend on the infection and the patient’s age and weight, and are given as prescribed. Veterinary products are dosed by body weight as directed on the label or by a veterinarian, with the stated withdrawal periods before meat or milk are used.
Interactions
- Probenecid raises penicillin levels.
- Tetracyclines and some other bacteriostatic antibiotics may reduce its effect.
- It may increase the effect of Methotrexate and alter the effect of Warfarin.
- Procaine can reduce the effect of sulfonamide antibiotics.
Contraindications
- Allergy to any penicillin or to procaine or other ester local anaesthetics.
- Previous serious allergy to cephalosporins: use only with great caution.
- Injection into a vein, or into the buttock of young children where nerve damage can occur.
Side Effects
Common: pain and swelling at the injection site, rash, diarrhoea. Allergic reactions range from hives to life-threatening anaphylaxis. Accidental injection into a blood vessel can cause a sudden reaction with fear, confusion, hallucinations, fits or fainting (Hoigne syndrome). When treating syphilis, fever, chills and aches may occur within hours (Jarisch-Herxheimer reaction).
Get urgent medical help for swelling of the face or throat, difficulty breathing, widespread rash, collapse, fits, or severe watery or bloody diarrhoea.
Pregnancy and Lactation
Penicillins are generally considered safe in pregnancy and breastfeeding when needed, and this is an important treatment for syphilis in pregnancy. Use as advised by the doctor.
Precautions and Warnings
- Tell the doctor about any past allergy before the injection; patients are observed for at least 30 minutes afterwards.
- Use with care in kidney disease and in newborns.
- Withdrawal periods must be followed for treated food-producing animals.
Overdose
Very high doses may cause nerve irritability and fits, especially in kidney failure. Medical staff give supportive care.
Therapeutic Class
Long-acting penicillin antibiotic (beta-lactam).
Storage
Store as directed on the pack: powder below 25°C in a dry place; ready-made suspensions usually in a refrigerator at 2 to 8°C, do not freeze. Keep out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.