Indications
Procaine Penicillin G is a penicillin antibiotic given by injection into a muscle. Its effect lasts longer than ordinary penicillin injections, so it is usually given once daily. It is used for moderate infections caused by penicillin-sensitive bacteria, such as some throat, chest, skin and soft tissue infections, and in some syphilis treatment plans. In animal health it is widely used, often combined with Benzathine Penicillin G and Dihydrostreptomycin, for bacterial infections in cattle, goats, sheep and other livestock.
How It Works
Penicillin blocks the building of the bacterial cell wall, so the bacteria break apart and die. Joining penicillin with procaine (a local anaesthetic) makes it dissolve slowly from the muscle, keeping useful penicillin levels in the blood for about a day after each injection.
Dosage and Administration
Given only by a doctor, nurse or, for animals, a veterinarian or trained person, as a deep intramuscular injection. It must never be injected into a vein. The dose and number of days are set by the prescriber according to the infection, age and body weight. For animals, follow the label or veterinarian’s directions for the dose per kg body weight and the course length. Complete the full course.
Interactions
- Probenecid raises and prolongs penicillin levels.
- Tetracyclines, Chloramphenicol and Erythromycin may reduce its effect.
- Penicillin may increase Methotrexate levels.
Contraindications
- Allergy to any penicillin or to procaine or other ester-type local anaesthetics.
- Must not be given into a vein.
- Tell the doctor about any allergy to Cephalosporins.
Side Effects
Common effects include pain or swelling at the injection site, rash, nausea and diarrhoea. Occasionally a sudden, short-lived reaction to procaine occurs straight after injection, with anxiety, confusion, a feeling of doom, seeing or hearing things, or a seizure; it usually settles within an hour. Serious allergic reactions are rare.
Get urgent medical help if there is difficulty breathing, swelling of the face or throat, widespread hives, fainting, a seizure, severe pain or colour change in the injected limb, or severe watery or bloody diarrhoea.
Pregnancy and Lactation
Penicillins are generally considered safe in pregnancy when needed. Small amounts pass into breast milk; breastfeeding can usually continue, but watch the baby for diarrhoea, thrush or rash. Ask your doctor before use.
Precautions and Warnings
- Tell the doctor about past reactions to penicillin, procaine or other medicines.
- Use with care in kidney disease, asthma or many allergies, and in newborns.
- Animals: observe the withdrawal period on the label before meat or milk from treated animals is used for food, so that drug residues do not reach people.
- Veterinary products are not for human use.
Overdose
Very high doses can cause nerve irritation, confusion and seizures, particularly with kidney failure. Seek emergency medical (or veterinary) care. Treatment is supportive.
Therapeutic Class
Antibiotic, intermediate-acting penicillin (beta-lactam).
Storage
Store as directed on the pack, usually 2 to 8°C (do not freeze), away from light, out of the reach of children. Shake well before use.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.