Benzathine penicillin is a long acting penicillin given as a deep injection into muscle. It releases slowly over weeks, which is what makes a single injection able to do the work of a long course of tablets.

What Benzathine Penicillin Is Used For

Preventing recurrence of rheumatic fever, as regular injections
Syphilis
Streptococcal throat infection
Some skin infections

Common Side Effects

Pain and soreness at the injection site
Fever or chills
Skin rash
Headache

Precautions

Anyone who has reacted to penicillin before must not receive it. It is given only into muscle, never into a vein, and patients are usually observed for a short period afterwards in case of an allergic reaction. Rheumatic fever prophylaxis often continues for years, and missing injections is the main reason heart valve damage progresses, so keep to the schedule.

This page is general information only. It is not a substitute for advice from your doctor or pharmacist, and it does not include dosage. Always follow the directions given to you and read the leaflet inside the pack.