|ATC code||J01 QJ51|
It is a form of penicillin which is a combination of benzylpenicillin and the local anaesthetic agent procaine. Following deep intramuscular injection, it is slowly absorbed into the circulation and hydrolysed to benzylpenicillin — thus it is used where prolonged low concentrations of benzylpenicillin are required.
This combination is aimed at reducing the pain and discomfort associated with a large health system.
Specific indications for procaine penicillin include:
- In the United States, Bicillin C-R (a injectable suspension which 1.2 million units of benzathine penicillin and 1.2 million units of procaine penicillin per 4 ml) is not recommended for treating syphilis, since it contains only half the recommended dose of benzathine penicillin. Medication errors have been made due to the confusion between Bicillin L-A & Bicillin C-R. As a result, changes in product packaging have been made; specifically, the statement "Not for the Treatment of Syphilis" has been added in red text to both the Bicillin CR and Billin CR 900/300 syringe labels.
- Respiratory tract infections where compliance with oral treatment is unlikely
- Alongside Pen V and Erythromycin, Bicillin C-R is used to treat strep throat, given as one IM injection
- Cellulitis, erysipelas
- Procaine penicillin is also used as an adjunct in the treatment of anthrax.
At high doses procaine penicillin can cause seizures and CNS abnormalities due to procaine present in it.