Procaine penicillin, which was introduced for medical use in 1948, is an antibiotic used to treat a number of bacterial infections, namely syphilis, anthrax, mouth infections, pneumonia, diphtheria, cellulitis, and animal bites. Basically, this medication works by killing bacteria that cause the aforementioned infections. Before taking the Procaine penicillin injections, you need to tell your doctor if you are allergic to penicillin. Besides, if you have asthma or kidney disease, you may need a dose adjustment or special tests to safely use procaine penicillin. You should also prepare yourself for the following side effects as they may occur as a result of using Procaine penicillin, and these side effects include pain at the site of injection, blood clotting problems, seizures, and allergic reactions including anaphylaxis. As for its use during pregnancy and breastfeeding, this medication is relatively safe. However, Procaine penicillin can make birth control pills less effective, in case you don’t want to get pregnant. Therefore, you need to ask your doctor about using a non-hormone method of birth control such as a condom, to prevent pregnancy while using procaine penicillin. In fact, hormonal forms of contraception (such as birth control pills, injections, implants, skin patches, and vaginal rings) may not be effective enough to prevent pregnancy during your treatment.