Benzathine benzylpenicillin

Benzathine benzylpenicillin, also known as benzathine penicillin G (BPG), is an antibiotic medication useful for the treatment of a number of bacterial infections.^[3] Specifically it is used to treat strep throat, diphtheria, syphilis, and yaws.^[3][5] It is also used to prevent rheumatic fever.^[5] It is given by injection into a muscle.^[3][5] It is known as "Peanut Butter Shot" in US military slang due to its viscosity.^[6]

Benzathine benzylpenicillin

Combination of
Benzylpenicillin	antibiotic
Benzathine	stabilizer
Clinical data
Trade names	Bicillin L-A,[1] Permapen, others
Other names	penicillin benzathine benzyl, benzathine penicillin, penicillin G benzathine, benzylpenicillin benzathine[2]
AHFS/Drugs.com	Professional Drug Facts
License data	US DailyMed: Penicillin G benzathine
Pregnancy category	AU: A
Routes of administration	Intramuscular injection[3]
ATC code	J01CE08 (WHO)
Legal status
Legal status	CA: ℞-only[4] US: ℞-only
Identifiers
CAS Number	41372-02-5 N
PubChem CID	15232
DrugBank	DB01053 Y
ChemSpider	14498 N
UNII	RIT82F58GK
KEGG	D02157 N
ChEBI	CHEBI:51352 N
ChEMBL	ChEMBL3989515 N
E number	E708 (antibiotics)
CompTox Dashboard (EPA)	DTXSID2047804
ECHA InfoCard	100.014.782
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Side effects include allergic reactions including anaphylaxis, and the site of injection is notoriously painful.^[5] When used to treat syphilis a Jarisch–Herxheimer reaction may occur.^[5] It is not recommended in those with a history of penicillin allergy or those with syphilis involving the nervous system.^[5][3] Use during pregnancy is generally safe.^[3] It is in the penicillin and beta lactam class of medications and works via benzylpenicillin.^[3][5] The benzathine component slowly releases the penicillin making the combination long acting.^[7]

Benzathine benzylpenicillin was patented in 1950.^[2][8] It is on the World Health Organization's List of Essential Medicines.^[9]

Medical uses

It is used to treat strep throat, diphtheria, syphilis, and yaws.^[3][5]

Chemopreventive

A single large 1.2-million-unit dose of intramuscular BPG is given to US military recruits. The Army in particular has a policy to inject all recruits if not allergic, though supply issues and individual base choices have reduced the coverage. A retrospective analysis shows that it reduces the rate of all-cause acute respiratory disease by 32% among Army recruits.^[10]

Adverse effects

2,400,000 units of Bicillin L-A brand of benzylpenicillin, for deep intramuscular injection

Further information: Penicillin drug reaction

The possible adverse effects are generally similar to other forms of penicillin. BPG is overall well-tolerated, but pain from the injection site is a common concern.^[11]

Society and culture

It is marketed by Pfizer (formerly by Wyeth) under the trade name Bicillin L-A.^[12]

Compendial status

• British Pharmacopoeia^[13]