Hetacillin

Hetacillin is a beta-lactam antibiotic that is part of the aminopenicillin family. It is a prodrug and has no antibacterial activity itself,^[1] but quickly splits off acetone in the human body to form ampicillin,^[2] which is active against a variety of bacteria.

Hetacillin

Clinical data
Trade names	Hetacin, Versapen
AHFS/Drugs.com	Veterinary Use
Routes of administration	Intramammary injection
ATC code	J01CA18 (WHO)
Legal status
Legal status	US: ℞-only
Identifiers
IUPAC name (2S,5R,6R)-6-[(4R)-2,2-dimethyl-5-oxo-4-phenylimidazolidin-1-yl]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid
CAS Number	3511-16-8 Y
PubChem CID	443387
DrugBank	DB00739 Y
ChemSpider	391616 N
UNII	TN4JSC48CV
KEGG	D01074 N
ChEMBL	ChEMBL1201116 N
CompTox Dashboard (EPA)	DTXSID4023121
ECHA InfoCard	100.020.466
Chemical and physical data
Formula	C19H23N3O4S
Molar mass	389.47 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC1([C@@H](N2[C@H](S1)[C@@H](C2=O)N3C(=O)[C@H](NC3(C)C)c4ccccc4)C(=O)O)C
InChI InChI=1S/C19H23N3O4S/c1-18(2)13(17(25)26)21-15(24)12(16(21)27-18)22-14(23)11(20-19(22,3)4)10-8-6-5-7-9-10/h5-9,11-13,16,20H,1-4H3,(H,25,26)/t11-,12-,13+,16-/m1/s1 N Key:DXVUYOAEDJXBPY-NFFDBFGFSA-N N
NY (what is this?)  (verify)

Administration

Hetacillin can be administered orally. The potassium salt, hetacillin potassium, is administered by injection, either intravenously^[3] or intramuscularly.^[4] It is sold under the trade name Hetacin for intramammary injection in veterinary use.^[5]

Hetacillin was withdrawn from the market for human use when the discovery was made that it had no advantages over ampicillin.^[6]

Chemistry

Hetacillin is prepared from ampicillin and acetone. In aqueous solutions it is unstable, with a half life of 15 to 30 minutes at 37 °C (99 °F) and pH 7, quickly releasing acetone again.^[7]