Hetacillin

Hetacillin

Systematic (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
Clinical data
Trade names	Hetacin
AHFS/Drugs.com	Veterinary Use
Legal status	US: ℞-only
Routes of administration	Intramammary injection
Identifiers
CAS Number	3511-16-8 Y
ATC code	J01CA18 (WHO)
PubChem	CID: 193260
DrugBank	DB00739 Y
ChemSpider	167708 Y
UNII	TN4JSC48CV Y
KEGG	D01074 N
ChEMBL	CHEMBL1201116 N
Chemical data
Formula	C19H23N3O4S
Molecular mass	389.469 g/mol
SMILES O=C(O)[C@@H]3N4C(=O)[C@@H](N2C(=O)C(c1ccccc1)NC2(C)C)[C@H]4SC3(C)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 Y Key:DXVUYOAEDJXBPY-XQERAMJGSA-N Y
NY (what is this?)  (verify)

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

Administration

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

Hetacillin was removed from the market for human use when the discovery was made that it is actually cleaved in the gastrointestinal tract to formaldehyde and had no advantages over ampicillin.

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.

As opposed to ampicillin, hetacillin is only marginally broken down by the bacterial enzyme beta-lactamase, at least in vitro.