Hetacillin Explained

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.__TOC__

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Hetacillin was withdrawn from the market for human use when the discovery was made that it had no advantages over ampicillin.^[6]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 and pH 7, quickly releasing acetone again.^[7]

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

Notes and References

1. Web site: Drugbank . Hetacillin .
2. Sutherland R, Robinson OP . Laboratory and pharmacological studies in man with hetacillin and ampicillin . British Medical Journal . 2 . 5555 . 804–8 . June 1967 . 5182358 . 1843140 . 10.1136/bmj.2.5555.804 .
3. Tsuji Y, Tomita M . [Clinical effect of intravenous injection of potassium hetacillin (Versapen 'Bristol') on pre- and post-operative infections] (in Japanese) . The Japanese Journal of Antibiotics . 23 . 4 . 400–2 . August 1970 . 5312791 .
4. Hara M, Takemoto S, Kawazu T . [Therapeutic experience with intramuscular injection of hetacillin (Versapen 'Bristol') in infection in children] (in Japanese) . The Japanese Journal of Antibiotics . 23 . 5 . 482–6 . December 1970 . 5314634 .
5. Hetacin-K Intramammary Infusion for
6. Smith JT, Hamilton-Miller J . Hetacillin: A Chemical and Biological Comparison with Ampicillin . Chemotherapy . 15 . 6 . 366–78 . 1970 . 5514976 . 10.1159/000220703 .
7. Faine S, Harper M . Independent antibiotic actions of hetacillin and ampicillin revealed by fast methods . Antimicrobial Agents and Chemotherapy . 3 . 1 . 15–8 . January 1973 . 4597707 . 444353 . 10.1128/aac.3.1.15 .