Introduction

Name

• Alfaxalone.

Class of drug

• Neuroactive steroid.
• General anesthetic.

Description

Chemical name

• 3-alpha-hydroxy-5-alpha-pregnane-11,20-dione.

Molecular formula

• C21H32O3.

Molecular weight

• 332.477 g.

Physical properties

• Clear, colorless solution for injection.

Storage requirements

• Do not freeze.
• Keep in outer carton.

Uses

Indications

• Induction of general anesthesia   Anesthesia: induction - overview  .
• Maintenance of general anesthesia   Anesthesia: maintenance - overview  .
• Target species are dogs and cats, but some experimental and clinical work has been carried out in horses.

Alfaxalone was previously solubilized with alphadolone and Cremophor® EL. It is now prepared in 2-hydroxypropyl-beta cyclodextrin which imparts water solubility to the complex and is not associated with histamine release unlike Cremophor® EL.

Administration

Pharmacokinetics

Precautions

Interactions

with other drugs

• Other CNS depressants potentiate the effect of alfaxalone.

Adverse Reactions

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Goodwin W A, Keates H L, Pearson M & Pasloske K (2013) Alfaxalone and medetomidine intravenous infusion to maintain anaesthesia in colts undergoing field castration. Equine Vet J 45 (3), 315-319 PubMed.
• Klöppel H & Leece L A (2011) Comparison of ketamine and alfaxalone for induction and maintenance of anaesthesia in ponies undergoing castration.Vet Anaesth Analg 38 (1), 37-43 PubMed.
• Leece E A, Girard N M & Maddern K (2009) Alfaxalone in cyclodextrin for induction and maintenance of anaesthesia in ponies undergoing field castration. Vet Anaesth Analg 36 (5), 480-484 PubMed.

Other sources of information

• Goodwin W, Keates H, Pasloske K et al (2009) Total Intravenous Anaesthesia (TIVA) in the Horse with Alfaxalone. In: Proc 10th WCVA (abstract). pp 87.
• Goodwin W, Keates H & Pasloske K (2006) Plasma Pharmacokinetics and Pharmacodynamics of Alfaxalone in Horses after Intravenous Administration of the Anaesthetic Agent Alfaxan at 1 mg/kg. In: Proc 9th WCVA (abstract). pp 152. 
• Pearson M, Keates H & Van Eps A (2006) A Cmparison between Alfaxalone in Cyclodextrin and Ketamine for Induction of Anaesthesia in Horses. In: Proc 9th WCVA. pp 152.