Effects of Saffan administered intravenously in the horse

Abstract

Saffan was injected intravenously on 41 occasions in 11 horses and ponies to investigate its possible use in clinical equine anaesthesia. The optimum dose for induction was 1-90 mg per kg. This dose was divided into two halves, the first half given in five seconds and the second half, containing suxamethonium chloride 0.1 mg per kg, in the next 10 seconds. Induction was associated with excitement for up to 30 secs after the assumption of recumbency. At this dose rate anaesthesia lasted five to eight minutes. Muscle relaxation was poor. Recovery was associated with marked tactile and audible hyperaesthesia. Slight stimulation resulted in twitching and violent kicking movements lasting up to 15 mins. Maintenance with halothane was satisfactory and recovery from this regime was uneventful. Anaesthesia could be maintained with Saffan alone. This agent would appear to offer no advantage over currently used anaesthetic agents in equine practice and to display several marked disadvantages.

The pharmacokinetics and pharmacodynamics of the injectable anaesthetic alfaxalone in the horse

“…Hall (1972) noted marked excitement and hyperaesthesia during recovery in four un‐premedicated horses after induction of anaesthesia with Althesin but found these effects were almost completely suppressed by prior administration of xylazine dosed at 1 mg kg −1 . A similar study found that pre‐medication with acepromazine maleate administered IV or intramuscularly failed to suppress these unwanted effects after Saffan administration (Eales 1976).…”

Alfaxalone compared with ketamine for induction of anaesthesia in horses following xylazine and guaifenesin

“…In both of these products, the neurosteroidal anaesthetic drugs were dissolved in polyoxyethylated castor oil (Cremophor‐EL). This formulation reportedly caused neuroexcitation in horses (Hall 1972; Eales 1976). A novel formulation of alfaxalone was released for use in cats and dogs in 2000 in Australia.…”

Alfaxalone in cyclodextrin for induction and maintenance of anaesthesia in ponies undergoing field castration

“…Alfaxalone in cyclodextrin has been developed to prevent the histamine release associated with the previously available preparation solubilised in Cremaphor EL. This earlier preparation has been used for induction and maintenance of anaesthesia in experimental horses and ponies without pre‐anaesthetic medication (Eales 1976). No advantages over other anaesthetic agents available at that time were evident and muscle relaxation was poor.…”