Alfaxan Multidose - Intravenous Injectable Anesthetic

Active Ingredient

Alfaxan Multidose Intravenous Injectable Anesthetic for use in Cats and Dogs contains the neuroactive steroid molecule alfaxalone (3-α-hydroxy-5-α-pregnane-11, 20-dione) and is registered with the Food and Drug Administration for use in dogs and cats for both the induction and maintenance of anesthesia. Although alfaxalone is a steroid molecule, it does not bind to sex hormone, glucocorticoid or mineralocorticoid receptors (i.e. nuclear receptors. 1,2)

Mode of Action

Alfaxalone produces anesthetic effects via enhancement of gamma-aminobutyric acid sub-type 1 (GABAA) receptor-mediated neurotransmission. GABAA receptors are widely distributed throughout the mammalian Central Nervous System (CNS). GABA is the major inhibitory amino acid transmitter of the mammalian CNS and receptors are present on almost half of all neurones.3 GABA acts by opening a pore in the receptor allowing the in-flow of chloride ions, causing hyperpolarization. Alfaxalone’s enhancement of GABA’s effects prevents development of action potentials and stops impulse transmission.

Features and Benefits of Alfaxan Multidose

Alfaxan is a 1% [10mg/mL] aqueous solution of alfaxalone in hydropropyl-beta-cyclodextrin [HP-β-CD]. The solution has a pH of 6.05-7.0. It is a clear, colorless, sterile solution for injection, presented in 10 mL, single use vials. Alfaxan should be stored in the outer carton at room temperature, avoiding freezing. Once a vial has been opened, vial contents should be drawn into sterile syringes; each syringe should be prepared for a single patient use only. Any unused, unpreserved Alfaxan should be discarded within six hours of initially broaching the vial. Alfaxan Multidose may be retained and used within 56 days of initially broaching the vial.

When Alfaxan Multidose is administered as recommended, the following will be observed.

• Smooth Induction
• No Pain
• Rapid : Rapid onset of anesthesia19
• No tissue irritation : No tissue irritation if inadvertently given peri-vascularly21
• Excellent Muscle Relaxation : Excellent muscle relaxation19, 20
• Cardio-pulmonary function : Minimal disruption to cardio-pulmonary function or vascular system parameters19, 20
• Stress Free Recovery ; Stree-free recovery19, 20, 22
• Wide Safety Margin : Alfaxan Multidose has a wide safety margin, with animals receiving significant overdoses (20 mg/kg dogs; 25 mg/kg cats) requiring only ventilation to allow recovery with no residual effects.19, 20
• Rapid Elimination : Alfaxan Multidose is rapidly eliminated from the body23 and is registered for use as an anesthetic maintenance agent.  Studies have shown that repeated, supra-clinical doses of Alfaxan Multidose administered IV at 10 mg/kg dogs (5X)24 and 25 mg/kg cats (5X)25 every 48 hours for three doses did not result in any deleterious effects. It can be used with confidence repeatedly over consecutive days
• Registered for Maintenance : Alfaxan Multidose is also registered for use as a maintenance anesthetic agent and produces clinically acceptable anesthetic quality and hemodynamic values when used for maintenance.26
• Compatible : Alfaxan Multidose is compatible with routine premedicant medications.16, 17, 27, 28

Alfaxan Multidose safety in cats

Acute tolerance to overdose of Alfaxan Multidose has been demonstrated up to five times the recommended dose of 5 mg/kg in the cat (25 mg/kg), with animals requiring only ventilation to allow recovery with residual effects.

Repeated overdosing with Alfaxan Multidose (five times the recommended dose) every 48 hours for three doses in cats caused no adverse effects.

Alfaxan Multidose can be used safely in kittens from four weeks of age59 (Alfaxan Multidose has not been evaluated in kittens less than four weeks of age).

Alfaxan Multidose safety in dogs

Acute tolerance to overdose of Alfaxan Multidose has been demonstrated up to five times the recommended dose of 2 mg/kg in the cat (i.e. 10 mg/kg), with animals requiring only ventilation to allow recovery with residual effects.

Repeated overdosing with Alfaxan Multidose (five times the recommended dose) every 48 hours for three doses in dogs caused no adverse effects.