Alfaxalone

Indications

ALFAXAN MULTIDOSE is indicated for the induction and maintenance of anesthesia and for induction of anesthesia followed by maintenance with an inhalant anesthetic, in cats and dogs.

Dosage and Administration

Administer by intravenous injection only. For induction, administer ALFAXAN MULTIDOSE over approximately 60 seconds or until clinical signs show the onset of anesthesia, titrating administration against the response of the patient. Rapid administration of ALFAXAN MULTIDOSE may be associated with an increased incidence of cardiorespiratory depression or apnea. Apnea can occur following induction or after the administration of maintenance boluses of ALFAXAN MULTIDOSE. The use of preanesthetics may reduce the ALFAXAN MULTIDOSE induction dose. The choice and the amount of phenothiazine, alpha 2 -adrenoreceptor agonist, benzodiazepine or opioid will influence the response of the patient to an induction dose of ALFAXAN MULTIDOSE. When using ALFAXAN MULTIDOSE, patients should be continuously monitored, and facilities for the maintenance of a patent airway, artificial ventilation, and oxygen supplementation must be immediately available. ALFAXAN MULTIDOSE contains preservatives. Use within 56 days of first puncture. Any unused ALFAXAN MULTIDOSE remaining after 56 days should be discarded. ALFAXAN MULTIDOSE should not be mixed with other therapeutic agents prior to administration. CATS Induction of general anesthesia in cats: Induction dose guidelines are based on data from the field study (see EFFECTIVENESS) and range between 2.2 - 9.7 mg/kg for cats that did not receive a preanesthetic, and between 1.0 - 10.8 mg/kg for cats that received a preanesthetic. The alfaxalone induction dose in the field study was reduced by 10 - 43%, depending on the combination of preanesthetics (dose sparing effect). Dose sparing of ALFAXAN MULTIDOSE will depend on the potency, dose, and time of administration of the various preanesthetics that are used prior to induction. To avoid anesthetic overdose, titrate the administration of ALFAXAN MULTIDOSE against the response of the patient. Anesthesia is usually observed within 60 seconds after the start of injection, and permits intubation within 1 - 2 minutes, irrespective of preanesthetic. The duration of anesthesia from a single induction dose ranges between 15 - 30 minutes in the unpreanesthetized cat. If a preanesthetic is used, anesthetic duration may be longer, depending on the class and dose of preanesthetic. Individual anesthesia times vary. Examples from the field study of average induction doses (and ranges) for cats that received various preanesthetics are presented as dosing guidelines in the table. The table is for guidance only. Draw up the maximum expected target dose and administer to effect. The actual induction dose should be based on patient response. Alfaxalone Induction Dose Guidelines: CATS Preanesthetic Average alfaxalone induction dose (and range) in mg/kg Number of cats No preanesthetic 4.0 (2.2-9.7) 33 Opioid + phenothiazine 3.2 (1.1-10.8) 96 Benzodiazepine + phenothiazine 3.6 (1.5-7.1) 23 Benzodiazepine + opioid + phenothiazine 2.3 (1.2-5.0) 26 Alpha 2 -adrenergic agonist with/without phenothiazine 3.6 (1.1-5.0) 15 Alpha 2 -adrenergic agonist + phenothiazine with/without benzodiazepine or opioid 2.9 (1.0-3.9) 11 Additional doses of ALFAXAN MULTIDOSE similar to those used for maintenance (1.1 - 1.5 mg/kg) may be administered to facilitate intubation. Maintenance of general anesthesia in cats: Following induction of anesthesia with ALFAXAN MULTIDOSE and intubation, anesthesia may be maintained using intermittent ALFAXAN MULTIDOSE intravenous boluses or an inhalant anesthetic agent. A maintenance bolus containing 1.1 - 1.3 mg/kg provides an additional 7 - 8 minutes of anesthesia in preanesthetized cats. A dose of 1.4 - 1.5 mg/kg provides an additional 3 - 5 minutes anesthesia in unpreanesthetized cats. Clinical response may vary, and is determined by the dose, rate of administration, and frequency of maintenance injections. ALFAXAN MULTIDOSE maintenance dose sparing is greater in cats that receive a preanesthetic. Examples from the field study of maintenance doses for preanesthetized and unpreanesthetized cats are presented as guidelines in the table. Maintenance dose and frequency should be based on the response of the individual patient. Alfaxalone Maintenance Dose Guidelines: CATS Dose and Duration Preanesthetized Cats Unpreanesthetized Cats Maintenance anesthesia doses 1.1 - 1.3 mg/kg 1.4 - 1.5 mg/kg Mean duration of anesthesia 7-8 minutes 3 - 5 minutes In the field study, recovery times (extubation to head lift) following alfaxalone maintenance anesthesia averaged 15 minutes in cats that did not receive a preanesthetic, and 17 minutes in preanesthetized cats. Inhalant anesthetic maintenance of general anesthesia in cats: Additional low doses of ALFAXAN MULTIDOSE, similar to a maintenance dose, may be required to facilitate the transition to inhalant maintenance anesthesia. DOGS Induction of general anesthesia in dogs: Induction dose guidelines are based on data from the field study (see EFFECTIVENESS) and range between 1.5 - 4.5 mg/kg for dogs that did not receive a preanesthetic, and between 0.2 - 3.5 mg/kg for dogs that received a preanesthetic. The alfaxalone induction dose in the field study was reduced by 23 - 50% depending on the combination of preanesthetics (dose sparing effect). Dose sparing of ALFAXAN MULTIDOSE will depend on the potency, dose, and time of administration of the various preanesthetics that are used prior to induction. To avoid anesthetic overdose, titrate the administration of ALFAXAN MULTIDOSE against the response of the patient. In the field study, the use of a preanesthetic appeared to decrease the occurrence of apnea following alfaxalone induction in dogs. In dogs, ALFAXAN MULTIDOSE usually produces recumbence within 60 seconds after the start of injection, and permits intubation within 1 - 2 minutes, irrespective of preanesthetic. The duration of anesthesia from a single induction dose is approximately 5 - 10 minutes in the unpreanesthetized dog. If a preanesthetic is used, anesthetic duration may be longer, depending on the class and dose of preanesthetic. Individual anesthesia times vary. Examples from the field study of average induction doses (and ranges) for dogs that received various preanesthetics are presented as dosing guidelines in the table. The table is for guidance only. Draw up the maximum expected target dose and administer to effect. The actual induction dose should be based on patient response. Alfaxalone Induction Dose Guidelines: DOGS Preanesthetic Average alfaxalone induction dose (and range) in mg/kg Number of dogs No preanesthetic 2.2 (1.5 - 4.5) 17 Benzodiazepine + opioid + acepromazine 1.7 (0.9 - 3.5) 39 Opioid + acepromazine 1.6 (0.6 - 3.5) 80 Alpha 2 -agonist 1.1 (0.21 - 2.00) 9 Additional doses of ALFAXAN MULTIDOSE similar to those used for maintenance (1.2 - 2.2 mg/kg) may be administered to facilitate intubation. Maintenance of general anesthesia in dogs: Following induction of anesthesia with ALFAXAN MULTIDOSE and intubation, anesthesia may be maintained using intermittent ALFAXAN MULTIDOSE intravenous boluses or an inhalant anesthetic agent. A maintenance bolus containing 1.2 - 1.4 mg/kg provides an additional 6 - 8 minutes anesthesia in preanesthetized dogs. A dose of 1.5 - 2.2 mg/kg provides an additional 6 - 8 minutes of anesthesia in unpreanesthetized dogs. Clinical response may vary, and is determined by the dose, rate of administration, and frequency of maintenance injections. ALFAXAN MULTIDOSE maintenance dose sparing is greater in dogs that receive a preanesthetic. Examples from the field study of maintenance doses for preanesthetized and unpreanesthetized dogs are presented as guidelines in the table. Maintenance dose and frequency should be based on the response of the individual patient. Alfaxalone Maintenance Dose Guidelines: DOGS Dose and Duration Preanesthetized Dogs Unpreanesthetized Dogs Maintenance anesthesia doses 1.2 - 1.4 mg/kg 1.5 - 2.2 mg/kg Mean duration of anesthesia 6 - 8 minutes 6 - 8 minutes In the field study, recovery times (extubation to head lift) following alfaxalone maintenance anesthesia averaged 22 minutes in dogs that did not receive a preanesthetic, and 15 minutes in preanesthetized dogs. Inhalant anesthetic maintenance of general anesthesia in dogs: Additional low doses of ALFAXAN MULTIDOSE, similar to a maintenance dose, may be required to facilitate the transition to inhalant maintenance anesthesia. DRUG INTERACTIONS No specific preanesthetic is either indicated or contraindicated with ALFAXAN MULTIDOSE. The necessity for and choice of preanesthetic is left to the discretion of the veterinarian. Preanesthetic doses may be lower than the label directions for their use as a single medication. ALFAXAN MULTIDOSE is compatible with benzodiazepines, opioids, alpha 2 -agonists, and phenothiazines as commonly used in surgical practice. In the field study, alfaxalone was used safely in cats and dogs that received frequently used veterinary products, including antibiotics, anticholinergics, vaccines, steroids, and dewormers.

Contraindications

ALFAXAN MULTIDOSE is contraindicated in cats and dogs with a known sensitivity to ALFAXAN MULTIDOSE or its components, or when general anesthesia and/or sedation are contraindicated.

Warnings

Animal safety: When using ALFAXAN MULTIDOSE, patients should be continuously monitored, and facilities for the maintenance of a patent airway, artificial ventilation, and oxygen supplementation must be immediately available. Rapid bolus administration or anesthetic overdose may cause cardiorespiratory depression, including hypotension, apnea, hypoxia, or death. Arrhythmias may occur secondary to apnea and hypoxia. In cases of anesthetic overdose, stop ALFAXAN MULTIDOSE administration and administer treatment as indicated by the patient’s clinical signs. Cardiovascular depression should be treated with plasma expanders, pressor agents, anti-arrhythmic agents or other techniques as appropriate for the treatments of the clinical signs. Human safety: Not for human use. Keep out of the reach of children. ALFAXAN MULTIDOSE should be managed to prevent the risk of diversion, through such measures as restriction of access and the use of drug accountability procedures appropriate to the clinical setting. Exercise caution to avoid accidental self-injection. Overdose is likely to cause cardiorespiratory depression (such as hypotension, bradycardia and/or apnea). Remove the individual from the source of exposure and seek medical attention. Respiratory depression should be treated by artificial ventilation and oxygen. Avoid contact of this product with skin, eyes, and clothes. In case of contact, eyes and skin should be liberally flushed with water for 15 minutes. Consult a physician if irritation persists. In the case of accidental human ingestion, seek medical advice immediately and show the package insert or the label to the physician. Note to physician: This product contains an injectable anesthetic.

Precautions

Rapid arousal: Careful monitoring of the patient is necessary due to possibility of rapid arousal. Preanesthesia: Benzodiazepines may be used safely prior to ALFAXAN MULTIDOSE in the presence of other preanesthetics (see DRUG INTERACTIONS). However, when a benzodiazepine was used as the sole preanesthetic, excitation occurred in some cats and dogs during ALFAXAN MULTIDOSE anesthesia and recovery. Apnea: Apnea may occur following administration of an induction dose, a maintenance dose or a dose administered during the transition to inhalant maintenance anesthesia, especially with higher doses and rapid administration. Endotracheal intubation, oxygen supplementation, and intermittent positive pressure ventilation (IPPV) should be administered to treat apnea and associated hypoxemia. Blood Pressure: The myocardial depressive effects of ALFAXAN MULTIDOSE combined with the vasodilatory effects of inhalant anesthetics can be additive, resulting in hypotension. Preanesthetics may increase the anesthesia effect of ALFAXAN MULTIDOSE and result in more pronounced changes in systolic, diastolic, and mean arterial blood pressures. Transient hypertension may occur, possibly due to elevated sympathetic activity. Body Temperature: A decrease in body temperature occurs during ALFAXAN MULTIDOSE anesthesia unless an external heat source is provided. Supplemental heat should be provided to maintain acceptable core body temperature until full recovery. Breeding Animals: ALFAXAN MULTIDOSE has not been evaluated in pregnant, lactating, and breeding cats. Alfaxalone crosses the placenta, and as with other general anesthetic agents, the administration of ALFAXAN MULTIDOSE may be associated with neonatal depression. Kittens and Puppies: ALFAXAN MULTIDOSE has not been evaluated in cats less than 4 weeks of age or in dogs less than 10 weeks of age. Compromised or Debilitated Cats and Dogs: The administration of ALFAXAN MULTIDOSE to debilitated patients or patients with renal disease, hepatic disease, or cardiorespiratory disease has not been evaluated. Doses may need adjustment for geriatric or debilitated patients. Caution should be used in cats or dogs with cardiac, respiratory, renal or hepatic impairment, or in hypovolemic or debilitated cats and dogs, and geriatric animals. Analgesia during anesthesia: Appropriate analgesia should be provided for painful procedures.

Adverse Reactions

Adverse Reactions in Cat Field Study Adverse Reaction Number of Cats a = 207 Hypotension (≤90 mm Hg) 92 Tachycardia (≥ 180 bpm) 61 Apnea (≥ 30 seconds) 32 (of 202) Hypertension (> 165 mm Hg) 23 Bradypnea (RR< 10 breaths/min) 16 Apnea (≥ 60 seconds) 12 (of 202) Bradycardia (≤90 beats/min) 10 Hypothermia (<97°F) 10 Hypoxia (SpO 2 <85%) 4 Emesis 1 Unacceptable Anesthesia Quality 1 a Each cat may have experienced more than one adverse reaction Additional adverse reactions for cats included vocalization, paddling, and muscle tremors. One cat that experienced tachycardia and hypoxia during anesthesia was euthanized 3 days later due to carcinoma involving the liver, pancreas and common bile duct. The relationship of the original tachycardia during anesthesia and the carcinoma is unknown. Adverse Reactions in Dog Field Study Adverse Reaction Number of Dogs a = 182 Bradypnea (RR< 10 breaths/min) 89 Apnea (≥ 30 seconds) 55 (of 137) Hypertension (> 165 mm Hg) 54 Tachycardia (≥ 180 bpm) 49 Apnea (≥ 60 seconds) 34 (of 137) Hypotension (≤70 mm Hg) 32 Hypothermia (<97°F) 28 Bradycardia (≤70 beats/min) 24 Hypoxia (SpO 2 <85%) 4 Lack of Effectiveness 3 Unacceptable Anesthesia Quality 1 Emesis 1 a Each dog may have experienced more than one adverse reaction Additional adverse reactions for dogs included vocalization, paddling, and muscle tremors. To report adverse reactions or to obtain a copy of the SDS for this product call 1-888-963-8471. For additional information about adverse drug experience reporting for animal drugs, contact FDA at 1-888-FDA-VETS or http://www.fda.gov/reportanimalae. OVERDOSE Rapid administration, accidental overdose, or relative overdose due to inadequate dose sparing of ALFAXAN MULTIDOSE in the presence of preanesthetics may cause cardiopulmonary depression. Respiratory arrest (apnea) may be observed. In cases of respiratory depression, stop drug administration, establish a patent airway, and initiate assisted or controlled ventilation with pure oxygen. Cardiovascular depression should be treated with plasma expanders, pressor agents, antiarrhythmic agents or other techniques as appropriate for the observed abnormality.

Description

ALFAXAN MULTIDOSE (alfaxalone) is a neuroactive steroid molecule with properties of a general anesthetic. Alfaxalone is chemically described as 3-α-hydroxy-5-α-pregnane-11, 20-dione, and has a molecular weight 332.5. The primary mechanism for the anesthetic action of alfaxalone is modulation of neuronal cell membrane chloride ion transport, induced by binding of alfaxalone to GABA A (gamma-aminobutyric acid) cell surface receptors.

Storage

Store at controlled room temperature 20°C - 25°C (68° to 77°F) with excursions between 15° and 30°C (59° and 86°F). ALFAXAN MULTIDOSE contains preservatives. The product can be used for 56 days after broaching the vial. Any unused ALFAXAN MULTIDOSE remaining after 56 days should be discarded.

Other labels for this ingredient

These labels are also stored for the same active ingredient. They are not identical to the one reprinted above, and each is listed by product and set id rather than merged with it.

• ALFAXAN MULTIDOSE IDX, Zoetis Inc.. Set id 190e55f2-7390-4b9c-a26c-56cf26ea13a7.
• ALFAXAN MULTIDOSE IDX, Jurox Pty. Limited. Set id 6fd00f51-db05-407f-ab80-cba1b6aa9596.

FDA adverse event reports

The FDA Center for Veterinary Medicine publishes the adverse event reports it receives through openFDA. The counts below are the reports naming alfaxalone as an active ingredient for each species this label names, as returned on 2026-09-16, coded by the VeDDRA reaction term the reporter chose. Reactions are counted per report, so one report can appear under several terms.

These are counts, not rates. Reporting is voluntary, the number of animals treated is not known, and a widely used product accumulates reports for that reason alone. A report records that an event followed a dose; it does not establish that the product caused it. The counts say nothing about how one product compares with another.