ペントバルビタールナトリウム

投与経路

禁忌

• Known hypersensitivity to barbiturates
• Severe liver disease
• Nephritis
• Severe respiratory depression
• Lidocaine-induced seizures
• Pregnancy (Category D - embryotoxic/teratogenic)

有害事象

• Respiratory depression (can be severe)
• Hypothermia
• Paradoxical excitement during recovery (especially in dogs)
• Cardiovascular depression (decreased contractility, hypotension)
• Severe tissue irritation and necrosis (if given perivascularly or SC)

薬物相互作用

• Acetaminophen · Increased risk for hepatotoxicity, particularly with large or chronic barbiturate doses.
• Lidocaine · Fatalities reported when treating lidocaine-induced seizures with pentobarbital; use diazepam instead.
• Phenytoin · Barbiturates may affect phenytoin metabolism and vice versa; blood level monitoring indicated.
• Rifampin · May induce enzymes that increase the metabolism of barbiturates.
• Antihistamines · May increase the CNS depressant effect of pentobarbital.
• Chloramphenicol · May increase the CNS depressant effect of pentobarbital.
• Opiates · May increase the CNS depressant effect of pentobarbital.
• Phenothiazines · May increase the CNS depressant effect of pentobarbital.

モニタリング

• Respiratory rate, depth, and effort (ventilatory support must be available)
• Heart rate and rhythm
• Blood pressure
• Body temperature (monitor for hypothermia)
• Depth of anesthesia/sedation

過量投与

In dogs, the reported oral LD50 is 85 mg/kg and IV LD50 is 40-60 mg/kg. **Fatalities from ingestion of meat from animals euthanized by pentobarbital have been reported in dogs.** **Treatment:** * Removal of ingested product from the gut if appropriate (e.g., gastric lavage, activated charcoal). * Provide aggressive respiratory (ventilatory) and cardiovascular support. * Forced alkaline diuresis is of little benefit. * Peritoneal dialysis or hemodialysis may be beneficial in severe intoxications.