Details About Overdose or Poisoning Generic Salt :: Pentobarbital
Drug Pharmacology ::
I. Pharmacology. Pentobarbitalis a short-acting barbiturate with anticonvulsant as well assedative-hypnotic properties. It is used as a third-line drug in thetreatment of status epilepticus. It also may reduce intracranialpressure in patients with cerebral edema by inducing vasoconstriction.After intravenous administration of a single dose, the onset of effectoccurs within about 1 minute and lasts about 15 minutes. Pentobarbitaldemonstrates a biphasic elimination pattern; the half-life of theinitial phase is 4 hours, and the terminal phase half-life is 35–50hours. Effects are prolonged after termination of a continuous infusion.
Drug Indications ::
Pentobarbitalis used for the management of status epilepticus that is unresponsiveto conventional anticonvulsant therapy (eg, diazepam, phenytoin, orphenobarbital). If the use of pentobarbital for seizure control isconsidered, consultation with a neurologist is recommended.
It is used to manage elevated intracranial pressure in conjunction with other agents.
Itmay be used therapeutically or diagnostically for patients withsuspected alcohol or sedative-hypnotic drug withdrawal syndrome.
Drug Contra-Indications ::
Known sensitivity to the drug.
Manifest or latent porphyria.
Drug Adverse Effects ::
IV. Adverse effects
Central nervous system depression, coma, and respiratory arrest may occur, especially with rapid bolus or excessive doses.
Hypotension may result, especially with rapid intravenous infusion.
Laryngospasm and bronchospasm have been reported after rapid intravenous injection, although the mechanism is unknown.
Use in pregnancy. FDAcategory D (possible fetal risk). Pentobarbital readily crosses theplacenta, and chronic use may cause hemorrhagic disease of the newborn(owing to vitamin K deficiency) or neonatal dependency and withdrawalsyndrome. However, these potential effects do not preclude its acute,short-term use in a seriously symptomatic patient (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions
Pentobarbital has additive CNS and respiratory depression effects with other barbiturates as well as sedative and opioid drugs.
Hepaticenzyme induction generally is not encountered with acute pentobarbitaloverdose, although it may occur within 24–48 hours.
Clearance may be enhanced by hemoperfusion, requiring supplemental doses during the procedure.
Drug Dose Management ::
Dosage and method of administration
Intermittent intravenous bolus. Give100 mg IV slowly over at least 2 minutes; repeat as needed at 2-minuteintervals to a maximum dose of 300–500 mg (children, 1–3 mg/kg IV,repeated as needed to a maximum total of 5–6 mg/kg or 150–200 mg).
Continuous intravenous infusion. Administera loading dose of 5–6 mg/kg IV over 1 hour (not to exceed 50 mg/min;children, 1 mg/kg/min), followed by maintenance infusion of 0.5–3mg/kg/h titrated to the desired effect. For treatment of statusepilepticus, use loading dose of 5–15 mg/kg given by IV infusion over 1to 2 hours, monitor blood pressure (vasopressor support may berequired, eg, dopamine) and provide respiratory support, and followwith maintenance infusion. Electroencephalographic achievement of burstsuppression usually occurs with a serum pentobarbital concentration of25–40 mcg/mL.
Oral. Theoral regimen for treatment of barbiturate or other sedative-drugwithdrawal syndrome is administration of 200 mg orally, repeated everyhour until signs of mild intoxication appear (eg, slurred speech,drowsiness, and nystagmus). Most patients respond to 600 mg or less.Repeat the total initial dose every 6 hours as needed. Phenobarbital isan alternative (see Phenobarbital).
Drug Chemical Formulations ::
Parenteral. Pentobarbital sodium (Nembutal and others), 50 mg/mL in 1- and 2-mL tubes and vials and 20- and 50-mL vials.
Oral. Capsules (50 and 100 mg) and suppositories (30, 60, 120, and 200 mg). Also available as an elixir equivalent to 20 mg/5 mL.
The suggested minimum stocking level to treat a 70-kg adult for the first 24 hours is two vials, 50 mL each, or the equivalent.