Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Injection, as sodium:
Nembutal: 50 mg/mL (20 mL, 50 mL) [latex free; contains alcohol, usp, propylene glycol]
Generic: 50 mg/mL (20 mL, 50 mL)
Solution, Injection, as sodium [preservative free]:
Generic: 50 mg/mL (20 mL, 50 mL)
Pharmacology
Mechanism of Action
Barbiturate with sedative, hypnotic, and anticonvulsant properties. Barbiturates depress the sensory cortex, decrease motor activity, alter cerebellar function, and produce drowsiness, sedation, and hypnosis. In high doses, barbiturates exhibit anticonvulsant activity; barbiturates produce dose-dependent respiratory depression; reduce brain metabolism and cerebral blood flow in order to decrease intracranial pressure
Pharmacokinetics/Pharmacodynamics
Distribution
Vd: Children: 0.8 L/kg (Schaible 1982); Adults: 1 L/kg (Ehrnebo 1974)
Metabolism
Hepatic via hydroxylation and glucuronidation (Wermeling 1985)
Excretion
Urine (<1%, as unchanged drug)
Onset of Action
Krauss 2006: Children and Adults: Sedation: IM: 10 to 15 minutes; IV: Almost immediate, within 3 to 5 minutes; Oral, Rectal: 15 to 60 minutes
Duration of Action
Krauss 2006: Children and Adults: Sedation: IM: 1 to 2 hours; IV: 15 to 45 minutes; Oral, Rectal: 1 to 4 hours
Half-Life Elimination
Terminal: Children: 26 ± 16 hours (Schaible 1982); Adults: Healthy: 22 hours (average) (Ehrnebo 1974); Range: 15 to 50 hours; dose dependent
Protein Binding
45% to 70%
Use: Labeled Indications
Sedative/hypnotic/preanesthesia: Short-term (<2 weeks) treatment of insomnia or as preanesthesia.
Seizures: Emergency control of certain anticonvulsive episodes (eg, status epilepticus, cholera, eclampsia, meningitis, tetanus, toxic reactions to strychnine or local anesthetics).
Use: Off Label
Barbiturate coma in severe brain injury patients/elevated intracranial pressurebyes
Based on the Brain Trauma Foundation Guidelines for the Management of Severe Traumatic Brain Injury, in patients with increased intracranial pressure (ICP) or traumatic brain injury, high-dose barbiturate therapy is effective and recommended for control of ICP when all other medical and surgical treatments have failed. Utilization of barbiturates for the prophylactic treatment of ICP in not indicated. Based on potential complications of barbiturate therapy, guidelines suggest use should be limited to patients who are hemodynamically stable prior to its introduction, and appropriate, continuous systemic monitoring should be available to avoid or treat any hemodynamic instability. Note: Barbiturate therapy has not shown clear benefit in improving outcomes.
Contraindications
Hypersensitivity to barbiturates or any component of the formulation; porphyria.
Dosage and Administration
Dosing: Adult
Note: Adjust dose based on patient's age, weight, and condition.
Sedative/hypnotic/preanesthesia:
IM: 150 to 200 mg, as a single dose.
IV: Initial: 100 mg; if needed, may administer additional increments after at least 1 minute, up to a total dose of 200 to 500 mg.
Seizures: IV: Note: Mechanical ventilation and cardiovascular monitoring required; titrate dose to cessation of electrographic seizures or burst suppression (NCS [Brophy 2012]).
Neurocritical Care Society recommendations (NCS [Brophy 2012]):
Loading dose: 5 to 15 mg/kg administered at a rate of ≤50 mg/minute, may give additional 5 to 10 mg/kg; follow with a continuous infusion.
Continuous infusion: 0.5 to 5 mg/kg/hour. If the patient experiences breakthrough status epilepticus while on continuous infusion, administer an additional 5 mg/kg bolus and increase infusion rate by 0.5 to 1 mg/kg/hour every 12 hours. Note: A period of at least 24 to 48 hours of electrographic control is recommended prior to withdrawing the continuous infusion; withdraw gradually to prevent recurrent status epilepticus.
Barbiturate coma in severe brain injury patients/elevated intracranial pressure (off-label use): IV: Loading dose: 10 mg/kg given over 30 minutes (or ≤25 mg/minute), followed by 5 mg/kg every hour for 3 doses; monitor blood pressure and respiratory rate. Maintenance infusion: Initial: 1 mg/kg/hour; may increase to 2 to 4 mg/kg/hour; maintain burst suppression on EEG (Censullo 2003; Eisenberg 1988).
Dosing: Geriatric
Avoid use (Beers Criteria [AGS 2019]).
Dosing: Pediatric
Note: Adjust dose based on patient's age, weight, and medical condition. Consider the potential for delayed metabolism or elimination in infants <6 months of age (Krauss 2006).
Hypnotic: Children: IM: 2 to 6 mg/kg; maximum dose: 100 mg/dose; Note: Use has generally been replaced by other agents.
Preoperative sedation: Note: Use has generally been replaced by other agents. Infants and Children:
IM: 2 to 6 mg/kg; maximum dose: 100 mg/dose (Krauss 2006)
IV: 1 to 3 mg/kg every 10 minutes up to a maximum total dose of 6 mg/kg, not to exceed total dose of 100 mg (Cote 2013)
Procedural sedation: Note: Use has generally been replaced by other agents.
IM: Infants and Children: IM: 2 to 6 mg/kg; maximum dose: 100 mg/dose (Krauss 2006)
IV:
Infants and Children: Initial: 1 to 2 mg/kg; additional doses of 1 to 2 mg/kg every 3 to 5 minutes to desired effect; usual effective total dose: 1 to 6 mg/kg; maximum total dose: 100 mg/dose (Krauss 2006; Mason 2004). Note: Patients receiving concurrent barbiturate therapy may require higher total mg/kg doses (up to 9 mg/kg) (Mason 2004).
Adolescents: 100 mg
Oral: Limited data available:
Infants: Oral: 4 mg/kg/dose, if needed supplemental 2 to 4 mg/kg/dose every 30 minutes; maximum total dose: 8 mg/kg (Mason 2004)
Children (Krauss 2006):
<4 years: Oral: 3 to 6 mg/kg; maximum dose: 100 mg/dose
≥4 years: Oral: 1.5 to 3 mg/kg; maximum dose: 100 mg/dose
Rectal: Limited data available (Krauss 2006): Children:
<4 years: 3 to 6 mg/kg; maximum dose: 100 mg
≥4 years: 1.5 to 3 mg/kg; maximum dose: 100 mg
Reduction of elevated ICP: Limited data available: Note: Intubation is required; adjust dose based on hemodynamics, ICP, cerebral perfusion pressure, and EEG.
Low dose: Children and Adolescents: IV: 5 mg/kg every 4 to 6 hours (Mazzola 2002)
High-dose pentobarbital coma: Children and Adolescents: IV: Loading dose: 10 mg/kg over 30 minutes, then 5 mg/kg every hour for 3 hours; initial maintenance infusion: 1 mg/kg/hour; adjust to maintain burst suppression on EEG; maintenance dose range: 1 to 2 mg/kg/hour (Adelson 2003; Rangel-Castillo 2008)
Sedation of mechanically ventilated ICU patient (who failed standard therapy): Limited data available: Infants, Children, and Adolescents: IV: Loading dose: 1 mg/kg followed by 1 mg/kg/hour infusion. Additional boluses at a dose equal to hourly rate may be given every 2 hours as needed. If ≥4 to 6 boluses are administered within 24 hours, then increase maintenance rate by 1 mg/kg/hour; reported required range: 1 to 6 mg/kg/hour (median: 2 mg/kg/hour). Tapering of dose and/or conversion to oral phenobarbital has been reported for therapy ≥5 days (Tobias 1995; Tobias 2000; Tobias 2000a). Note: Higher rates of adverse effects were observed in a small report that used higher loading and initial maintenance doses (Yanay 2004).
Status epilepticus refractory to standard therapy: Note: Mechanical ventilation and cardiovascular monitoring required; titrate dose to cessation of electrographic seizures or burst suppression (AES [Glauser 2016]; NCS [Brophy 2012])
IV: Infants, Children, and Adolescents: Loading dose: 5 mg/kg; maintenance infusion: Initial: 1 mg/kg/hour, may increase up to 3 mg/kg/hour (usual range: 1 to 3 mg/kg/hour); maintain burst suppression on EEG for 24 to 48 hours (no seizure activity), tapering pentobarbital rate by 0.5 mg/kg every 12 hours has been reported (Abend 2008; Holmes 1999; Kim 2001; NCS [Brophy 2012])
High-dose pentobarbital coma: IV: Infants and Children: Loading dose: 10 to 15 mg/kg given slowly over 1 to 2 hours; monitor blood pressure and respiratory rate. Maintenance infusion: Initial: 1 mg/kg/hour; may increase up to 5 mg/kg/hour (usual range: 0.5 to 5 mg/kg/hour); maintain burst suppression on EEG; if the patient experiences breakthrough status epilepticus while on continuous infusion, administer an additional 5 mg/kg bolus and increase infusion rate by 0.5 to 1 mg/kg/hour every 12 hours until burst suppression. A period of at least 24 to 48 hours of electrographic control is recommended prior to withdrawing the continuous infusion; withdraw gradually to prevent recurrent status epilepticus (Holmes 1999; NCS [Brophy 2012]). Note: Loading doses of 20 to 35 mg/kg (given over 1 to 2 hours) have been utilized in pediatric patients for pentobarbital coma, but these higher loading doses often cause hypotension requiring vasopressor therapy.
Reconstitution
Continuous IV infusion: May dilute in D5W or NS to a concentration of 4 or 8 mg/mL (Murray 2014; Walker 1981); caution should be used when diluting pentobarbital as there have been reports in clinical practice of precipitation occurring when diluted to concentrations >8 mg/mL (Gupta 2001; Sugai 1998).
Administration
Administer by deep IM or slow IV injection.
IM: Inject into a large muscle. No more than 5 mL (250 mg) should be injected at any one site because of possible tissue irritation.
IV: Do not exceed 50 mg/minute; IV push doses may be given undiluted. Parenteral solutions are highly alkaline; avoid extravasation; avoid intra-arterial injection.
Extravasation management: If extravasation occurs, stop infusion immediately and disconnect (leave cannula/needle in place); gently aspirate extravasated solution (do NOT flush the line); remove needle/cannula; elevate extremity. Apply warm compresses (Reynolds 2014).
Storage
Store at 20°C to 25°C (68°F to 77°F). Protect from freezing and avoid excessive heat. When mixed with an acidic solution, precipitate may form; use only clear solution.
Drug Interactions
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy
Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination
Beta-Blockers: Barbiturates may decrease the serum concentration of Beta-Blockers. Exceptions: Atenolol; Levobunolol; Metipranolol; Nadolol. Monitor therapy
Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification
Blood Pressure Lowering Agents: Barbiturates may enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy
Brexanolone: CNS Depressants may enhance the CNS depressant effect of Brexanolone. Monitor therapy
Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Bromopride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination
Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification
Calcium Channel Blockers: Barbiturates may increase the metabolism of Calcium Channel Blockers. Management: Monitor for decreased therapeutic effects of calcium channel blockers with concomitant barbiturate therapy. Calcium channel blocker dose adjustments may be necessary. Nimodipine Canadian labeling contraindicates concomitant use with phenobarbital. Exceptions: Clevidipine. Monitor therapy
Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Chloramphenicol (Systemic): May decrease the metabolism of Barbiturates. Barbiturates may increase the metabolism of Chloramphenicol (Systemic). Consider therapy modification
Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification
Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy
CycloSPORINE (Systemic): Barbiturates may increase the metabolism of CycloSPORINE (Systemic). Consider therapy modification
Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Doxycycline: Barbiturates may decrease the serum concentration of Doxycycline. Consider therapy modification
Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy
Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification
Esketamine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Estrogen Derivatives (Contraceptive): Barbiturates may diminish the therapeutic effect of Estrogen Derivatives (Contraceptive). Contraceptive failure is possible. Management: Use of a non-hormonal contraceptive is recommended. Consider therapy modification
Felbamate: May increase the serum concentration of Barbiturates. Barbiturates may decrease the serum concentration of Felbamate. Management: Monitor for elevated barbiturate concentrations/toxicity if felbamate is initiated/dose increased, or reduced concentrations/effects if felbamate is discontinued/dose decreased. Refer to phenobarbital dosing guidelines for patients receiving that agent. Monitor therapy
Fexinidazole [INT]: May increase the serum concentration of Products Containing Propylene Glycol. Avoid combination
Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification
Griseofulvin: Barbiturates may decrease the serum concentration of Griseofulvin. Monitor therapy
Hemin: Barbiturates may diminish the therapeutic effect of Hemin. Avoid combination
HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
HydrOXYzine: May enhance the CNS depressant effect of Barbiturates. Management: Consider a decrease in the barbiturate dose, as appropriate, when used together with hydroxyzine. With concurrent use, monitor patients closely for excessive response to the combination. Consider therapy modification
Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
LamoTRIgine: Barbiturates may decrease the serum concentration of LamoTRIgine. Management: See lamotrigine prescribing information for specific age-dependent dosing guidelines regarding concurrent use with a barbiturate, as well as for adjusting lamotrigine dosing if concurrent barbiturate therapy is discontinued. Consider therapy modification
Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Consider therapy modification
Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy
Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Mefloquine: May diminish the therapeutic effect of Anticonvulsants. Mefloquine may decrease the serum concentration of Anticonvulsants. Management: Mefloquine is contraindicated for malaria prophylaxis in persons with a history of convulsions. Monitor anticonvulsant concentrations and treatment response closely with concurrent use. Consider therapy modification
Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification
Methoxyflurane: Barbiturates may enhance the nephrotoxic effect of Methoxyflurane. Barbiturates may increase the metabolism of Methoxyflurane. Avoid combination
MetroNIDAZOLE (Systemic): May enhance the adverse/toxic effect of Products Containing Propylene Glycol. A disulfiram-like reaction may occur. Avoid combination
MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy
Mianserin: May enhance the CNS depressant effect of Barbiturates. Mianserin may diminish the therapeutic effect of Barbiturates. Barbiturates may decrease the serum concentration of Mianserin. Avoid combination
Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Multivitamins/Minerals (with ADEK, Folate, Iron): May decrease the serum concentration of Barbiturates. Monitor therapy
Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination
Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination
OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination
Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification
Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy
Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy
Primidone: May enhance the adverse/toxic effect of Barbiturates. Primidone is converted to phenobarbital, and thus becomes additive with existing barbiturate therapy. Monitor therapy
Progestins (Contraceptive): Barbiturates may diminish the therapeutic effect of Progestins (Contraceptive). Contraceptive failure is possible. Management: Use of alternative, nonhormonal contraceptives is recommended. Consider therapy modification
Propacetamol: Barbiturates may increase the metabolism of Propacetamol. This may 1) diminish the desired effects of propacetamol; and 2) increase the risk of liver damage. Monitor therapy
Pyridoxine: May increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day) Monitor therapy
Rifamycin Derivatives: May increase the metabolism of Barbiturates. Monitor therapy
ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy
Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy
Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy
Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy
Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification
Somatostatin Acetate: May enhance the adverse/toxic effect of Barbiturates. Specifically, Somatostatin Acetate may enhance or prolong Barbiturate effects, including sedative effects. Avoid combination
Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification
Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Teniposide: Barbiturates may decrease the serum concentration of Teniposide. Management: Consider alternatives to combined treatment with barbiturates and teniposide due to the potential for decreased teniposide concentrations. If the combination cannot be avoided, monitor teniposide response closely. Consider therapy modification
Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination
Theophylline Derivatives: Barbiturates may decrease the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline. Monitor therapy
Tricyclic Antidepressants: Barbiturates may increase the metabolism of Tricyclic Antidepressants. Consider therapy modification
Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Ulipristal: Barbiturates may decrease the serum concentration of Ulipristal. Avoid combination
Valproate Products: May increase the serum concentration of Barbiturates. Barbiturates may decrease the serum concentration of Valproate Products. Monitor therapy
Vitamin K Antagonists (eg, warfarin): Barbiturates may increase the metabolism of Vitamin K Antagonists. Management: Monitor INR more closely. An anticoagulant dose increase may be needed after a barbiturate is initiated or given at an increased dose. Anticoagulant dose decreases may be needed following barbiturate discontinuation or dose reduction. Consider therapy modification
Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification
Adverse Reactions
Frequency not defined.
Cardiovascular: Bradycardia, hypotension, syncope
Central nervous system: Abnormality in thinking, agitation, anxiety, ataxia, central nervous system stimulation, confusion, depression, dizziness, drowsiness, hallucination, headache, insomnia, nervousness, nightmares, psychiatric disturbance
Dermatologic: Exfoliative dermatitis, skin rash
Gastrointestinal: Constipation, nausea, vomiting
Hematologic & oncologic: Megaloblastic anemia
Hepatic: Hepatotoxicity
Hypersensitivity: Angioedema, hypersensitivity reaction
Local: Injection site reaction
Neuromuscular & skeletal: Hyperkinesia, laryngospasm
Respiratory: Apnea (especially with rapid IV use), hypoventilation, respiratory depression
Miscellaneous: Fever
Warnings/Precautions
Concerns related to adverse effects:
- CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).
- Respiratory depression: May cause respiratory depression particularly when administered intravenously; use with caution in patients with respiratory disease. Intubation is typically required prior to treatment for seizures or traumatic brain injury (NCS [Brophy 2012]).
Disease-related concerns:
- Depression: Use with caution in patients with depression or suicidal tendencies.
- Hepatic impairment: Use with caution in patients with hepatic impairment; reduce dose as appropriate. Do not use in patients showing premonitory signs of hepatic coma.
- Renal impairment: Use with caution in patients with renal impairment; reduce dose as appropriate.
- Substance abuse: Use with caution in patients with a history of drug abuse; potential for drug dependency exists. Tolerance, psychological and physical dependence may occur with prolonged use.
Concurrent drug therapy issues:
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Special populations:
- Debilitated patients: Use with caution in patients who are debilitated; marked excitement, depression, and confusion may occur.
- Elderly: Use with caution in elderly patients; marked excitement, depression, and confusion may occur.
- Pediatric neurotoxicity: In pediatric and neonatal patients <3 years of age and patients in third trimester of pregnancy (ie, times of rapid brain growth and synaptogenesis), the repeated or lengthy exposure to sedatives or anesthetics during surgery/procedures may have detrimental effects on child or fetal brain development and may contribute to various cognitive and behavioral problems. Epidemiological studies in humans have reported various cognitive and behavioral problems, including neurodevelopmental delay (and related diagnoses), learning disabilities, and ADHD. Human clinical data suggest that single, relatively short exposures are not likely to have similar negative effects. No specific anesthetic/sedative has been found to be safer. For elective procedures, risk vs benefits should be evaluated and discussed with parents/caregivers/patients; critical surgeries should not be delayed (FDA 2016).
Dosage form specific issues:
- Propylene glycol: Some dosage forms may contain propylene glycol; large amounts are potentially toxic and have been associated with hyperosmolality, lactic acidosis, seizures, and respiratory depression; use caution (AAP 1997; Zar 2007). See manufacturer’s labeling.
Other warnings/precautions:
- Acute or chronic pain: Use caution when administering to patients with acute or chronic pain; paradoxical excitement could be induced or important symptoms could be masked.
- Appropriate use: IV administration: Solution for injection is highly alkaline and extravasation may cause local tissue damage. Too rapid IV administration may cause respiratory depression, apnea, laryngospasm, or vasodilation with hypotension.
- Withdrawal: Anticonvulsants should not be discontinued abruptly because of the possibility of increasing seizure frequency; therapy should be withdrawn gradually to minimize the potential of increased seizure frequency, unless safety concerns require a more rapid withdrawal.
Monitoring Parameters
Respiratory status (for conscious sedation, includes pulse oximetry), cardiovascular status, CNS status; cardiac monitor and blood pressure monitor required; clinical signs of propylene glycol toxicity (for continuous high-dose and/or long duration IV use), including serum creatinine, BUN, serum lactate, and osmolal gap (Miller 2008; Pillai 2014)
Barbiturate coma: Monitor oxygenation as well as arterial and central venous pressures to guide fluid and vasoactive therapy for maintenance of blood pressure; temperature
Elevated ICP: Monitor ICP, CPP, EEG
Pregnancy
Pregnancy Risk Factor
D
Pregnancy Considerations
Barbiturates can be detected in the placenta, fetal liver and fetal brain. Fetal and maternal blood concentrations may be similar following parenteral administration. An increased incidence of fetal abnormalities may occur following maternal use. When used during the third trimester of pregnancy, withdrawal symptoms may occur in the neonate including seizures and hyperirritability; symptoms may be delayed up to 14 days. Use of hypnotic doses during labor does not impair uterine activity; however, use of full anesthetic doses decrease the force and frequency of uterine contractions. Respiratory depression may occur in the newborn when sedative-hypnotic barbiturates are administered to the mother during labor; resuscitation equipment should be available, especially for premature infants.
Patient Education
What is this drug used for?
- It is used to treat sleep problems.
- It is used to calm you before a procedure.
- It is used to treat seizures.
- It is used to put you to sleep for surgery.
- It may be given to you for other reasons. Talk with the doctor.
Frequently reported side effects of this drug
- Fatigue
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Trouble breathing
- Slow breathing
- Shallow breathing
- Severe dizziness
- Passing out
- Anxiety
- Confusion
- Depression
- Severe injection site redness, burning, pain, swelling, or irritation
- Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
