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Special Alerts
Sedative-Hypnotic Drug Products: Labeling Changes to Include Stronger Precautions Regarding Adverse Events − March, 2007
The U.S. Food and Drug Administration (FDA) has requested that all manufacturers of sedative-hypnotic drug products, including Seconal® (secobarbital), revise the labeling to include a greater emphasis on the risks of adverse events. The events include severe hypersensitivity reactions including anaphylaxis and/or angioedema, as well as hazardous sleep-related activities (eg, sleep-driving − driving while not fully awake after consumption of sedative-hypnotic drug, with no recollection of the event). Other activities may include preparing and ingesting food, as well as use of the telephone, while asleep. The events may occur at any time during therapy including with the first dose administered.
Manufacturers must provide written notification to healthcare providers regarding the new warnings. In addition, manufacturers are to develop “Patient Medication Guides” designed to educate consumers about the potential risks and to advise them of precautionary measures that can be taken. This advice will contain recommendations on correct utilization of the medication as well as the avoidance of the consumption of ethanol and/or other CNS-depressant agents.
The FDA is also recommending manufacturers conduct studies evaluating the frequencies of sleep-driving (and other sleep-related behaviors) with the individual products. Patients should also be informed of the potential for an allergic reaction to occur as well as the signs and symptoms of anaphylaxis. Patients should be fully prepared and trained on the appropriate emergency self-treatment of an anaphylactic reaction.
Additional information on the sedative-hypnotic products and sleep disorders is available at the following websites:
http://www.fda.gov/cder/drug/infopage/sedative_hypnotics/default.htm
www.fda.gov/womens/getthefacts/sleep.html
Medication Safety Issues
Sound-alike/look-alike issues:
Seconal® may be confused with Sectral®
Pronunciation
(see koe BAR bi tal)
U.S. Brand Names
Index Terms
Generic Available
No
Pharmacologic Category
Use
Preanesthetic agent; short-term treatment of insomnia
Restrictions
C-II
Pregnancy Risk Factor
D
Lactation
Enters breast milk/use caution (AAP rates “compatible”)
Contraindications
Hypersensitivity to barbiturates or any component of the formulation; marked hepatic impairment; dyspnea or airway obstruction; porphyria; pregnancy
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).
• Hypersensitivity reactions: Postmarketing studies have indicated that the use of hypnotic/sedative agents for sleep has been associated with hypersensitivity reactions including anaphylaxis as well as angioedema.
• Paradoxical responses: May cause paradoxical responses, including agitation and hyperactivity, particularly in acute pain, chronic pain and pediatric patients.
• Sleep-related activities: An increased risk for hazardous sleep-related activities such as sleep-driving; cooking and eating food, and making phone calls while asleep have also been noted. Discontinue treatment in patients who report a sleep-driving episode.
Disease-related concerns:
• Cardiovascular disease: Use with caution in patients with cardiovascular disease; may cause hypotension.
• Depression: Use with caution in patients with depression or suicidal tendencies.
• Drug abuse: Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Tolerance, psychological and physical dependence may occur with prolonged use.
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Renal impairment: Use with caution in patients with renal impairment.
• Respiratory disease: Use with caution in patients with respiratory disease; may cause respiratory depression.
Concurrent drug therapy issues:
• Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.
Special populations:
• Elderly: Use with caution in the elderly; closely monitor elderly or debilitated patients for impaired cognitive or motor performance.
• Pediatrics: Use with caution in children.
Other warnings/precautions:
• Appropriate use: Symptomatic treatment of insomnia should be initiated only after careful evaluation of potential causes of sleep disturbance. Failure of sleep disturbance to resolve after 7-10 days may indicate psychiatric and/or medical illness.
• Withdrawal: Abrupt cessation may precipitate withdrawal, including status epilepticus in epileptic patients.
Adverse Reactions
Frequency not defined.
Cardiovascular: Hypotension
Central nervous system: Dizziness, lightheadedness, “hangover” effect, drowsiness, CNS depression, fever, confusion, mental depression, unusual excitement, nervousness, faint feeling, headache, insomnia, nightmares, hallucinations
Dermatologic: Exfoliative dermatitis, rash, Stevens-Johnson syndrome
Gastrointestinal: Nausea, vomiting, constipation
Hematologic: Agranulocytosis, megaloblastic anemia, thrombocytopenia, thrombophlebitis, urticaria
Local: Pain at injection site
Respiratory: Apnea, laryngospasm, respiratory depression
Postmarketing and/or case reports: Anaphylaxis, angioedema, complex sleep-related behavior (sleep-driving, cooking or eating food, making phone calls)
Overdosage/Toxicology
Symptoms of overdose include unsteady gait, slurred speech, confusion, jaundice, hypothermia, fever, hypotension, respiratory depression, and coma. Charcoal hemoperfusion or hemodialysis may be useful, especially in the presence of very high serum barbiturate levels when the patient is in shock, coma, or renal failure. Forced alkaline diuresis is of no value in the treatment of intoxications with short-acting barbiturates.
Drug Interactions
Induces CYP2A6 (strong), 2C8 (strong), 2C9 (strong)
Acetaminophen: Barbiturates may enhance the hepatotoxic potential of acetaminophen overdoses
Antiarrhythmics: Barbiturates may increase the metabolism of antiarrhythmics, decreasing their clinical effect; includes disopyramide, propafenone, and quinidine
Anticonvulsants: Barbiturates may increase the metabolism of anticonvulsants; includes ethosuximide, felbamate (possibly), lamotrigine, phenytoin, tiagabine, topiramate, and zonisamide; does not appear to affect gabapentin or levetiracetam
Antineoplastics: Limited evidence suggests that enzyme-inducing anticonvulsant therapy may reduce the effectiveness of some chemotherapy regimens (specifically in ALL); teniposide and methotrexate may be cleared more rapidly in these patients
Antipsychotics: Barbiturates may enhance the metabolism (decrease the efficacy) of antipsychotics; monitor for altered response; dose adjustment may be needed
Beta-blockers: Metabolism of beta-blockers may be increased and clinical effect decreased; atenolol and nadolol are unlikely to interact given their renal elimination
Calcium channel blockers: Barbiturates may enhance the metabolism of calcium channel blockers, decreasing their clinical effect
Chloramphenicol: Barbiturates may increase the metabolism of chloramphenicol and chloramphenicol may inhibit barbiturate metabolism; monitor for altered response
Cimetidine: Barbiturates may enhance the metabolism of cimetidine, decreasing its clinical effect
CNS depressants: Sedative effects and/or respiratory depression with barbiturates may be additive with other CNS depressants; monitor for increased effect; includes ethanol, sedatives, antidepressants, opioid analgesics, and benzodiazepines
Corticosteroids: Barbiturates may enhance the metabolism of corticosteroids, decreasing their clinical effect
Cyclosporine: Levels may be decreased by barbiturates; monitor
CYP2A6 substrates: Secobarbital may decrease the levels/effects of CYP2A6 substrates. Example substrates include ifosfamide and rifampin.
CYP2C8 Substrates: Secobarbital may decrease the levels/effects of CYP2C8 substrates. Example substrates include amiodarone, paclitaxel, pioglitazone, repaglinide, and rosiglitazone.
CYP2C9 Substrates: Secobarbital may decrease the levels/effects of CYP2C9 substrates. Example substrates include bosentan, celecoxib, dapsone, fluoxetine, glimepiride, glipizide, losartan, montelukast, nateglinide, paclitaxel, phenytoin, sulfonamides, trimethoprim, warfarin, and zafirlukast.
Doxycycline: Barbiturates may enhance the metabolism of doxycycline, decreasing its clinical effect; higher dosages may be required
Estrogens: Barbiturates may increase the metabolism of estrogens and reduce their efficacy
Felbamate may inhibit the metabolism of barbiturates and barbiturates may increase the metabolism of felbamate
Griseofulvin: Barbiturates may impair the absorption of griseofulvin, and griseofulvin metabolism may be increased by barbiturates, decreasing clinical effect
Guanfacine: Effect may be decreased by barbiturates
Immunosuppressants: Barbiturates may enhance the metabolism of immunosuppressants, decreasing its clinical effect; includes both cyclosporine and tacrolimus
Loop diuretics: Metabolism may be increased and clinical effects decreased; established for furosemide, effect with other loop diuretics not established
MAO inhibitors: Metabolism of barbiturates may be inhibited, increasing clinical effect or toxicity of the barbiturates
Methadone: Barbiturates may enhance the metabolism of methadone resulting in methadone withdrawal
Methoxyflurane: Barbiturates may enhance the nephrotoxic effects of methoxyflurane
Oral contraceptives: Barbiturates may enhance the metabolism of oral contraceptives, decreasing their clinical effect; an alternative method of contraception should be considered
Theophylline: Barbiturates may increase metabolism of theophylline derivatives and decrease their clinical effect
Tricyclic antidepressants: Barbiturates may increase metabolism of tricyclic antidepressants and decrease their clinical effect; sedative effects may be additive
Valproic acid: Metabolism of barbiturates may be inhibited by valproic acid; monitor for excessive sedation; a dose reduction may be needed
Warfarin: Barbiturates inhibit the hypoprothrombinemic effects of oral anticoagulants via increased metabolism; this combination should generally be avoided
Ethanol/Nutrition/Herb Interactions
Ethanol: Avoid ethanol (may increase CNS depression).
Herb/Nutraceutical: Avoid valerian, St John's wort, kava kava, gotu kola (may increase CNS depression).
Mechanism of Action
Depresses CNS activity by binding to barbiturate site at GABA-receptor complex enhancing GABA activity, depressing reticular activity system; higher doses may be gabamimetic
Pharmacodynamics/Kinetics
Onset of hypnosis: 15-30 minutes
Duration: 3-4 hours with 100 mg dose
Distribution: 1.5 L/kg; crosses the placenta; appears in breast milk
Protein binding: 45% to 60%
Metabolism: Hepatic, by microsomal enzyme system
Half-life elimination: 15-40 hours, mean: 28 hours
Time to peak, serum: Within 2-4 hours
Excretion: Urine (as inactive metabolites, small amounts as unchanged drug)
Dosage
Oral:
Children:
Preoperative sedation: 2-6 mg/kg (maximum dose: 100 mg/dose) 1-2 hours before procedure
Sedation: 6 mg/kg/day divided every 8 hours
Adults:
Hypnotic: Usual: 100 mg/dose at bedtime; range 100-200 mg/dose
Preoperative sedation: 100-300 mg 1-2 hours before procedure
Monitoring Parameters
Blood pressure, heart rate, respiratory rate, CNS status
Patient Education
Use exactly as directed; do not increase dose or frequency or discontinue without consulting prescriber. Drug may cause physical and/or psychological dependence. While using this medication, do not use alcohol or other prescription or OTC medications (especially, pain medications, sedatives, antihistamines, or hypnotics) without consulting prescriber. Maintain adequate hydration (2-3 L/day of fluids) unless instructed to restrict fluid intake. You may experience drowsiness, dizziness, or blurred vision (use caution when driving or engaging in tasks requiring alertness until response to drug is known); nausea or vomiting (small frequent meals, frequent mouth care, chewing gum, or sucking lozenges may help); or constipation (increased exercise, fluids, fruit, or fiber may help). Report skin rash or irritation; CNS changes (confusion, depression, increased sedation, excitation, headache, insomnia, or nightmares); respiratory difficulty or shortness of breath; difficulty swallowing or feeling of tightness in throat; unusual weakness or unusual bleeding in mouth, urine, or stool; unusual swelling, especially on face or neck; or other unanticipated adverse effects. Pregnancy/breast-feeding precautions: Do not get pregnant while taking this medication. Use appropriate contraceptive measures. Consult prescriber if breast-feeding.
Geriatric Considerations
Use of this agent in the elderly is not recommended due to its long half-life and addiction potential.
Dental Health: Effects on Dental Treatment
No significant effects or complications reported
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Nursing: Physical Assessment/Monitoring
Assess effectiveness and interactions of other medications patient may be taking. Assess patient for history of addiction; long-term use can result in dependence, abuse, or tolerance and evaluate periodically for need for continued use. Be alert to possibility of anaphylaxis any time during therapy. Assess for CNS depression, abnormal thinking, and behavior changes. Monitor vital signs and respiratory status. After long-term use, taper dosage slowly when discontinuing. Oral: For inpatient use, institute safety measures. For outpatient use, monitor effectiveness and adverse reactions at beginning of therapy and periodically with long-term use. Assess knowledge/teach patient appropriate use, interventions to reduce side effects, and adverse symptoms to report.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, as sodium: 100 mg
References
Levine HL, Cohen ME, Duffner PK, et al, “Rectal Absorption and Disposition of Secobarbital in Epileptic Children,” Pediatr Pharmacol (New York), 1982, 2(1):33-8.
Monteil RA, Raybaud H, Madinier I, et al, “Occurrence of Oral Mucosal Necrosis in a Patient With Barbiturate-Induced Coma,” Oral Surg Oral Med Oral Pathol, 1991, 72(5):562-4.
Nahata MC, Starling S, and Edwards RC, “Prolonged Sedation Associated With Secobarbital in Newborn Infants Receiving Ventilatory Support,” Am J Perinatol, 1991, 8(1):35-6.
Tracqui A, Kintz P, Mangin P, et al, “A Fatality Involving Secobarbital, Nitrazepam, and Codeine,” Am J Forensic Med Pathol, 1989, 10(2):130-3.
Wolfert RR and Cox RM, “Room Temperature Stability of Drug Products Labeled for Refrigerated Storage,” Am J Hosp Pharm, 1975, 32(6):585-7.
Lexi-Comp.com
Last full review/revision June 2007
Content last modified June 2007
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