Secobarbital Sodium (2 brand names, 3 dosage forms, 3 routes)
Available dosage forms: CAPSULE, SUPPOSITORY, INJECTABLE.
Routes of administration: ORAL, RECTAL, INJECTION.
Brand Names
- SECOBARBITAL SODIUM
- SECONAL SODIUM
Related Health Topics
Indications and Usage
A. Hypnotic, for the short-term treatment of insomnia, since it appears to lose its effectiveness for sleep induction and sleep maintenance after 2 weeks (see Clinical Pharmacology).B. Preanesthetic
Dosage and Administration
Dosages of barbiturates must be individualized with full knowledge of their particular characteristics. Factors of consideration are the patient’s age, weight, and condition.Adults—As a hypnotic, 100 mg at bedtime. Preoperatively, 200 to 300 mg 1 to 2 hours before surgery.Pediatric Patients—Preoperatively, 2 to 6 mg/kg, with a maximum dosage of 100 mg.Special patient population—Dosage should be reduced in the elderly or debilitated because these patients may be more sensitive to barbiturates. Dosage should be reduced for patients with impaired renal function or hepatic disease.
Contraindications
Seconal Sodium is contraindicated in patients who are hypersensitive to barbiturates. It is also contraindicated in patients with a history of manifest or latent porphyria, marked impairment of liver function, or respiratory disease in which dyspnea or obstruction is evident.
Adverse Reactions
The following adverse reactions and their incidences were compiled from surveillance of thousands of hospitalized patients who received barbiturates. Because such patients may be less aware of some of the milder adverse effects of barbiturates, the incidence of these reactions may be somewhat higher in fully ambulatory patients.More than 1 in 100 PatientsThe most common adverse reaction estimated to occur at a rate of 1 to 3 patients per 100 is the following:Nervous System: SomnolenceLess than 1 in 100 PatientsAdverse reactions estimated to occur at a rate of less than 1 in 100 patients are listed below, grouped by organ system and by decreasing order of occurrence:Nervous System: Agitation, confusion, hyperkinesia, ataxia, CNS depression, nightmares, nervousness, psychiatric disturbance, hallucinations, insomnia, anxiety, dizziness, abnormality in thinkingRespiratory System: Hypoventilation, apneaCardiovascular System: Bradycardia, hypotension, syncopeDigestive System: Nausea, vomiting, constipationOther Reported Reactions: Headache, injection site reactions, hypersensitivity reactions (angioedema, skin rashes, exfoliative dermatitis), fever, liver damage, megaloblastic anemia following chronic phenobarbital use
Drug Interactions
Most reports of clinically significant drug interactions occurring with the barbiturates have involved phenobarbital. However, the application of these data to other barbiturates appears valid and warrants serial blood level determinations of the relevant drugs when there are multiple therapies.1. Anticoagulants—Phenobarbital lowers the plasma levels of dicumarol and causes a decrease in anticoagulant activity as measured by the prothrombin time. Barbiturates can induce hepatic microsomal enzymes, resulting in increased metabolism and decreased anticoagulant response of oral anticoagulants (eg, warfarin, acenocoumarol, dicumarol, and phenprocoumon). Patients stabilized on anticoagulant therapy may require dosage adjustments if barbiturates are added to or withdrawn from their dosage regimen.2. Corticosteroids—Barbiturates appear to enhance the metabolism of exogenous corticosteroids, probably through the induction of hepatic microsomal enzymes. Patients stabilized on corticosteroid therapy may require dosage adjustments if barbiturates are added to or withdrawn from their dosage regimen.3. Griseofulvin—Phenobarbital appears to interfere with the absorption of orally administered griseofulvin, thus decreasing its blood level. The effect of the resultant decreased blood levels of griseofulvin on therapeutic response has not been established. However, it would be preferable to avoid concomitant administration of these drugs.4. Doxycycline—Phenobarbital has been shown to shorten the half-life of doxycycline for as long as 2 weeks after barbiturate therapy is discontinued.This mechanism is probably through the induction of hepatic microsomal enzymes that metabolize the antibiotic. If barbiturates and doxycycline are administered concurrently, the clinical response to doxycycline should be monitored closely.5. Phenytoin, Sodium Valproate, Valproic Acid—The effect of barbiturates on the metabolism of phenytoin appears to be variable. Some investigators report an accelerati
Overdosage
The toxic dose of barbiturates varies considerably. In general, an oral dose of 1 g of most barbiturates produces serious poisoning in an adult. Death commonly occurs after 2 to 10 g of ingested barbiturate. The sedated, therapeutic blood levels of secobarbital range between 0.5 to 5 mcg/mL; the usual lethal blood level ranges from 15 to 40 mcg/mL. Barbiturate intoxication may be confused with alcoholism, bromide intoxication, and various neurologic disorders. Potential tolerance must be considered when evaluating significance of dose and plasma concentration.Signs and Symptoms—Symptoms of oral overdose may occur within 15 minutes and begin with central nervous system depression, underventilation, hypotension, and hypothermia, which may progress to pulmonary edema and death. Hemorrhagic blisters may develop, especially at pressure points.In extreme overdose, all electrical activity in the brain may cease, in which case a “flat” EEG normally equated with clinical death cannot be accepted as indicative of brain death. This effect is fully reversible unless hypoxic damage occurs. Consideration should be given to the possibility of barbiturate intoxication even in situations that appear to involve trauma.Complications such as pneumonia, pulmonary edema, cardiac arrhythmias, congestive heart failure, and renal failure may occur. Uremia may increase CNS sensitivity to barbiturates if renal function is impaired. Differential diagnosis should include hypoglycemia, head trauma, cerebrovascular accidents, convulsive states, and diabetic coma.Treatment—To obtain up-to-date information about the treatment of overdose, a good resource is your certified Regional Poison Control Center. Telephone numbers of certified poison control centers are listed in the Physicians’ Desk Reference (PDR). In managing overdosage, consider the possibility of multiple drug overdoses, interaction among drugs, and unusual drug kinetics in your patient.Protect the patient’s airway and support ventilati