Phenobarbital Sodium (1 brand name, 1 dosage form, 1 route)
Available dosage forms: POWDER.
Routes of administration: INTRAVENOUS.
Brand Names
- SEZABY
Related Health Topics
Dosage and Administration
Dosages of barbiturates must be individualized with full knowledge of their particular characteristics and recommended rates of administration. Factors to consider are the patient’s age, weight and condition. Suggested doses of phenobarbital sodium for specific indications follow:
Contraindications
Barbiturates are contraindicated in patients with known barbiturate sensitivity. Barbiturates are also contraindicated in patients with a history of manifest or latent porphyria, marked impairment of liver functions or with severe respiratory distress where dyspnea or obstruction is evident. Large doses are contraindicated in nephritic subjects. Barbiturates should not be administered to persons with known previous addiction to the sedative-hypnotic group since ordinary doses may be ineffectual and may contribute to further addiction. Intraarterial administration is contraindicated. Its consequences vary from transient pain to gangrene. Subcutaneous administration produces tissue irritation, ranging from tenderness and redness to necrosis and is not recommended. (See DOSAGE AND ADMINISTRATION, Treatment of Adverse Effects Due to Inadvertent Error in Administration.)
Adverse Reactions
The following adverse reactions and their incidence were compiled from surveillance of thousands of hospitalized patients. Because such patients may be less aware of certain of the milder adverse effects of barbiturates, the incidence of these reactions may be somewhat higher in fully ambulatory patients.
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.
Overdosage
The toxic dose of barbiturates varies considerably. Barbiturate intoxication may be confused with alcoholism, bromide intoxication and various neurological disorders. For sedation, therapeutic blood levels of phenobarbital range from 5-40 µg/mL; the lethal blood level is greater than 80 µg/mL and usually ranges from 100-200 µg/mL. Acute overdosage with barbiturates is manifested by CNS and respiratory depression which may progress to Cheyne-Stokes respiration, areflexia, constriction of the pupils to a slight degree (though in severe poisoning, they may show paralytic dilation), oliguria, tachycardia, hypotension, lowered body temperature and coma. Typical shock syndrome (apnea, circulatory collapse, respiratory arrest and death) may occur. 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. 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. To obtain up-to-date information about the treatment of overdosage, 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 overdose, interaction among drugs and the unusual drug kinetics in your patient. Treatment of overdosage is mainly supportive and consists of the following: Maintenance of an adequate airway, with assisted respiration and oxygen administration as necessary. Monito