No

Anticonvulsant, Barbiturate; Barbiturate; General Anesthetic

Induction of anesthesia; adjunct for intubation in head injury patients; control of convulsive states; treatment of elevated intracranial pressure

C-III

C

Hypersensitivity to barbiturates or any component of the formulation; status asthmaticus; severe cardiovascular disease; porphyria; inflammatory bowel disease or lower gastrointestinal neoplasm (rectal gel); should not be administered by intra-arterial injection

Laryngospasm or bronchospasms may occur; use with extreme caution in patients with reactive airway diseases (asthma or COPD). Use with caution when the hypnotic may be prolonged or potentiated (excessive premedication, Addison's disease, hepatic or renal dysfunction, myxedema, increased blood urea, severe anemia, or myasthenia gravis). Potential for drug dependency exists, abrupt cessation may precipitate withdrawal, including status epilepticus in epileptic patients. Do not administer to patients in acute pain. Use caution in patients with unstable aneurysms, cardiovascular disease, renally impairment, or hepatic disease. Use caution in elderly, debilitated, or pediatric patients. May cause paradoxical responses, including agitation and hyperactivity, particularly in acute pain and pediatric patients. Use with caution in patients with depression or suicidal tendencies, or in patients with a history of drug abuse. Tolerance, psychological and physical dependence may occur with prolonged use. May cause CNS depression, which may impair physical or mental abilities. Patients must be cautioned about performing tasks which require mental alertness (ie, operating machinery or driving). Effects with other sedative drugs or ethanol may be potentiated. May cause respiratory depression or hypotension, particularly when administered intravenously. Use with caution in hemodynamically unstable patients (hypotension or shock) or patients with respiratory disease. Repeated dosing or continuous infusions may cause cumulative effects. Extravasation or intra-arterial injection causes necrosis due to pH of 10.6, ensure patient has intravenous access.

Cardiovascular: Bradycardia, hypotension, syncope

Central nervous system: Drowsiness, lethargy, CNS excitation or depression, impaired judgment, "hangover" effect, confusion, somnolence, agitation, hyperkinesia, ataxia, nervousness, headache, insomnia, nightmares, hallucinations, anxiety, dizziness

Dermatologic: Rash, exfoliative dermatitis, Stevens-Johnson syndrome

Hematologic: Agranulocytosis, thrombocytopenia, megaloblastic anemia

Local: Pain at injection site, thrombophlebitis with I.V. use

Gastrointestinal: Nausea, vomiting, constipation

Renal: Oliguria

Respiratory: Laryngospasm, respiratory depression, apnea (especially with rapid I.V. use), hypoventilation, apnea

Miscellaneous: Gangrene with inadvertent intra-arterial injection

Symptoms of overdose include respiratory depression, hypotension, shock

Hypotension should respond to I.V. fluids and placement of patient in Trendelenburg position; if necessary, pressors such as norepinephrine may be used; patient may require ventilatory support

Barbiturates are enzyme inducers. Patients should be monitored when these drugs are started or stopped for a decreased or increased therapeutic effect respectively.

Increased toxicity when combined with other CNS depressants, antidepressants, benzodiazepines, chloramphenicol, or valproic acid; respiratory and CNS depression may be additive

MAOIs may prolong the effect of thiopental

Barbiturates stimulate the metabolism of beta-blockers and decrease their serum concentrations; consider a renally-eliminated beta-blocker (atenolol, nadolol)

Barbiturates may enhance the hepatotoxic potential of acetaminophen via an increased formation of toxic metabolites

Barbiturates may increase chloramphenicol metabolism and chloramphenicol may inhibit the metabolism of barbiturates. Barbiturates may increase the metabolism of corticosteroids, cyclosporine, disopyramide, griseofulvin, nifedipine, oral contraceptives, phenytoin, propafenone, quinidine, verapamil; dosage adjustments may be useful.

Barbiturates may enhance the metabolism of methadone resulting in methadone withdrawal

Reconstituted solutions remain stable for 3 days at room temperature and 7 days when refrigerated; solutions are alkaline and incompatible with drugs with acidic pH, such as succinylcholine, atropine sulfate, etc. I.V. form is incompatible when mixed with amikacin, benzquinamide, chlorpromazine, codeine, dimenhydrinate, diphenhydramine, glycopyrrolate, hydromorphone, insulin, levorphanol, meperidine, metaraminol, morphine, norepinephrine, penicillin G, prochlorperazine, succinylcholine, tetracycline

Short-acting 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.

Onset of action: I.V.: Anesthesia occurs in 30-60 seconds

Duration: 5-30 minutes

Distribution: V_d: 1.4 L/kg

Protein binding: 72% to 86%

Metabolism: In the liver primarily to inactive metabolites but pentobarbital is also formed

Half-life: 3-11.5 hours, decreased in children vs adults

I.V.:

Infants: 5-8 mg/kg

Children 1-12 years: 5-6 mg/kg

Adults: 3-5 mg/kg

Maintenance anesthesia:

Children: 1 mg/kg as needed

Adults: 25-100 mg as needed

Increased intracranial pressure: Children and Adults: 1.5-5 mg/kg/dose; repeat as needed to control intracranial pressure

Seizures:

Children: 2-3 mg/kg/dose, repeat as needed

Adults: 75-250 mg/dose, repeat as needed

Rectal administration: (Patient should be NPO for no less than 3 hours prior to administration)

Suggested initial doses of thiopental rectal suspension are:

<3 months: 15 mg/kg/dose

>3 months: 25 mg/kg/dose

Note: The age of a premature infant should be adjusted to reflect the age that the infant would have been if full-term (eg, an infant, now age 4 months, who was 2 months premature should be considered to be a 2-month old infant).

Doses should be rounded downward to the nearest 50 mg increment to allow for accurate measurement of the dose

Inactive or debilitated patients and patients recently medicated with other sedatives, (eg, chloral hydrate, meperidine, chlorpromazine, and promethazine), may require smaller doses than usual

If the patient is not sedated within 15-20 minutes, a single repeat dose of thiopental can be given. The single repeat doses are:

<3 months: <7.5 mg/kg/dose

>3 months: 15 mg/kg/dose

Adults weighing >90 kg should not receive >3 g as a total dose (initial plus repeat doses)

Children weighing >34 kg should not receive >1 g as a total dose (initial plus repeat doses)

Neither adults nor children should receive more than one course of thiopental rectal suspension (initial dose plus repeat dose) per 24-hour period

Dosing adjustment in renal impairment: Cl_cr <10 mL/minute: Administer at 75% of normal dose

Note: Accumulation may occur with chronic dosing due to lipid solubility; prolonged recovery may result from redistribution of thiopental from fat stores

Rapid I.V. injection may cause hypotension or decreased cardiac output

Respiratory rate, heart rate, blood pressure

Therapeutic: Hypnotic: 1-5 mg/mL (SI: 4.1-20.7 mmol/L); Coma: 30-100 mg/mL (SI: 124-413 mmol/L); Anesthesia: 7-130 mg/mL (SI: 29-536 mmol/L); Toxic: >10 mg/mL (SI: >41 mmol/L)

potassium (S)

No information available to require special precautions

No effects or complications reported

Residual sedation following recovery is normal, due to slow release of the drug from lipid depots; patients should not drive or engage in similarly dangerous activities until at least the following day

Monitor vital signs every 3-5 minutes; monitor for respiratory distress; place patient in Sim's position if vomiting, to prevent from aspirating vomitus; avoid extravasation, necrosis may occur

Injection, as sodium: 250 mg, 400 mg, 500 mg, 1 g, 2.5 g, 5 g

Suspension, rectal, as sodium: 400 mg/g (2 g)