(thye oh PEN tal)
Note: Not available in the U.S. and/or Canada
Anesthesia: Induction of anesthesia and adjunctive agent for anesthesia
Anticonvulsant: Treatment of convulsive states
Elevated intracranial pressure: Treatment of elevated intracranial pressure
Hypersensitivity to thiopental, barbiturates, or any component of the formulation; respiratory obstruction; acute asthma; when an adequate airway cannot be maintained during operation; severe shock; severe respiratory disease; constrictive pericarditis; porphyria (variegate or acute intermittent); myotonic dystrophy; inflammatory conditions of mouth, jaw, and neck; complete absence of suitable veins
Anesthesia, induction: IV: 3-6 mg/kg (maximum total dose 500 mg) (Barash, 2009; Miller, 2010). Note: Dose needs to be adjusted according to patient 's response and factors such as age, sex, weight, preexisting conditions, premedication, and coadministration with adjuvant drugs. When there is concern regarding a possible abnormal response, consider use of a test dose equal to 10% to 20% of the usual induction dose to identify patients for whom a dosage adjustment is required (Barash, 2009).
Anesthesia, maintenance: IV: 25-100 mg as needed every 10-12 minutes (Miller, 2010)
Increased intracranial pressure: IV: 1.5-3 mg/kg/dose; repeat as needed to control intracranial pressure
Seizures: IV: 75-125 mg/dose; repeat as needed. Convulsions following the use of a local anesthetic may require doses of 125-250 mg given over a 10 minute period; dose will be dependent on the amount of local anesthetic given and its convulsant properties.
Anesthesia, induction: IV: Note: Dose needs to be adjusted according to patient 's response and factors such as age, sex, weight, preexisting conditions, premedication, and coadministration with adjuvant drugs. When there is concern regarding a possible abnormal response, consider use of a test dose equal to 10% to 20% of the usual induction dose to identify patients for whom a dosage adjustment is required (Barash, 2009).
Manufacturer recommendations: Refer to adult dosing; smaller doses are advisable.
Alternative recommendations: Decrease adult dose by approximately 30% to 50%; limit induction dose to ≤3 mg/kg (Rivera, 2009; Sorensen, 2011).
Anesthesia, maintenance: IV: Decrease adult dose by approximately 30% to 50% (Rivera, 2009).
Anesthesia, induction: IV: 2-5 mg/kg administered over 10-15 seconds; repeat dose after 1 minute if needed (maximum total dose 7 mg/kg). Note: Dose needs to be adjusted according to patient 's response and factors such as age, sex, weight, preexisting conditions, premedication, and coadministration with adjuvant drugs. When there is concern regarding a possible abnormal response, consider use of a test dose equal to 10-20% of the usual induction dose to identify patients for whom a dosage adjustment is required (Barash, 2009).
Increased intracranial pressure: IV: 1-2 mg/kg/dose; repeat as needed to control intracranial pressure (AAP, 1998)
Manufacturer recommendations: There are no dosage adjustments provided in manufacturer 's labeling, however, use with caution as hypnotic effect may be prolonged or potentiated. In surgical patients with chronic renal failure (n=7) receiving an induction dose of thiopental, thiopental free fraction concentrations were significantly higher as compared to surgical patients with normal renal function (n=7) (~28% vs. ~15%, respectively, p<0.05). The rate and extent of thiopental distribution and elimination was found to be similar to patients with normal renal function (Burch, 1982).
Alternative recommendations: CrCl <10 mL/minute: Administer at 75% of normal dose (Aronoff, 2007).
There are no dosage adjustments provided in manufacturer 's labeling, however because thiopental is metabolized by the liver doses should be reduced in patients with hepatic impairment.
Injection, powder for reconstitution: Refer to the manufacturer 's reconstitution instructions. Typical final concentrations: Note: Do not prepare concentrations <20 mg/mL in sterile water for injection (causes hemolysis).
For injection or intermittent infusion: 20 mg/mL or 25 mg/mL; up to 50 mg/mL has been used.
Administer IV push slowly over at least 10-15 seconds. Rapid IV injection may cause hypotension or decreased cardiac output. Avoid extravasation, necrosis may occur. Check IV catheter placement prior to administration. If inadvertent intra-arterial administration occurs, treat with a local anesthetic (eg, prilocaine 2%, 5 mL) or papaverine (40-80 mg), preferably through the catheter used for the thiopental injection. Anticoagulant therapy may also be started to reduce the risk of thrombosis.
Irritant with vesicant-like properties; ensure proper needle or catheter placement prior to and during infusion. Avoid extravasation.
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 dry warm compresses (Reynolds, 2014).
Some products may contain sodium.
Store powder for reconstitution below 25 ‚ °C (77 ‚ °F); use immediately after reconstitution. When reconstituted solution is stored between 2 ‚ °C and 8 ‚ °C (35 ‚ °F and 46 ‚ °F), reported stability times vary (consult specific product labeling).
Stable in D51/4NS, D51/2NS, D5W, 1/2NS, NS; incompatible with D5LR, D10W, D10NS, LR.
Y-site administration: Incompatible with alfentanil, ascorbic acid, atracurium, atropine, diltiazem, dobutamine, dopamine, ephedrine, epinephrine, fenoldopam, furosemide, hydromorphone, labetalol, midazolam, naloxone, nicardipine, norepinephrine, pancuronium, pantoprazole, phenylephrine, succinylcholine, sufentanil, vecuronium.
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy
Aminophylline: May diminish the therapeutic effect of Thiopental. Monitor therapy
Antipsychotic Agents (Phenothiazines): May enhance the adverse/toxic effect of Thiopental. 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
Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
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 patches (Butrans brand) at 5 mcg/hr in adults when used with other 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
Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Chloramphenicol: May decrease the metabolism of Barbiturates. Barbiturates may increase the metabolism of Chloramphenicol. Consider therapy modification
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy
Contraceptives (Estrogens): Barbiturates may diminish the therapeutic effect of Contraceptives (Estrogens). Contraceptive failure is possible. Management: Use of a non-hormonal contraceptive is recommended. Consider therapy modification
Contraceptives (Progestins): Barbiturates may diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Use of alternative, nonhormonal contraceptives is recommended. Consider therapy modification
CycloSPORINE (Systemic): Barbiturates may increase the metabolism of CycloSPORINE (Systemic). Consider therapy modification
Diazoxide: Thiopental may enhance the hypotensive effect of Diazoxide. Monitor therapy
Dimethindene: 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 (e.g., opioids, barbiturates) with concomitant use. 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
Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification
Hemin: Barbiturates may diminish the therapeutic effect of Hemin. Avoid combination
HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Consider starting with a 20% to 30% lower hydrocodone dose when using together with any other CNS depressant. Dose reductions in the other CNS depressant may also be warranted. 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
Ketamine: May enhance the adverse/toxic effect of Thiopental. 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
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
Meperidine: Barbiturates may enhance the CNS depressant effect of Meperidine. Barbiturates may increase serum concentrations of the active metabolite(s) of Meperidine. Monitor therapy
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
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: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Mirtazapine: CNS Depressants may enhance the CNS depressant effect of Mirtazapine. 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
Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination
OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: When oxycodone is combined with another CNS depressant, a dose reduction of one or both agents should be considered. The extended release oxycodone starting dose should be reduced 50% to 67% when initiated in patients already receiving CNS depressants. 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 [INT]: CNS Depressants may enhance the CNS depressant effect of Piribedil [INT]. 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
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
St Johns Wort: May enhance the CNS depressant effect of Thiopental. Monitor therapy
SulfiSOXAZOLE: May enhance the therapeutic effect of Thiopental. Management: Consider thiopental dosing carefully when used together with sulfisoxazole as reduced thiopental doses may be required. Monitor patient response to treatment extra closely if using this combination. Consider therapy modification
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: Start tapentadol at a dose of one-third to one-half of the normal dose if being initiated in a patient who is taking another drug with CNS depressant effects. Monitor closely for evidence of excessive CNS depression. 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
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
Thiazide and Thiazide-Like Diuretics: Barbiturates may enhance the orthostatic hypotensive effect of Thiazide and Thiazide-Like Diuretics. 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
Valerian: May enhance the CNS depressant effect of Thiopental. Monitor therapy
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
Respiratory rate, heart rate, blood pressure
Percentage of plasma bound drug decreases and the volume of distribution and half-life are increased.
Percentage of protein binding may be lower in pediatric patients; the half-life may be increased in the neonate.
Concerns related to adverse effects:
- Extravasation: Thiopental is an irritant with vesicant-like properties. Ensure proper needle or catheter placement prior to and during infusion; avoid extravasation. Irritation, venospasm, extensive tissue necrosis, and/or sloughing have been reported with extravasation.
- Hypotension: May cause hypotension; use with caution in hemodynamically unstable patients; use is contraindicated in severe shock.
- Respiratory depression: May cause respiratory depression; use with caution patients with respiratory disease. Use is contraindicated in patients with severe respiratory disease.
Disease-related concerns:
- Anemia: Use with caution in patients with severe anemia; may prolong or potentiate hypnotic effect. Reduced doses are recommended.
- Asthma: Use with caution in patients with asthma; may cause laryngospasm or bronchospasms. Use is contraindicated in patients experiencing acute asthmatic episodes (eg, status asthmaticus).
- Burns: Use with caution in patients with burns.
- Cachexia: Use with caution in patients with cachexia.
- Cardiovascular disease: Use with caution in patients with cardiovascular disease. Thiopental causes respiratory depression and a reduction in cardiac output; may precipitate acute circulatory failure in patients with cardiovascular disease particularly constrictive pericarditis.
- Endocrine insufficiency: Use with caution in patients with endocrine sufficiency (pituitary, thyroid, adrenal, pancreas) such as Addison 's disease, myxedema, thyrotoxicosis, and diabetes; may prolong or potentiate hypnotic effect. Reduced doses are recommended.
- Hemodynamic instability: Use with caution in hemodynamically unstable patients (hypotension, hypovolemia, dehydration, severe hemorrhage, or shock); may exacerbate condition; reduced doses are recommended. Use is contraindicated in patients experiencing severe shock.
- Hepatic impairment: Use with caution in patients with hepatic impairment; may prolong or potentiate hypnotic effect.
- Hyperkalemia: Reduced doses are recommended with hyperkalemia.
- Muscular dystrophies: Use with caution in patients with muscular dystrophies or myotonias (contraindicated in some product labeling); may prolong or potentiate hypnotic effect.
- Myasthenia gravis: Use with caution in patients with myasthenia gravis; may prolong or potentiate hypnotic effect.
- Myxedema: Use with caution in patients with myxedema; may prolong or potentiate hypnotic effect.
- Renal impairment: Use with caution in patients with renal impairment; may prolong or potentiate hypnotic effect.
- Substance abuse: Use with caution in patients with a history of alcohol or drug abuse; increased doses may be necessary in patients who have a habituation or addiction to alcohol or drugs of abuse.
- Uremia: Use with caution in patients with severe uremia; may prolong or potentiate hypnotic effect.
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.
- Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.
Special populations:
- Debilitated patients: Use with caution in patients who are debilitated.
- Elderly: Use with caution in the elderly; recovery of cognitive and psychomotor functions may be slower due to pharmacokinetic differences and age related hepatic impairment.
- Excessively premedicated patients: Use with caution in patients excessively premedicated; may prolong or potentiate hypnotic effect.
Other warnings/precautions:
- Appropriate use: Administer only by IV route; avoid intra-arterial injection. Intra-arterial injection causes severe arterial spasm and intense burning pain around the injection site.
- Cumulative effect: Repeated dosing or continuous infusions may cause cumulative effects. Use of a continuous infusion increases the likelihood of overdosage, with a subsequent prolonged recovery period.
- 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.
Animal reproduction studies have not been conducted with thiopental sodium. Thiopental crosses the placenta and appears in cord blood. The pharmacokinetics of thiopental may be influenced by pregnancy (Gin, 1997; Russo, 1998); the manufacturer recommends limiting the total dose to 250 mg.
Short-acting barbiturate with sedative, hypnotic, and anticonvulsant properties. Barbiturates exert different effects on synaptic transmission, mostly those dependent on gamma-aminobutyric acid (GABA), and reversibly depress the activity of excitable tissues. In high doses, barbiturates exhibit anticonvulsant activity; barbiturates produce dose-dependent respiratory depression.
Vss: ~0.4-3.5 L/kg (Russo, 1998)
Hepatic, primarily to inactive metabolites but pentobarbital is also formed (Russo, 1998)
Urine (primary; mostly as inactive metabolites)
Anesthetic: IV: Within 30-40 seconds
20-30 minutes after a single dose
~5-22 hours (low doses; first-order elimination); ~9-50 hours (long-term infusion or high doses; Michaelis-Menten elimination) (Russo, 1998)
72% to 93% (Russo, 1998)