METHOHEXITAL SODIUM
| METHOHEXITAL SODIUM (meth-oh-hex'i-tal) Brevital Sodium Classifications: general anesthetic; barbiturate; Therapeutic: general anesthetic; barbituate Prototype: Thiopental Pregnancy Category: B Controlled Substance: Schedule IV |
Availability
500 mg, 2.5 g, 5 g powder for injection
Action
Rapid, ultra-short-acting barbiturate anesthetic agent. More potent than thiopental but has less cumulative effect and shorter duration of action, and recovery is more rapid.
Therapeutic Effect
Induces brief general anesthesia without analgesia by depression of the CNS.
Uses
Induction of anesthesia, as supplement for other anesthetics, and as general anesthetic for brief operative procedures.
Contraindications
Hypersensitivity to methohexital sodium; agranulocytosis; barbiturate hypersensitivity; hepatic encephalopathy; intraarterial administration; shock, heart failure, PVD, severe hypo- and hypertension, respiratory depression, infants <1 mo; neonates.
Cautious Use
Pregnancy (category B), labor; adrenal insufficiency, anemia, carbamazepine hypersensitivity; cardiac disease, COPD; uncontrolled asthma, status asthmaticus, sleep apnea, respiratory insufficiency, CNS depression; depression, ethanol intoxication; exfoliative dermatitis; hepatic disease; hydantoin hypersensitivity, older adult; neuromuscular disease; obesity; porphyria; pulmonary disease, renal disease, uremia, renal impairment; seizure disorders, status epilepticus, seizures; shock.
Route & Dosage
| Induction of Anesthesia Adult: IV 50–120 mg at a rate of 5 mg q5min, then 20–40 mg q4–7min prn Child/Infant: IM 6.6–10 mg/kg of 5% solution IV 1–2 mg/kg PR 20–35 mg/kg (max: 500 mg/dose) |
Administration
Intravenous
PREPARE: Direct: Prepare a 1% solution (10 mg/mL) by diluting with sterile water for injection, D5W, or NS. Use only clear, colorless solutions. Do not allow contact with rubber stoppers or parts of syringes treated with silicone because solution is incompatible with acid solutions (see IMCOMPATIBILITIES). ADMINISTER: Direct: Give 5 mg over 5–10 sec. INCOMPATIBILITIES Solution/additive: Atropine, chlorpromazine, glycopyrrolate, hydralazine, kanamycin, lidocaine, mechlorethamine, methyldopa, prochlorperazine, promazine, promethazine, streptomycin. Y-site: Fenoldopam. |
- Store drug in sterile water for injection at room temperature for at least 6 wk. Solutions prepared with isotonic NaCl injection or 5% dextrose injection are stable for ONLY about 24 h.
Adverse Effects (≥1%)
CV: Hypotension, cardiac arrhythmias, cardiac arrest. Musculoskeletal: Muscle spasm. CNS: Postoperative psychomotor impairment that persists for 24 hours, anxiety, drowsiness, emergence delirium, restlessness, and seizures. Respiratory: Bronchospasm, cough, hiccups, respiratory depression, apnea, dyspnea, respiratory arrest. Skin: Phlebitis and nerve injury adjacent to the injection site, local irritation, edema, ulceration, necrosis.Interactions
Drug: Alcohol and other cns depressants enhance CNS depression.Pharmacokinetics
Absorption: 17% absorbed PR. Distribution: Crosses CNS, placenta and excreted in breast milk. Metabolism: Oxidized in liver. Elimination: Primarily excreted in urine.Nursing Implications
Assessment & Drug Effects
- Hiccups are common, particularly with rapid injection; they sometimes persist after anesthesia.
- Keep facilities for assisting respiration and administration of oxygen readily available in the event of respiratory distress.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug