methohexital

CV: CARDIORESPIRATORY ARREST, hypotension

Derm: erythema, pruritus, urticaria

EENT: rhinitis

GI: abdominal pain, hiccups, nausea, salivation, vomiting

Local: pain at IM site, phlebitis at IV site

MS: muscle twitching

Neuro: anxiety, emergence delirium, headache, restlessness, SEIZURES

Resp: APNEA, bronchospasm, coughing, dyspnea, LARYNGOSPASM, respiratory depression

Misc: shivering, allergic reactions

Interactions ⬆ ⬇

Drug-drug:

Additive CNS depression with alcohol, antihistamines, opioid analgesics, and sedative/hypnotics.

Drug-Natural Products:

St. John's wort may affect methohexital levels and effectiveness; avoid use.
Concomitant use of kava, valerian, skullcap, chamomile, or hops can ↑ CNS depression.

Route/Dosage ⬆ ⬇

IV (Adults ): Induction: 1–1.5 mg/kg. Maintenance: 20–40 mg every 4–7 min as intermittent doses or 3 mL of a 0.2% solution/min.
IM (Children >1 mo): Induction: 6.6–10 mg/kg of a 5% solution.
Rect (Children >1 mo): Induction: 25 mg/kg using a 1% solution.

Availability ⬆ ⬇

Powder for injection: 500 mg/vial

Assessment ⬆ ⬇

Assess BP, ECG, heart rate, and respiratory status continuously throughout methohexital therapy. Methohexital should be used only by individuals qualified to administer anesthesia and experienced in endotracheal intubation. Equipment for this procedure should be immediately available. Apnea may occur immediately after IV injection, especially in the presence of opioid premedication.
Monitor IV site carefully. Extravasation may cause pain, swelling, ulceration, and necrosis. Intra-arterial injection may cause arteritis, vasospasm, edema, thrombosis, and gangrene of the extremity.

Toxicity and Overdose:

Overdose may occur from rapid injection (drop in BP, possibly to shock levels) or excessive or repeated injections (respiratory distress, laryngospasm, apnea).

Implementation ⬆ ⬇

Do not confuse Brevital with Brevibloc.
- Dose is individualized according to depth of anesthesia desired; concurrent use of other medications and/or nitrous oxide; patient’s condition, age, weight, and sex.
- Geriatric patients may require smaller doses than young patients. Tolerance may develop with repeated use, such as for burns. Individuals tolerant to alcohol or barbiturates may require higher doses.
IM: Reconstitution: Reconstitute 500 mg vial with 10 mL sterile water of injection (preferred) or 0.9% NaCl. No further dilution is needed.

IV Administration:

IV: Repeated doses or continuous infusion of methohexital may cause prolonged somnolence and respiratory and circulatory depression. If the patient requires a second anesthetic in the same day, reduction in the dose of methohexital may be required.
- Methohexital may be given in doses sufficient to produce deep surgical anesthesia, but such doses may cause dangerous respiratory and circulatory depression.
- Premedication with anticholinergics (atropine, glycopyrrolate) may be used to decrease mucous secretions. Opioid analgesics may be administered preoperatively to enhance the poor analgesic effects of methohexital. Preoperative medications should be given so that peak effect is attained shortly before induction of anesthesia. Muscle relaxants, if required, should be administered separately.
IV Push: Diluent: Only use bacteriostatic-free diluents. Reconstitution: Reconstitute 500 mg vial with 50 mL of sterile water for injection (preferred), D5W, or 0.9% NaCl.Concentration: 10 mg/mL (1% solution). Solution should be freshly prepared and used within 24 hr of reconstitution. Refrigerate and keep sealed. Do not administer solution containing a precipitate.
Rate: Induction dose is administered at a rate not to exceed 1 mL (10 mg) over 5 sec.
Continuous Infusion: Reconstitution: To prepare a 0.2% solution (2 mg/mL, reconstitute each 500 mg vial with 15 mL of sterile water for injection. Initial solution will be yellow. Diluent: Further dilute the 500 mg vial in 250 mL of D5W or 0.9% NaCl.Concentration: 10 mg/mL (1% solution). Solution should be used only if clear and colorless.
- Diluent: To prepare a 0.2% solution, dilute 500 mg in 250 mL of D5W or 0.9% NaCl. To avoid hypotonicity, do not dilute with sterile water.Concentration: 0.2% solution.
- Solution is stable for 24 hr.
Rate: Anesthesia is maintained by intermittent injections every 4–7 min or by continuous infusion.
Y-Site Compatibility:
- acyclovir
- aminocaproic acid
- aminophylline
- atropine
- azithromycin
- bivalirudin
- bleomycin
- calcium chloride
- calcium gluconate
- carboplatin
- chloramphenicol
- chlorothiazide
- cisplatin
- cyclophosphamide
- cytarabine
- dactinomycin
- dexamethasone
- dexmedetomidine
- digoxin
- erythromycin
- etoposide
- fludarabine
- fluorouracil
- furosemide
- heparin
- hydrocortisone
- hydromorphone
- ifosfamide
- isoproterenol
- methotrexate
- milrinone
- mitoxantrone
- octreotide
- paclitaxel
- pantoprazole
- phenobarbital
- phentolamine
- potassium chloride
- procainamide
- propranolol
- tigecycline
- tirofiban
- vasopressin
- vinblastine
- vincristine
- voriconazole
Y-Site Incompatibility:
- alemtuzumab
- chlorpromazine
- dacarbazine
- daunorubicin hydrochloride
- doxorubicin hydrochloride
- epirubicin
- eptifibitide
- etoposide phosphate
- gemtuzumab ozogamicin
- hydralazine
- idarubicin
- irinotecan
- methadone
- mitomycin
- nicardipine
- ondansetron
- promethazine
- rocuronium
- topotecan
- vecuronium
- vinorelbine

Patient/Family Teaching ⬆ ⬇

Methohexital may cause psychomotor impairment for 24 hr after administration. Caution patient to avoid driving or other activities requiring alertness for 24 hr.
Advise patient to avoid use of alcohol or other CNS depressants, including opioids, for 24 hr after anesthesia, unless directed by health care professional.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding. May cause dose-related fetal heart rate slowing and newborn sedation. These effects can be minimized by using low doses (0.5–1.0 mg/kg).

Evaluation/Desired Outcomes ⬆ ⬇

Loss of consciousness.
Maintenance of desired level of anesthesia without complications.

US Brand Names ⬆ ⬇

Contr. Subst. Schedule ⬆ ⬇

Code ⬆

NDC Code

23155- Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.
- 23155-893- Methohexital Sodium
  - 23155-893-31- 1 VIAL in 1 CARTON (23155-893-31) / 500 mg in 1 VIAL

42023- Endo USA, Inc.
- 42023-105- Brevital Sodium
  - 42023-105-01- 1 VIAL in 1 CARTON (42023-105-01) / 1 INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION in 1 VIAL

72643- Solara Active Pharma Sciences Limited
- 72643-021-
  - 72643-021-04- 25 kg in 1 DRUM (72643-021-04)

72643- Solara Active Pharma Sciences Limited
- 72643-021-
  - 72643-021-05- 50 kg in 1 DRUM (72643-021-05)

83270- ONESOURCE SPECIALTY PHARMA LIMITED
- 83270-003- Methohexital Sodium
  - 83270-003-01- 500 mg in 1 VIAL (83270-003-01)

ROUTE	ONSET	PEAK	DURATION
IV	within 60 sec	unknown	5–7 min
IM‡	2–10 min	unknown	unknown

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇

Time/Action Profile ⬆ ⬇

Contraind./Precautions ⬆ ⬇

Adv. Reactions/Side Effects ⬆ ⬇