Methohexital Sodium (methohexital sodium)

Dosage of methohexital sodium is highly individualized, and the drug should be administered only by those completely familiar with its quantitative differences from other barbiturate anesthetics. Dosage of the drug is expressed in terms of the sodium salt.

In addition, dosage of induction anesthetics should be adjusted according to response, age, weight, gender, physical and clinical status, underlying pathologic conditions (e.g., shock, intestinal obstruction, malnutrition, anemia, burns, advanced malignancy, ulcerative colitis, uremia, alcoholism), and the type and amount of premedication or concomitant medication(s). Dosages of the drug also should be titrated to clinical effect.

No dosing information is available for this tab.

No dosing information is available for this tab.

No dosing information is available for this tab.

The CNS depressant effect of methohexital sodium may be additive with that of other CNS depressants, including alcohol and propylene glycol. Prior chronic administration (e.g., for seizure disorder) of barbiturates or phenytoin appears to reduce efficacy of methohexital sodium.

Concomitant use of barbiturates may affect absorption and elimination of several drugs (e.g., phenytoin, halothane, anticoagulants, corticosteroids, alcohol, solutions containing propylene glycol).

There are no contraindication interactions for this drug.

Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

Agents That May Cause Respiratory Depression/Sodium Oxybate

SEVERITY LEVEL: 2-Severe Interaction: Action is required to reduce the risk of severe adverse interaction.

MECHANISM OF ACTION: Oxybate by itself may be associated with severe somnolence or respiratory depression. Concurrent use with other CNS depressants may further increase the risk for respiratory depression or loss of consciousness.(1-3)

CLINICAL EFFECTS: Concurrent use of sodium oxybate and sedative hypnotics or alcohol may further increase the risk for profound sedation, respiratory depression, coma, and/or death.(1,2) Fatalities have been reported.(3)

PREDISPOSING FACTORS: Based upon FDA evaluation of deaths in patients taking sodium oxybate, risk factors may include: use of multiple drugs which depress the CNS, more rapid than recommended oxybate dose titration, exceeding the maximum recommended oxybate dose, and prescribing for unapproved uses such as fibromyalgia, insomnia or migraine. Note that in oxybate clinical trials for narcolepsy 78% - 85% of patients were also receiving concomitant CNS stimulants.(1-3)

PATIENT MANAGEMENT: Avoid use of concomitant opioids, benzodiazepines, sedating antidepressants, sedating antipsychotics, general anesthetics, or muscle relaxants, particularly when predisposing risk factors are present. If combination use is required, dose reduction or discontinuation of one or more CNS depressants should be considered. If short term use of an opioid or general anesthetic is required, consider interruption of sodium oxybate treatment.(1,2) Respiratory depression can occur at any time during opioid therapy, especially during therapy initiation and following dosage increases. The risk of opioid-related overdose or overdose-related death is increased with higher opioid doses, and this risk persists over the course of therapy. Consider these risks when using concurrently with other agents that may cause CNS depression.(4) Discuss opioid reversal agents (e.g., naloxone, nalmefene) with all patients when prescribing or renewing an opioid analgesic or medicine to treat opioid use disorder (OUD). Consider prescribing an opioid reversal agent (e.g., naloxone, nalmefene) to patients prescribed medicines to treat OUD or opioid analgesics who are at increased risk of opioid overdose (such as those taking CNS depressants) and when a patient has household members/close contacts at risk for accidental overdose. Discuss the options for obtaining an opioid reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program).(5)

DISCUSSION: The FDA evaluated sodium oxybate postmarket fatal adverse event reports from the FDA Adverse Event Reporting System(AERS)and from the manufacturer. Although report documentation was not always optimal or complete, useful information was obtained. Factors which may have contributed to fatal outcome: concomitant use of one or more drugs which depress the CNS, more rapid than recommended oxybate dose titration, exceeding the maximum recommended oxybate dose, and prescribing for unapproved uses such as fibromyalgia, insomnia or migraine. Many deaths occurred in patients with serious psychiatric disorders such as depression and substance abuse. Other concomitant diseases may have also contributed to respiratory and CNS depressant effects of oxybate.(3)

Moderate Interaction: Assess the risk to the patient and take action as needed.

Anesthesia Agents/Glp-1 Receptor Agonists

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: GLP-1 receptor agonists can cause delayed gastric emptying.(1,2)

CLINICAL EFFECTS: Gastric contents may remain in the stomach after preoperative fasting, which could increase the risk of regurgitation and aspiration.(1,2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The American Society of Anesthesiologists (ASA) recommends the following for patients receiving elective procedures: - For patients on daily dosing, consider holding GLP-1 agonists on the day of the procedure. For patients on weekly dosing, consider holding GLP-1 agonists a week prior to the procedure. - Consult an endocrinologist for patients taking GLP-1 agonists for diabetes management if the GLP-1 agonist is held longer than the dosing schedule to avoid hyperglycemia. - For patients requiring urgent or emergent procedures, proceed and treat the patient as 'full stomach.'(3)

DISCUSSION: In one case report, a 31-year-old patient taking semaglutide followed preoperative fasting guidelines but food residue was discovered upon endoscopy, leading to cancellation of the surgical procedure.(4) In a case report, a semaglutide-treated patient experienced regurgitation upon induction of general anesthesia despite a 20 hour preoperative fasting period. The patient received semaglutide two days before the scheduled procedure.(5) A case report of a 42-year-old patient after fasting for 18 hours showed substantial gastric content upon endoscopy. The patient experienced intraoperative pulmonary aspiration of gastric contents which were suctioned from the trachea and bronchi using bronchoscopy.(6)

There is no enhanced messaging for this drug.

• Porphyria

• Hypotension
• Severe hepatic disease
• Shock
• Status asthmaticus

• Chronic heart failure
• Chronic obstructive pulmonary disease
• Focal epilepsy
• Kidney disease with reduction in glomerular filtration rate (GFr)
• Morbid obesity
• Severe anemia
• Severe uncontrolled hypertension

There is no enhanced messaging for this drug.

Less Frequent

• Dyspnea
• Respiratory depression
• Thrombophlebitis

Rare or Very Rare

• Abnormal hepatic function tests
• Acute respiratory failure
• Anaphylaxis
• Apnea
• Bronchospastic pulmonary disease
• Cardiac arrest
• Hypotension
• Radial nerve palsy
• Seizure disorder
• Vasodilation of blood vessels

Less Frequent

• Cough
• Hiccups
• Muscle fasciculation

Rare or Very Rare

• Acute abdominal pain
• Chills
• Delirium
• Drowsy
• Erythema
• Headache disorder
• Injection site sequelae
• Laryngismus
• Nausea
• Pruritus of skin
• Rhinitis
• Sialorrhea
• Tachycardia
• Vomiting

No enhanced messaging available.

No enhanced messaging available.

Reproduction studies in rabbits and rats using methohexital sodium doses 4 and 7 times the usual human dose, respectively, have not revealed evidence of harm to the fetus. The manufacturer states that although the drug has been used in women undergoing delivery by cesarean section, it should be considered that methohexital readily and rapidly crosses the placenta. There are no adequate and controlled studies to date using methohexital sodium in pregnant women, and the drug should be used during pregnancy only when clearly needed.

Based on animal data, repeated or prolonged use of general anesthetics and sedation drugs, including methohexital sodium, during the third trimester of pregnancy may result in adverse neurodevelopmental effects in the fetus. The clinical relevance of these animal findings to humans is not known; the potential risk of adverse neurodevelopmental effects should be considered and discussed with pregnant women undergoing procedures requiring general anesthetics and sedation drugs. (See Cautions: Pediatric Precautions.)

Because barbiturates are distributed into milk, the drug should be used with caution in nursing women.

No enhanced messaging available.