butorphanol

Action and Spectrum

Actions and Spectrum:

butorphanol acts as partial agonist at the mu-opioid receptor, and antagonist at the kappa-opioid receptor.

Drug Interaction

Adverse Reaction

>10%:

Sedation (43%)

Nasal congestion (13%)

Dizziness (19%)

Insomnia (11%)

Nausea and/or vomiting (13%)

1-10%:

Anxiety

Anorexia

Bronchitis

Constipation

Dizziness

Dyspnea

Epistaxis

Floating feeling

Lethargy

Headache

Sinusitis

Tinnitus

URI

Tremor

Vasodilation

<1%:

Bradycardia

Apnea

Chest Pain

Tachycardia

Respiratory depression

Black Box Warning

Contraindication / Caution

Contraindication/Caution:

Contraindications:

• Hypersensitivity to the drug
• Respiratory depression, especially in patients with compromised respiratory function
• Severe liver or kidney disease
• Head injury or increased intracranial pressure
• Seizure disorders
• Patients in shock or coma
• Alcohol or sedative use

Cautions:

• Obesity
• Chronic obstructive pulmonary disease (COPD)
• Sleep apnea
• Myasthenia gravis
• Pancreatitis
• Prostatic hypertrophy
• Urinary retention
• Dehydration
• Adrenal insufficiency

Pregnancy / Lactation

Pregnancy consideration:

Category C, if used prolongedly, may fall in category D

Breastfeeding warnings:

The drug is excreted in breast milk.

Pregnancy category:

Category A: well-controlled and Satisfactory studies do not show risk to the fetus in the first/later trimester.

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Category N: No data is available for the drug under this category.

Pharmacology

Pharmacology:

butorphanol is a synthetic, opioid agonist-antagonist medication with pharmacological effects like those of other opioid drugs.

Pharmacodynamics:

The pharmacodynamics of butorphanol involves its interaction with specific opioid receptors in the CNS, including the mu-opioid receptors and the kappa-opioid receptors.

As a partial agonist at the mu-opioid receptor, butorphanol binds to these receptors. It produces pain relief, sedation, and feelings of relaxation, like other opioid drugs.

As an antagonist, butorphanol also reduces the effects of other opioid drugs that bind to these receptors. This can help to mitigate the risk of respiratory depression, a potentially life-threatening side effect associated with the use of high-potency opioid drugs.

Pharmacokinetics:

• Absorption: butorphanol is rapidly absorbed after oral, intranasal, or intravenous administration, with peak plasma concentrations occurring within 30 minutes to 1 hour. Intranasal administration results in rapid and high plasma concentrations, while oral administration results in lower and slower absorption.
• Distribution: butorphanol has a moderate volume of distribution, with the drug distributing into most body tissues, including the central nervous system.
• Metabolism: butorphanol is metabolized primarily in the liver by the cytochrome P450 (CYP) system, specifically CYP3A4, and CYP2D6.
• Elimination: The elimination half-life of butorphanol ranges from 2 to 4 hours, with the drug being eliminated primarily in the urine as metabolites.

Adminstartion

Administration:

butorphanol is an opioid medication typically administered by injection or nasal spray. The injection form is given intramuscularly (into a muscle) or intravenously (into a vein). The nasal spray form is given intranasally (into the nose).

The dose and route of administration of butorphanol may vary depending on the medical condition being treated and the individual’s response to the medication. Do not exceed the recommended dose.

Patient Information Leaflet

Patient information leaflet

Generic Name: butorphanol

Pronounced: bue-TOR-fa-nol

Why do we use butorphanol?

butorphanol is a synthetic opioid that is used primarily for pain management and anesthesia. It acts as a mixed agonist-antagonist at opioid receptors in the brain and spinal cord. This means it has both agonist (activating) and antagonist (blocking) effects at different opioid receptors.

butorphanol is used for:

• Pain relief: Alleviates moderate to severe pain by binding to opioid receptors and reducing pain signals in the central nervous system.
• Anesthesia: Used as a pre-anesthetic medication or in combination with other anesthetics to enhance sedation and reduce the required amount of anesthetic agents during medical procedures.
• Migraine treatment: Sometimes prescribed as a nasal spray for acute migraines when other medications are insufficient. It may manage migraines through effects on opioid receptors and anti-inflammatory properties.
• Sedation: Induces sedation in specific medical situations or for procedural sedation, thanks to its analgesic and sedative properties.