Butorphanol is an opioid analgesic that alters the response and perception of pain. It is used to treat the following conditions:

• For the management of severe pain that requires an opioid analgesic and for which other treatments are inadequate.

• Pain management during labor

• As a preoperative (pre-anesthetic medication)

• As a supplement to balanced anesthesia. 

Butorphanol Dose in Adults

Butorphanol dose for the management of Pain:

• 2 mg intramuscular.
• The dose may be repeated every 3 - 4 hours if needed to the usual dose of 1 - 4 mg every 3 - 4 hours as needed OR
• 1 mg intravenous every 3 - 4 hours as needed to the usual range of 0.5 - 2 mg every 3 - 4 hours as needed OR
• Intranasal (spray):
  • One spray (equivalent to 1 mg per spray) in one nostril.
  • An additional one spray in one nostril may be given if adequate pain relief is not achieved.

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Discontinuation of therapy:

• The drug should be very slowly tapered off to prevent withdrawal symptoms.
• Some experts recommend reducing the dose by 10% per week.
• The patient should be monitored for clinical features of withdrawal. Clonidine may be added to blunt the withdrawal symptoms. For the relief of pain, alternative non-opioid analgesics should be used.

Use as a Preoperative medicine:

• 2 mg intramuscular 60 - 90 minutes before surgery

Dose during anesthesia (as a Supplement to balanced anesthesia):

• 2 mg intravenous before induction or an incremental dose of 0.5 - 1 mg (up to 0.06 mg/kg).

Dose in Pain during labor as an alternative agent (fetus more than 37 weeks gestation and no signs of fetal distress):

• 1 to 2 mg intravenous or intramuscular four hours apart.

Butorphanol Dose in Children

Not recommended.

Pregnancy Risk Factor C

• Butorphanol passes the placental barrier
• It can be used to manage pain during labor.
• It is important to monitor the child for signs of apnea or respiratory distress.
• If a fetal heartbeat is abnormal, it should be taken with caution.

[US Boxed Warning]

• With prolonged opioid use during pregnancy, neonatal withdrawal syndrome may occur.
• A child might present with autonomic symptoms such as fever, temperature instability and vomiting, diarrhea, vomiting or poor nutrition & weight gain.
• Neurologic features include high pitch crying, increased muscle tone, irritability and seizure.

Butorphanol during breastfeeding:

• Breastmilk can contain a small amount of the drug.
• Manufacturers recommend that you weigh the benefits and risks of using the drug.
• If used while breastfeeding, it is important to monitor the child for sedation or apnea.

Butorphanol Dose in Renal Disease:

• Intramuscular:
  • 1 mg 6 hourly as and when required.
• Intravenous:
  • 0.5 mg based on the patients' response. The dose may be required after 6 hours if required.
• Nasal spray:
  • One spray (equivalent to 1 mg per spray) in one nostril.
  • The dose may be repeated after 90 to 120 minutes if needed, however, repeat dosing should be generally given 6 hours apart.

Butorphanol Dose in Liver Disease:

• Intramuscular:
  • 1 mg 6 hourly as and when required.
• Intravenous:
  • 0.5 mg based on the patients' response. The dose may be required after 6 hours if required.
• Nasal spray:
  • One spray (equivalent to 1 mg per spray) in one nostril.
  • The dose may be repeated after 90 to 120 minutes if needed, however, repeat dosing should be generally given 6 hours apart.

Common Side Effects Of Butorphanol Include:

• Central nervous system:
  • Drowsiness
  • Dizziness
  • Insomnia
• Gastrointestinal:
  • Nausea and vomiting
• Respiratory:
  • Nasal congestion

Less Common Side Effects Of Butorphanol Include:

• Cardiovascular:
  • Palpitations
  • Vasodilatation
• Central nervous system:
  • Anxiety
  • Burning sensation
  • Confusion
  • Euphoria
  • Floating feeling
  • Headache
  • Lethargy
  • Nervousness
  • Paresthesia
• Dermatologic:
  • Cold and clammy skin
  • Diaphoresis
  • Pruritus
• Gastrointestinal:
  • Anorexia
  • Constipation
  • Stomach pain
  • Unpleasant taste
  • Xerostomia
• Neuromuscular & skeletal:
  • Tremor
  • Weakness
• Ophthalmic:
  • Blurred vision
• Otic:
  • Otalgia
  • Tinnitus
• Respiratory:
  • Bronchitis
  • Cough
  • Dyspnea
  • Epistaxis
  • Nasal discomfort
  • Pharyngitis
  • Rhinitis
  • Sinus congestion
  • Sinusitis
  • Upper respiratory tract infection

Contraindication to Butorphanol include:

• Allergy to butorphanol (including anaphylaxis), or any component of formulation
• Acute severe bronchial asthma
• Respiratory depression
• Gastrointestinal obstruction including paralytic ileus.

Warnings and Precautions

• CNS depression:
  • It can cause CNS depression.
  • Therefore, people who perform tasks that require mental alertness, such as operating heavy machinery, should be cautious with the drug.
• Hypotension
  • Hypovolemia in patients with cardiovascular diseases such as myocardial Infarction or other drugs that can cause diuresis and hypotension could increase the hypotensive effects on butorphanol.
• Phenanthrene hypersensitivity:
  • Hypersensitivity reactions to opioid agonists such as codeine, hydromorphone and oxycodone should be notified.
• Respiratory depression [US Boxed Warning]
  • Opioids can cause life-threatening respiratory depression.
  • Opioid-induced respiratory depression may be exacerbated by concurrent use of sedatives.
• Conditions abdominales:
  • It can make it difficult to diagnose patients with acute abdominal conditions.
• Adrenocortical Insufficiency
  • Long-term use is associated with secondary hypogonadism and adrenal insufficiency resulting in sexual dysfunction, infertility, osteoporosis, and mood disorders.
• Insufficiency of the biliary tract:
  • Opioids can cause constriction in the sphincter Oddi. 
  • You should be cautious with Opioids in cases of pancreatitis or biliary tract dysfunction.
• Cardiovascular disease
  • Patients with acute myocardial infarction, coronary insufficiency, or ventricular dysfunction should be advised the drug only when benefits clearly outweigh the risks.
• CNS depression and coma
  • Patients who are coma- or impaired conscious may be at high risk for carbon dioxide retention.
• Delirium tremens:
  • Patients suffering from delirium tremens must be cautious when taking the drug.
• Head trauma
  • It can cause an increase of intracranial pressure.
  • Patients with intracranial lesion, head injury or elevated intracranial tension should not use it.
• Hepatic impairment
  • Patients with hepatic impairment are advised to use the drug with caution. Dose adjustment is highly recommended.
• Mental health conditions
  • Patients suffering from psychiatric disorders like anxiety, depression, or post-traumatic stress disorder are more at risk of opioid overdose.
  • Therefore, it is important to monitor such patients regularly.
• Obesity:
  • Patients suffering from morbid obesity should be informed about the dangers of taking this drug.
• Prostatic hyperplasia, urinary stricture
  • It can cause urinary retention. Patients with prostatic hyperplasia or urinary stricture should not use it.
• Psychosis:
  • Patients suffering from psychosis should be cautious when taking the drug.
• Renal impairment
  • Patients with impaired renal function should be cautious when using it. Adjustment of the dose is advised.
• Respiratory disease
  • Patients at high risk for respiratory failure such as cor pulmonale and chronic obstructive lung disease (cor pulmonale) should be advised to avoid the drug.
  • These patients should consider alternative therapies.
• Seizures:
  • Patients with seizure disorders should not use it.
• Serotonin syndrome:
  • Serotonin syndrome can be fatal in patients who have been taking butorphanol and other serotonergic drugs, such as SSRIs and SNRIs.
  • Serotonin syndrome symptoms should be closely monitored in patients
    • Mental status changes
      • Agitation, delirium, hallucination, coma, and seizures.
    • Autonomic features
      • Tachycardia, excessive sweating, and labile blood pressure
    • Neuromuscular changes:
      • Myoclonus, rigidity and tremors
    • Gastrointestinal symptoms:
      • Nausea, vomiting, diarrhea.
• Sleep-disordered breathing
  • Patients with severe or chronic conditions such as obesity, heart disease, and sleep-related breathing problems should be cautious about taking the drug.
• Thyroid dysfunction:
  • Patients suffering from thyroid dysfunction should be cautious when taking the drug.

Butorphanol: Drug Interaction

Monitor:

• Pain symptoms
• Respiratory drive
• Mental status
• Blood pressure
• Bowel function
• Clinical features  of addiction, abuse, or misuse
• Clinical features of hypogonadism or hypoadrenalism.
• Evaluate the benefits and risks every 3 months

How to administer Butorphanol?

• Intranasal:
  • Prime the pump prior to the first use and if not used for more than 48 hours by striking one to two sprays in the air. Avoid spraying on self or others.
• Parenteral:
  • It may be administered as a slow intravenous or a deep intramuscular injection.

Mechanism of action of Butorphanol:

• It acts as a partial agonist and a kappa (partial agonist), receptor agonist in CNS.
• It causes analgesia, alters pain perception and response. 
• It can also cause respiratory depression and sedation, just like other opioids.

TheStart of actionThe time between intramuscular administration and nasal administration is approximately 15 minutes. Peak effects are seen within 0.5 to 1 hour following intramuscular preparations and intravenous preparations, and between 1 and 2 hours after nasal preparations.

It has been aDuration of actionAfter the Intramuscular or Intravenous injections, and between 3 and 4 hours and 4 and 5 hours after nasal administration, you will notice a difference. It's fast and well.absorbedIt is 80%Proteins boundIt is. It isMetabolizedIt is found in the liver and has bioavailability between 60 and 70% when administered through the nasal route. It has been ahalf-life eliminationPatients with renal impairment have a waiting time of between 2 and 9 hours.

This is extended to 3 to 9 hours for patients with renal impairment, and 16.8 hours for patients with hepatic impairment.

TheTime to reach plasma peak concentrationIt takes between 20 and 40 minutes to complete the intramuscular administration. It takes 30 to 60 minutes for the nasal administration. It isexcretedPrimarily via urine

International Brands of Butorphanol:

• Beforal
• Bunol
• Butaro
• Butodol
• Butophan
• Butrum
• Moradol
• Nuo
• Yang
• Orfadol
• Stadol
• Verstadol
• Ziphanol

Butorphanol brands in Pakistan: