Butorphanol

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Butorphanol

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Method of action: Analgesic, Antitussive, Sedative

Treatment option: Pain

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Butorphanol

What is Butorphanol?

Butorphanol is a synthetic analgesic medication belonging to the opioid agonist-antagonist group. It is primarily used for the management of pain and is chemically derived from the morphinan series. By interacting with specific receptors in the central nervous system, it alters the perception of pain and the emotional response to it.

Mechanism of Action

The medication works through a dual action on opioid receptors. It acts as a partial agonist or antagonist at the mu (μ) opioid receptors and as an agonist at the kappa (κ) opioid receptors. This specific pharmacological profile distinguishes it from pure opioid agonists. The activation of kappa receptors contributes to the relief of pain, while its interaction with mu receptors can provide analgesia with a different profile of effects compared to traditional opioids.

Common Applications

Butorphanol is utilized in various clinical settings where pain management is required. Its applications include:

  • Management of Acute Pain: It is often used for the relief of moderate to severe pain, such as pain following surgical procedures.
  • Obstetric Care: The medication is sometimes employed for pain relief during labor.
  • Migraine Management: In certain formulations, it is used to address the intense pain associated with severe migraine headaches when other treatments have not been effective.
  • Preoperative Sedation: It may be used as a supplement to balanced anesthesia to provide sedation and pain control before or during medical procedures.

Available Forms

Because butorphanol is poorly absorbed when taken orally due to significant metabolism in the liver, it is typically administered through routes that bypass the digestive system. These include:

  • Intranasal Spray: A common form for outpatient migraine management.
  • Injectable Solution: Used primarily in hospital settings for intravenous or intramuscular administration.

What side effects are possible with Butorphanol?

Possible side effects and safety information

The safety profile of Butorphanol, as detailed in official regulatory documents, is structured around frequency-classified adverse reactions, effects on specific physiological systems, and documented serious risks.

Officially Documented Adverse Reactions

The most commonly reported adverse reactions involve the Central Nervous System (CNS) and the gastrointestinal tract. Regulatory frequency classifications indicate that effects such as somnolence and dizziness are often categorized as Very Common, while nausea, vomiting, and headache are typically categorized as Common. Adverse reactions are grouped by System-Organ Class, affecting the Nervous System (e.g., confusion, lethargy), Gastrointestinal System (e.g., constipation, dry mouth), and Cardiovascular System (e.g., hypotension, palpitations).

Serious Safety Risks and Regulatory Constraints

Official labeling emphasizes the risk of life-threatening respiratory depression, which is considered the most serious adverse reaction. This risk is documented to be greatest when treatment is initiated or following a dosage increase. Butorphanol is also associated with the risk of Opioid Use Disorder (addiction, abuse, and misuse) and the potential for physical dependence with repeated administration.

Population-Specific Safety Notes

The regulatory profile includes safety considerations for specific groups. Older adults may exhibit greater sensitivity to the effects of the medicine, and dose selection requires caution. Patients with hepatic or renal impairment may experience reduced clearance, leading to prolonged exposure. Furthermore, the medicine is contraindicated in individuals with significant pre-existing respiratory depression or known hypersensitivity to Butorphanol, defining key safety limitations for its use.

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory documentation for butorphanol emphasizes the risk of serious and life-threatening overdose, which primarily involves severe central nervous system (CNS) and respiratory depression. The most critical manifestation is life-threatening or fatal respiratory depression.

Overdose may present with profound sedation, coma, and in high intravenous doses, narcosis. Documented clinical signs may include changes such as pinpoint pupils (miosis) or marked mydriasis due to secondary hypoxia.

Overdose Manifestation Action Required by Regulation
Life-threatening respiratory depression Seek immediate medical attention
Suspected or known overdose Call 911 or get emergency medical help right away

The official labeling notes that accidental exposure of even one dose, particularly in a child, can result in a fatal overdose. Treatment of severe butorphanol overdose focuses on symptomatic and supportive measures, including maintaining ventilation and protecting the patient's airways. Naloxone, a specific opioid antagonist, is documented as the agent used to reverse the respiratory depression. Due to the drug's characteristics, the duration of respiratory depression may be prolonged, requiring continued close observation.

Therapeutic Uses of Butorphanol

What Butorphanol treats: main uses and benefits

Butorphanol is generally applied in clinical settings for symptoms related to physical discomfort that require additional therapeutic support. The medication provides supportive relief when symptoms create noticeable physiological strain and is applied in scenarios where additional management of discomfort is required.

It is commonly used to address pronounced acute pain in conditions characterized by periods of heightened symptoms, such as post-operative recovery, pain from renal or ureteral colic, and the severe pain of an acute migraine attack. The medication also plays a role in specialized contexts, including use as an adjunct for balanced anesthesia, and is relevant for easing symptoms that become more disruptive during the phases of early active labor.

The therapeutic relevance is aligned with: “The medication supports the process of easing pronounced symptoms related to physical discomfort in critical situations.” Butorphanol may assist with managing symptoms that create noticeable functional strain.

Therapeutic Focus: Acute Symptom Support
Target Symptom Level Moderate-to-severe pain
Common Clinical Contexts Post-surgical, acute episodic pain, labor
Supportive Benefit Supports easing the overall symptom burden

Regulatory References

  1. DailyMed NIH Labeling for Butorphanol Tartrate Injection

Eligibility and Restrictions for Use

Eligibility Profile: Who Can and Cannot Use Butorphanol

The eligibility profile for Butorphanol is strictly defined by regulatory documents to mitigate risks, primarily focusing on respiratory function and drug clearance. Use is contraindicated (absolutely prohibited) for patients with a known hypersensitivity to butorphanol, acute or severe bronchial asthma, significant respiratory depression, or a known or suspected gastrointestinal obstruction (e.g., paralytic ileus).


Eligibility Status by Population

Population Group Regulatory Status
Pediatric Patients (<18 years) Not Established/Not Recommended. Safety and efficacy are not established in this population.
Older Adults (Geriatric) Use with Caution. Dose selection must be cautious, typically starting at the low end of the dosing range.
Hepatic or Renal Impairment Conditional Use. Requires a reduced initial dose and extended repeat dose intervals due to impaired drug clearance.
Pregnancy/Lactation Restricted/Not Recommended. Prolonged use in pregnancy can lead to Neonatal Opioid Withdrawal Syndrome. Excreted into human milk, requiring infant monitoring.

Butorphanol is generally allowed for adult patients (18 years and older) who do not possess any of the contraindications or high-risk conditions. Patients with pre-existing conditions like chronic pulmonary disease or a history of substance abuse require additional caution and monitoring.

What should I know about interactions with other medicines?

Interactions with Other Medicines and Products

Official regulatory documents require attention to several significant medication interactions with Butorphanol, primarily due to its central nervous system effects and its mixed opioid agonist/antagonist activity.


Key Interaction Categories

Interacting Product Category Regulatory Constraint/Basis
Monoamine Oxidase Inhibitors (MAOIs) Contraindicated: Should not be used in patients who have received an MAOI within the last 14 days due to the risk of severe, unpredictable reactions.
CNS Depressants Additive Effect: Co-administration with alcohol, sedatives, hypnotics, general anesthetics, tranquilizers, or other opioids may result in profound additive CNS depressant effects.
Serotonergic Drugs Risk of Serotonin Syndrome: Concurrent use with medicines that affect the serotonergic neurotransmitter system (e.g., SSRIs, SNRIs, triptans) may increase the risk of Serotonin Syndrome.
Pure Opioid Agonists Precipitation of Withdrawal: Use in patients physically dependent on pure opioid agonists may precipitate an acute opioid withdrawal syndrome due to Butorphanol's antagonist action.

Additional Constraints

Butorphanol may reduce the efficacy of diuretics, such as thiazides and loop diuretics. Concomitant use with anticholinergics or medicines possessing anticholinergic activity (e.g., some antihistamines or antipsychotics) may increase the risk of severe constipation or urinary retention. These interactions necessitate careful patient monitoring and management to mitigate potential risks.

Mechanism of Action

How Butorphanol Works: Opioid Receptor Modulation


Kappa-Opioid Receptor (kappa-OR) Agonism

Butorphanol acts as a full agonist at the kappa-opioid receptors (kappa-OR) primarily located in the central nervous system, particularly within the spinal cord. Activation of these G-protein coupled receptors inhibits adenylate cyclase activity and modulates ion channel conductance. This action restricts the release of pro-nociceptive neurotransmitters, modifying early molecular steps that shape systemic physiological outcomes and resulting in the modulation of enhanced physiological signaling.


Mu-Opioid Receptor (mu-OR) Partial Agonism/Antagonism

The drug is pharmacologically classified as a mixed agonist-antagonist, exhibiting either partial agonist or antagonist activity at the mu-opioid receptors (mu-OR). This dual activity engages distinct mechanisms that regulate specific overactive processes, affecting systems where mu-receptor-mediated transmitters dominate. This leads to predictable physiological adjustments that modify the downstream effects of elevated mediator concentrations associated with full mu-OR agonism.

Dosage and Administration Information

How to Use Butorphanol: Administration Guidelines

This section outlines the administration methods and dosing constraints for Butorphanol.

Administration Routes and Standard Dosing

Butorphanol is used via parenteral (Intravenous (IV) and Intramuscular (IM)) and intranasal (IN) routes. The administration schedule is typically as-needed (PRN) for pain.

Route Standard Single Dose (Adult) Frequency
Intravenous (IV) 1 mg (range 0.5 mg to 2 mg) Every 3 to 4 hours
Intramuscular (IM) 2 mg (range 1 mg to 4 mg) Every 3 to 4 hours
Intranasal (IN) 1 mg (one spray) or 2 mg (severe pain) Every 3 to 4 hours

Administration Procedures and Special Instructions

Specific protocols govern the use of each dosage form:

  • Intranasal Spray: The device must be primed before the first use by actuating (pumping) until a fine spray appears. If unused for 48 hours or longer, it must be re-primed. For an initial 2 mg intranasal dose, patients should remain recumbent (lying down) immediately following administration.
  • Intravenous Injection: The solution must be injected slowly over a period of 3 to 5 minutes.

Population-Specific Dosing Rules

Dosage adjustments are utilized for certain patient groups:

  • Elderly and Hepatic/Renal Impairment: The initial dose is reduced by half compared to the standard adult dose (e.g., 0.5 mg IV or 1 mg IM/IN). The repeat dosing interval is extended to a minimum of 6 hours.
  • Discontinuation: In physically dependent patients, the dosage is tapered gradually (e.g., 25% to 50% reduction every 2 to 4 days) before cessation.

Recent Clinical Evidence

Research evidence / Overview of Studies for Butorphanol

This section provides an overview of the types of official research that have explored Butorphanol, outlining the conditions and outcomes that were measured in clinical trials. It focuses on the patterns observed in research and identifies what remains uncertain, without providing any medical or clinical guidance.

Evidence for Use in Acute Pain Following Surgery

Butorphanol was studied in Randomized Controlled Trials (RCTs) and subsequent analyses that look at the results of multiple studies combined. This research focused on adult patients who were studied for outcomes related to physical discomfort following a variety of operations, including general, orthopedic, and abdominal surgeries.

These short-term studies monitored patient-reported outcomes describing perceived discomfort using standardized scales. Researchers also examined related factors, such as the calming or sedative effect that was observed in the study participants. The research primarily tracks outcomes over the first 24 to 48 hours after surgery, with findings describing patterns observed in the studies related to the measurement of time before patients received subsequent analgesic compounds.

Evidence for Managing Acute, Severe Episodic Pain

Research has explored the use of Butorphanol, particularly the nasal spray formulation, in settings involving conditions associated with acute or disruptive episodes, with a strong focus on acute, severe migraine headache. These trials compared the medicine to placebo and other compounds, with researchers aiming to measure the rate of change in the reported discomfort and the time over which observed effects were observed.

Studies report how symptoms evolved in the observed populations in a short-term framework. Data for certain groups remain insufficient, especially for specific types of acute, non-migraine pain (such as renal colic) compared to the evidence base for migraine. Additionally, the research is heavily weighted toward research exploring short-term symptom changes during the episode itself.

Key Uncertainties and Research Gaps

Research summaries note that the evidence quality varies across studies due to differing trial designs and patient selection. In certain acute pain settings, comparative evidence is lacking. For groups where research has been conducted, such as women in labor, the evidence concerning its use as an adjunct therapy is noted as controversial. This indicates that certainty remains low in this specific context. Furthermore, data for children and adolescents remain insufficient for general pain management.

Key Studies & References

  1. Label: BUTORPHANOL TARTRATE spray, metered - FDA/DailyMed
  2. Label: BUTORPHANOL TARTRATE injection, solution - FDA/DailyMed
  3. Butorphanol premedication improves postoperative lung function and analgesic outcomes in laparoscopic surgery: a randomized dose-response study
  4. Intravenous butorphanol as an adjunct to patient-controlled epidural analgesia with ropivacaine and sufentanil in labor

Frequently Asked Questions (FAQ)

Common questions about Butorphanol (FAQ)

Q: What is Butorphanol used for besides pain relief?

A: According to official product information, Butorphanol is also indicated for uses other than the management of severe pain. It is used as a preoperative or pre-anesthetic medication, as a supplement to balanced anesthesia procedures, and specifically for the relief of pain that occurs during labor.


Q: Do people feel 'high' when taking Butorphanol?

A: Official regulatory documents list euphoria, which is an intense feeling of well-being or happiness, as an uncommon central nervous system side effect. This is grouped with other possible CNS effects like sedation, dizziness, or unusual dreams. As with any medication, individual responses and the occurrence of side effects described in the labeling may vary.


Q: Does Butorphanol cause tolerance if taken for a long time?

A: Yes, official information indicates that chronic use may lead to the development of physical dependence and tolerance. Tolerance is described as the body potentially requiring a higher amount of the medicine to achieve comparable effects over time. Long-term use is associated with the risk of physical dependence.


Q: Can Butorphanol be used for chronic pain management?

A: Official labeling suggests Butorphanol should be reserved for managing pain that is severe enough to require an opioid when alternative treatments have not been adequate. It is generally advised not to be used for extended periods unless the severe nature of the pain requires continued opioid relief.


Q: How quickly does Butorphanol start working after it is taken?

A: Regulatory pharmacokinetic data specifies the onset of pain relief based on the administration route. The effect is typically noticed within a few minutes after it is administered intravenously (IV). For intramuscular (IM) and intranasal administration, the onset of effects is typically noticed within 10 to 15 minutes.


Q: How long do the effects of Butorphanol last in the body?

A: The pain-relieving effects of Butorphanol typically last between three and four hours. This duration of action is consistent with the drug being administered every three to four hours as needed.


Q: What are the symptoms of Butorphanol overdose?

A: Symptoms of a suspected acute overdose, based on regulatory information, can include severe, life-threatening respiratory depression (breathing that is very slow or shallow), extreme drowsiness, cold and clammy skin, or constricted pupils. Official labeling advises seeking emergency medical attention immediately if an overdose is suspected.


Q: What happens if I miss a scheduled dose of Butorphanol?

A: Official guidance for a missed regular dose suggests taking it as soon as the dose is remembered. However, if it is nearly time for the next scheduled dose, the prior dose should be skipped to maintain the proper dosing interval. Taking a double dose to make up for a missed one is not recommended in official guidelines.


Q: Is it true that Butorphanol has a 'ceiling effect'?

A: Due to its classification as a mixed agonist-antagonist opioid, official pharmacological descriptions indicate that Butorphanol has dose-related limits on both its pain-relieving effectiveness and its effect on breathing. This dose-related limit on efficacy is a concept often referenced in discussions of mixed agonist-antagonists.


Q: Does Butorphanol come with any special warnings or black box warnings?

A: Yes, the FDA requires a Boxed Warning—sometimes called a Black Box Warning—to highlight specific serious risks. These risks include the potential for addiction and misuse; the risk of life-threatening respiratory depression; dangers from using it with other central nervous system depressants; and the risk of Neonatal Opioid Withdrawal Syndrome if used during pregnancy.


Q: How long does Butorphanol stay in your system after the last dose?

A: Pharmacokinetic data in official labeling indicates that the time it takes for half of the drug to be eliminated from the body, known as the elimination half-life, is approximately four to seven hours. The complete clearance of the drug from the body is understood to occur over the span of several half-lives.


Q: Is Butorphanol a controlled substance?

A: Yes, Butorphanol is classified as a controlled substance. It is specifically designated as a Schedule IV controlled substance by the U.S. Drug Enforcement Administration (DEA).


Q: Can people who have had a head injury use Butorphanol?

A: Official warnings state that Butorphanol must be used with caution in individuals who have sustained a head injury, brain tumors, or have increased pressure inside the skull. The caution is due to the potential for opioids to obscure the clinical course of an injury or condition that causes elevated pressure in the skull.


Q: Are there contraindications related to heart conditions for Butorphanol?

A: Official warnings document that Butorphanol requires caution in individuals who have experienced an acute myocardial infarction (heart attack) or have coronary insufficiency. This caution is advised due to the potential for the medicine to increase systemic and pulmonary arterial pressure.


Q: What is the significance of the DEA scheduling for Butorphanol?

A: The Schedule IV classification signifies that Butorphanol has a low potential for abuse relative to Schedule III controlled substances. However, its status still subjects it to strict federal and state regulations regarding how it can be prescribed, stored, and dispensed.


Q: Is Butorphanol a Schedule IV drug?

A: Yes, regulatory documents confirm that Butorphanol is classified as a Schedule IV controlled substance.


Q: How does Butorphanol compare to other common pain medications?

A: Butorphanol is pharmacologically distinct from common pure opioid analgesics because it is classified as a mixed agonist-antagonist. This means it activates some opioid receptors (kappa) while having partial or blocking effects on others (mu), giving it a unique profile among strong pain-relieving compounds.


Q: Are there any major food or drink items that interact with Butorphanol?

A: Official interaction warnings primarily focus on other medications and products that can cause central nervous system (CNS) depression. Alcohol, for instance, is listed as a CNS depressant that may cause profound additive effects when taken with Butorphanol. The official documentation emphasizes the importance of reviewing all substances used during treatment.


Q: Can Butorphanol affect my ability to drive or operate machinery?

A: Official safety warnings related to dizziness and somnolence (drowsiness) indicate that the medication may impair the physical or mental ability required to perform tasks such as driving or operating heavy machinery. This medication is classified as a central nervous system depressant.


Q: What research is available on the long-term safety of Butorphanol?

A: Research summaries published in official documents primarily focus on short-term outcomes, often tracking pain relief over 24 to 48 hours following a procedure or episode, such as a migraine. Explicit long-term safety data is not prominently discussed in the overviews of the clinical evidence.


Q: What type of pain is Butorphanol most effective for?

A: Butorphanol is officially indicated for the management of pain, and regulatory-cited research primarily focuses on its use in acute settings. This includes acute, severe pain following surgical procedures, as well as acute, severe episodic pain, particularly migraine headaches.


Q: What documentation suggests Butorphanol should be used short-term?

A: Clinical trial evidence summarized in official documents is heavily focused on short-term studies, tracking outcomes over a brief period. This focus is consistent with the general recommendation that Butorphanol should not be used for an extended period of time unless required by severe, persistent pain.


Q: Is Butorphanol used for general anesthesia or sedation?

A: Official indications state that Butorphanol may be used as a supplement to balanced anesthesia procedures. Furthermore, research studies have noted that a calming or sedative effect was observed in patients who received the medication.


Q: Does Butorphanol cause respiratory depression in all patients?

A: The official safety profile identifies the risk of life-threatening respiratory depression (slowed or shallow breathing) as the most serious adverse reaction, but it is not stated to affect all patients. The risk is documented to be greatest when treatment is first initiated or immediately following an increase in dosage.

How should Butorphanol be stored and disposed of?

Storage and Disposal Requirements for Butorphanol

Butorphanol must be stored securely, out of sight and out of reach of children, in a secure location at all times. The injectable solution must be stored at 20°C to 25°C (68°F to 77°F) (USP Controlled Room Temperature), protected from light, and must not be frozen.


Packaging and Disposal

The Butorphanol nasal spray unit must be stored in the child-resistant container when not in use. Disposal of unused or expired product should prioritize return to a DEA-registered collector or drug take-back program. If this is not available, the product may be mixed with an undesirable substance (e.g., dirt) and placed in a sealed bag before being discarded in the household trash, following explicit regulatory instructions.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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