butorphanol tartrate
Stadol, Stadol NS

Available forms
Available by prescription only
Injection: 1-ml vials (1 mg/ml); 1-ml, 2-ml, and 10-ml vials (2 mg/ml)
Nasal spray: 10 mg/ml

Indications and dosages
 Moderate to severe pain. Adults: 1 to 4 mg I.M. q 3 to 4 hours, p.r.n. Or, 0.5 to 2 mg I.V. q 3 to 4 hours, p.r.n., or around the clock. Or, give 1 mg by nasal spray (1 spray in one nostril). Repeat if pain relief is inadequate after 60 to 90 minutes. Repeat q 3 to 4 hours, p.r.n. For severe pain, an initial 2 mg by nasal spray in patients able to remain recumbent (one spray in each nostril). Repeat no more than q 3 to 4 hours, p.r.n.
Elderly: one-half usual parenteral dose q 6 to 8 hours. Base subsequent doses on patient response. Or, 1 mg nasal spray (1 spray in each nostril) and repeat in 90 to 120 minutes, p.r.n.
 Pain during labor. Adults: 1 to 2 mg I.M. or I.V. q 4 hours but not less than 4 hours before delivery is expected.
 Preoperative anesthesia. Adults: 2 mg I.M. 60 to 90 minutes before surgery or 2 mg I.V. shortly before induction.
≡ Dosage adjustment. Patients with hepatic or renal impairment should receive the usual parenteral adult dose at 6- to 8-hour intervals, p.r.n.

Pharmacodynamics
Analgesic action: The exact mechanisms of action are unknown. Drug is believed to competitively antagonize some opiate receptors and agonize others, thus relieving moderate to severe pain. Like narcotic agonists, it causes respiratory depression, sedation, and miosis.

Pharmacokinetics
Absorption: Well absorbed after I.M. administration.
Distribution: Rapidly crosses the placental barrier, and neonatal serum levels are 0.4 to 1.4 times maternal levels.
Metabolism: Metabolized extensively in the liver, primarily by hydroxylation, to inactive metabolites.
Excretion: Excreted in inactive form, mainly by the kidneys. About 11% to 14% of a parenteral dose is excreted in feces.

Contraindications and precautions
Contraindicated in patients receiving repeated doses of narcotic drugs or with narcotic addiction; may precipitate withdrawal syndrome. Also contraindicated in patients hypersensitive to drug or to the preservative benzethonium chloride.
  Use cautiously in emotionally unstable patients and in those with a history of drug abuse, head injury, increased intracranial pressure, acute MI, ventricular dysfunction, coronary insufficiency, respiratory disease or depression, and renal or hepatic dysfunction.

Interactions
Drug-drug. Barbiturate anesthetics such as thiopental: Cause additive CNS and respiratory depressant effects and possibly apnea. Monitor patient closely.
Cimetidine: May potentiate butorphanol toxicity, causing disorientation, respiratory depression, apnea, and seizures. Use cautiously and be prepared to administer narcotic antagonist if toxicity occurs.
CNS depressants (antihistamines, barbiturates, benzodiazepines, muscle relaxants, narcotic analgesics, phenothiazines, sedative-hypnotics, tricyclic antidepressants): Potentiate respiratory and CNS depression, sedation, and hypotensive effects. Reduced butorphanol dose is usually needed.
Digitoxin, phenytoin, rifampin: Cause drug accumulation and enhanced effects. Reduce butorphanol dose.
General anesthetics: Cause severe CV depression. Avoid use together.
Narcotic antagonists: Patient who becomes physically dependent on opioids may experience acute withdrawal syndrome. Use cautiously and monitor patient closely.
Pancuronium: May increase conjunctival changes. Monitor patient.
Drug-lifestyle. Alcohol use: May potentiate respiratory and CNS depression, sedation, and hypotensive effects of drug. Discourage alcohol use.

Adverse reactions
CNS: confusion, nervousness, lethargy, headache, somnolence, dizziness, insomnia, anxiety, paresthesia, euphoria, hallucinations, increased intracranial pressure.
CV: palpitations, flushing, vasodilation, hypotension.
EENT: blurred vision, nasal congestion (with nasal spray), tinnitus.
GI: taste perversion, nausea, vomiting, constipation, anorexia.
Respiratory: respiratory depression.
Skin: rash, hives, excessive diaphoresis.
Other: clamminess, sensation of heat.

Effects on lab test results
None reported.

Overdose and treatment
No information available.

Special considerations
• Patient using nasal form for severe pain may start with 2 mg (1 spray in each nostril) provided he remains recumbent. Dose isn’t repeated for 3 to 4 hours.
• Monitor patient for respiratory depression.
• Mild withdrawal symptoms have been reported with long-term use of the injectable form.
• Drug has the potential to be abused. Closely supervise emotionally unstable patients and those with a history of drug abuse when long-term therapy is necessary.
Pregnant patients
• Safe use during pregnancy (except during labor) hasn’t been established.
Breast-feeding patients
• Use of drug in breast-feeding women isn’t recommended.
Pediatric patients
• Safety and efficacy in children younger than age 18 haven’t been established.
Geriatric patients
• Lower doses are usually indicated for elderly patients because they may be more sensitive to therapeutic and adverse effects of the drug. Plasma half-life is increased by 25% in patients older than age 65.

Patient education
• Teach patient how to use nasal spray. Patient should use 1 spray in one nostril unless otherwise directed.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use