
Mechanism of effect
The exact mechanism of action is unknown, but is believed to interact with an opiate receptor site in the CNS (probably in or associated with the limbic system). The opiate antagonistic effect may result from competitive inhibition at the opiate receptor, but may also be a result of other mechanisms. Butorphanol is a mixed agonist-antagonist that exerts antagonistic or partially antagonistic effects at mu opiate receptor sites, but is thought to exert its agonistic effects principally at the kappa and sigma opiate receptors.
Pharmacodynamic
Butorphanol blocks pain impulses at specific sites in the brain and spinal cord.
Pharmacokinetics
Half-life: 4.6 hr
Onset: <10 min (IV); 5-10 min (IM); within 15 min (nasal)
Duration: 3-4 hr (IV/IM); 4-5hr (nasal);
Peak effect: 0.5-1hr (IM); 4-5min (IV)
Bioavailability: 60-70% (nasal)
Protein Bound: 80%
Vd: 487 L (range: 305-901 L)
Metabolites: hydroxybutorphanol; N-dealkylation & conjugation of butorphanol & its metabolites
Metabolism: Liver (hydroxylation)
Excretion: Urine (primarily)
Dosage
Adult
Pain
IV: 1 mg IV q3-4hr PRN; dosage range 0.5-2 mg q3-4hr
IM: 2 mg IM q3-4 hr; dosage range 1-4 mg q3-4hr
Intranasal
- Initial: 1 mg (1 spray in 1 nostril); may repeat once after 60-90 min if inadequate pain relief
- Depending on pain severity, by give initial dose of 2 mg (1 spray in each nostril); patient must remain recumbant; do not repeat this dose
- Maintenance: 1 mg (1 spray in 1 nostril) q3-4hr prn
Balanced Anesthesia
2 mg IV before induction and/or 0.5-1 mg increments during anesthesia (higher dose may be required, up to 0.06 mg/kg, or 4 mg/70 kg)
Total cumulative dose varies; typically ranges between 4-12.5 mg (0.06-0.18 mg/kg)
Labor Pain
1-2 mg/dose IV/IM; may repeat PRN q4hr
Decrease dose if concomitantly used with other analgesics or CNS depressants
Do not administer within 4 hr of anticipated delivery
Preoperative & Preanesthesia
2 mg IM 60-90 minutes preop
This dose is approximately equipotent to morphine 10 mg or meperidine 80 mg
Pediatric
<18 years old: Not recommended
Drug contraindications
cardiovascular conditions , cardiac arrhythmias , Myocardial Infarction , Coronary Artery Disease (CADSide effects
Sinusitis , Anxiety , Insomnia , Nosebleeds , Headache , nausea , dry mouth , dizziness , vomiting , Blurred vision , vertigo , palpitations , anorexia , somnolence , Tremor , itching , sweating , nasal stuffiness , Restlessness , stomach pain , rhinitis , Nose irritation , Floating feelingInteractions
fentanyl , Tapentadol , Oxycodone , propoxyphene , Promazine , Chloral hydrate , Mibefradil , Molindone , cobicistat , Delavirdine , Letermovir , Asenapine , Alvimopan , Paraldehyde , Belladonna , Procarbazine , Tramadol , Tranylcypromine , Cimetidine , Selegiline , Oxymorphone , hydromorphone , nalbuphine , Hydrocodone , Acetaminophen and benzhydrocodone , Dipipanone , Diamorphine , Papaveretum , Dextromoramide , codeine , Pentazocine , Diphenoxylate , Eluxadoline , Sufentanil , Alfentanil , isocarboxazid , Levorphanol , methylene blue , rasagiline , morphine , meperidine , Methadone , Clonidine , Linezolid , Buprenorphine , Sodium Oxybate , Phenelzine , Apalutamide , elagolix , Estazolam , Ethchlorvynol , oleandomycin , Aminoglutethimide (Oral) , lasmiditan , voxelotorAlerts
Drug abuse, emotional lability, head injury, hepatic/renal impairment, incr ICP, GI/urinary obstruction, BPH, hypothyroidism
Less risk of respiratory sedation than with pure opioid agonist
May produce withdrawal in opioid dependent pts
Avoid alcohol
Points of recommendation
Follow all directions on your prescription label. Butorphanol can slow or stop your breathing. Never use butorphanol in larger amounts, or for longer than prescribed. Tell your doctor if the medicine seems to stop working as well in relieving your pain.
Butorphanol may be habit-forming, even at regular doses. Never share this medicine with another person, especially someone with a history of drug abuse or addiction. MISUSE OF NARCOTIC MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription. Selling or giving away butorphanol is against the law.
Do not stop using butorphanol suddenly after long-term use, or you could have unpleasant withdrawal symptoms. Ask your doctor how to avoid withdrawal symptoms when you stop using butorphanol.
Store butorphanol at room temperature away from moisture and heat.
Ask a Pharmacist