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It’s actions are similar to that of other partial agonists such as, pentazocine or nalbuphine. The agonist activity of butorphanol is believed to be exerted at the kappa and sigma receptors.
Butorphanol binds to opiate receptors at sites in the central nervous system and alters perception and response to pain. It also has the ability to act as an antitussive.
Duration of action following dose appears to be 4 hours.
It is absorbed in the gut with its highest distribution levels being in the kidney, liver, and intestine. Levels throughout other tissues are found to be higher than plasma. The drug is metabolized in the liver, crosses placental barrier, and distributed into breast milk. It is excreted in urine and bile, and eliminated in the feces.
Safety in pregnant and very young animals has not been determined.
Use cautiously in hypothyroidism, severe renal insufficiency, or severely debilitated.
Butorphanol, if used with other central nervous system depressants may increase the CNS or respiratory depression of those drugs. It is recommended to decrease butorphanol’s dosage if used in conjunction with those particular drugs.
Respiratory: decreased respiratory rate
GU: urinary retention
Other: In the event of signs of overdose, such as cardiac and respiratory depression, administer naloxone 0.01 to 0.10 mg/kg SC, IP (narcotic reversal) (1), fluids, O2, and vasopressors.
1 mg/kg to 5 mg/kg , SQ , q2hrs to q4hrs 1(Sedation)
0.18 mg/lb to 10 mg/lb SQ , or 1 mg/lb , PO , q4hrs to q6hrs 3
0.25 mg/lb to 1 mg/lb , SQ (effective for pain) 3
When combined with diazepam: 0.25 mg/lb butorphanol and 1 mg/lb diazepam. 3
Posted on June 23, 2003, 14:43,
Last updated on May 24, 2013, 07:21