BUTORPHANOL

 BUTORPHANOL

BRAND NAME:- BUTRUM 1mg/ml, 2mg/ml inj.

BUTORPHANOL is a morphinan-type synthetic agonist–antagonist opioid analgesic. Used to treat moderate to severe pain.

PHARMACODYNAMIC:-

Butorphanol is a synthetic opioid agonist-antagonist analgesic with a pharmacological and therapeutic profile that has been well established since its launch as a parenteral formulation in 1978. Butorphanol has agonistic activity at the κ-receptor and antagonistic activity at the μ-receptor. It also exhibits partial agonistic activity at the σ-receptor.  The introduction of a transnasal formulation of butorphanol represents a new and noninvasive presentation of an analgesic for moderate to severe pain. This route of administration bypasses the gastrointestinal tract, and this is an advantage for a drug such as butorphanol that undergoes significant first-pass metabolism after oral administration. The onset of action and systemic bioavailability of butorphanol following transnasal delivery are similar to those after parenteral administration. Butorphanol blocks pain impulses at specific sites in the brain and spinal cord. 

MECHANISM OF ACTION:-

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. 

USES:-

used to treat moderate to severe pain.

SIDE EFFECTS:-

Drowsiness, dizziness, blurred vision, flushing, headache, nausea, vomiting, constipation, nasal irritation/congestion, trouble sleeping, dry mouth, and sweating may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. 

DOSE:- It has been used in a dose of 1-4mg i.m. or i.v. for postoperative and other short- lasting (e.g. renal colic) painful condition,but should be avoided in patients with cardiac ischaemia. The t½ and duration of action is similar to  morphine.