Lets begin.
Chemicals derived from opium or related to morphine chemically are called opiates.
1) Natural opium alkaloids
- Morphine, Codeine.
A) Acts on Mu(Causes dependency-Euphoria) , kappa(Dysphoria - Psychomimetic) and delta receptors as agonist. Hence used as supraspinal and Spinal analgesic.
B) Treatment of poisoning: Naloxone 0.4-0.8 mg i.v. repeatedly for 2-3 minutes.
C) Can be administered through oral, rectal, i.m, i.v, intrathecal, epidural routes. Used as preanaesthetic medications
D) Useful in MI and acute pulmonary edema(Both by i.v. route)
E) Contraindicated in head injury, hypothyroidism patient, pregnancy.
A) Partial agonist at mu receptor.
B) 1/10th analgesic of morphine and less efficacious.
Diacetyl morphine(Heroine), Pholcodine, Ethylmorphine.
Dextromethopran is devoid of constipating action.
A) To control shivering after anesthesia
B) Used during labour as analgesic
C) Safer in asthma.
D) Pethidine and pentazosin both are anticholinergics. Hence they causes tachycardia. Perhaps, they are contraindicated in MI but useful in biliary colic
A) Causes truncal rigidity due action on mu receptor.
B) Can be given as transdermal patch and as well as buccal transmucosal
A) Agonist action on mu receptor + blocks NMDA reuptake of monoamines and hence useful in neuropathic and cancer pain (Not controlled by morphine)
B) Can be given by oral, rectal, i.v, s.c, routes.
C) Long plasma half-life hence less dependency and tolerance. Therefore used as maintenance therapy in opioid dependency
A) It is a weak mu receptor agonist and decrease reuptake of NA and 5-HT hence used as analgesia. This is abolished by Ondasteron.