5th Semester → CNS Pharmacology

Non-narcotic analgesics

بالنسبة لل other opioid فهنركز على أهم حاجه من كل دوا :

1- codeine :

. it's methylated morphine

. Bioavailability= 60% then metabolized to morphine by CYP2D6

. Potency: 20% so with high dose give the same effect of morphine so, respiratory depression is high incident with it

. Used as antitussive

. Contraindicated with post tonsillectomy in children

2- tramadol :

. Less potent than morphine

. Prevent reuptake of serotonin and NE so with high dose cause seizure due to ↑ NE and serotonin

. Used during labor and delay premature ejaculation

. Adverse effects: seizure

. Contraindicated with epilepsy

3- meperiden

. Metabolized to nor meperidine which neurotoxic that cause inhibition of serotonin reuptake and have atropine like action

. Selective on kappa receptor

. 4 less: → analgesic

→ addiction

→ respiratory depression

→ emitic

. 5 NO : → used in cough

→ vagal stimulatio

→ miosis

→ constipation

→ narcosis

. 2 L: → local anathitic

→ large dose cause neurotoxicity

. Uses : billary colic, inferior MI and Bradycardia and preanesthetic and obstric analgisia

. Adverse effects: hypertension, hyperthermia and atropine like side effects

. Contraindicated with MAO inhibitors


4- fentanyl :. About 100 times potent than morphine

. Administrated IV intrathecal not orally because it's extensive 1 st pass metabolism

. Used as analgesic supplementery for preanesthia

. Adverse effects: respiratory depression More serious with it

✅ Opioid antagonist

. Naloxone and Naltrexone: used with acute toxicity with morphine for relief respiratory depression and neonatal ataxia

. Side effects: withdrawl effects with addicted patients

✅ Partial antagonist

. Pentazocine and Nalbuphone used as:In absence of morphine → agonist In presence of morphine → antagonist → withdrawl effects with addicted patient and Have celling effect