Evaluation of analgesic Agents Screening of Analgesics 454 PHL Lab # PHL Lab # 2

March 5, PHL Lab II Gamra Hamad Outlines Classification of analgesics Morphine; MOA, Pharmacological effects, Uses, Side effects Morphine antagonists Method of screening of narcotic analgesic Classification of analgesics Morphine; MOA, Pharmacological effects, Uses, Side effects Morphine antagonists Method of screening of narcotic analgesic

March 5, PHL Lab II Gamra Hamad Analgesics Narcotics –Ex. Morphine, Pethadine, Fentanyl Non-narcotics –Ex. NSAID Narcotics –Ex. Morphine, Pethadine, Fentanyl Non-narcotics –Ex. NSAID

March 5, PHL Lab II Gamra Hamad Morphine Naturally occurring substance Papaver Somniferous Works on Opioid Receptors µ (mu), δ (delta), and к (kappa ) G-protein coupled receptors, inhibition of adenylate cyclase ↑ opening of Pot. Channels (hyperpolarization of PSN) ↓ opening of Cal. Channels ( ↓ NT) Naturally occurring substance Papaver Somniferous Works on Opioid Receptors µ (mu), δ (delta), and к (kappa ) G-protein coupled receptors, inhibition of adenylate cyclase ↑ opening of Pot. Channels (hyperpolarization of PSN) ↓ opening of Cal. Channels ( ↓ NT)

March 5, PHL Lab II Gamra Hamad Morphine: Pharmacological Action s Analgesia Euphoria Respiratory depression Cough suppression Nausea & vomiting Pupillary constriction Delay of gastric emptying Histamine release Analgesia Euphoria Respiratory depression Cough suppression Nausea & vomiting Pupillary constriction Delay of gastric emptying Histamine release

March 5, PHL Lab II Gamra Hamad Morphine: Side Effects Sedation Respiratory depression Constipation N & V Itching ↑ IOP Tolerance & dependence Euphoria Hypotension Sedation Respiratory depression Constipation N & V Itching ↑ IOP Tolerance & dependence Euphoria Hypotension

March 5, PHL Lab II Gamra Hamad Morphine Antagonists: Naloxone Competitive inhibitor Blocks the actions of endogenous opioid peptides as well as morphine Treatment of respiratory depression caused by opioid overdose Competitive inhibitor Blocks the actions of endogenous opioid peptides as well as morphine Treatment of respiratory depression caused by opioid overdose

March 5, PHL Lab II Gamra Hamad Screening of Narcotic Analgesics Principle: record the response of animal to a painful stimulus before & after administration of analgesic Thermal method –Hot plate method –Radiant heat method (light) –Tail-flick method (electronic current) Mechanical method – tail clip method Principle: record the response of animal to a painful stimulus before & after administration of analgesic Thermal method –Hot plate method –Radiant heat method (light) –Tail-flick method (electronic current) Mechanical method – tail clip method

March 5, PHL Lab II Gamra Hamad Screening of Analgesic Action By Hot Plate Method Material – Drugs: Morphine Unknown – Instruments:  Cages  Stop watches  Thermostatically controlled hot plate  Thermometer – Animals: 30 mice Material – Drugs: Morphine Unknown – Instruments:  Cages  Stop watches  Thermostatically controlled hot plate  Thermometer – Animals: 30 mice

March 5, PHL Lab II Gamra Hamad Studying Morphine Analgesic Action Method Group I, 6 mice Test sensitivity of animal to heat (not exceed 10 sec.) Morphine (IP) 0.2ml/10 gm Test sensitivity of animal to heat every 10 min for 60 min Record ur results in the table Method Group I, 6 mice Test sensitivity of animal to heat (not exceed 10 sec.) Morphine (IP) 0.2ml/10 gm Test sensitivity of animal to heat every 10 min for 60 min Record ur results in the table

March 5, PHL Lab II Gamra Hamad Method: cont. Method Group II, 6 mice Test sensitivity of animal to heat (not exceed 10 sec.) Unknown (IP) 0.2ml/10 gm Test sensitivity of animal to heat every 10 min for 60 min Record ur results in the table Method Group II, 6 mice Test sensitivity of animal to heat (not exceed 10 sec.) Unknown (IP) 0.2ml/10 gm Test sensitivity of animal to heat every 10 min for 60 min Record ur results in the table

March 5, PHL Lab II Gamra Hamad Table Table 1 Change in the reaction time (sec.) over 60 min. in group injected with morphine using hot-plate method Anim al # 0 min. 10 min. 20 min. 30 min. 40 min. 50 min. 60 min Mean

March 5, PHL Lab II Gamra Hamad Graph Morphine Unknown

March 5, PHL Lab II Gamra Hamad Screening of Non-narcotic Analgesics MOA: Inhibition of COX Non-narcotic: 1- Electrical method 2- Chemical ( Writhing method) MOA: Inhibition of COX Non-narcotic: 1- Electrical method 2- Chemical ( Writhing method)

March 5, PHL Lab II Gamra Hamad Writhing Method Principle: The painful stimulus is induced by IP injection of an irritant substance (e.g. acetic acid) Writhing: Stretching of the body, withdrawing of the limb, retraction of the abdomen & the stomach touches the ground Principle: The painful stimulus is induced by IP injection of an irritant substance (e.g. acetic acid) Writhing: Stretching of the body, withdrawing of the limb, retraction of the abdomen & the stomach touches the ground

March 5, PHL Lab II Gamra Hamad Writhing method Material Animal: Mouse Painful stimulus: Chemicals e.g. acetic acid Drug used: NSAID e.g. Na salicylate Material Animal: Mouse Painful stimulus: Chemicals e.g. acetic acid Drug used: NSAID e.g. Na salicylate

March 5, PHL Lab II Gamra Hamad DrugOnset of writhingNo. of writhing Acetic acid (control) Na salicylate (100mg/kg) Na salicylate (200mg/kg)