5. Drugs which relieve pain be central action . Certain drugs can relieve specific types of pain (not proper analgesic drugs) e.g., atropine in colics. Peripheral analgesic include : physical protectives, local and surface anaesthetics , obtundants , astringents and counterirritants
6. Central Analgesics include: No drug dependence No euphoria or drowsiness. Subcortical on thalamus Relieve low intensity pain, e.g., headache , neuralgia, myalgia Analgesic antipyretics Addictive Produce euphoria and stupor Act cortical and subcortical . Can relieve any type (except itching ). Opioid (narcotic ) analgesic
15. Pyrazolone derivatives : rarely used due to bone marrow depression Adverse effects : GIT upset, salt and water retention, oedema, h7ypertension , bone marrow depression, liver and renal toxicity, skin rash, and bronchospasm. Indole derivatives : is potent Adverse effects: GIT disturbances , frontal headache , vertigo, confusion, psychosis , blood dyscrasias , liver and kidney toxicity, kin rash and asthma. Classification Of NSAIDS
16. Sulindac : it is prodrug which is converted into active metabolite and ahs kess gastric irritation. Anthranilic acid derivatives : fenamates Central analgesic action (which is specific with mefenamic acid . Propionic acid derivatives (IBUPROFEN : Most safe Oxicams : Piroxicam (Feldene). It has enterohepatic cycle, so has long plasma half life
18. Gastric irritation , increased occult blood in stools. Hypersensitivity reaction: asthma, rash, …… Idiosyncracy: In patient: with G-6-PD deficiency ->haemolytic anaemia Prolonged use may lead to hypoprothrombinaemia.
20. 1- Epigastric distress, naused and v0omiting ( # PGS in GIT) 2- CVS & M.I.: with Cox-2 inhibitors (rofecoxib ) 3- Coagulation disorders (reversible ) 4- Renal toxicity (# Pgs). 5- Hypersensitivity N.B. Newer NSAIDS have lower incidence of gastric distribution but higher incidence of renal damage adverse effects of NSAIDs
21. Kinetics Major Minor Conjugate with Toxic metabolite glucuronic and (N-acetyle Benzo quinone acid sulphate which is detoxificated by glutathione acetaminophen (paracetamol )