Published on August 6, 2014

Author: profsatya48090



H1 RECEPTOR ANTAGONISTS – H1 ANTIHISTAMINES: Competitively antagonize actions of histamine at H 1 receptors H 1 RECEPTOR ANTAGONISTS – H1 ANTIHISTAMINES LIPID DERIVED AUTACOIDS (PROSTAGLANDINS): LIPID DERIVED AUTACOIDS (PROSTAGLANDINS) DR.V. SATHYA NARAYANAN M.D PROFESSOR OF PHARMACOLOGY Eicosanoids: Eicosanoids Derivatives of 20 Carbon atom polyunsaturated essential fatty acids Derived from cell membrane phospholipids Most universally distributed autacoids Prostaglandins - PGs Leukotrienes - LTs Thromboxanes – TXs PROSTAGLANDINS: PROSTAGLANDINS Derivatives of prostanoic acid Synthesized locally in response to appropriate stimuli Like injury, infection ACTIONS – PGE2: ACTIONS – PGE2 Vasodilatation, fall in BP Contraction of uterus, softening of cervix Dilatation of bronchi Decreases acid secretion, increases mucus secretion Increases peristalsis of intestines ACTIONS – PGE2: ACTIONS – PGE2 kidney - Natriuresis, vasodilatation, renin release Pyrogenic Sensitize afferent nerves to noxious stimuli Release ant.pituitary hormones, steroids, insulin metabolism - Antilipolytic, insulin like action ACTIONS – PGF2alpha : ACTIONS – PGF2alpha Vasodilatation Contraction of uterus, softening of cervix Constriction of bronchi Spasmogenic on intestines Release gonadotropins, prolactin PROSTACYCLIN – PGI2: PROSTACYCLIN – PGI2 Vasodilatation, fall in BP Inhibit platelet aggregation Dilate bronchi, inhibit histamine release Dec. acid secretion PROSTACYCLIN – PGI2: PROSTACYCLIN – PGI2 Weak spasmogenic Kidney - Natriuresis, vasodilatation, renin release Sensitize afferent nerves to noxious stimuli THROMBOXANE A2: THROMBOXANE A2 Vasoconstriction Platelet aggregation Constriction of bronchi PATHOPHYSIOLOGICAL ROLE: PATHOPHYSIOLOGICAL ROLE Facilitate fertilization PGs mediate initiation and progression of labour Dysmenorrhoea associated With Increased PGs PATHOPHYSIOLOGICAL ROLE: PATHOPHYSIOLOGICAL ROLE Mediate vasodilatation and exudation at the site of inflammation PGI2- regulation of local vascular tone Maintaining patency of ductus arteriosus Prevent platelet aggregation (PGI2), Promote aggregation – TX A2 PATHOPHYSIOLOGICAL ROLE: PATHOPHYSIOLOGICAL ROLE Mediate pyrogen induced fever, malaise Algesic in inflammation Facilitate aqueous humour drainage  GLAUCOMA PATHOPHYSIOLOGICAL ROLE: PATHOPHYSIOLOGICAL ROLE Imbalance cause asthma Involved in mediating fluid loss in toxin induced diarrhea Antiulcerogenic and natural ulcer protective Role in the Growth of polyp, cancer of colon Intrarenal regulators of renal blood flow PROSTANOID RECEPTORS: PROSTANOID RECEPTORS DP – affinity for PGD2 EP - affinity for PGE2 FP – affinity for PGF2alpha IP – affinity for PGI2 TP – affinity for TXA2 All are G-protein coupled receptors Some act through cAMP and others via IP3 CLINICAL USES: CLINICAL USES RESTRICTED BECAUSE OF Limited availability Short lasting action Cost Side effects CLINICAL USES: CLINICAL USES SYNTHETIC PROSTAGLANDINS ARE USED Because they are more stable Long acting more specific PROSTAGLANDIN Analogues DINOPROST : PROSTAGLANDIN Analogues DINOPROST EXOGENOUS PG F2 α Intra amniotic injection INDICATIONS termination of pregnancy ( midterm), Induction of labor DINOPROSTONE : DINOPROSTONE synthetic PGE2 analog 10 times more potent than dinoprost PREPARATIONS- Vaginal gel, vaginal tab, cervical gel, i.v inj , Oral tablet Uses: cervical ripening, induction of labour termination of pregnancy (midterm) – dinoprostone 20 mg suppository + gemeprost 1mg vaginal pessary CARBOPROST: CARBOPROST 15methyl PGF2 alpha Prolonged action INDICATIONS : to arrest Post Partum Hemorrhage – alternative to ergometrine & oxytocin midterm abortion Cervical ripening DOSAGE : 0.25 mg deep i.m GEMEPROST: GEMEPROST PGE1 INDICATIONS Medical termination of pregnancy 1 st tri - 1mg pessary 2 nd tri – 1mg pessary every 3 hours ( max -5) To soften the cervix in 1 st trimester ALPROSTADIL: ALPROSTADIL Synthetic PGE1 Indications : Keep the patency of D.A in children with Congenital Heart Disease Prevent platelet aggregation Peripheral vascular disease Impotence Misoprostol: Misoprostol Synthetic PGE1 analogue Actions :inhibits gastric acid secretion cytoprotective IND : peptic ulcer prophylaxis of NSAID induced ulcers. DOSE :400mg twice daily ADR : diarrhoea C/I : pregnancy (abortion) epoprostenol- PGI2: epoprostenol - PGI2 ACTIONS : inhibits platelet aggregation vasodilatation INDICATIONS :cardiac bypass to prevent hemoperfusion platelet hemodialysis aggregation primary pulmonary hypertension Has to be given intravenously LATANOPROST: LATANOPROST Long acting PGF2 α derivative Eye Drops to be put into conjunctival sac 1 st choice drugs in wide angle Glaucoma SIDE EFFECTS: SIDE EFFECTS Nausea, vomiting Watery diarrhoea Uterine cramps Vaginal bleeding Flushing Shivering, fever Hypotension, tachycardia LEUKOTRIENES: LEUKOTRIENES LTC4,LTD4,LTE4  SRS – A of anaphylaxis Mediate inflammation LTC4, LTD4 are the most important mediators of allergic asthma Abdominal colic in anaphylaxis Contribute pain of inflammation LT receptor antagonists – Montelukast, Zafirlukast PLATELET ACTIVATING FACTOR: PLATELET ACTIVATING FACTOR Synthesized by - platelets,WBC, kidney, - vascular endothelial cells ACTIONS : vasodilation, Chemotaxis aggregation of WBC & degranulation BP Broncho constriction Platelet aggregation Vasular permeability ulcerogenic PLATELET ACTIVATING FACTOR PATHOPHYSIOLOGICAL ROLE: PLATELET ACTIVATING FACTOR PATHOPHYSIOLOGICAL ROLE Pain and Inflammation Bronchial asthma Anaphylactic shock Hemostasis and thrombosis Implantation of embryos Parturition PAF ANTAGONISTS: PAF ANTAGONISTS GINKGOLIDE B Stroke Intermittent claudication Sepsis MI Shock Asthma Contraceptive Alprazolam, triazolam THERAPEUTIC USES OF PROSTAGLANDINS: THERAPEUTIC USES OF PROSTAGLANDINS Abortion Induction of labour Cervical priming Post Partum Hemorrhage Peptic ulcer Glaucoma To maintain patency of ductus arteriosus To avoid platelet damage Peripheral vascular disease WHAT”S DIFFERENT ?!! : WHAT”S DIFFERENT ?!! An U.N SURVEY: An U.N SURVEY A worldwide survey was conducted by the UN. The only question asked was: “would you please give your honest opinion about solutions to the food shortage in the rest of the world?” The survey was a huge failure…… In Africa they didn’t know what food meant.. In India they didn’t know what honest meant… In Europe they didn’t know what shortage meant…. In China they didn’t know what opinion meant…… In the Middle East they didn’t know what solutions meant…… In South America they didn’t know what please meant…….. And in the USA they didn’t know what the rest of the world meant …………!!! Two things are infinite: the universe and THE human stupidity; and I'm not sure about the universe……. -Albert Einstein: Two things are infinite: the universe and THE human stupidity; and I'm not sure about the universe……. -Albert Einstein

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