The document discusses oxytocics, which are drugs that stimulate uterine contractions. It focuses on oxytocin, ergot alkaloids, and prostaglandins. Oxytocin acts through G protein-coupled receptors in the uterus and stimulates prostaglandin release to induce contractions. Ergot alkaloids like ergometrine act mainly on serotonin receptors in the uterus to produce powerful, prolonged contractions. Prostaglandins like PGE2 and PGF2a are synthesized locally in the uterus and membranes and help induce labor by ripening the cervix and stimulating contractions.

2. OXYTOCICS Venkataramu.B.S 9term, MIMS

3. “ OXYTOCICS are the drugs of varying chemical nature that have the power to excite contraction of the uterine muscles .” Ergometrine & Methergin E2&F2 ά PGE 2 & PGF 2 ά OXYTOCICS OXYTOCIN ERGOT DERIVATIVES PROSTAGLANDINS

5. Diagram depicts a sagittal section through the hypothalamus and pituitary gland. The posterior pituitary consists of axon terminals of magnocellular neurons arising in the supraoptic and paraventricular nuclei of the hypothalamus. ● ● ● ●

7. During lactation … Axon terminals myoepithelial cells contract STIMULUS RESPONSE oxytocin mechanoreceptors in the nipple/ areola hypothalamic neuronal activity MILK EJECTION Suckling

14. Seizures & death Inadvertent activation of vasopressin receptors - 30-40mIU/min 40-50IU/min Pul. Edema Heart Failure water Intoxication- hyponatremia Antidiuresis excessive fluid retention activation of vasopressin receptors -

16. INDICATIONS -To accelerate Abortion (inevitable, Missed). -Molar preg. -To stop bleeding. -Induction of Abortion. To induce labour. For cervical ripening. Augmentation of labour. Uterine inertia. Active management of 3 rd stage To minimise blood loss. Control PPH DIAGNOSTIC Contraction stress test (CST) Oxytocin sensitivity test (OST) THERAPEUTIC PREGNANCY LABOUR PUERPERIUM EARLY LATE

20. Methods of administration Controlled intravenous Infusion 1-4mU/min (↑gradually) . INTRAMUSCULAR

22. Calculation of dose delivered in milliunits(mU) & its correlation with drop rate per minute NOTE: In majority of cases, max. response is seen with 16 mU/min i.e 2U in 500ml RL at 60 drops per min Units of oxytocin mixed in 500ml Ringer solution 1unit=1000 miliunits(mU) Drops per minute (15drops=1ml) 15 30 60 In terms of mU/min 1 2 8 2 4 8 4 8 16 16 32 64

24. Table showing convenient regime Dose of oxytocin Solution used Escalating Drop rate at intervals of 20-30min To start with 1unit If no response-2units If still no response-8units 500ml Ringer solution -do- -do- 15-30-60 15-30-60 15-30-60

28. PHARMACOKINETICS of Ergometrine & methergin -:Composition of ergot preparations:- Absorption ORAL PARENTERAL(IM,IV) rapidly absorbed peak concentrations (plasma) -60 to 90min PREFERED ROUTE Preparation ampoules tablets Ergometrine 0.25mg/ 0.5mg 0.5-1.0mg methergin 0.2mg 0.5-1.0mg Syntometrine (sandoz) 0.5mg Ergometrine+ 5U-syntocinon

31. The uterine smooth muscle fibers when contracted compress traversing blood vessels –Principle for its clinical use.

33. PROPHYLACTIC : AFTER DELIVERY OF ANT. SHOULDER / FOLLOWING DELIVERY OF BABY at the time of delivery of the placenta.

34. CAUTIONS

38. SYNTHESIS & ACTION Lungs & liver Lungs & liver

42. PROSTAGLANDIN

44. PG analogues & Common ROA PGE 1 (methyl ester) – MISOPROSTOL (vaginal, oral, rectal) PGE 2 – DINOPROSTONE (vaginal, extra amniotic) (NOTE: less toxic, more effective so widely used.) PGF 2 ά - DINOPROSTONE TROMETHAMINE PGF 2 ά (methyl analogue) – CARBOPROST (i.m., intra/extra-amniotic) -:Preparations:- Tablet -0.5mg dinoprostone (prostinE 2 ) Vaginal suppository- 20mg PGE 2 /50mg PGF 2 ά lipid base Vaginal pessary- 3mg PGE 2 ProstinE 2 gel- 500 μ g into cervical canal, below internal OS/1-2mg in the posterior fornix. -:Parenteral :- PGE 2 - ProstineE 2 1mg/ml PGF 2 ά -ProstinF 2 ά (Dinoprost tromethamine) 5mg/ml Methyl analogue of PGF2 ά - Carboprost 2.5mg/10ml vial

48. T H A N K Y O U ☻