drugs used in labour i.e. used to initiate and augmentation of labourthe labour

This PPT content :
Drugs used in labour :
Oxytocin
Prostaglandins
Methergin etc

1. Drugs used in labour

2. Prostaglandins It Act locally (autocrine and paracrine hormones) on the contiguous cells. P GE 2 and PGF2-both cause myometrial contraction . PG E2 is primarily important for cervical ripening whereas PGP F2 alpha for myometrial contraction . Classification of prostaglandins PGE1( misoprost PGE2( Dinoprost) PGE F2 ALPHA (Dinoprost tromethamine )

3. 1.Misoprostol( PGE1) has been used for cervical ripening. Primarily it has been used for peptic ulcer disease. Tr ansvaginal misoprostol is used for induction of labour. A dose of 50 µg every 3 hours to a maximum of six doses or 25 µg every 4 hours to a maximum of eight doses or orally 50 µg every 4 hours has been used. Misoprostol has been found to be as effective as PGE2 for cervical ripening and induction of labour. The optimum dose of misoprostol is yet to be determined. To date no evidence of teratogenic or carcinogenic effects has been observed

4. Cont . ADVANTAGES OF PGE1 over PGE2 Misoprostol is cheap, stable at room temperature, long self life, easily administered (oral or vaginal or rectal) and has less side effects. Induction delivery interval is short. Need of oxytocin augmentation is less. Failure of induction is less. RISKS Incidence of tachysystole (hyperstimulation), meconium passage are high. Rupture of uterus though rare, has also been observed. It should not be used for cases with previous caesarean birth because the risk of rupture is high. Misoprostol is not yet approved for use in pregnancy by FDA. Use of misoprostol for induction of abortion . (a) Hyperstimulation: Contractions > 5 in 10 min time and lasting for at least 2 minutes. Fetal heart rate (FHR) change may or may not be present . (b) Tachysystole is the hyperstimulation without FHR changes (c) Hyperstimulation syndrome is the hyperstimulation or tachysystole with FHR abnormalities

5. 2.Dinoprostol ( PGE2) PGE2 has greater collagenolytic properties and also sensitises the myometrium to oxytocin. Intracervical application of dinoprostone (PGE2-0.5 mg) gel is the gold standard for cerv i cal ripening . It may be repeated after 6 hours for 3 or 4 doses if required. The woman should be in bed for 30 minutes following application and is monitored for uterine activity and fetal heart rate . Side effects It is costly compared to oxytocin . Nausea, vomiting, diarrhoea, pyrexia, bronchospasm, tachycardia and chills . Cervical laceration may occur (PGF2a) when used as an abortifacient . Tachysystole (hyperstimulation) of the uterus, may occur during induction and may continue for a variable period . Risk of uterine rupture in cases with uterine scar .

6. Cont . It i s widely used because it is less toxic and more effective than PGF2q. It is however more costly. Vaginal tablet - Contains 3 mg dinoprostone (Prostin E2). In the posterior fornix followed by 3 mg after 6-8 hour maximum 6 mg. Vaginal pessary (with retrival device) releasing dinoprostone approximately 10 mg over 24 hours. It is removed when cervical ripening is adequate. Prostin E2 (Dinoprostone) gel - 500 µg into the cervical canal, below the level of internal os or 1-2 mg in the posterior for nix . Parenteral : (a) PGE2 (LV) - Prostin E2 containing 1 mg/ml (b) PGF2 alpha Prostin F2a (Dinoprost tromethamine) containin5 mg/ml (c) Methyl analogue of PGF20 (Carboprost - containing 250 µg/ml).

7. Mifepristone progesterone receptor antagonists) it blocks both progesterone and glucocorticoid receptors . RU 486, 200 mg vaginally daily for 2 days has been found to ripen the cervix and to induce labour. Onapristone (ZK 98299) is a more selective progesterone receptor antagonists.

8. Oxytocin It i s an endogenous uterotonic that stimulates uterine contractions. Oxytocin receptors present in the myometrium are more in the fundus than in the cervix. Receptor concentrations increase during pregnancy and in labour . Oxytocin acts by (a) receptor mediation (b) voltage mediated calcium channels (c) prostaglandin production. Because of short half life (3-4 minutes) plasma levels fall rapidly when intravenous infusion is stopped . Oxytocin is effective for induction of labour when the cervix is ripe. It is less effective as a cervical ripening agent.

9. Oxytocin Oxytocin is a naturally occurring hormone that exerts a stimulatory effect on myometrial contractility. The effect of oxytocin on the myometrium is mainly dependent on the concentration of oxytocin receptors present. Receptors are not present in non-pregnant myometrium; they appear at around 13 weeks of pregnancy and increase in concentration until term. The highest concentration is in the uterine fundus. Synthetic oxytocin is given antenatally to aid uterine contractility, either in induction of labour or in augmentation of labour, or postpartum for prevention or treatment of uterine atony.

10. Cont. It can be given by any parenteral route. In labour it is generally given by intravenous infusion in order that the amount given can be titrated against its effect. It takes 20-30 minutes for oxytocin to reach a steady state and the rate of infusion of oxytocin should therefore not be increased at time intervals less than 30 minutes. The half-life of oxytocin is 10-12 minutes For treatment and prevention of post- partum haemorrhage , larger doses of oxytocin can be given either by intravenous or intramuscular bolus or by intravenous infusion. Care should be taken when administering intravenous bolus doses, which should be given by slow injection.

11. Mode of action directly acting on the myometrium later during labour. Dose For induction: It starts with 0.5 – 1unit in Rl with 15,30,60drops increasing at every 15 mins . If no response 2 unit in RL 500ml with the same rate. Controlling PPH: 10-20unit of oxytocin

12. Indications of oxytocin A. Therapeutic 1. Early PREGNANCY Abortion ( inevitable or missed abortion) T o stop bleeding following evacuation of the uterus us ed as an adjunt to induction of abortion along Other n agent PGE, Or PGE2 2. Late pregnancy To induce labour To ripen the cervix before induction Augmentation of labour Uterine inertia B. Diagnostic Contraction stress test Oxytocin sensitivity test

13. Indications of oxytocin Therapeutic Labour In active management of third stage of labour Expulsion of placenta Puerperium It minimize blood loss To control PPH Diagnostic

14. Contraindications of oxytocin In pregnancy Grand multipara Contracted pelvis History of c- section or hysterotomy Malpresentation In labour All the contraindications in pregnancy Obstructed labour Incoordinate uterine contraction Fetal distress Other Hypovolemic state Cardiac disease

15. Danger signs Maternal danger signs Uterine hyperstimulation( overactivity ) Uterine rupture : High risk: grand multipara, malpresentation, Contracted pelvis, excessive oxytocin Water intoxication Hypotension antidiuresis FetaL danger signs Fetal distress

16. Cont. The major side-effect of oxytocin is water retention and hyponatraemia, which is particularly relevant in women with pre-eclampsia . This effect is compounded when the vehicle for administration of oxytocin is 5% dextrose.

17. Methergine( ergot derivatives) This is used in the treatment and prevention of post- partum haemorrhage. It is a powerful constrictor of smooth muscle and therefore causes myometrial con- traction. Methylergonetrine( methergine), ergometrine( ergonovine), syntometrine(sandoz) MODE OF ACTION It directly acting on the smooth muscles of uterus and stimulate the uterus in a state of spasm and cause them to contract . DOSE AND ROUTE Oral route: 1mg IM: 0.5 mg IV: 0.25 mg

18. Indication and contraindications It stop uterine bleeding after delivery and abortion. It cut short the normal duration of 3 rd stage of labour in order to minimise the blood loss given after the delivery of anterior shoulder during crowing. CONTRAINDICATION SEVERE PPH RH –VE MOTHER MULTIPLE PREGNANCY TWIN PREGNANCY ORGANIC CARDIAC DISEASE Severe hypertension

19. Side effects nausea, vomiting and hypertension . In women with pre-eclampsia

20. EPIDOSIN(VALETHAMATE BROMIDE NF) Relaxation of the spasm of the smooth muscle without causing any serious reaction . Epidosin injection is a smooth muscle relaxant and is used to manage pain related to muscle spasms and menstruation (painful periods). It is also used in the urinary tract and bile stone colic. It is also used for cervical dilatation (opening of the cervix) in the first stage of labour. Contraindications of Epidosin 8 MG
If you are allergic to valethamate or any other ingredients of the Epidosin injection.
If you have problems with your liver or kidneys.
If you have glaucoma.
If you have any intestinal blockage or obstruction.
If you suffer from a condition called Pyloric stenosis, wherein the opening between the stomach and small intestine thickens.
If you have ulcerative colitis (a condition that causes inflammation in the digestive tract).

21. Cont. Side effects of Epidosin 8 MG Dry mouth Flushing of face Constipation Difficulty in swallowing Difficulty in passing urine Rapid heartbeats Blurred vision Glaucoma (increased pressure within the eyeball)

22. Drugs used in postnatal periods BROMOCRIPTINE Bromocriptine belongs to the group of medicines known as ergot alkaloids. Bromocriptine blocks the release of a hormone called prolactin from the pituitary gland. Prolactin affects the menstrual cycle and milk production. A dopamine agonist, binds to dopamine receptors and inhibits pituitary prolactin secretion. Administration of bromocriptine also induces a cyclic and physiologic estrogen secretion and is useful in treating symptomatic galactorrhea and inducing ovulation. Indication Amenorrhea Hyperprolactinemia Type 2 DM Acromegaly Parkinson’s disease