Here is Ppt on Oxytocin ,Uterine Stimulant and Uterine relaxant( tocolytic drugs). this is all you will need to learn for the exam. Hope you like it! #Medicine #pharmacology #health #baby #women #childbirth #uterinestimulant #hormones #science #heathcare #heathtech #brain #pitutarygland #mbbs #bpharm #bams #bhms #bums #bvms

1. OXYTOCIN
Second year Pharm D
Pharmacology

2. Release Oxytocin & Antidiuretic Hormones which is synthesized in
Hypothalamus
POSTERIOR PITUITARY
HORMONES
ADH ( Vasopressin ) Derivative of supraoptic nucleus.
While Oxytocin is derived from Paraventricular Nucleus

3. OXYTOCIN
Oxy - quick Tokos- childbirth
Appears Essential role in Child birth but Essential role is in Milk Ejection
Oxytocin - Peptide Hormone
Primary Role is milk ejection
Faciliatory role in initiation of labor and parturition.
Half Life - 5 mins.
Not bound to plasma proteins.
metabolized by liver & excreted through Kidneys.
2 mg + 1 IU of Oxytocin.

4. PHARMACOLOGICAL
ACTIONS?

5. Estrogen -> Sensitizes uterus to oxytocin action
Non-pregnant and early Pregnant - resistant to oxytocin ( ONLY 8 %
SENSITIVITY )
pregnant uterus - most sensitive
last trimester - increase sensitivity
The onset of birth - Max
Actual abortion or threatened -> uterus sensitivity
increases
Rate of contraction of the fundus increases during the onset of labor or
abortion
Facilitates relaxation of the cervix & uterus
progesterone -> decreases it
local PG release increases oxytocin
oxytocin levels quickly fall during puerperium
UTERUS

6. High doses -> oxytocin-> vasodilation -> decreases bp & reflex
tachycardia
oxytocin present on limbic system - plays imp role in parenting and
matins .
oxytocin -> closure of umbilical vessels at the time of birth
oxytocin increases doses -> exerts weak Adh-like action & has mild
antidiuretic effects
Also released during orgasm.
MISCELLANEOUS

7. OXYTOCIN RECEPTOR & ANTAGONISTS
Oxytocin receptor -> Gpcr -> Stimulated lead to generation of Ip3 &
subsequent mobilization of ca2+
Oxytocin receptor - Increases in gestation period . varies in diff
periods of pregnancy .
Oxytocin antagonists example - Atosiban
from intracellular stores & depolarization-induced activation of voltage-
sensitive ca2+ channels.

8. Intranasal spray of oxytocin ( 25 - 30 IU )
each nostril ( in a sitting position )
2-3 mins before nursing.
used in milk-yielding cows to facilitate " milk let down " does not
increase milk production.
Rh problem, maternal Dm, pre-eclampsia. erythroblastosis &
placental insufficiency
To promote Milk ejection & resultant Breast engorgement
Initiation and Augmentation of Labor
Oxytocin is used to induce labor in the following situations
a) Situations req early vaginal delivery
THERAPEUTIC USES

9. Oxytocin ->( slow IV infusion) 5 IU / 500 ml glucose normal saline
Drug is discontinued if contractions of uterus increases.
Uterine Inertia :
Oxytocin ( 2-5 IU / 500ml Glucose saline) can be infused
to augment contractions if uterine contractions are feeble or weak
Oxytocin not to be used to accelerate normally progressing labour .
3) Control of postpartum Bleeding
-> Oxytocin % IU , IM or IV immediate resp
IM Oxytocin -> After placenta is expelled causes tetanic contractions of
uterus and arrests postpartum Hemorrhage

10. CONTINUE..
Desamino Oxytocin:- Buccal formulation of oxytocin, which is
convenient to administer, but is less potent.
Induction of labor :- 50IU Buccal tablets repeated 30 min till effects
are observed.
Max dose is 10 tablets or 500 IU
Uterine inertia - 25 IU every 30 min till the desired effects are observed
Breast Engorgement & milk let down 25-50 IU just before Breast-
feeding.

11. Non Judicious use - foetal / maternal soft tissue injury,
Large doses + normal saline = water intoxication.(serious in cases
of pre eclampsia)
Contraindications :- Cephalo-pelvic disproportion
rupture of uterus & foetal asphyxia
Weak adv effects
Breech presentation, Placenta previa, foetal distress,
In these cases delivery by Caesarean section is preferred.
ADVERSE EFFECTS &
CONTRAINDICATIONS

12. UTERINE
STIMULANTS
Oxytocic Drugs

13. MOA:- Drugs & Hormones used clinically to enhance
uterine contractions.
1° goal to Induce / augment contractions during delivery
or at various stages of labor.
Use:- Restricting an extended pregnancy, preventing
early rupture of membranes aiding placental
insufficiency.
minimizing PPH.
OXYTOCIC DRUGS

14. Oxytocin PG's
Ergot
Alkaloids
Oxytocic
Drugs.

15. Ergot Alkaloids:- Ergometrine And synthetic analogues are used.
MOA :- Increase Myometrial contraction of uterus.
Therapeutic Doses :- Contractions are Sustained with interviening
relaxation. No relaxation in higher doses btw 2 tonic contractions.
These are Agonist- Antagonist of serotonin T2 receptor(partial
activation. sustained release) and alpha adrenergic receptor
present on myometrium(block norepinephrine action, enhance
contraction) .
Eg:-
dihydroergonovine - more selective and more potent effect on uterus.
methylergonovine.
Uterus more sensitive to Ergometrine .
ERGOT ALKALOIDS

16. 1) Management of 3 Rd stage of labor
Dose :- 0.2 - 0.5 mg IM - Given on appearance of anterior Foetus
Shoulder.
Contractions Occur within 2-3 mins
Oxy 5 IU may be added
Not to be used for inducing labor or accelerating normal progressing
labor unless there is uterine atony.
Since the cervical Segment is also contracted there is a risk of foetal
distress, compression , asphyxia and death.
2) To treat Post Partum Hemorrhage
Dose :- 0.2-0.5 mg IM
Use :- Administered to prevent PPH after normal or caesarean delivery.
Therapeutic Uses

17. Contractions of Myometrial meshwork compress the bleeding arteries
which stops the bleeding.
C) To ensure Normal Involution
Multipara and other cases - Uterus may not involute rapidly,
0.125 Ergometrine can be given TDS for 7 days
Adverse effects :-
mostly safe but may cause nausea vomiting headache and milk
secretion ( due to dopaminergic action - inhibiting of prolactin
release)
Contraindicated in Angina pectoris MI and Cerebrovascular disease,
transient Ischemic attacks and HTN
Continue

18. Prostaglandin :-
Eg :-
PGE2 - dinoprostone
PGF2alpha - carboprost
PGE1 - misoprostol
Used as potent uterine stimulant specially in later part of pregnancy and
to cause ripening of the cervix .
Misoprostol - PGE1 derivative. Route- Oral. Induce abortion first few
weeks.
Carboprost tromethamine - PGE 2 derivative. Intra Amniotic Inj. Used to
control Postpartum bleeding.
IM carboprost 0.2-0.5 mg every hour - immediate action and sustained
uterine contraction.
PROSTAGLANDIN

19. PG's are not constantly used with Oxytocin cuz of the possibility of
uterine rupture.
Imp points about PG
-PGE2 and PGF2alpha used to terminate pregnancy and to induce
cervical ripening.
PG - 1 St and 2 nd trimester abortion
soften cervix before abortion. By increasing proteoglycan content and
changing the collagen characteristics.
PG > Oxytocin to induce labor in women with Pre-Eclampsia, Eclampsia,
Cardiac or renal disease as they have diuretic and natriuretic effects.
Continue

20. UTERINE
RELAXANT
Tocolytic Drugs.

21. MOA:-
1) Act directly to suppress myometrial smooth muscle contraction
-> Decrease Ca2+ intracellularly
2) Indirectly Inhibit -> synthesis actions of Prostaglandin on Oxytocin
-> Release
-> Receptor
Uses :- Prevention of premature labor (, 37 weeks )
Treat dysmenorrhea
Contain :- Beta 2 adrenergic receptors
MgSo4
CCB
TOCOLYTIC DRUGS

22. MOA:- Bind to Beta 2 receptor on the myometrium
Activate Adenyl cyclase
Increase cAMP Levels
Activate cAMP dependent protien kinase
Decrease Ca2+ conc intracellularly
muscle relaxation
BETA 2 AGONIST

23. CONTINUE
SE:- Palpitations, tremors, N/V, SOB , Hyperglycemia, hypokalemia,
hypotension.
Serious SE:- pulmonary edema, cardiac insufficiency , arrhythmias and
Myocardial ischemia.
Eg :- ritodrine, salbutamol, terbutaline, orciprenaline and isoxsuprine

24. MOA :- When given by IV it controls convulsions and reduce BP in Patients
of pre eclampsia
Directly inhibits cellular action potentials, uncouples excitation -
contraction in myometrial cells.
Uses:- usually preferred in PI with cardiac problems Dm hyperthyroidism,
HTN
Magnesium Sulfate -> Plasma range 6mEq/L - 7.5 mEq/L
SE:- Sweating, flushing, headache, palpitation.
Tocolysis is hard to achieve Below 7.5mEq/L
Above these levels patients initially lose patellar reflexes.
Above 10 - 12 meq/L there is respiratory depression and arrest both in
mother and neonate.
Higher than these levls - cardiac arrhythmias and cardiac arrest
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9.
MAGNESIUM SULFATE

25. MOA:- Impairs Ca2+ entry into myometrial cells via voltage gated l
type channels
At present nifedipine use restricted for prophylaxis of recurrent
premature labor
Dose - 10 mg every 1/2 hr till uterine contractions subside followed
by 10 mg oral QID used for tocolytic purposes.
Side effects :- tachycardia and hypotension appear as prominent
side effects.
Eg:- Nifedipine
CCB

26. THANK YOU!
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