DRUG'S IN PREGNANCY

⚜UTROTONIC DRUGS (ECBOLICS-OXYTOCICS)⚜
(1)🔅Oxytocin (Syntocinon):
🔸Action:
- increases the frequency & strength & duration of uterine contractions (tonic contraction).
- act on uterus mainly (increase prostaglandin level).
🔸Indication:
a- management of certain types of abortion to help the uterus to expel its contents and prevent post-abortive bleeding.
b- induction of labour.
c- oxytocin sterss test to assess fetal well-being .
d- prevention/treatment of PPH.
e- uterine inertia during labour.
f- placental abruption.
g- management of third stage of labour.
h- durring caesarean section
to hasten separation of placenta & reduce bleeding.
i- breast engorgement oxytocin nasal drop or spray or buccal tablet at time of breast feeding to increase milk flow.
🔸Contraindication:
a- obstructed labour (cephalo-pelvic
disproportion).
b- malpresentation as oblique or transverse lie.
c- hypertonic uterine. dysfunction.
d- uterine scar.
e- fetal distress.
f- placental insufficiency.
🔸Complication(Side effect):
a- uterine hyperstimulation.
b- uterine rupture.
c- cervical lacerations.
d- contraction ring.
e- secondary uterine inertia with subsequent PPH.
f- fetal asphyxia high dose can cause neonatal jaundice.
g- amniotic fluid embolism & water intoxication due to antidiuretic effect.
h- maternal hypotension with rapid iv injection.
🔸Route of administration:
- orally: a tablet is placed between gum & cheek and left to dissolve slowly in 30m. can repeated every 1/2h.
- intramuscularly: but this is avoided before delivery of the fetus.
- intravenously: by drip method and this is the best.
- intrauterine: during ceasarean section.
- nasal spray or drop.
(2)🔅- Ergometrine (ergonovine):
🔸Action:
- causes a prolonged uterine spasm. the action lasts about 4 hours. should never be used before delivery of the fetus as it may lead to tonic contraction of uterus causing fetal asphyxi & rupture of uterus.
🔸Indication:
a- management of certain types of abortion & postabortive bleeding.
b- prevention/treatment of PPH.
c- during ceasarean section.
d- management of third stage of labour.
e- subinvolution of labour.
🔸Contraindication:
a- HTN, eclampsia as it raises blood pressure.
b- heart disease.
c- before delivery of fetus.
🔸Route & Dose:
- orally: as tablets or drops.1mg starts action after 7 m.
- intramuscularly: 0.5mg starts action after 3.5m.
- intravenously: 0.25 mg start action in 45 s.
🔸Complication:
- dyspnoea, bradycardia.
- transient HTN.
- vasoconstriction.
- stroke, MI, pulmanary oedema.
(3)🔅- Prostaglandin:
🔸Action:
- ripening of the cervix are drug of choice to induction of labour if cervix is unripen (break down the collagen fibres and increase amount of hyaluronic acid which is hygroscopic lead to cervical oedema make the cervix soft & dilate easily ).
- stimulation or starting of uterine contraction at any stage of labour.
- increase sensitivity & receptors of oxytocin (act
through normal physiology).
🔸Indication:
a- induction of labour.
b- induction of abortion.
c- treatment of atonic PPH.
🔸Contraindication:
generally contraindication in woman with - asthma. - ischaemic heart disease. - pulmonary hypertension. - epilepsy.
🔸complication:
- nausea & vomiting.
- diarrhoea. - bronchospasm.
- maternal pyrexia. - uterine rupture. - uterine hyper-stimulation. - cervical lacerations.
🔸Route:
- orally. - intramuscularly.
- intravenously. - intramyometrial. - vaginal “best route” as tablets or gel form. - intracervical gel.
             ⚜(Important Note)⚜
🔆Advantage Of Prostaglandins Over Oxytocin Infusion For Labour Induction🔆
🔸prostaglandins are used when the cervix is unripe while oxytocin is not used in this situation.
🔸reduced incidence of neonatal jaundice & hyperbilirubinaemia which may occur with oxytocin infusion.
🔸maternal water intoxication may occur with oxytocin infusion when a large dose is given for long period.
(4)🔅- Magnesium sulphate:
🔸Action:
(Magnesium sulphate can also be used as tocolytics “first agent due to high safety” - tocolytics drugs delay the onset of labour for not more than 48 hrs)
- cerebral vasodilator.
- membrane stabilizer.
(displace intracellular Ca by Mg so, inhibition of contraction)
🔸Indication:
- severe pre-eclampsia to
prevent occurance of fit.
- abort fit in eclampsia.
- used as tocolytics.
🔸Contraindication:
- neuromuscular disease.
- Myasthenia Gravis.
- renal failure.
- cardiac disease.
🔸Complication:
- respiratory depression.
- cardiac arrest
(therapeutic range in the
serum: 2-3 mmol/L)
Sings Of toxicity.
- BP below 110/70 mmHg.
- RR below 16 breath/min.
- oliguria (<30 mL/h).
- absent knee jerk reflex.
🔸Route:
- 5 g over 20 min via an infusion pump.
- continue with 2 g/h
🔸Antidote:
   - calcium gluconate.
         ⚜TOCOLYTIC DRUGS⚜
(1)🔅- Ritodrine ( yutopar ):
🔸Indication:
- transfer the pt to suitable area (<48 hr).
- to inhibit uterine contractions to prevent preterm labour.
- give steroid to the mother for lung maturity.
🔸Action:
beta-agonists cause relaxation of smooth muscle fibres by stimulating beta-adrenergic receptors on the cell membrane.
🔸Side Effect (complication):
a- maternal: - general as headache. nausea. vomiting. flushing. sweating. tremors.
- cardiac: tachycardia. arhythmias. palpitations. myocardial ischaemia. chest pain. HF. S-HNT. D hypotension. P oedema.
- metabolic: hyperglycaemia. hyperinsulinaemia. hypokalaemia. hypocalcaemia. antidiuretic effect. raise thyroid activitie.
- others: paralytic ileus. skin rash. pruritus.
b- fetal: tachycardia. arhythmias. loss of beat to beat variation. myocardial ischaemia. HF. hypotension. hypokalaemia. hypocalcaemia. hyperbilirubinamia. pulmonary oedema.
🔸Contraindications:
- heart failure. - hypertension
- hyperthyroidism. - APH. - uncontrolled diabetes.
🔸Route & Dose:
- Iv 50mg in 500ml 5% dextrose solution start by 50 micrograms/m and increase by 50 micrograms every 10minutes until uterine contractions cease. the infusion should be continued for at least 12 h after cessation of contractions.
- Orally: one tablet 10mg every 6-8h.
(2)🔅- Atosiban (tractocile):
🔸Indication as ritodrine
🔸Action:
oxytocin antagonist
🔸Side Effect:
less side effect, but expensive.
🔸Route & Dose:
- intravenous infusion in 5% dextrose solution or normal saline. 18mg/h for 3h then 6mg/h for up to 45h.
(3)🔅- Nifedipine:
🔸Action:
calcium channel blocker
(prevent Ca entry to cell).
🔸Side Effect:
- orthostatic hypotension.
- severe headache.
🔸Dose and Route:
- sublingual or orally as 10-20mg 3 times daily.
(4)🔅- Indomethacin (Indocid):
🔸Action:
prostaglandin synthetase
inhibitor (NSAID)
🔸side Effect:
- fetal: - premature closure of ductus arteriosus (>34wks) lead to pulmonary hypertension. heart failure. and even death.- necrotizing enterocolitis. - oligohydramnios.
🔸Route & Dose:
- orally: 25mg/6h.
- suppository: 100mg is inserted twice daily for 3 or 4 days not more but can repeated after 5 days.
⚜ANTIHYPERTENSIVE DRUGS⚜
(1)🔅- Methyldopa (aldomet):
🔸Indication:
- prevention of cerebrovascular accident .
- lower BP gradually aiming of diastolic PB 90-100 mmHg (pre-eclampsia).
🔸Action:
inhibits the release of noradrenaline by acting on vasopressor centers in brain stem (central action) lead to vasodilatation and decrease in peripheral resistance.
🔸Side Effect:
- postural hypotension,
depression, insomnia
(2)🔅- Hydralazine (IV):
🔸Action:
relaxation of arteriolar smooth muscle (peripheral vasodilator) and decrease peripheral resistance.
🔸Dose and Route:
- oral dose is 25-50mg every 6 hours.
- intravenously for rapid control of high blood pressure in severe pre-eclampsia and eclampsia.
🔸Methods of iv administration:
a-)  intermittent method.
- Give 5mg iv as a bolus slowly then give 5 - 10 mg every 15-20 m till the diastolic blood pressure is 90-100 mmHg keep thes level by repeating the injection as necessary.
b-) Continuous infusion.
100mg in a liter of 5% glouse solution given iv at a rate of 2 mg/h (5 drops/m) the rate is increased or decreased every 15-20 m to reach a diastolic pressure of 90-100 mmHg which is maintained.
🔸Side Effect:
flushing, headache,
tachycardia, lupuslike syndrome.
(3)🔅- Nifedipine:
🔸Action:
calcium channel blocker
(prevent Ca entry to cell)
🔸Dose and Route:
- sublingual or orally as 10-20mg 3 times daily.
🔸Side Effect:
orthostatic hypotension,
severe headache.
(4)🔅- Labetalol:
🔸Action:
alpha- & beta- adrenergic blocker so contraindicated in asthma.
🔸Dose and Route:
- orally 200mg 3 time daily and can be incerease.
- iv in acute cases.
🔸Side Effects:
- reduced placental blood flow. - intrauterine growth restriction. - preterm labour. - fetal bradycardia.
- respiratory depression.
- hypoglycaemia in newborn.
(note)all above antihypertensive 👆🏻are rapidly acting except methyldopa which may effect appears after 2-3 days.
- two drugs commonly used for treatment of hypotensive disorders of pregnancy are methyldopa & hydralazine.
            ⚜STEROID⚜
single course of maternal
- steroids (two injections IM 12-24 hrs apart) given between 28 & 34 wks gestation & received within 7 days of delivery (for fetal lung maturation) “dexamethasone”"betamethasone"
  ⚜Lignocaine(Lidocaine)⚜
🔸Action:
- local anaesthetics.
🔸Indication:
- preineal & dental anasthesia.
- ventricular arrhythmia.
🔸Contraindication:
- hypovolaemia.
- complete heart block.
🔸Side effect:
- CNS effect (confusion, convulsion)
- respiratory depression, hypotension, bradycardia
🔸Dose:
Infiltration by injection. maximum dose 200 mg (or 500 mg if given in solution contain adrenaline)
        ⚜Anticoagulant⚜
- Heparin cause prolongation of APTT (low molecular weight, assessed by factor X assay).
🔸Complication:
1) osteoporosis “if used for > 6 months”.
2) idiosyncratic thrombocytopenia “rare”
         ⚜Antimalarial⚜
(1)🔅- Quinine:
- IV:- loading dose 20 mg/kg over 4 hr.
- then, 10 mg/kg/8 hr for 7 days.
- oral:- after recover consciousness; Quinine 10 mg/kg & clindamycin 5 mg/kg 3 times per day for 7 days.
🔸Side Effect:
- hypomagnesaemia & hypoglycaemia (that kill the fetus).
- overdose; headache, dizziness, severe CNS disturbance & delirium.
- rapid IV administration can precipitate hypotension & fatal cardiovascular toxicity.
(2)🔅- Artesunate: - IV:- 2.4 mg/kg at hr 0, 12, 24, & then every 24 hr - oral: 2 mg/kg for 7 days + clindamycin as above.

د/سامي عارف عبدالجليل الشميري.