This topic contains anticonvulsants used in obstetrics such as magnasium sulphate, diazepam, phenytoin and anticoagulants such as heparin and warfarin.

1. BY, MS. PRIYANKA GOHIL
MSc (N) OBG, PhD SCHOLAR
MBNC,UTU

2. Convulsion in pregnancy is largely due to eclampsia.
Other causes are epilepsy, meningitis, cerebral maleria and
cerebral rumors.
Eclampsia should be considered first unless proved otherwise
by history, examination and investigation.

3. MODE OF ACTION:
It decreases the acetylcholine release from the nerve endings
and reduces the motor end plate sensitivity to acetylcholine.
It also blocks the calcium channels.
It causes vasodilation, increases cerebral, uterine and renal
blood flow.
It decreases intracranial edema.

4. DOSE
IM: Loading dose- 4 g IV (20% solution) over 3-4 min.
To follow 10 g (50% solution) deep IM on alternate buttock
every 4 hours.
IV: Loading dose: 4-6 g over 15-20 min, Maintenance dose is 1-
2 g/hr infusion.
Repeat injections are given only if knee jerks are present, urine
output >30 ML/hr and respiration rate > 12/min.
Therapeutic levels of serum mg is 4-7 mEq/L.

5. SIDE EFFECTS
MgSO4 is relatively safe and is the drug of choice.
Muscular paresis (diminished knee jerks) respiratory faillure.
Renal function is to be monitored.
It does not affect the duration of labour.
Antidote: injection calcium gluconate 10% 10 ML IV
Fetal effects are usually absent.
It is contraindicated in patients with myasthenia gravis.

6. MODE OF ACTION:
Central muscle relaxant and anticonvulsant.
DOSE:
Initially 20-40 mg IV to be followed by an infusion containing
500 ML of dextrose with 40 mg of diazepam, the drip rate
being 30 drops/min or adjusted as per need
Status epilepsticus: 10-20 mg IV after 1 hour, may be followed
by IV infusion to a maximum of 3 mg/kg over 24 hours

7. SIDE EFFECTS
Mother: Hypotension
Fetus: Respiratory depressant effect which may last for even
three weeks after delivery
Hypotonia, thermoregulatory problem in newborn.

8. MODE OF ACTION:
Centrally acting anticonvulsant
DOSE:
Eclampsia: 10 mg/kg IV- at the rate not more than 50 mg/min
followed 2 hours later by 5 mg/kg
Epilepsy: 300-400 mg daily orally in devided doses.
Status epilepticus: 18 mg/kg slow IV (50 mg/min), maintenance
dose of about 100 mg is given at an interval of 6-8 hours.
BP and ECG monitoring should be done.

9. SIDE EFFECTS
Maternal: Hypotension, cardiac arrythmias and phlebitis at the
injection site.
Fetal hydantoin syndrome (characteristic pattern of mental and
physical birth defects that results from maternal use of the
anti-seizure drug) when used in first trimester is observed in 5-
10 % offspring.
This may be due to the disease itself with a genetic
predisposition or due to drug metabolism and deficient folate
level.

11. Anticoagulants are not commonly used in pregnancy.
Cardiac disease, venous thrombosis, antiphospholipid
syndrome (disorder in which the immune system mistakenly
attacks normal proteins in the blood) are some of the
indications.

12. Also known as unfractionated heparin
Low molecular weight heparin
MODE OF ACTION
Inibits action of thrombin.
It also enhances the activity of antithrombin III.

13. DOSE
5000-10,000 IU to be administered parenterally.
Deep vein thrombosis and pulmonary embolism: loading dose is
5000 units IV followed by continuous infusion of 18
units/kg/hour
Pregnancy: 5000-10,000 SC every 12 hours
Deltaparin sodium (Fragmin): 2500 units SC evry 24 hours

14. SIDE EFFECTS
Maternal: Hemorrhage, urticaria with long-term use
thrombocytopenia, hypokalemia.
Fetal: It does not cross the placenta
Low molecular weigth heparins- as effective and safe as
unfractionated heparin.
Longer half life and once daily dose is cinvenient.
Standard dose does not require monitoring.

15. MODE OF ACTION
Interfers with synthesis of vitamin K dependent factors (II, VII,
IX, X)
DOSE:
 10 mg orally for initial 2 days then 3-9 mg daily ( taken at the
same time each day) depending upon the prothrombin time.

16. SIDE EFFECTS
Maternal: Hemorrhage
Fetal: Cornadi's syndrome( skeletal and facial abnormalities),
optic atrophy, microcephaly, chondrodysplasia punctata
(skeletal displasia).