ANTI EPILEPTICS DURING PREGNANVY
- 1. DRUG PRESENTATION ANTICONVULSANTS DURING PREGNANCY PRESENTED BY : RITU CHAHAL 2017033
- 2. INTRODUCTION • Prescribing antiepileptic drugs (AEDs) in pregnancy is a challenge to the clinician. In women with proven epilepsy, it may be dangerous to stop or even change the AED regimen during pregnancy. Changes could lead to injury or death in both the mother and the fetus. Most women with epilepsy are consigned to continue their AEDs before, during and after pregnancy. Drug levels should be monitored consistently during pregnancy. The risks to the fetus must be delineated in terms of side effects from specific drugs as well as risks from the seizure disorder itself.
- 4. PHARMACOKINETICS • Absorption by oral route is slow, mainly because of its poor aqueous solubility. • Widely distributed in the body and is 80-90% bound to plasma protein. • Metabolism is in the liver. • Excreted through the kidneys.
- 5. CONT… 1. Most conventional drugs (except gabapentin) metabolized in liver & in some cases active metabolite formed. 2. Many antiseizure drugs are medium to long acting because slow plasma clearance. 3. Older antiseizure drugs are potent inducer of hepatic microsomal enzyme ex. carbamazepine & phenytoin. 4.Drugs that induce hepatic drug metabolizing enzyme make antiseizure drugs inadequate for seizure control.
- 6. MECHANISM OF ACTION • 1. Prolongation of Na+ channel inactivation. Phenytoin Carbamazepine Valproate Lamotrigine
- 7. CONT… 2. Inhibition of T type Ca++ channel. Ethosuximide Valproate lamotrigine
- 8. CONT… • 3. Facilitation of GABA mediated chloride channel opening Barbiturate Benzodiazepine Valporic acid Gabapentine
- 9. INDICATIONS • Prevention and control of seizure activity. • Long- term maintenance treatment of epilepsy. • Acute treatment of convulsions and status epilepticus. • Brain surgery, Head injury = Prophylactic AED Theary
- 10. CONTRAINDICATIONS • Hypersensitivity to drugs • History/Presence of Atrioventricular block • Bone marrow depression • Hepatic impairment • Dyspnea or airway obsrtruction
- 11. MAGNESIUM SULPHATE Action : Decreases the Ach in motor nerve terminals, which is responsible for anticonvulsants properties. Uses : It is valuable drug, lowering seizure threshold in women with pregnancy-induced hypertension. Dose and Route : 4gm IV slowly over 5-10 min following by 5 gm MgSO4 IM into each buttock. Side effects : Maternal – Hypotension, cardiac arrythmias, phlebitis at injection site. Fetal – Prolonged use by epileptic patient may cause carinofocal abnormalities, mental retardation, microcephaly and growth deficiencies.
- 12. NURSING CONSIDERATION Assess • Vital signs 15 min after IV dose. • Monitor magnesium levels. • If using during labour, time contractions, determine intensity. • Urine output should remain 30 ml/hr or more, if less notify physician. Administer • Only after calcium gluconate is available for treating magnesium toxicity. • Using infusion pump or monitor carefully IV at less then 150 mg/min, circulatory collapse may occur. • Only dilution.
- 13. CONT… Perform/Provide • Seizer precautions, place client in single room with decreased stimuli, padded side rails. • Positioning of the client in left lateral recumbent position to decrease hypotension and increase renal blood flow. Evaluate • Mental status, sensorium, memory. • Discontinue infusion if respirations are below 12/min or fetal distress.
- 14. DIAZEPAM Action- Depresses subcortical levels of CNS, anticonvulsants and antianxiety. Doasge And Route- PO, 2to 10 mg tid-qid. IV 5 to 20 mg (bolus), 2mg/min, may repeat after 5-10min, not to exceed 60 mg, may repeat in 30 min if seizures reappear. Side Effects- Mother- Hypotension, Dizziness, drowsiness, headache. Fetal- Respiratory depressant effects, which may last for even 3 weeks after birth.
- 15. NURSING CONSIDERATION Assess • BP in lying and standing positions, if systolic pressure falls 20 mmHg, hold drug and inform physician. • Blood studies: CBC. • Hepatic studies. Administer • IV into large vein to decrease chance of extravasation. • PO with milk or food to avoid GI symptoms.
- 16. CONT… Provide • Assistance with ambulation during beginning therapy since drowsiness and dizziness may occur. • Safety measures include side rails. Evaluate • Therapeutic response • Mental status, sleeping pattern. • Physical dependence, headache, nausea, vomiting.
- 17. PHENYTOIN Action – Inhibits spread of seizure activity in motor cortex. Dosage and route of administration- Eclampsia: 10 mg/kg IV at the rate not more than 50mg/minute, followed 2 hours later by 5 mg/kg. Side Effects- Maternal- Hypotension, cardiac arrhythmias and phlebitis at injection site. Fetal- Prolonged use by epileptic patients may cause craniofocal abnormalities, mental retardation, microcephaly and growth deficiency.
- 18. NURSING CONSIDERATION Assess • Blood studies: CBC, Platelets every 2 weeks until stabilized. Administer • After diluting with normal saline, never water. Evaluate • Mental status, memory. • Respiratory depression. • Sore throat, brushing.
- 19. PHENOBARBITONE Action : Decreases impulsive transmission and increases seizure threshold at cerebral cortex level. Dose and Route : 120-240 mg/day in divided doses. Side Effects : Maternal – Sedation, drowsiness, hangover headache, hallucinations. Fetal – Withdrawal syndrome.
- 20. NURSING CONSIDERATION Assess • Blood studies, liver function tests during long term treatment. • Therapeutic level 15 to 40 mg/ml. Evaluate • Mental status, mood affect and memory. • Respiratory depression. • Fever, sore throat bruising, rash.
- 21. CARBAMEZAPINE Action : Decreases synaptic transmission in the CNS hence have anticonvulsant property. Dose and Route : 600-1200 mg/day in divided doses. Therapeutic level : 6-12 mcg/ml. Side Effects : Maternal – Drowsiness, leukopenia, ataxia, mild hepatotoxicity. Fetal – Possible carinofacial and neural tube defects
- 22. VALPORIC ACID Action- It blocks Na+ channels , increases the activity of GABA in the brain. Dose and Route- 300-500 mg. PO, divided doses Side Effects- Maternal- Ataxia, drowsiness, alopecia, hepatotoxicity, thrombocytopenia. Fetal- Neural tube defects, carinofacial and skeletal defects.
- 23. NURSING CONSIDERATIONS • Assess vital signs 15 min after iv dose ; access for fetal distress. • Monitor drug therapeutic levels periodically. • Provide seizure precautions, place client in single room with decreased stimuli, padded side rails. • Positioning of the client in left lateral position to decrease hypotension and increases renal blood flow. • Evaluate mental status, sensorium, memory. • Administer drug into large vein to decrease chance of extravasation. • Oral drug should be taken with milk or food to avoid GI symptoms. • Teach family not to discontinue medication abruptly