Anticonvulsants 1.5

Question 1

Oral Contraceptives

Answer 1

• The effective levels of contraceptives are altered
by anticonvulsants
– Hepatic metabolism
– Plasma protein binding
• Consequences
– Unplanned pregnancy
– Increased birth defects

Question 2

Pregnancy: Planned pregnancy

Answer 2

• increase folic acid prior to conception
• Switch from barbiturates and phenytoin and stabilize
on new drug
• Possible Teratogenic Effect of Phenytoin
Administration:
– “Fetal Hydantoin Syndrome”: Characteristics: cleft lip, cleft
palate, congenital heart disease, slowed growth, mental
deficiency
• 25-30% of women with epilepsy will have increased
seizures during pregnancy DESPITE continued use of
medication.
– Changes in metabolism: increased drug clearance, increased
maternal volume

More frequent lab values
• Optimal therapy: Monotherapy at lowest possible
dose to control seizures
• Do not completely remove anticonvulsant

Question 3

Pregnancy: Other

Answer 3

More frequent lab values
• Optimal therapy: Monotherapy at lowest possible
dose to control seizures
• Do not completely remove anticonvulsant
• Do not switch anticonvulsant if pregnancy was
unplanned

Question 4

Pregnancy:

Answer 4

• Lack of Anticonvulsant Therapy During Pregnancy in
Epileptic Patients:
– Frequency of Seizures Increase
– Anoxic conditions can increase the incidence of birth
defects (7% compared to 2-3% in general population)
• Malformations increase with combination therapy
• Lower doses may be beneficial in 1st trimester
• Therapeutic drug monitoring:
– To detect alterations in metabolism—especially important
during last trimester when increased drug clearance may
require dosage adjustment

Question 5

Non Pharmacological Therapies for

Epilepsy

Answer 5

Vagal Nerve Stimulation
Surgery
• Removal of epileptic foci
• Only as a last resort

Question 6

Vagal nerve Stimulator

Answer 6

Implant of pulse generator
• Mechanism unknown
Uses
• Partial onset seizures
• Refractory patients for multiple drugs
• Depression
• Very expensive