Neurology

How does carbamazepine affect cytochrome P450 metabolism?

Induces

In which organ is carbamazepine mainly metabolised?

Liver

How may carbamazepine affect plasma concentrations of hormonal contraceptives?

Decreases levels – alternative/back-up contraception should be considered

Does carbamazepine cross the placenta?

Yes

What is the mechanism of action of sodium valproate?

Increases the availability/activity of gamma-aminobutyric acid (GABA) – an inhibitory neurotransmitter – to brain neurones

Is sodium valproate safe in pregnancy?

No – teratogenic

Is sodium valproate found in breast milk?

Yes

List 4 teratogenic effects which may be associated with carbamazepine and sodium valproate

1) Neural tube defects

2) Craniofacial defects

3) Cardiovascular malformations

4) Neurodevelopmental disorders

How may sodium valproate affect platelet count?

Reduces i.e., thrombocytopenia

How does phenytoin affect cytochrome P450 metabolism?

Induces

What side-effect can phenytoin have on the gums?

Gum hypertrophy

Which vitamin deficiencies may be side-effects of phenytoin?

1) Folate

2) Vitamin D