Valproic Acid
Trade names: Depakene, Depakine, Sodium valproate,
Valparin
Class: anticonvulsants, vascular headache
suppressants Pregnancy:
(Category D) Action:
§ Increase levels of GABA, an inhibitory neurotransmitter in the
CNS.§ Therapeutic Effects:
ü Suppression of absence seizures
ü Decreased manic behavior
ü Decreased frequency of migraine headaches.
Uses:
§ Simple and complex absence seizures § Partial seizures with
complex symptomatology § Divalproex only:
ü Manic
episodes associated with bipolar disorder (delayed-release only) ü Prevention of migraine headache (delayed and extended
release).
§ Unlabelled Uses:
ü IV: Treatment of migraine
headache.
Dose:
§ by mouth, initially, 600 mg daily given in 2 divided doses,
preferably after food, increasing by 200 mg/day at 3-day intervals to a max. of
2.5 g daily in divided doses, usual maintenance 1–2 g daily (20–30 mg/kg
daily);
§ CHILD up to 20 kg, initially 20 mg/kg daily in divided doses,
may be increased provided plasma concentrations monitored (above 40 mg/kg daily
also monitor clinical chemistry and haematological parameters);
§ over 20 kg, initially 400 mg daily in divided doses increased
until control (usually in range of 20–30 mg/kg daily); max. 35 mg/kg daily
§ By
intravenous injection (over 3–5 minutes) or by intravenous infusion,
continuation of valproate treatment when oral therapy not possible, same as
current dose by oral route.
Contraindications:
§ Hypersensitivity
§ Hepatic impairment
§ Some products contain tartrazine; avoid in patients with known
hypersensitivity.
Side effects:
§ CNS: confusion, dizziness,
headache, sedation.
§ EENT: visual disturbances.
§ GI: HEPATOTOXICITY,
indigestion, nausea,
vomiting, anorexia,
constipation, diarrhea, hypersalivation, increased appetite,
pancreatitis.
§ Derm: rashes.
§ Hemat: leucopenia, prolonged
bleeding time, thrombocytopenia.
§ Metab: hyperammonemia.
§ Neuro: ataxia, paresthesia.
Nursing
considerations:
§ Valproic acid may cause an upset stomach. Instruct the pt to
take it with food and to drink plenty of water and not to take the liquid with
carbonated beverages.
§ If you give this drug to a child, observe and keep a record of
the child's moods, behavior, attention span, hand-eye coordination, and ability
to solve problems and perform tasks requiring thought. Ask the child's teacher
to keep a similar record.
