McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 2 3 Antiseizure agents

TABLE 23.2

DRUGS IN FOCUS Drugs for treating generalised seizures

Drug name

Dosage/route

Usual indications

Hydantoins

Adult: 100 mg PO t.d.s., up to 300–400 mg/ day; 10–15 mg/kg IV Paediatric: 5–8 mg/kg per day PO; 5–10 mg/kg IV in divided doses Adult: 60–100 mg/day PO; 200–320 mg IM or IV for acute episodes, may be repeated in 6 hours; reduce dose with elderly and with renal or hepatic impairment Paediatric: 3–6 mg/kg per day PO; 4–6 mg/ kg per day IM or IV; 15–20 mg/kg IV over 10–15 mins for status epilepticus Adult: 250 mg PO five to six times per day Paediatric (>8 years): 250 mg PO five to six times per day Paediatric (<8 years): 125–250 mg PO t.d.s.

Treatment of tonic–clonic seizures, prevention of status epilepticus and treatment of seizures after neurosurgery

phenytoin (Dilantin)

Barbiturates and barbiturate-like drugs phenobarbitone (generic)

Long-term treatment of tonic–clonic seizures localised in the cortex; treatment of cortical focal seizures, simple partial seizures, febrile seizures; used as a sedative/hypnotic; emergency control of status epilepticus and acute seizures associated with eclampsia, tetanus and other conditions Alternative choice in treatment of tonic– clonic, partial, febrile and refractory seizures; may be combined with other agents to treat seizures that cannot be controlled by any other antiseizure agents Treatment of absence and myoclonic seizures; administered to people who do not respond to succinimides; being studied for use in the treatment of panic attacks, restless leg movements during sleep, hyperkinetic dysarthria, acute manic episodes, multifocal tic disorders, neuralgias and as an adjunct in the treatment of schizophrenia Treatment of severe convulsions, clonic– tonic seizures, status epilepticus; treatment of alcohol withdrawal and tetanus; relieves tension, preoperative anxiety; being studied for use in treatment of panic attacks; this drug is no longer used for long-term management of epilepsy Treatment of absence seizures, especially in children with open-angle and secondary glaucoma; to decrease oedema associated with heart failure and drug use; and as a prophylaxis and for mountain sickness Drug of choice for myoclonic seizures; second-choice drug for treatment of absence seizures; also effective in mania, migraine headaches and complex partial seizures Treatment of epilepsy not well controlled by other antiepileptic drugs Adjunct for treatment of absence seizures Drug of choice for treatment of absence seizures

primidone (Mysoline)

Benzodiazepines clonazepam (Rivotril)

Adult: initially 1.5 mg/day PO in three divided doses, up to a maximum 20 mg/day Paediatric (<2 years): 0.5–1 mg/day Paediatric (2–5 years): 1.5–3 mg/day Paediatric (6–12 years): 3–6 mg/day

Adult: 2–10 mg PO b.d. to q.i.d.; 0.2 mg/kg PR, may repeat in 4–12 hours; 2–20 mg IM or IV Geriatric or debilitated people: 2–2.5 mg PO daily to b.d.; or 2–5 mg IM or IV Paediatric: 1–2.5 mg PO t.d.s. to q.i.d.; or 0.3–0.5 mg/kg PR with a repeat in 4–12 hours if needed; 0.25 mg/kg IV over 3 mins, may repeat in 15–30 mins for up to three doses

diazepam (Valium)

Succinimides

Adult and paediatric: 20–30 mg/day in two divided doses

ethosuximide (Zarontin)

Drugs that modulate the inhibitory neurotransmitter gamma-aminobutyric acid acetazolamide (Diamox) 250–1000 mg/day PO regardless of age; 250 mg PO daily if used with other antiepileptics

sodium valproate (Epilim)

Initially, 600 mg/day. Maximum 2.5 g/day Paediatric: use extreme caution, determine dose by age and weight

vigabatrin (Sabril)

Initially, 1000–3000 mg/day PO

zonisamide (Zonegran)

Adults (>16 years): 100 mg PO daily up to 600 mg/day