Emergency treatment of convulsive status epilepticus
Forms and strengths, route of administration
250 mg in 5 ml ampoule (50 mg/ml) for infusion in 0.9% sodium chloride DO NOT DILUTE IN GLUCOSE.
DO NOT ADMINISTER BY IM INJECTION.
Dosage and duration
Child 1 month and over and adult: one dose of 15 to 20 mg/kg to be administered over 20 minutes minimum and 60 minutes maximum
The concentration of the diluted solution should be between 5 and 10 mg/ml. The infusion rate should not exceed 1 mg/kg/minute or 50 mg/minute(25 mg/minute in elderly patients or patients with cardiac disorders).
For example:
Child weighing8 kg: 160 mg (20 mg x 8 kg), i.e. 3.2 ml of phenytoinin 17 ml of 0.9% sodium chloride over 30 minutes
Adult weighing 50 kg: 1 g (20 mg x 50 kg), i.e. 20 ml of phenytoin in a bag of 100 ml of0.9% sodium chloride over 30 minutes
Contra-indications, adverse effects, precautions
Do not administer in patients with bradycardia, atrioventricular block.
Administer with caution in patients with hepatic impairment (reduce dosage), heart failure, cardiac rhythm disorders, hypotension.
Administer with caution in patients taking:
sulfonamides, chloramphenicol, fluconazole, isoniazid, fluoxetine (effects of phenytoin increased);
rifampicin , ciprofloxacin, ritonavir, folic acid (effects of phenytoin decreased).
May cause:
hypotension, bradycardia, conduction disorders, depression of the central nervous system when administered too quickly;
irritation or swelling at injection site; necrosis in the event of extravasation;
hepatotoxicity; haematologic disorders; allergic and cutaneous reactions, sometimes severe.
Use a large catheter.
Monitor closely heart rate, blood pressure and respiratory rate during and after administration. Reduce the infusion rate in the event of a drop in blood pressure or bradycardia.
For women taking estroprogestogen, use condoms until next menstruation (decreases the efficacy of the contraceptive).
Pregnancy and breast-feeding: risks related to status epilepticus are greater than risks related to phenytoin.
Remarks
Never dilute phenytoin in glucose (risk of precipitation).
After each infusion, rinse with 0.9% sodium chloride to limit local venous irritation due to alkaline pH of phenytoin.
Do not mix with other drugs in the same infusion.
Storage
– Below 25 °C
If refrigerated a deposit may form in the solution that later dissolves at room temperature. Check the solution is completely clear before administration.