Reviewed by Dr Malcolm Battin, Brenda Hughes, Julia Blagburn, Robyn Wilkinson
July 1999
Dose and Pharmacology Newborn Drug Protocol Index Newborn Services Home Page


Management of  Phenytoin Administration


IV Preparation

Oral Preparation



Slow IV Infusion (Avoid administration via central lines)

  1. Dilute immediately prior to use to 5 mg/ml by adding to sodium chloride 0.9% 5. No other diluent is acceptable.
  2. Use a Pall 0.2 micron in-line filter during administration.
  3. Administer at a rate not faster than 1.0 mg/kg/minute 6 using a syringe pump. Diluted solution must be administered within one hour of preparation 5. Observe diluted solution for the formation of crystals.
  4. Flush line with sodium chloride 0.9% before and after administration of phenytoin.
  5. Do NOT mix with other drugs, IV solutions, blood or blood products.


  1. Enteral feeding decreases the absorption of oral phenytoin. Do not give oral feeds for 30 minutes before and after phenytoin dose. Give oral dose with water to increase absorption 6.
  2. As oral phenytoin tends to adhere to the PVC tubing, flush naso-gastric tube with 2ml of water after administration.

Observation and Documentation

  1. Monitor for adverse effects.
  2. Assess for signs of toxicity.
  3. Monitor BP closely. ECG monitor during intravenous therapy.
  4. Assess for and document any seizure activity.
  5. Observe administration site closely. Extravasation may cause tissue inflammation and necrosis.


Selected References

1 Roberts RJ. Drug therapy in infants: Pharmacologic principles and clinical experience. Philadelphia, WB Saunders 1984: p104-110.
2 Painter MI, Pippenger C, Wasterlain C, et al. Phenobarbitol and phenytoin in neonatal seizures; Metabolism and tissue distribution. Neurology 1981; 31:110-7
3 Loughnan PM, Greenwald A, Purton WW, et al. Pharmacokinetic observations of phenytoin disposition in the newborn and young infant. Arch Dis Child 1977; 52:302.
4 Young TE, Mangum OB. Neofax. A Manual of drugs used in neonatal care. Ross Laboratories 5th Ed 1992; p50-51.
5 Loe E. et al. Paediatric Pharmacopoeia, Royal Children’s Hospital Melbourne and Leicester Royal Infirmary Children’s Hospital. WB Saunders Co. Ltd; 1998: London
6 Paediatric Formulary. (4th ed. ) Guy’s, St. Thomas’ and Lewisham Hospitals.
7 Stockley I. Drug Interactions 4th ed. The Pharmaceutical Press; 1996: London
8 Kemp C, McDowell J (eds). Paediatric Pharmacopoeia 12th ed. Pharmacy Dept. Royal Children's Hospital; 1997: Melbourne
9 Phenytoin Injection (DBL) Data Sheet. Baxter Healthcare Ltd.;1996:Auckland.