Clinical toxicology in the neonatal intensive care unit.

The role of the clinical toxicologist in the neonatal nursery may be an extremely important one in the evaluation of epidemic-like toxic reactions occurring from: (a) the inappropriate use of medications; (b) the accidental contamination of parenterals; and (c) the introduction of relatively new products into the nursery environment. The newborn with high respiratory demands, thin epidermis with a large surface area to body mass ratio, and nutritional support being derived completely from parenteral sources provides a great number of routes of entry for the introduction of toxins. In approaching these problems, the clinician needs a structured approach in considering the impact of the route of administration, the contents of the product and the ability of the newborn to eliminate the toxin in question. In addition, some knowledge of the specialised structures and diseases of the newborn is required to adequately analyse the impact of a potential toxin on newborn disease processes. What we normally consider as adverse drug reactions are extremely rare in the neonate. Hypersensitivity phenomenon and the classic non-dose-related side effects described in adults are rare occurrences. This makes it a challenge for the clinical toxicologist to analyse and attempt to identify a toxic substance in the nursery. Having identified a toxin in the newborn, treatment may be complicated by the inability to use many of the standard forms of therapy, e.g. activated charcoal, diuresis, and extracorporeal removal. The lack of practicality of these procedures increases the necessity for good supportive care. Exchange transfusion, rarely considered in older children and adults, may offer the only viable option for rapid removal of a drug.