Theophylline dose prediction.

Two methods of predicting the optimal dose of theophylline in children aged 2 to 13 years were assessed. The observed plasma concentration was within 95% confidence limits of that predicted on eight of 14 occasions using a traditional multiple point pharmacokinetic method. Using a nomogram derived from the plasma concentration 6 hours after dosing and the logarithm of the calculated dose, which were significantly correlated, there was a significant relation between the dose predicted and the actual dose required to produce a concentration of 55 mumol/l.

Serum salicylate levels in a breast fed infant.

All drugs should be given with caution to pregnant or breast feeding women. Recent concern about the role of salicylates in the aetiology of Reye's syndrome has prompted the DHSS to restrict the use of aspirin in children. The case of a 9 week old breast fed infant whose serum contained 0.47 mmol/l of salicylate is reported. Her mother was taking aspirin 2.4 g/day, and it is concluded that salicylates must not be taken by breast feeding mothers.

Re-evaluation of saliva for monitoring theophylline concentrations.

Variability of the mixed saliva/plasma theophylline relation was examined in seven children aged 2 to 13 years. Good correlation between plasma and saliva concentrations was found, but on the three occasions there was considerable inter- and intrapatient variability. There was no significant or consistent relation between unstimulated and stimulated saliva concentrations or between saliva concentrations and sample volumes. Plasma theophylline concentrations cannot be predicted accurately from saliva values.