Volume 108 Theophylline clearance over time 1 0 1 5 Number 6 dosage for the management of chronic asthma. J PEDIATR 1978;92:125, 4. Arnold JD, Hill GN, Sansom IN. A comparison of the pharmacokinetics of theophylline in asthmatic children in the acute episode and in remission. Eur J Clin Pharmacol 1981 ;20:443. 5. Ekwo E, Weinberger M. Evaluation of a program for the pharmacologic management of children with asthma. J Aller- gy Clin Immunol 1978;61:240. 6. Jackson JE, Powell JR, Wandell M, et al. Cimetidine decreases theophylline clearance. Am Rev Respir Dis !981;123:615. 7. Weinberger M, Hudgel D, Spector S, Chidsey C. Inhibition of theophyltine clearance by troteandomycin. J Allergy Clin lmmunol 1977;59:228. 8. LaForce CF, Miller MF, Chai H. Effect of erythromycin on theophylline clearance in asthmatic children. J PEDIATR 1981;99:153. 9. Landay RA, Gonzalez MA, Taylor JC. Effect of phenobarbi- tal on theophylline disposition. J Allergy Clin lmmunol 1978;62:27. 10. Weinberger M. The pharmacology and therapeutic use of theophyl!ine. J Allergy Clin Immunol 1984;73:525. 11. Loughnan PM, Sitar DS, Ogilvie R1, et al. Pharmacokinetic analysis of the disposition of intravenous theophylline in young children. J PEDIATR 1976;88:874. 12. Weinberger MW, Matthay RA, Ginchansky EJ, eta!. Intra- venous aminophylline dosage: use of serum theophylline measurement for guidance. JAMA 1976;235:2110. 13. Ellis EF, Koysooko R, Levy G. Pharmacokinetics of theoph- ylline in children with asthma. Pediatrics 1976;58:542. 14. Powell JR, Vozeh S, Hopewell P, et al. Theophylline disposi- tion in acutely ill hospitalized patients. Am Rev Respir Dis 1978;! 18:229. 15. Vozeh S, Powell JR, Riegelman S, et al. Changes in theoph- ylline clearance during acute illness. JAMA 1978;240:1882. 16. Wilson AF. Drug treatment of acute asthma. JAMA 1977;237:1141. 17. Chang KC, Bell TD, Lauer BA, Chai H. Altered theophylline pharmacokinetics during acute respiratory viral illness. Lan- cet 1978;1:1132. Clinical and laboratory observations Upper gastrointestinal tract bleeding acquired in a pediatric intensive care unit: Prophylaxis trial with cimetidine Jacques Lacroix, M.D., Claire Infante-Rivard, M.D., Ph.D., Marie Gauthier, M.D., Elisabeth Rousseau, M.D., and Nicolaas van Doesburg, M.D. From the Department of Pediatrics, Pediatric intensive Care Unit, H6pital Sainte-Justine, University of Montreal Stress increases gastric acid secretion, and acid plays a key role in stress ulcers? Menguy 2 found by endoscopy that gastric mucosal lesions developed within hours after a severe stressful event. On this basis, suppression of gastric acid secretion might logically be expected to reduce the incidence of upper intestinal tract bleeding occurring in an intensive care unit, where stress is severe. Upper gastroin- Submitted for publication Oct. 17, 1985; accepted Dec. 10, 1985. Reprint requests: Jacques Lacroix, M.D., H6pital Sainte-Justine, 3175 C6te Ste.-Catherine, Montr6at Qu6bec, Canada H3T 1 C5. testinal tract bleeding occurs frequently in adults 3-s and in burned children, 9 but it has not been specifically studied in children with medical diagnoses in a pediatric intensive care unit. We undertook a double-blind controlled trial to study the effect of cimetidine Versus placebo on the pH of gastric DIC PICU PSI UG!B Disseminated intravascular coagulation Pediatric intensive care unit Physiologic stability index Upper gastrointestinal tract bleeding