Theophylline poisoning in an infant. A case report

A case of an infant poisoned with theophylline is described. Theophylline elimination was by first-order kinetics; the implications of this observation are discussed.     

Carbon monoxide poisoning.

Carbon monoxide is a common domestic and industrial poison which may be lethal. Survivors can develop permanent neuropsychiatric disability. The mechanisms of toxicity are poorly understood and the traditional criteria used to determine the severity of the poisoning have low predictability. Oxygen is the recommended antidote to carbon monoxide, but it appears that oxygen under hyperbaric conditions repeated either daily or as indicated by the patient's condition may be required to provide an effective dose. A reliable marker of the severity of carbon monoxide poisoning is urgently needed so that trials of alternative regimens can proceed.     

Theophylline for the prevention of radiocontrast nephropathy: a meta-analysis.

BACKGROUND: Radiocontrast nephropathy is a common cause of acute renal failure in hospitalized patients. Several studies have examined the capacity of theophylline or aminophylline to prevent radiocontrast nephropathy, with conflicting results. We conducted a meta-analysis of published randomized controlled trials to determine if the pre-procedural administration of theophylline or aminophylline prevents radiocontrast-induced declines in kidney function. METHODS: We searched MEDLINE, EMBASE, the Cochrane Collaboration Database, bibliographies of retrieved articles, and consulted with experts to identify relevant studies. Randomized controlled trials of theophylline or aminophylline in hospitalized patients receiving radiocontrast were included. Studies were excluded if they did not report changes in serum creatinine or creatinine clearance within 48 h after radiocontrast exposure. RESULTS: Seven randomized controlled trials satisfied all inclusion criteria and were included in the analysis (pooled sample size n = 480). The difference in mean change in serum creatinine was 11.5 micromol/l (95% confidence intervals 5.3-19.4 micromol/l, P = 0.004) lower in the theophylline- or aminophylline-treated groups than controls. One participant (0.6%) required dialysis. CONCLUSIONS: Prophylactic administration of theophylline or aminophylline appears to protect against radiocontrast-induced declines in kidney function. Whether these agents reduce the proportion of patients who experience large decrements in serum creatinine concentration, or require dialysis, is unknown.     

Lead poisoning treated with haemodialysis.

A 27-year-old woman ingested as an abortifacient 40 grams of litharge (PbO). She was treated with EDTA infusion and haemodialysis. The half-life of lead in the blood was 9 hours during combined haemodialysis and EDTA infusion and 96 hours when EDTA was given alone. Signs and symptoms attributable to acute lead intoxication were mild.     

Strychnine poisoning. A clinical case

A patient was admitted following ingestion of 300 mg of strychnine. Early diagnosis and timely reanimation treatment led to his full recovery though he had swallowed a quantity of strychnine greater than the medium lethal dose (50-100 mg for adult).     

Theophylline: potentiation of arginine-induced somatostatin release from the isolated rat pancreas.

Somatostatin's release from the isolated rat pancreas was studied using a perfusion technique. Arginine at a concentration of 19 mM produced a biphasic increase in somatostatin release from the perfused rat pancreas. Both first and second phases of somatostatin's increase are significantly higher in the presence of 1 mM theophylline than in the absence of the drug. These results indicate the possible inclusion of the adenylate cyclase--cyclic AMP system in the regulatory mechanism of rat pancreatic somatostatin secretion.     

Estimation of Theophylline Clearance During Continuous Arteriovenous Hemofiltration

Pharmacologic agents and other non-protein-bound compounds smaller than 5,000 daltons have the potential to be removed by continuous arteriovenous hemofiltration (CAVH). A proposed method for estimating drug clearance by CAVH (ClCAVH) equates ultrafiltrate clearance to the product of the sieving coefficient and the average ultrafiltration rate. This simplified approach for estimating ClCAVH would be a clinically useful method for calculating replacement doses, as it economizes on the sampling and analytical requirements associated with the conventional method. Presented are some theoretical considerations and a brief evaluation of the accuracy of this proposed method. The evaluation was conducted using an animal model whereby CAVH was performed in four male beagles. During the hemofiltration period, an i.v. bolus of theophylline, 6 mg/kg, was administered over 15 s. Samples for analysis of theophylline were collected from the arterial, venous, and ultrafiltrate ports at 0, 5, 15, 30, 45, 60, 90, 120, 180, 240, 360, and 480 min following dosage administration. The volume of ultrafiltrate produced during each collection interval was measured. Theophylline serum concentrations were determined by a high performance liquid chromatography assay. Statistically, the simplified method was found to result in significantly (p less than 0.05) larger estimates of ultrafiltrate clearance when compared to the conventional method. However, the average magnitude of difference was only 9% and does not constitute a clinically significant margin between the two methods.