Chlorpyrifos: a ten-year US poison center exposure experience.

We performed a retrospective review of data based on poison center exposure inquiries related to chlorpyrifos (CP) and the corresponding poison center-determined medical outcomes reported to the Toxic Exposure Surveillance System (TESS) of the American Association of Poison Control Centers. Ten y (1985-1994) of TESS data were obtained. Medical outcomes representing all inquiries, accidental/unintentional inquiries, and intentional/suicidal inquiries were tabulated. Published TESS data was also tabulated to allow comparison of CP exposure inquiries to all non-pharmaceutical and insecticides/pesticides exposure inquiries for like time periods. Frequency of antidote use, product sales data, CP-related fatality reports, and pertinent issues related to telephone derived surveillance data were also reviewed; 36, 183 CP exposure inquiries were identified. Of all CP exposure inquiries, 27, 473 (75.9%) were assessed as having no significant health consequences; 4,511 (12.5%) outcomes were judged unrelated and 2,980 (8.2%) were unable to be followed. Reported significant medical outcomes for the remaining exposure inquiries were moderate 1,092 (3.0%), major 119 (0.3%) and death 8 (0.02%). Considering only calls with outcomes judged causally related to CP, where a given level of effect could reasonably be determined, 95.8% (27,473/28,692) of these calls resulted in no significant health effects. Use of antidotes specific to organophosphates were infrequent [atropine, 1.0% (385) and 2-PAM, 0.5% (177) of all cases respectively]. Despite the number of reported CP exposure inquiries, relatively few resulted in outcomes of consequence. TESS data suggested that the majority of patients undergoing medical evaluation and/or treatment after a suspected CP exposure do not require specific antidotes. TESS data serves as a useful first step in evaluating product safety. Assessment of product toxicity requires additional investigation of reported adverse effects and circumstances related to the incident.

The OPQ: a proposed instrument for predicting poisoning accident recurrence in young children.

A 26-item self-report questionnaire for parents/guardians was constructed for potential use with first-exposure childhood poisoning victims to predict high risk for subsequent poisoning episodes. Data were obtained from 185 subjects served by 1 of 5 US regional poison control centers. The resulting device was labeled the OPQ. Its retrospective validity (R = 0.71) and test-retest reliability (0.81) are viewed as sufficient. The test itself, with accompanying scoring key and norms, are provided here in the hope that other clinicians and researchers will join in subjecting the OPQ to prospective validity studies and other forms of Scale refinement.

Potentiation of warfarin anticoagulation by sulfisoxazole.

The prothrombin time (PT) of a patient undergoing warfarin sodium anticoagulation became elevated when sulfisoxazole was given concurrently. The warfarin dose index is used to demonstrate that this PT prolongation was the result of a warfarin-sulfisoxazole interaction. The mechanism of this interaction may involve displacement of warfarin from serum albumin. Sulfisoxazole should be used cautiously, if at all, in patients taking warfarin.

Phencyclidine intoxication: a literature review.

The history, symptoms, diagnosis and treatment of phencyclidine hydrochloride (PCP) intoxication and the pharmacology of PCP are reviewed. Intoxication with low to moderate doses of PCP (5-20 mg) resembles an acute, confusional state generally lasting four to six hours. High doses (greater than 20 mg) may cause serious neurologic and cardiovascular complications and the patient is often comatose for several days. Treatment involves supportive psychological and medical measures. Evacuation of the stomach with activated charcoal and a saline cathartic may be indicated and succinylcholine chloride may ease intubation. Diazepam and chlorpromazine may be used to control the combative patient and the "PCP psychosis" patient, respectively. Antihypertensive agents are not usually needed, but diazoxide and hydralazine hydrochloride have been used to treat hypertensive crises. Diazepam and phenytoin have been used to treat seizures. Ion-trapping by continuous gastric suctioning and by urine acidification with ammonium chloride may increase clearance of PCP. Forced diuresis with furosemide in conjunction with acidification may further increase PCP clearance. Use of physostigmine is based on conjecture.