Apparent poisoning by wood preservatives: an attributional syndrome.

Recent reports have pointed to an increased number of patients presenting with multisystem symptoms which they attribute to chemical exposures or to heightened chemical sensitivity. Twenty patients exposed to wood preservative products, who attended a joint toxicology and psychiatric clinic, were reviewed by a retrospective case note analysis. Thirteen patients attributed their symptoms to the wood preservative soon after the exposure, and seven patients developed the attribution only at a later date. Reported symptoms referred to all body systems, but there were few physical signs. Clinical findings suggest that the acute symptoms were consistent with the expected toxic effects, but the chronic symptoms could not be explained physically. Patient's beliefs about chemical poisoning could be understood as arising in the context of an attributional process, representing a sociopsychosomatic syndrome precipitated by wood preservative exposure. Patient management included a discussion of findings from assessments, published information, along with counseling where appropriate. Follow-up information from their general practitioners indicated a possible improvement in 50% of patients.

Paracetamol overdose in pregnancy analysis of the outcomes of 300 cases referred to the Teratology Information Service.

A prospective study was carried out to investigate the outcome of pregnancy in 300 women who had self-administered an overdose of paracetamol, either alone, or as part of a combined preparation. Exposure occurred in all trimesters. The most striking feature of this study is that the majority of the pregnancies had normal outcomes. Over half of the mothers (160 = 53%) required treatment for the overdose, and 49 of these had specific antidotes (33 mothers had acetylcysteine and 16 mothers had methionine). The rest of the mothers were given nonspecific treatments including ipecacuanha (52), gastric lavage (42), and charcoal (16). None of the mothers died. There were 219 liveborn infants with no malformations, 61 of whom had been exposed in the first trimester. Eleven liveborn infants had malformations; none was exposed in the first trimester. On other infant exposed at 18 weeks had a diaphragmatic hernia; this pregnancy was terminated at 22 weeks. In none of these 12 infants can the malformations be directly associated with paracetamol exposure. There were no apparent differences either in the sex ratio or the body weights of term infants. There were seven full-term infants with neonatal problems that seem unrelated to paracetamol exposure. Six premature infants also had neonatal problems, which were more likely to be related to their degree of prematurity rather than paracetamol exposure. There was no obvious relationship between the time of exposure and the time of delivery. The overall conclusion is that paracetamol overdose per se is not an indication for termination of pregnancy.

Features, prevention and management of acute overdose due to antidiabetic drugs.

Hypoglycaemic medication forms a disparate group of therapeutic compounds including insulin, the sulphonylureas and biguanides. They are all designed to prevent hyperglycaemia and in general are well tolerated. Careful prescribing practice and patient education by the physician can do much to reduce the risk of adverse effects from diabetic therapy. However, the presentation of adverse effects, together with accidental and non-accidental overdose, is a frequent clinical problem. Furthermore, the possible impairment of hypoglycaemic awareness in patients prescribed human insulin has added complexity to diabetic management. The cardinal features of insulin overdose are hypoglycaemia and hypokalaemia. The sulphonylureas predominantly cause hypoglycaemia, while the biguanides may precipitate lactataemia and acidosis. Recognition of hypoglycaemia is therefore crucial in avoidance of toxicity. Intravenous dextrose is the mainstay of therapy following gut decontamination (for the oral agents). The efficacy of glucagon is dependent on hepatic glycogen stores and should therefore be used with caution. Diazoxide is not recommended. More recently, octreotide has been shown to be effective in sulphonylurea overdose. Patients should be admitted and monitored with serial blood sugar measurements for a minimum of 1 to 2 days as clinically warranted.

A study of self poisoning with oral salbutamol--laboratory and clinical features.

1. The recent increase in asthma mortality coupled with reports of fatal asthma associated with beta-2-agonist therapy, has stimulated interest in the plasma concentrations of beta-2-agonists that produce systemic toxicity. 2. We prospectively studied 17 patients (9 male), mean age 23 years (range 2-72), who attended the emergency departments of hospitals throughout the United Kingdom having recently ingested an overdose of salbutamol. 3. Clinical, laboratory, ECG data, plasma and urine samples were obtained from each patient. Plasma was assayed for salbutamol concentration using a high performance TLC-photodensitometric method. 4. The mean (+/- s.d.) salbutamol dose reported to have been ingested was 89(+83)mg and the mean plasma salbutamol concentration was 166 (range 18-449) ng ml-1. The mean plasma potassium was 2.9 (s.d. +/- 0.6) mM (n = 16). None of the patients in this study developed serious cardiac dysrrhythmias. 5. There were significant correlations between the plasma salbutamol concentration and plasma potassium concentration (r = -0.85; P < 0.00005) and between plasma salbutamol concentration and pulse rate (r = 0.66; P < 0.005). 6. We conclude that in these patients, without respiratory decompensation, suprapharmacological plasma concentrations of salbutamol were tolerated without serious cardiac arrhythmias or any fatalities.

Paracetamol poisoning in pregnancy: an analysis of the outcomes of cases referred to the Teratology Information Service of the National Poisons Information Service.

A study was carried out to investigate the outcome of pregnancy in 115 women who had been exposed to paracetamol overdose. Follow up was obtained in 48 cases. Exposure occurred in all trimesters, and the most striking feature of this series is that the majority of the pregnancy outcomes were normal. None of the mothers died. There were 39 live born infants with no malformation, 14 of whom had been exposed in the first trimester. Four babies, exposed in the third trimester had neonatal problems, but these seem unrelated to paracetamol. There were two live born infants with gross malformations (spina bifida occulta; and cleft lip and palate). However, as the overdoses occurred at weeks 26 and 28 respectively, long after the structural development of these organs, the malformations could not have been caused by the paracetamol. There were two spontaneous abortions, both in the first trimester, which occurred two weeks after the overdose which may be related to the paracetamol. The overall conclusion is that paracetamol overdose per se is not necessarily an indication for termination of pregnancy.

Pharmacokinetics and toxic effects of diltiazem in massive overdose.

A 50-year-old man with ischaemic heart disease took 98 tablets of diltiazem 60 mg with alcohol. He developed a junctional bradycardia, hypotension and reduced cardiac function refractory to intravenous calcium gluconate. He survived with temporary cardiac pacing and infusion of dopamine. As much as half the dose was vomited back, but nonetheless the plasma diltiazem concentration reached 6090 micrograms/l before falling mono-exponentially with a half-life of 8.6 h. Sinus rhythm returned when the plasma concentration of diltiazem was around 750 micrograms/l. Standard resuscitative procedures sufficed to treat massive diltiazem overdosage.

Unsubstantiated complaints of being poisoned. Psychopathology of patients referred to the national poisons unit.

The psychopathology of a series of patients referred to a combined psychiatric-toxicological assessment service with the specific complaint of being, or having been, poisoned is described, and related to the nature of their exposure to incriminated agents. The need for and value of this service are discussed.

The relationship between plasma ibuprofen concentrations and toxicity in acute ibuprofen overdose.

1. The information available from the literature and from a prospective survey of ibuprofen overdose being undertaken by the London centre of the National Poisons Information Service (NPIS) was examined utilizing the Generalized Linear Interactive Modelling (GLIM) statistical computing package. 2. This confirmed that timed ibuprofen plasma concentrations were related to the symptoms of tachycardia, dizziness, tinnitus, ocular symptoms and coma/stupor as well as to reversible renal impairment and plasma hepatic enzyme elevation. 3. The best model of the relationship between symptomatic toxicity and timed ibuprofen plasma concentrations, was an exponential equation in time. Because of the lack of specificity or sensitivity in this model, and absence of demonstrable clinical advantages from its application, we do not recommend its use as a guide to predict toxicity. 4. However analysis of a larger information base utilizing similar methodology could, by increasing the statistical power of the resultant model, provide a useful means of predicting ibuprofen toxicity. 5. A previously postulated relationship between post-ingestion ibuprofen plasma concentrations and toxicity was not confirmed.