Identification of drugs ingested in acute poisoning: correlation of patient history with drug analyses.

The aim of this study was to assess the reliability of patient history in the identification of the drugs taken by patients who have an acute drug overdose. To this end, a prospective study involving 51 cases of acute, deliberate drug poisoning was carried out (patients with ethanol as the only apparent cause of intoxication were excluded). Information based on interviews with the patients and their companions or on circumstantial evidence (e.g., drug containers found) was compared with the results from drug analyses of various body fluids. The information obtained on admission was completely in accordance with the laboratory findings in only 27% of the cases. Minor discrepancies between the history and the results from drug analyses concerning the identity of the drugs taken were found in 55% of the cases. In 18% of the cases, the discrepancies were considered clinically important. Serious symptoms occurred in approximately 20% of the patients, but none of them were the result of incorrect information obtained on admission. All the patients survived. These results support the prevailing view that rapid identification of the drugs taken in overdose by means of comprehensive drug screens would have little effect on the treatment of most cases of acute poisoning. However, such assays would enable optimal treatment of many cases of acute poisoning by reducing the need for supervision and costly treatments and facilitating the identification of cases that would require prompt drug-specific treatment.

Decreases by magnesium of QT dispersion and ventricular arrhythmias in patients with acute myocardial infarction.

AIMS: Magnesium treatment suppresses ventricular arrhythmias in acute myocardial infarction and possibly mortality after infarction, but the underlying mechanisms are inadequately understood. We tested whether the effect of magnesium could be attributed to an influence on the autonomic control of the heart, changes in disturbed repolarization, relief of ischaemia or limitation of myocardial injury. METHODS AND RESULTS: Fifty-nine consecutive patients with acute myocardial infarction were randomized to receive 70 mmol of magnesium (n = 31) infused over 24 h or placebo (n = 26). Occurrence of ventricular arrhythmias and heart rate variability (SD of 5-min mean sinus beat intervals over a 24 h period, SDANN; low frequency/high frequency amplitude ratio, LF/HF ratio), and the number of ischaemic episodes on vectorcardiography were measured from the first day of treatment. QT dispersion corrected for heart rate was measured from the 12-lead ECG. Magnesium decreased the number of hourly ventricular premature beats (P < 0.001) and the number of ventricular tachycardias (P < 0.05). QT dispersion corrected for heart rate was decreased in both measurements at 24 h and 1 week (P < 0.001). SDANN and LF/HF ratio were unchanged. The number of ischaemic episodes on vectorcardiography were equal, and peak creatine kinase MB release did not differ between the groups. In testing the pathophysiological mechanisms, serum magnesium levels after infusion correlated with hourly ventricular premature beats (rs = -0.47; P < 0.01), ventricular tachycardias (rs = -0.26; P < 0.05), and QT dispersion corrected for heart rate (rs = -0.75; P < 0.001), but not with SDANN, LF/HF ratio or peak creatine kinase MB. QT dispersion corrected for heart rate correlated with hourly ventricular premature beats (rs = 0.48; P < 0.001) and ventricular tachycardias (rs = 0.27; P < 0.05). CONCLUSIONS: Magnesium suppresses early ventricular arrhythmias in acute myocardial infarction. The decreased arrhythmicity is related to enhancement of homogeneity in repolarization, but not to attenuation of prevailing ischaemia, improvement of autonomic nervous derangements or myocardial salvage.

A prospective study of acute poisonings in Finnish hospital patients.

1. We have carried out a prospective study of all adult patients presenting with acute poisoning during one month to the Helsinki University Central Hospital (Meilahti Hospital). 2. Two hundred and twenty-six cases of acute poisoning (113 males and 113 females) presented to the emergency department. Most cases in both men (66%) and women (67%) involved alcohol. As to drugs, psychotropic agents predominated in both men and women. The frequency of patient presentation peaked between 7 p.m. and 9 p.m. and was lowest between 8 a.m. and 10 a.m. In most cases, the delay from ingestion of the poison to presentation was longer than 4 h. 3. The clinical status of the patients on arrival was generally good; more than half (55%) of them were fully awake. Serious symptoms (e.g. unconsciousness, insufficient respiration necessitating intubation, aspiration, convulsions or hypotension) occurred in 15% of the presentations. There were no fatalities. 4. One hundred and thirty-five patients (60%) received at least one 50-g dose of activated charcoal. However, charcoal was given in 86% of the cases of drug poisoning. Gastric lavage was performed in 112 cases (50%), and 106 cases (47%) involved both gastric lavage and administration of charcoal. Twenty-one patients received antidotes (flumazenil, calcium gluconate or naloxone) and three patients were hemodialysed. 5. Of the 226 cases, 142 (63%) were managed solely in the emergency department. Of the 84 cases admitted to the hospital, eight had to be managed in the intensive care unit. Almost all patients (94%) were discharged within 24 h. 6. In this survey on 226 consecutive cases of acute poisoning, about two-thirds of the cases involved alcohol, while the most common drugs taken were psychotropic agents. The poisoning was mild in the great majority of the cases. Activated charcoal was generally administered in all but trivial cases of drug poisoning.

Family history as a risk factor of coronary heart disease in patients under 60 years of age.

The role of family history as a risk factor of coronary heart disease was explored in the first-degree relatives of 121 female and 586 male survivors of a recent acute myocardial infarction and in those of 130 control women. It was significantly more common for female patients than male patients to have first-degree relatives with coronary artery disease before the age of 65 (76% vs 62%, P = 0.0026). For the sisters of the female patients the cumulative risk of coronary heart disease by the age of 65 years was almost twice that of the sisters of the male patients (25.9% vs 15.8%, P = 0.0123). The risk for the brothers of the females did not significantly differ from that of the brothers of the male patients, but it was 3.5 times that of the brothers of the controls. Thus, while a history of coronary heart disease in first-degree relatives is a risk factor for the disease, the risk is greater in women than in men.

Provocation of ventricular tachycardia by antimalarial drug halofantrine in congenital long QT syndrome.

This report deals with two patients who suffered sustained episodes of torsade de pointes ventricular tachycardia while using the novel antimalarial drug halofantrine. Both patients had congenital long QT syndrome, and their QT interval was further prolonged at the time of the event. This first electrocardiographic documentation of ventricular arrhythmias together with halofantrine's known prolonging effect on the QT interval demonstrates that the drug has the potential to induce life-threatening arrhythmias.

Lupus anticoagulant and cardiac manifestations in systemic lupus erythematosus.

The occurrence of cardiac manifestations and their relationship with the lupus anticoagulant (LA) in SLE was studied in 74 patients who were followed up for 22 years (median), of which 16 years were after the initial LA testing. Pericarditis was the most common cardiac event occurring in 16 (22%) patients but it did not correlate with LA. Valvular heart disease, coronary artery disease, left ventricular failure and/or cor pulmonale were observed in 16 (22%) patients. Taken together, their occurrence was associated with a history of leg ulcers (odds 3.8, P = 0.028) but not with LA or other common clinical manifestations of the antiphospholipid syndrome. Valvular heart disease in five patients was significantly associated with LA (P = 0.05). Cor pulmonale due to chronic pulmonary embolism was present in two patients with LA. Myocardial infarctions in five patients occurred late in the course of disease but in relatively young patients (mean 43 years). Fatal myocardial infarction in the absence of atherosclerosis in two LA-positive patients supports a pathogenetic role for LA in these cases. In conclusion, of the various cardiac complications in SLE, valvular heart disease and cor pulmonale appear to be connected with the antiphospholipid syndrome. Both conditions should be actively sought in patients with LA to decrease possible adverse events (arterial emboli and right ventricular failure) affecting the patients' prognosis.

Itraconazole prevents terfenadine metabolism and increases risk of torsades de pointes ventricular tachycardia.

Terfenadine, a nonsedating H1-selective antihistamine, is widely used in many countries. We report pharmacokinetic results in a patient who developed a prolonged QT-interval in ECG and symptomatic torsades de pointes ventricular tachycardia as a consequence of the interaction of itraconazole and terfenadine. Both drugs were taken in the recommended doses: terfenadine 60 mg b.d. and itraconazole 100 mg b.d. Terfenadine metabolism was delayed by itraconazole, leading to an increased level of unmetabolised terfenadine. Seven weeks after the cessation of itraconazole treatment, terfenadine was rapidly metabolized to its active metabolite and did not prolong the QT-interval when given as a single provocation dose (120 mg). The findings suggest that intraconazole in therapeutic doses inhibits terfenadine metabolism. It is also possible that unmetabolised terfenadine alone, without an increased level of its active metabolite, may cause torsades de pointes. The concomitant use of terfenadine and itraconazole (and ketoconazole) should be avoided.