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Biomedical subjects

J Tenczer

Publications and source records attributed to J Tenczer.

At least 19 recordsLinked to original sources
PubMed1992

Clinical course, therapy, outcome and analytical data in amitriptyline and combined amitriptyline/chlordiazepoxide overdose.

A total of 103 cases of amitriptyline (AT) overdose (group 1) and 81 cases of overdose with a fixed combination of AT and chlordiazepoxide (CDE) (group 2), treated at our Intensive Care Unit or reported to our Poison Information Center between 1985-1990, were evaluated with respect to clinical course, symptoms and outcome, as well as efficacy of therapy. The mean amount of AT was considerably higher in group 1 compared to group 2 (13 mg kg-1 vs 7.7 mg kg-1). The most frequent symptoms in both groups were impaired consciousness, anticholinergic symptoms, seizures, arrhythmia and hypotension. Respiratory insufficiency necessitated respirator therapy in 63 of the patients. Two patients in group 1 and one patient in group 2 did not survive. Therapy included primary detoxification by gastric lavage and repeated administration of activated charcoal. In four of eight patients with cardiac conduction disturbances, hypertonic sodium bicarbonate led to a significant reduction in QRS duration and AV interval. Physostigmine was effective in eight of 14 patients with pronounced anticholinergic symptoms. No effect was observed in the other six patients. Haemoperfusion, which was performed in five patients, led to rapid improvement of coma after initiation of therapy in four patients. The clinical efficacy of haemoperfusion in AT overdose despite the high volume of distribution of AT deserves further investigation. The rather high average overdose of AT implies that large package sizes of AT were available to the patients. A major step towards prevention of serious AT overdose would be the prescription of package sizes containing a total of less than 500 mg AT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Formation of formaldehyde adducts from various drugs by use of methanol in a toxicological screening procedure with gas chromatography-mass spectrometry.

Use of methanol as a solvent in a toxicological screening procedure with gas chromatography-mass spectrometry may be associated with artifact formation. Artifacts with a molecular ion of [M + 12]+ are formed from various drugs, such as amphetamine, propafenone, flecainide, beta-blockers and prilocaine. The mechanism of artifact formation was studied by mass spectral techniques, labelling and nuclear magnetic resonance spectroscopy. It was shown that the artifacts were generated by the addition of formaldehyde and subsequent loss of water. Formaldehyde is probably formed by thermal dehydrogenation of methanol in the injection port of the gas chromatograph.

Adrenergic beta-Antagonists↗
PubMed1991

Mass spectral characterization of urinary metabolites of D,L-kawain.

The urinary metabolism of D,L-kawain was studied in humans after an oral dose of 200 mg. Ten metabolites of kawain could be identified by gas chromatography-mass spectrometry with electron impact and chemical ionization. The main metabolic pathways were hydroxylation of the phenyl ring, reduction of the 7,8-double bond, hydroxylation of the lactone ring with subsequent dehydration and opening of the lactone ring. The metabolites were mainly excreted in the form of their conjugates.

Gas Chromatography-Mass Spectrometry↗
PubMed1990

Clinical experience with the benzodiazepine antagonist flumazenil in suspected benzodiazepine or ethanol poisoning.

The clinical efficacy of different doses of the specific benzodiazepine antagonist flumazenil was studied in a total of 72 patients with benzodiazepine or ethanol overdose. In a randomized double-blind study, 18 patients (group 1) and eight patients (group 2) with suspected benzodiazepine overdose received 5 mg (group 1) or 1 mg (group 2) flumazenil or placebo, respectively. The stage of coma, heart rate, blood pressure and respiratory rate were monitored within the following 15 min. If no change in the stage of coma was observed, 5 mg (group 1) or 1 mg (group 2) flumazenil were given, and the stage of coma, heart rate and blood pressure were again monitored. In a similar way, the effect of 5 and 1 mg flumazenil was investigated in 13 patients (group 3) and four patients (group 4) with ethanol intoxication. In an open trial, the clinical efficacy of flumazenil for the diagnosis of benzodiazepine or ethanol overdose was studied in 29 patients (group 5). In all patients, a toxicological screening confirmed benzodiazepine or ethanol overdose. None of the patients receiving placebo showed effects on stage of coma, heart rate, blood pressure or respiratory rate. Patients with benzodiazepine overdose who received 5 mg flumazenil regained consciousness about 1-2 min after the end of injection. The effect of 1 mg flumazenil (group 2) on benzodiazepine-induced coma was less pronounced. In patients with ethanol overdose (group 3), ethanol-induced coma was reversed after 5 mg flumazenil more slowly than in patients of group 1. No effect of flumazenil on ethanol-induced coma was observed in group 4. In group 5, flumazenil proved to be useful for diagnosing benzodiazepine or ethanol intoxication. In one patient with coma due to carbamazepine overdose, flumazenil was also found to be effective. Additionally, a possible analytical interference of flumazenil and its metabolites with the identification of other benzodiazepines by a toxicological screening procedure was studied. Even after an oral dose of 200 mg flumazenil, no interference with immunological benzodiazepine assays (EMIT, TDX, and RIA) was found. A metabolite and an artifact of flumazenil could be identified in urine by gas chromatography/mass spectrometry.

Adolescent↗
PubMed1988

[Fatal diltiazem poisoning].

The diagnosis at postmortem examination and the results of the chemical analysis in a case of a diltiazem intoxication are presented. Two metabolites were identified as desacetyldiltiazem and N-desmethyldiltiazem.

Alcoholism↗
PubMed1988

Two-to-one sinoatrial block. Normalization by carotid massage.

In a clinical case of 2:1 sinoatrial block, carotid massage, paradoxically, released the sinoatrial block and doubled the manifest sinus rate. This resulted from a deceleration of the sinus discharge rate which allowed consecutive sinus impulses to traverse the sinoatrial junction.

Aged↗
PubMed1987

A study of modulated ventricular parasystole by programmed stimulation.

To analyze the phase-dependent sensitivity of the parasystolic pacemaker to nonparasystolic beats, 11 patients with modulated ventricular parasystole were studied using the ventricular extrastimulus method. The intrinsic parasystolic cycle lengths ranged from 1,100 to 1,800 ms. Premature stimuli altered the duration of the parasystolic cycle lengths by amounts that depended on timing of the test impulses within the parasystolic cycles. Premature impulses delivered during the first part of the parasystolic cycles prolonged the parasystolic cycle lengths to 107 to 151% of the intrinsic parasystolic cycle lengths and impulses applied during the second part abbreviated them to 70 to 81% of the intrinsic parasystolic cycle lengths. In 10 patients the accelerating effects were of greater magnitude than the decelerating effects. Transition from the accelerating to slowing phases was progressive or unstable in 9 patients and abrupt in 2. Changes induced by individual stimuli were short-lived and the parasystolic pacemakers returned immediately to their original rates. In 1 patient the biphasic sensitivity of parasystole to premature stimuli was shown to sustain for 21 days.

Aged↗
PubMed1987

Gap in bundle-branch conduction elicited by programmed His bundle stimulation.

The gap phenomenon in right bundle-branch conduction was elicited during programmed stimulation of the His bundle. Premature beats with short and long coupling intervals showed undisturbed intraventricular conduction, while the premature beat with intermediate coupling interval blocked within the right bundle branch. The electrophysiologic mechanism of "supernormal" conduction of the earliest beats was conduction delay at a proximal site within the His bundle which allowed recovery of the right bundle branch. This study shows that programmed His bundle stimulation is a valuable method in analyzing conduction characteristics of the distal atrioventricular conduction system in cases where atrioventricular nodal refractoriness would preclude this by atrial stimulation.

Adult↗
PubMed1987

Hemoperfusion in severe chlorprothixene overdose.

Two to twelve hours after suicidal ingestion of an estimated dose of 10 g chlorprothixene, a 31-year-old female was admitted to the emergency ward of the clinic with cardiorespiratory arrest. After successful resuscitation, the further clinical course was complicated by persistent ventricular extrasystoles and ventricular fibrillation which necessitated repeated defibrillation. Since the patient did not respond satisfactorily to supportive treatment, a combined hemoperfusion/hemodialysis was performed. Under extracorporeal detoxication, elimination of chlorprothixene from plasma was accompanied by substantial improvement of the patient's clinical condition, although only about 1.6% of the estimated dose had been removed. This case seems to indicate that evaluation of the therapeutic efficacy of hemoperfusion should not be based exclusively on the relation of the amount of the eliminated drug to total absorbed dose.

Adult↗
PubMed1987

Poisoning with over-the-counter doxylamine preparations: an evaluation of 109 cases.

One hundred and nine cases of monointoxication with doxylamine were evaluated with respect to age distribution, amount ingested, plasma level, and clinical symptomatology. The age of 60% of the patients ranged between 16 and 30 years. In about 60% of the cases 10 to 40 times a single therapeutic dose (25 mg) was ingested. Doxylamine plasma concentrations exceeded the maximum plasma level after a therapeutic dose by a factor of 10 to 40 in two-thirds of cases. The most frequent symptoms included impaired consciousness, seizures, tachycardia, mydriasis and a 'psychosis' similar to that in catatonic stupor. A serious complication may be rhabdomyolysis with subsequent impairment of renal function and acute renal failure. No symptoms were observed in 39% of the patients. No correlation was found between the amount ingested or doxylamine plasma level and the clinical symptomatology. Primary detoxication included gastric lavage, administration of activated charcoal and sodium sulfate. Regarding the high frequency of doxylamine overdose and its possible complications the question arises as to whether doxylamine-containing preparations should be subjected to prescription.

Adolescent↗
PubMed1987

Clinical symptomatology of diphenhydramine overdose: an evaluation of 136 cases in 1982 to 1985.

In West Germany, the antihistaminic diphenhydramine is marketed as a non-prescription hypnotic. Results of toxicological screening in cases of drug overdose indicate that poisoning with diphenhydramine represents a substantial part (4.5%) of the total number of intoxications. A total of 136 cases of diphenhydramine poisoning in 1982-1985 were evaluated with respect to age, ingested dose, plasma level, and clinical symptomatology. All patients had taken diphenhydramine with suicidal intent. Two-thirds of the patients were aged 14-30 years. In about 50% of the cases, between 6 and 40 times a therapeutic dose was ingested. Diphenhydramine plasma levels showed a wide range (0.1-4.7/micrograms/ml) due to differences in ingested dose and time between ingestion and admission to hospital. Impaired consciousness was the most common symptom. Psychotic behavior similar to catatonic stupor--often combined with anxiety--was highly specific for diphenhydramine poisoning. Further symptoms included hallucinations, mydriasis, tachycardia, and less frequently diplopia, respiratory insufficiency, and seizures. Primary treatment included gastric lavage, administration of activated charcoal and sodium sulfate. In one case, hemodialysis and ultrafiltration were performed which had only limited effect on diphenhydramine plasma elimination kinetics. This patient died of diphenhydramine overdose and extreme hypothermia. All intoxications except the one mentioned before had an uncomplicated clinical course. In vitro experiments indicate that diphenhydramine may be almost completely removed from the plasma compartment by hemoperfusion. Routine analysis of urine samples in diphenhydramine overdose led to the identification of 4 previously unknown metabolites and artifacts of diphenhydramine.

Adolescent↗
PubMed1987

Urinary metabolism of chlorphenoxamine in man.

After an oral dose of 40 mg of 4-chlorophenyl-methylbenzyloxy-N,N-dimethyl-ethylamine(chlorphe noxamine, Systral) urinary metabolism was studied by gas chromatography/mass spectrometry. Besides the unchanged drug, 8 metabolites and 7 artifacts and derivates could be identified. Metabolism is similar to that of the structurally related antihistaminic drugs diphenhydramine and doxylamine. The main metabolic pathways are: 1. N-demethylation, 2. oxidative desamination and formation of an alcohol and a carbonic acid derivative, 3. cleavage of the ether bond, and 4. hydroxylation of the phenyl ring. For determination of chlorphenoxamine in plasma an assay using gas chromatography was developed. Chlorphenoxamine plasma levels were beyond the limit of detection (10 ng/ml) 30, 60, 120, 240, 480, and 1200 min after oral intake.

Ethylamines↗