clozapine and Hypotension

Atypical antipsychotic medications (second-generation antipsychotics) have been increasingly used in the treatment of a number of psychotic disorders since their introduction in 1988, with the newest medication introduced in 2002. Justification for their use includes claims of equal or improved antipsychotic activity over first-generation antipsychotics, increased tolerability, and decreased side effects. However, there are still significant adverse effects and toxicities with this class of medications. Toxicologic exposures and fatalities associated with atypical antipsychotics continue to increase in the United States, with 32,422 exposures and 72 deaths in 2003. There have also been Food and Drug Administration warnings in the past year about how some atypical antipsychotics have been marketed to minimize the potentially fatal risks and claiming superior safety to other atypical antipsychotics without adequate substantiation, indicating the toxicologic potential of these agents may be underestimated.. Continued research to evaluate adverse effects and tolerability of atypical antipsychotics compared with first-generation antipsychotics and each other is reviewed. This article also reviews the pharmacodynamics, pharmacokinetics, and drug interactions with these medications. New therapeutic monitoring recommendations for this class of medications have also been proposed. Finally, clinical toxicity in overdose and management are reviewed.. While new atypical antipsychotic medications may have a safer therapeutic and overdose profile than first-generation antipsychotic medications, many adverse and toxic effects still need to be considered in therapeutic monitoring and overdose management.

Topics: Antipsychotic Agents; Aripiprazole; Basal Ganglia Diseases; Benzodiazepines; Cardiomyopathies; Child; Clozapine; Diabetes Mellitus; Dibenzothiazepines; Drug Interactions; Drug Overdose; Dry Eye Syndromes; Humans; Hyperlipidemias; Hypotension; Olanzapine; Piperazines; Quetiapine Fumarate; Quinolones; Risperidone; Seizures; Thiazoles

Clozapine is a potent antipsychotic commonly used for refractory schizophrenia. Adverse effects are well recognised including constipation, intestinal obstruction, agranulocytosis and cardiomyopathy. We present a case of paradoxical refractory hypotension following epinephrine administration in a patient taking clozapine. A psychiatric inpatient who had been taking clozapine for many years developed paralytic ileus and obstruction requiring surgical intervention. Following initiation of epinephrine administration intraoperatively he developed refractory hypotension which improved only when epinephrine was weaned off. This effect is likely due to uninterrupted β

Topics: Antipsychotic Agents; Clozapine; Epinephrine; Humans; Hypotension; Male; Schizophrenia

Topics: Adult; Antipsychotic Agents; Clozapine; Combined Modality Therapy; Electroconvulsive Therapy; Humans; Hypotension; Inpatients; Male; Psychotic Disorders; Takotsubo Cardiomyopathy

Topics: Antipsychotic Agents; Clozapine; Drug Overdose; Emergency Service, Hospital; Female; Humans; Hypotension; Vasoconstrictor Agents; Vasopressins; Young Adult

Topics: Adrenergic alpha-Antagonists; Antipsychotic Agents; Clozapine; Epinephrine; Gastroesophageal Reflux; Hemodynamics; Humans; Hypotension; Intraoperative Complications; Lung Neoplasms; Male; Middle Aged; Schizophrenia; Tobacco Use Disorder; Vasoconstrictor Agents; Vasopressins

Although the new atypical antipsychotic, quetiapine fumarate, is growing in popularity over its progenitor, clozapine, clinical experience with overdose of this agent remains limited. Observation of an overdose situation provided a unique opportunity to define the safety, clinical effects, and pharmacokinetics of this medication more clearly.. A patient admitted immediately after ingesting an overdose of 30 tablets of 100 mg of quetiapine was observed carefully to document effects of the medication. These observations were compared with the only two other published cases of overdose, to the known pharmacology of the drug, and to serial measurements of serum drug concentrations obtained to document the time course of elimination of the drug.. Consistent with the two previously published cases, the main clinical effects of overdose were hypotension, tachycardia, and somnolence as predicted by its known alpha-adrenergic receptor and histamine receptor blockade. These effects were managed with fluid resuscitation and supportive measures. No cardiac arrhythmias other than tachycardia have been reported, but the tachycardia was of an unexpectedly long duration in this case. Decline in serum quetiapine concentration followed a biexponential pattern with a terminal elimination half-life of 22 hours. Unexpectedly low peak serum concentrations in three patients with overdose suggest that absorption is highly reduced, either by the effects of the overdose or by the activated charcoal administered.. Quetiapine appears to have greater safety in overdose than traditional antipsychotic agents. Its toxicity is consistent with its receptor pharmacology. Elevated serum concentrations associated with this overdose remained above the limit of detection long enough to document a terminal elimination half-life of 22 hours in this patient. This is much more consistent with previously noted duration of clinical effects and detectable serum concentrations after overdose than the published half-life of 6 hours. Physicians should be aware that any new drug that is active at low concentrations may have had its half-life underestimated during preclinical development because of the difficulty in detecting the drug after the distribution phase has ended.

Topics: Adrenergic alpha-Antagonists; Adult; Antipsychotic Agents; Clozapine; Dibenzothiazepines; Drug Overdose; Female; Half-Life; Humans; Hypotension; Quetiapine Fumarate; Sleep Stages; Tachycardia

Topics: Adrenergic alpha-Antagonists; Antipsychotic Agents; Cardiopulmonary Bypass; Clozapine; Hemodynamics; Humans; Hypotension; Male; Middle Aged; Schizophrenia

Topics: Adult; Benzodiazepines; Clozapine; Delirium; Dizziness; Drug Administration Schedule; Drug Interactions; Drug Therapy, Combination; Humans; Hypotension; Male; Middle Aged; Schizophrenia; Schizophrenic Psychology; Unconsciousness

In addition to the low risk of agranulocytosis, several more frequent side effects are associated with clozapine therapy. We tried to estimate the incidence of these side effects. We analysed 391 treatments in 315 inpatients, who received clozapine alone or combined with other neuroleptic and antidepressant drugs. Two thirds were combined treatments, one third were treatments with clozapine alone (i.e., no other neuroleptic, antidepressant or anticonvulsive drugs were allowed). The numbers in brackets show the incidence based on the analysis of the treatments with clozapine alone. In 49% (61%) of the treatments a rise in the liver enzyme values was observed. However, counting only the cases in which a two-fold increase over the normal values was observed, the incidence was reduced to 20% (31%). Increase in temperature was observed in 4% (6%) and leukopenia (leukocyte count under 3500/microliters) was recorded in 2% (2%). Hypotensive dysregulation (systolic blood pressure under 90 mm Hg) was observed in 25% of all treatments and pharmacogenic delirium in 8%. No cases of agranulocytosis were observed. Mean treatment duration was 56 days, mean daily dosage 257 mg. The mean age of the patients was 34 years. In the overall evaluation 71% of the treatments were classified as successful; clozapine therapy was continued after discharge in 68% of the treatments. Adverse reactions (delirium, rise in temperature, hypotension, fatigue, rise in liver enzymes) necessitated a change of medication in 17% of the treatments. Changeover to another neuroleptic drug due to ineffectiveness of clozapine was necessary in 7% of the treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Clozapine; Dibenzazepines; Female; Fever; Humans; Hypotension; Leukocyte Count; Liver; Male; Psychoses, Substance-Induced