Seizures from neuroleptics

Other sedative-hypnotic medications, such as barbiturates, may play a useful role in severe withdrawal from this group of drugs. For example, in a case series of GBL withdrawal, use of intravenous pentobarbital in the range of 1-2 mg/kg/hour lowered the total requirement for intravenous lorazepam (Sivilotti et al. 2001). Antipsychotic medications are often used to reduce psychotic agitation. However, because antipsychotic medications lower the seizure threshold and may contribute to loss of central control of temperature leading to hyperthermia or neuroleptic malignant syndrome (NMS), they are not indicated as first-line medications for GHB withdrawal delirium (Dyer and Roth 2001 McDaniel and Miotto 2001 Sharma et al. 2001). If anti-... 

The answer is c. (Hardman7 p 408.) Clozapine differs from other neuroleptic agents in that it can induce seizures in nonepileptic patients In patients with a history of epileptic seizures for which they are not receiving treatment, stimulation of seizures can occur following the administration of neuroleptic agents because they lower seizure threshold and cause brain discharge patterns reminiscent of epileptic seizure disorders. 

Adverse effects of the TCAs on the brain include confusion, impaired memory and cognition and occasionally delirium some of these effects have been reported to occur in up to 30% of patients over the age of 50. These effects may occasionally be confused with a recurrence of the s)nnptoms of depression and are probably due to the central antimuscarinic activity of these drugs. Tremor also occurs frequently, particularly in the elderly, and may be controlled by the concurrent administration of propranolol. Neuroleptics are normally not recommended to be used in combination with TCAs as they are liable to accentuate the side effects of the latter drugs. The risk of seizures, and the switch from depression to mania in bipolar patients, has also been reported following TCA administration. 

Overall, amoxapine appears to have some advantage over other tricyclic antidepressants possible earlier onset of action and relative freedom from serious cardiotoxic effects. Its major drawbacks are the potential for neuroleptic adverse effects, a high incidence of seizures, deaths in overdose (2), and the possibility of long-term neurological damage. 

All basic and advanced life-support measures should be implemented. Gastric decontamination should be performed. Butyrophenones are readily absorbed by activated charcoal. Aggressive supportive care should be instituted. Dystonic reactions respond well to intravenous benztropine or diphenhydramine. Oral therapy with diphenhydramine or benztropine should be continued for 2 days to prevent recurrence of the dystonic reaction. For patients suffering from neuroleptic malignant syndrome, a potentially fatal condition associated with the administration of antipsychotic drugs, dantrolene sodium, and bromocriptine have been used in conjunction with cooling and other supportive measures. Arrhythmias should be treated with lidocaine or phenytoin. Diazepam is the drug of choice for seizures phenytoin is used to prevent recurrence. Hemodialysis and hemoperfu-sion have not been shown to be effective. 

The principal manifestations of phenothiazine toxicity involve the CNS and cardiovascular system. Signs of CNS toxicity include sedation, coma, respiratory depression (uncommon), seizures, hypothermia or hyperthermia, and extrapyramidal movement disorders (acute dystonia, parkinsonism, akathisia, tardive dyskinesia, and neuroleptic malignant syndrome) the extrapyramidal symptoms result from an imbalance between inhibitory dopamine and... 

The pharmacology of benzodiazepine derivatives differs significantly from that of the neuroleptics, in that the benzodiazepines have no psychoplegic (antipsychotic) activity and cause no extrapyramidal, autonomic, or endocrine side effects. In addition, unlike the neuroleptics, which lower the seizure threshold, these substances are anticonvulsants. In addition, they are anxiolytics, muscle relaxants, and mild sedatives. Although the benzodiazepine derivatives do not produce pronounced autonomic or CV side effects, they can reduce or block the emotionally induced changes in cardiovascular functions, probably through actions on the limbic system. 

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