Acute brain syndrome after propranolol

Toxic psychosis: an unusual presentation of propranolol intoxication

Timely diagnosis of acute propranolol intoxication requires a high index of suspicion and a knowledge of the multiple ways in which these patients may present to the emergency department. We report a case of severe propranolol intoxication that presented as an acute psychotic episode preceding cardiovascular decompensation and seizures by several hours. Though acute reversible psychosis has been appreciated after initiating or increasing propranolol dosage therapeutically, this association has not been reported in the literature regarding beta blocker overdose or intoxication. Propranolol psychosis and several other pertinent aspects of this case are discussed.

Neuropsychiatric adverse drug reactions: passive reports to Health and Welfare Canada's adverse drug reaction database (1965-present)

OBJECTIVE

Since 1965, Health and Welfare Canada has operated an adverse drug reaction (ADR) program. The program accepts spontaneous reports of adverse drug reactions, and maintains an ADR database. The purpose of this article is to summarize the Psychiatric ADRs reported to this database since 1965. The nature of the information prohibits its use in the evaluation of epidemiological hypotheses about the etiology of drug-induced mental disorders. However, in an exploratory sense, the contents of the database may contribute to the development of epidemiological hypotheses about the etiology of drug-induced mental disorders. Of particular interest are areas of apparent contradiction between the contents of the database and the clinical literature.

METHODS

The database was searched for reports of ADRs to a group of drugs which have been frequently implicated in causing psychiatric toxicity. All reports characterized as "psychiatric disorders" were down-loaded from the database for the analysis (n = 1822). The reports were further classified into nine categories according to the type of psychiatric symptoms described.

RESULTS

There were several reports of hallucinations caused by methyldopa, and also several reports of benzodiazepine-induced hallucinations and encephalopathy. These reactions have not been described in the literature. Also, there were few reports of digoxin-induced organic depression, and an absence of reports of organic mania induced by H-2 blockers, despite descriptions of these sorts of reactions in the clinical literature.

CONCLUSIONS

Further research is needed to define the neuropsychiatric toxicity associated with medical drugs. Clinicians must continue to consider the potential role of medications in the etiology of psychiatric symptoms.

Ocular inflammatory pseudotumor associated with propranolol therapy

A 60-year-old man presented with a unilateral mass involving the iris and ciliary body associated with iridocyclitis, which was refractive to both topical and systemic corticosteroid therapy. After a systemic work-up was negative, anterior chamber paracentesis and transcorneal biopsy were performed to rule out malignant melanoma and other tumors. The lesion proved to be an inflammatory lymphoid process, which resolved when systemic propranolol administration was withdrawn. Evidence for the possible role of propranolol in the induction of an intraocular inflammatory pseudotumor is presented.

Drug-induced neurological disorders

When a patient presents with a neurological or neuromuscular disorder, it is essential to consider drugs as a possible cause. Drugs can affect virtually any part of the neuraxis and the resulting disorders can usually be classified in terms of the anatomical site affected and the clinical presentation. In general, the signs and symptoms of drug-induced neurological disorders are virtually indistinguishable from those seen in naturally occurring disease but are usually reversible if diagnosed early enough. Cortical depression may produce coma, particularly in overdose cases, but a large number of drugs can also initiate seizures in susceptible individuals. The effects of drugs in the pathogenesis of headaches are certainly underestimated, and the eye, hearing and balance mechanisms can be severely damaged by certain drugs before symptoms prompt investigation. The long term effects of antipsychotic drugs on basal ganglia demand that these drugs are used only when absolutely essential and for as short a period as possible. Finally, there is increasing awareness of the role of drugs in the development of neuromuscular disorders such as peripheral neuropathies, myasthenic syndromes and myopathies.

Adverse psychiatric reactions to modern medication

From this survey it will be apparent that many psychiatric reactions to drugs are largely caused by their direct toxic actions or from combinations of drugs. As such, they are often dose related, although age and slow speed of detoxification will increase the risk of patients developing delirium, hallucinations, sleep disturbances, anxiety etc. Similar toxic reactions can also occur when drugs to which a patient has developed some measure of tolerance are abruptly withdrawn. In this context the effects of drugs upon patterns of sleep may be important determinants of adverse withdrawal symptoms. In contrast are the reactions which resemble one or other of the functional psychoses. In these patients it appears that a past history of an affective or schizophrenic psychosis is the best predictor of a similar illness being precipitated by a particular drug. Nonetheless, with substances like reserpine and cycloserine there is good reason for thinking that, given a sufficient quantity, practically any patient can develop an adverse psychiatric reaction.