Several observational studies using different methodologies show an increased risk of pulmonary embolism (PE) in psychiatric patients. The purpose of this paper was to report a case of massive, bilateral pulmonary thromboembolism induced by clozapine in a schizophrenic patient who was also using high doses od typical antipsychotics.(1) This case report is significant in various ways:

1. 1. To present the occurrence of pulmonary embolism (PE) as a rare adverse effect of clozapine that is treatable, but sometimes fatal;

2. 2. Increasing awareness of the potential danger that may result from drug interactions (clozapine and high doses od typical antipsychotics). (2,3) A 56-year-old woman was admitted to the psychiatric ward of a hospital with suicidal ideation, auditory hallucinations. Her psychiatric history included paranoid schizophrenia with numerous suicide attempts and she has been hospitalised a number of times. Medical history included obesity, hypertension, hyperlipidemia. The patient smoked one pack of cigarettes per day.Medications taken prior to admission were clozapine 400 mg daily, chlorpromazine 50 mg daily, haloperidol 30 mg daily, haloperidol decanoate 50 mg/21 day. On admission, clozapine was continued, haloperidol and chlorpromazine were discontinued. On hospital day seven, the patient developed shortness of breath, sudden chest pain and swelling of the legs. A complete physical examination in psychiatric intensive care was carried out expanded laboratory tests, CT lung scan. A computerized tomography angiogram showed diffuse,massive pulmonary thromboembolism in the right and left main pulmonary branches, with possible infarction.

This case report highlights the importance of monitoring the use of antipsychotics and physicians should consider discontinuing or switching the drug treatment in patients experiencing that medical condition.