The most common side effect is nausea. Epigastric pain, dyspepsia, and diarrhea also have been reported.
Hypotension (usually transient) and syncope may occur at the initiation of treatment, and hypertension may occur later. Other cardiovascular effects include dysrhythmias (with high doses), exacerbation of angina and vasospastic disorders such as Raynaud disease, and intravascular thrombosis resulting in acute myocardial infarction (one case report).
Nervous system side effects vary considerably and include headache, drowsiness, fatigue, hallucinations, mania, psychosis, agitation, seizures, and cerebrovascular accident. Multiple interrelated risk factors include dose, concurrent drug therapy, and preexisting medical and psychiatric disorders.
Rare effects include pulmonary toxicity (infiltrates, pleural effusion, and thickening) and myopia with long-term, high-dose treatment (months). There has been one case of retroperitoneal fibrosis.
Use in pregnancy. FDA Category B (See Introduction in Section III). This drug has been used therapeutically during the last trimester of pregnancy for treatment of a ...