Hypotension and postural hypotension have been the most frequently reported adverse reactions (See WARNINGS section). Nausea and vomiting occurred in about three percent of patients, primarily when bretylium (bretylium tosylate injection ) tosylate was administered rapidly by the intravenous route (See PRECAUTIONS section). Vertigo, dizziness, light-headedness and syncope, which sometimes accompanied postural hypotension, were reported in about 7 patients in 1000.
Bradycardia, increased frequency of premature ventricular contractions, transitory hypertension, initial increase in arrhythmias (See WARNINGS section), precipitation of anginal attacks, and sensation of substernal pressure have also been reported in a small number of patients, i.e., approximately 1-2 patients in 1000.
Renal dysfunction, diarrhea, abdominal pain, hiccups, erythematous macular rash, flushing, hyperthermia, confusion, paranoid psychosis, emotional lability, lethargy, generalized tenderness, anxiety, shortness of breath, diaphoresis, nasal stuffiness and mild conjunctivitis, have been reported in about 1 patient in 1000. Hyperthermia has also been reported (see WARNINGS). The relationship of bretylium (bretylium tosylate injection ) tosylate administration to these reactions has not been clearly established.