Haloperidol and Cardiovascular disease

Neuroleptic agents may cause hypotension (including orthostatic hypotension), reflex tachycardia, increased pulse rate, syncope and dizziness, particularly during initiation of therapy or rapid escalation of dosage. Tolerance to the hypotensive effects often develops after a few doses to a few weeks. Rarely, fatal cardiac arrest has occurred secondary to severe hypotension. Other reported adverse cardiovascular effects include hypertension, edema, arrhythmias, thrombophlebitis, myocarditis, angina, myocardial infarction, congestive heart failure, and ECG abnormalities such as PR and QT interval prolongation, diffuse T-wave flattening, and ST segment depression. Therapy with neuroleptic agents should be administered cautiously in patients with severe cardiovascular disease, pheochromocytoma, a predisposition to hypotension, or conditions that could be exacerbated by hypotension such as a history of myocardial infarction, angina, or ischemic stroke. Close monitoring of cardiovascular status, including ECG changes, is recommended at all dosages. If parenteral therapy is given, patients should be in a supine position during administration and for at least 30 to 60 minutes afterwards. Patients who experience orthostatic hypotension should be cautioned not to rise too abruptly. Occasionally, when severe, hypotension may require treatment with vasoconstrictive agents such as norepinephrine or phenylephrine. Epinephrine should not be used, however, since neuroleptic agents can reverse its vasopressor effects and cause a further lowering of blood pressure.

Haloperidol should be administered cautiously to patients with severe cardiovascular disorders because of the possibility of transient hypotension and/or precipitation of anginal pain. In the presence of severe hypotension requiring vasopressor therapy, the preferred drugs may be norepinephrine, phenylephrine, or metaraminol, as usual doses of epinephrine may be ineffective since haloperidol inhibits its vasopressor effect.