Circulation
Treatment for hypertension
Following MAOI poisoning, first-line treatment for hypertension is sedation with titrated intravenous benzodiazepines—see Sympathomimetic toxidrome / Sedation.
If hypertension persists despite benzodiazepines, use an antihypertensive drug. In patients with MAOI poisoning, blood pressure can rapidly fluctuate, so a short-acting antihypertensive drug such as intravenous glyceryl trinitrate is preferable—see Sympathomimetic toxidrome / Treatment for hypertension.
Treatment for hypotension
Hypotension occurs in severe MAOI poisoning and indicates a poor prognosis. For hypotension due to MAOI poisoning, first-line treatment is intravenous fluid resuscitation.
If hypotension persists, start inotropic support with noradrenaline (norepinephrine)—see Noradrenaline (norepinephrine) intravenous infusion instructions for advice on preparation and administration. The mechanisms of refractory hypotension are unclear; early bedside echocardiography is useful to determine the relative contributions of negative inotropy and vasodilation to hypotension, and hence guides treatment choice—discuss with a clinical toxicologist. Avoid indirect sympathomimetic drugs (eg metaraminol).
Treatment for arrhythmias
For cardiorespiratory arrest and life-threatening arrhythmias, follow advanced life support protocols1 and seek advice from a clinical toxicologist.
Avoid using beta blockers for treating arrhythmias as they can elevate blood pressure further, because of unopposed alpha-agonist effects.