The one true contraindication to giving nitrates in patients with chest pain is hypotension. The old teaching is that patients with possible inferior MIs should not be given nitrates (or be given with cautious) due to the potential for right-sided heart involvement and need for high preload to maintain blood pressures. However, more recent studies have shown no increased incidence of hypotension post nitro administration in patients with inferior MIs compared to other territorial MIs. Therefore, suspected inferior MI alone should not prohibit you from giving nitrates. However, it is best practice in ALL patient’s receiving nitroglycerine to monitor their blood pressure closely and be prepared to give IV fluids if hypotension develops. Finally, patients on phosphodiesterase inhibitors, such as erectile dysfunction medications like Viagra or Cialis, should not receive nitroglycerine due to the risk of severe and refractory hypotension.
