Highlighter is on. Drag to highlight text. Click a highlight to remove it.
ALL / Cardiology

Nitrates

Nitrates

Nitrates are a group of drugs which have vasodilating effects. The main indications for their use is in the management of angina and the acute treatment of heart failure. Sublingual glyceryl trinitrate is the most common drug used in patients with ischaemic heart disease to relieve angina attacks.

Mechanism of action
  • nitrates cause the release of nitric oxide in smooth muscle, activating guanylate cyclase which then converts GTP to cGMP, which in turn leads to a fall in intracellular calcium levels
  • in angina they both dilate the coronary arteries and also reduce venous return which in turn reduces left ventricular work, reducing myocardial oxygen demand

Side-effects
  • hypotension
  • tachycardia
  • headaches
  • flushing

Nitrate tolerance
  • many patients who take nitrates develop tolerance and experience reduced efficacy
  • the BNF advises that patients who develop tolerance should take the second dose of isosorbide mononitrate after 8 hours, rather than after 12 hours. This allows blood-nitrate levels to fall for 4 hours and maintains effectiveness
  • this effect is not seen in patients who take modified release isosorbide mononitrate
+PassMedicine Notes

Nitrates are a group of drugs which have vasodilating effects. The main indications for their use is in the management of angina and the acute treatment of heart failure. Sublingual glyceryl trinitrate is the most common drug used in patients with ischaemic heart disease to relieve angina attacks.

Mechanism of action
  • nitrates cause the release of nitric oxide in smooth muscle, activating guanylate cyclase which then converts GTP to cGMP, which in turn leads to a fall in intracellular calcium levels
  • in angina they both dilate the coronary arteries and also reduce venous return which in turn reduces left ventricular work, reducing myocardial oxygen demand
Side-effects
  • hypotension
  • tachycardia
  • headaches
  • flushing
Nitrate tolerance
  • many patients who take nitrates develop tolerance and experience reduced efficacy
  • the BNF advises that patients who develop tolerance should take the second dose of isosorbide mononitrate after 8 hours, rather than after 12 hours. This allows blood-nitrate levels to fall for 4 hours and maintains effectiveness
  • this effect is not seen in patients who take modified release isosorbide mononitrate


Saved ✓

MEDIA