What they do

Vasodilators cause your blood vessels to dilate or relax and therefore reduce resistance. This will lower your blood pressure, allow blood to flow more easily around your body and improve your symptoms.

Some vasodilators are taken regularly. However, some short-acting vasodilators (such as glyceryl trinitrate / nitroglycerin) may be taken as a spray or tablets that are used under the tongue 'when needed' for chest pain (angina). They may also be given in the form of patches and ointments which are applied to the skin.

Side effects

Vasodilators may cause low blood pressure, which can make you feel faint or dizzy when sitting or standing up quickly. Other side effects include headaches, flushing, heart palpitations and nasal congestion. Headaches are especially common with long-acting vasodilators, such as nitrates.

Top tips

Dizziness is common with any drug that lowers blood pressure, but your heart can function better at these lower pressures.

If you do feel dizzy in the morning, try moving your feet back and forth about ten times before you stand up. Or, you may find it helpful to dangle your legs over the side of the bed before sitting up, and then sit at the side of the bed for a minute before standing. You should avoid standing up quickly, either from sitting or bending down, as this can make you feel dizzy. Take your time and allow your body to adjust.

Also known as:

  • Glyceryl trinitrate / GTN / nitroglycerin preparations
    (Coro-Nitro Pump Spray®, Glytrin Spray®, Nitrolingual Pumpspray®, Nitromin®, Suscard®, Deponit®, Minitran®, Nitro-Dur®, Percutol®, Transiderm-Nitro®)
  • Isosorbide dinitrate
    (Angitak®, Isoket Retard®)
  • Isosorbide mononitrate
    (Angeze®, Angeze SR®, Chemydur 60X®, Elantan®, Ismo®, Elantan LA®, Imdur®, Isib 60XL®, Ismo Retard®, Isodur®, Isotard®, Modisal LA®, Modisal XL®, Monomax®, Monomil X®, Monosorb XL 60®, Zemon®)
  • Hydralazine
  • Minoxidil
  • Nesiritide


How ACE inhibitors work in heart failure Animation explaining how vasodilators work in heart failure

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