Pharmacological treatment

Various medications have been used to treat neurocardiogenic syncope.

Beta blockers (Anti hypertensive and anti anginal drugs) such as Bisoprolol or Atenolol at low dose can be effective. These drugs may act by preventing the inappropriate activation of the stretch receptors in the left ventricular muscle.

Fludrocortisone (a mineralocorticoid used to treat low blood pressure) increases blood pressure by reducing urinary sodium and water loss. This minimises the effects of venous pooling in the legs.

Small doses of an SSRI (Selective serotonin re-uptake inhibitors used to treat depression) such as Fluoxetine (Prozac) or Paroxetine (Seroxat) can be effective. It is thought that serotonin helps regulate stretch receptor activation.

Midodrine (a vasoconstrictor) acts by constricting the arterioles that control blood pressure. This action raises blood pressure.

Disopyramide (anti-arrhythmic drug) minimises vagotonic reflex slowing of the heart.

If one drug is not effective, it is always worthwhile trying one of the others from a different class.

Many of the clinical trials that showed benefit from treatment were not placebo-controlled. Results from the few placebo-controlled trials that have been carried out so far have generally been disappointing. Midodrine currently has the strongest scientific evidence – two trials – but is not routinely available in the UK.

The fact that so many different medications are used in the treatment of neurocardiogenic syncope indicates that none is entirely effective. Sometimes, a combination of drugs is required.

Abolition of symptoms indicates successful treatment. Although the Tilt Table Test may be rendered negative, repeating the test on treatment is not a good indicator of success and is not recommended.

Medication should be reduced once symptoms have been abolished for a year or so. If symptoms do not recur as the dose is reduced, then the medication may be discontinued.