POTS is a heterogeneous condition meaning that the causes and pathophysiology vary between patients. Because of this, not all patients will respond the same way to a treatment. Therefore, treatment plans must be tailored to each patient for maximum efficacy. Some treatments that may be effective include:
- Fludrocortisone is a mineralocorticoid. It acts on the kidney to conserve sodium and water and is used to increase plasma volume, especially in patients with measured or suspected low blood volume.
- Beta blockers, including propranolol, block the receptors that are responsible for the effects of epinephrine and norepinephrine (catecholamines produced by the sympathetic nervous system). We have shown in a placebo-controlled trial that propranolol decreases heart rate and acutely improves symptoms in patients with POTS. Interestingly, we found that symptoms were more improved by low dose rather than high dose propranolol. The use of beta blockers in POTS is controversial, but we have seen many patients, including those who have previously failed beta blocker therapy, have success with propranolol.
- Desmopressin (DDAVP) is a synthetic derivative of vasopressin that acts to decrease urine formation by increasing water reabsorption in the kidneys. By decreasing urine formation, it leads to plasma volume expansion. In a placebo-controlled trial, we showed that DDAVP decreased standing heart rate, change in heart rate with standing, and improved symptoms.
Side effects associated with DDAVP include headaches, edema, and hyponatremia (low salt concentration in the blood). Because patients with POTS are encouraged to drink copious amounts of water and DDAVP causes free water retention it is theoretically possible that regular use in POTS could lead to severe hyponatremia. Caution should be exercised in using DDAVP regularly without data from long term studies that evaluate the side effects associated with regular use. We do have several patients who use DDAVP for special events, with instructions to take no more than one dose per week.
- Pyridostigmine is an acetylcholinesterase inhibitor which means that it decreases the degradation of the neurotransmitter acetylcholine. In a placebo-controlled trial, we found that Pyridostigmine decreased standing heart rate and improved symptoms in patients with POTS.
- Alpha 1 agonists (such as midodrine) cause vasoconstriction and help to decrease venous pooling. This may be beneficial because some patients have excessive blood pooling in their extremities when they are upright.
- Central sympatholytics, such as guanfacine and methyldopa (Aldomet), act on the brain to decrease sympathetic nervous system tone. Because of this, these drugs are most beneficial at stabilizing heart rate and blood pressure in patients with central hyperadrenergic POTS.