Medication: Medication Overview

Medication is only used after a trial of non-pharmacological (without medication) treatment such as increased fluids, salts, compression and exercise.

Firstly, all medicines that worsen symptoms need to be stopped. At this moment there are no approved medicines for the treatment of PoTS and therefore are prescribed “off licence”.  Medication needs to be optimised to control symptoms so activity levels can be increased. Treatments must be tailored to each patient, taking into account the cause of their PoTS,  and objective evidence from investigations, as the same medicine may have a different effect on an individual.  Side effects should be monitored very closely.  It is often a cause of very deep frustration to sufferers who might need to try many different drugs before finding the right combination*.

Specialists have their favourite choice of drugs and may tailor their choice according to the symptoms of the patients or co-existing medical conditions. Fludrocortisone, midodrine, beta blocker or ivabradine tend to be used initially*. Sometimes a combination of drugs is necessary. Fludrocortisone and Midodrine are licensed for use in orthostatic hypotension which is another form of autonomic dysfunction. PoTS is diagnosed in the absence of orthostatic hypotension.

Drugs which slow down heart rate

• Beta Blockers – propranolol, bisoprolol, labetalol, metoprolol
• Ivabradine

Alpha Agonists 

Midodrine 

Midodrine is licenced for use in orthostatic hypotension and there should be ,if possible evidence of this before its use. The aim of an alpha agonist is to narrow blood vessels to help return the blood back to the heart. Side effects are high blood pressure and urinary retention which can lead to more frequent urinary tract infections. It is very short acting and timing needs titrating before dosage titration, blood pressure should be carefully monitored initially and when stable at least yearly.

Serotonin-Noradrenaline Reuptake Inhibitors (SNRI) 

Bupropion, venlafaxine, duloxetine

SNRIs may worsen tachycardia in patients with PoTS

Medications that Increase Blood Volume 

Fludrocortisione  

A mineralocorticoid, licensed for use in orthostatic hypotension, the action of which is to retain salt and water. Its main action, therefore, is to increase the volume of blood within the blood vessels. Because it is a type of steroid with mainly mineralocorticoid actions, it does not have the side effects that other steroids have (glucocorticoids such as prednisolone/hydrocortisone /steroid asthma inhalers) that often worry patients. Blood potassium levels need to be monitored regularly. Should ideally be used with evidence of orthostatic hypotension.

Desmopressin 

This is a hormone that reduces urine production, promotes fluid retention and therefore decreases heart rate, improving symptoms of PoTS. Blood sodium levels need to be monitored.        

Other Medications 

Clonidine or Methyldopa may be used in Hyperadrenergic PoTS . These lower the heart rate and may reduce blood pressure by working directly on the brain.  

Octreotide narrows blood vessels in the abdominal cavity.  Daily injections and side effects can be a drawback, but a long-acting form that can last weeks has been developed

Pyridostigmine acts at the nervous system to reduce heart rate by increasing: 

• Vagal tone – part of the parasympathetic ‘rest and digest’ nervous system 
• Sympathetic tone – influences of the sympathetic nervous system on muscle tone 

Side effects may include stomach pain, nausea, and diarrhoea, which can be troublesome for some patients.   

Modafinil is a stimulant normally used in some sleep disorders, and may improve alertness and decrease mental clouding in those with PoTS. Modafinil may increase tachycardia in some patients but this effect is not usually very severe.  

*No evidence, but usually recommended by specialists