Table 2:

Pharmacological treatments for postural orthostatic tachycardia syndrome

Drug	Dosing	Quality of evidence*	Adverse effects	Other considerations
Heart rate inhibitors
Propranolol	10–20 mg orally up to 4 times daily	Moderate	Hypotension, bradycardia, bronchospasm	Can worsen asthma
Ivabradine	2.5–7.5 mg orally twice daily	Moderate	Visual disturbances, bradycardia	Expensive
Pyridostigmine	30–60 mg orally up to 3 times daily	Low	Increased gastric motility and cramping
Vasoconstrictors
Midodrine	2.5–15 mg orally 3 times daily	Moderate	Headache, scalp tingling, supine hypertension	Avoid within 4 hr of bedtime to avoid supine hypertension
Sympatholytic drugs
Methyldopa	125–250 mg orally twice daily	Low	Hypotension, fatigue, brain fog	Start with a low dose
Clonidine	0.1–0.2 mg orally 2–3 times daily or long-acting patch	Low	Hypotension, fatigue, brain fog	Start with a low dose; withdrawal can lead to rebound tachycardia and hypertension
Blood volume expanders
Fludrocortisone	0.1 to 0.2 mg orally per day	Low	Hypokalemia, edema, headache	Serum potassium should be monitored
Desmopressin	0.1 to 0.2 mg orally per day, as needed	Low	Hyponatremia, edema	Serum sodium should be monitored if used chronically

^*We critically appraised the literature using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology.⁴⁴ We rated the quality of the evidence as high, moderate, low or very low based on the likelihood that further research would change confidence in the estimate of effect.