Inclusion Criteria:  Established diagnosis of typical vasovagal syncope Age 18-50 years  Exclusion Criteria:  Systolic BP >130 mmHg History of hypertension or cardiac arrhythmias History of cardiovascular disease or cerebral ischemic events Allergic reaction to any of the drug components Contraindication to tilt testing Any physical or psychological symptom, based on the clinical judgment of the investigators that would make a participant unsuitable for the study Any use of a medication(s) based on the clinical judgment of the investigators that would make a participant unsuitable for the study (e.g. fludrocortisone, theophylline, prazosin, doxazosin, terazosin, MAO-inhibitors, pseudoephedrine, decongestant and PDE5 inhibitors). Unwilling to discontinue Midodrine or beta-blocker therapy 48 hours before tilt table testing. Women who are pregnant (confirmed with pregnancy test on day of study) or lactating.