Clinical and Neural Effects of L-DOPS on Low- and Normal- Supine Blood Pressure Variants of Orthostatic Intolerance

An exciting new study

We are looking for participants aged 18-50 who suffer from recurrent fainting or near fainting spells due to Vasovagal Syncope to participate in a trial investigating the benefit of a new medication - L-DOPS - in this condition. Participants will have either low or normal lying blood pressures. Participants will have had symptoms occurring at least weekly for ≥ 6 months. Symptoms include lightheadedness, weakness, blurred vision, fainting or near fainting.

Study details

The Human Neurotransmitters laboratory at Baker IDI has commenced a new study looking at the effect of a drug called L-DOPS in patients with Vasovagal syncope in association with either low or normal lying blood pressure. The study involves detailed examination of sympathetic nervous system function on two occasions in addition to clinical evaluations. The sympathetic nervous system, the stimulant arm of the nervous system is responsible for our "flight and fight" response to a threatening situation. The sympathetic nervous system is also crucial in the control of blood pressure and allows us to stand upright and supply blood to our vital organs, including the brain, in the face of gravity that pulls blood towards our legs. L-DOPS is a nerve transmitter precursor that is converted by the body to noradrenaline, the main nerve messenger of the sympathetic nervous system. We are studying whether increasing noradenaline by the use of L-DOPs improves physiological responses and symptoms in patients with these forms of orthostatic intolerance.


To be eligible for this study, you must:

  • be aged 18-50
  • have a disorder of Orthostatic Intolerance consistent with Vasovagal Syncope with either low or normal lying blood pressure
  • have had other conditions that could cause these symptoms excluded
  • be able to withhold medications that affect blood pressure for the duration of the study
  • be prepared to use appropriate contraception for the duration of the study
  • not be pregnant or breastfeeding
  • not be taking antidepressant medications
  • have no history of hypertension, heart disease, diabetes 

Patients with the Postural Orthostatic Tachycardia Syndrome (POTS) cannot be enrolled in this study.

What happens in the study?

During the study you will have two detailed assessments of your sympathetic nervous system, one at the beginning of the study and one at the end. These assessments take 4 hours each and involve invasive procedures such as the recording of nerve signals and the placement of a small tube in an artery and a vein in your arm.

Following an open label tolerability phase, the study will involve the blinded administration of the trial drug or placebo for 28 days each with clinical assessments at the end of each period. Further open label administration of L-DOPS is undertaken prior to the final assessment.

The total study duration is 4 months.

All study visits are performed at The Alfred Hospital, Commercial Rd , Melbourne.

Participants will be reimbursed for parking costs.


If you would like to participate, or would like to know how you can help, please email Susan on