Midodrine in Hepatopumonary Syndrome

Inclusion Criteria:

- Moderate to very severe hepatopulmonary syndrome, defined as the presence of all of
the following:

1. Liver disease or portal hypertension

2. Intrapulmonary shunting on contrast-enhanced echocardiogram

3. Hypoxemia [A-a gradient ≥15mmHg (or ≥20mmHg if age >64) and PaO2<80mmHg on
arterial blood gas testing]

- Ability to provide informed consent

- Ability to comply with study medication use and testing, in the opinion of the
principal investigator or co-investigator

Exclusion Criteria:

- Vulnerable study population, including imprisoned individuals, non-English speaking
patients

- Participation in other investigational drug studies

- Any of the following conditions:

- Systolic blood pressure>160mmHg or diastolic blood pressure >100mmHg

- Heart rate <50bpm

- Urinary retention at baseline

- Left ventricular ejection fraction <50%

- Women who are pregnant, nursing, or who plan to become pregnant while in the trial

- Women of child-bearing potential not willing or able to use highly effective methods
of birth control