Clinical Research Directory

Inclusion Criteria: * 1\. A diagnosis of PAH group 1 in any of the following subtypes: 1. Idiopathic 2. Heritable 3. Associated with drugs and toxins 4. Associated with * Connective tissue disease * Portal hypertension * Congenital heart disease 2. Symptomatic PAH in WHO functional class II-III. 3. Clinically stable. Clinical stability is defined as the absence of symptom exacerbation, as determined by the treating physician, and no need for unplanned hospitalization due to worsening pulmonary hypertension within three months before the study.) 4. Fertile women (under 50 years of age) must use reliable contraception (such as intrauterine devices or hormonal contraceptives) throughout the study and must maintain a negative pregnancy test. 5\. Age ≥ 18 years. 6. Ability to perform cardio-pulmonary exercise test. Exclusion Criteria: * 1\. Diagnosis of PH group 2, 3,4, or 5. 2. Known allergy to colchicine. 3. Unstable PAH requiring treatment escalation or hospitalization. 4. Listed for lung transplantation at the time of screening 5. Planned initiation of IV prostacyclin therapy or current dose escalation planned. 6\. Treatment with colchicine before recruitment. 7. Impaired renal function with an eGFR \< 30 mL/min/m2 within four weeks of screening. 8\. Severe liver dysfunction (Child-Pugh class C). 9. Patients with blood dyscrasias. 10. Concomitant strong CYP3A4 inhibitors. 11. Concomitant P-glycoprotein inhibitors. 12. Pregnancy or breastfeeding.