Old drug, new hope: colchicine may stop Post-Clot leg damage

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Age ≥18 years at the time of screening. 2. Objectively confirmed first, symptomatic acute proximal lower-limb deep vein thrombosis (DVT), involving the popliteal vein or more proximal veins, diagnosed within the previous 48 hours. 3. Planned initiation of standard anticoagulation therapy, including: * Low-molecular-weight heparin (LMWH) bridging to vitamin K antagonists (VKA) or direct oral anticoagulants (DOACs), * DOAC monotherapy according to local guidelines, * Fondaparinux or other guideline-recommended regimens. Note: Standard anticoagulation regimens include dose reduction of apixaban or rivaroxaban at the sixth month, as per local practice. 4. Ability and willingness to provide written informed consent and comply with all study procedures. Exclusion Criteria: Participants meeting any of the following criteria will be excluded: 1. History of prior DVT in the same limb. 2. Known contraindications to anticoagulation or anticipated inability to comply with study procedures. 3. Current use of colchicine or clinical indication requiring colchicine therapy. 4. Known hypersensitivity or allergy to colchicine. 5. Severe hepatic impairment, defined as ALT or AST \>3× upper limit of normal, or severe renal impairment (creatinine clearance \<30 mL/min). 6. Active malignancy with an estimated life expectancy \<12 months. 7. History of active or chronic gastrointestinal disease that may interfere with colchicine tolerance, including: 1. Inflammatory bowel disease (Crohn's disease or ulcerative colitis), 2. Collagenous colitis, 3. Irritable bowel syndrome, 4. Chronic or recurrent diarrhea. 8. Recent (\<30 days) or ongoing use of systemic immunosuppressive therapy, including but not limited to corticosteroids, cyclosporine, or tumor necrosis factor-alpha inhibitors. 9. Pregnancy or breastfeeding, or unwillingness to use effective contraception during the study period. 10. Concomitant use of strong CYP3A4 inhibitors or P-glycoprotein inhibitors contraindicated with colchicine. 11. Major bleeding event within the past 30 days or assessed as high bleeding risk by the investigator. 12. Inability or unwillingness to provide informed consent or to comply with study procedures.