Multiple Sclerosis is a condition in which the body’s immune system mistakenly attacks the protective coating of nerve fibers, leading to problems with movement, balance, sensation, and thinking. In the forms called primary progressive multiple sclerosis and secondary progressive multiple sclerosis, disability tends to get worse steadily over time. The study will give participants a daily oral tablet of Indapamide, a medicine normally used to lower blood pressure, to see if it can slow this decline.

The purpose of the study is to determine whether the medication can prevent or lessen further disability in people with these disease forms. Participants will take the tablet each day for about 12 months and will visit the clinic at the start, midway, and at the end to check safety and to measure walking ability using a simple 25‑foot walk test called the T25FW. No other experimental treatment will be given.

During the year, participants will keep a short diary of any new symptoms or side effects and will have routine blood checks to monitor health. The final visit will include the same walking test and a review of overall condition. The study is open‑label, meaning the medication being taken is known to both the doctors and the participants.