Not yet. Sumarin is used primarily to treat African sleeping sickness. It works by causing the parasites to lose energy,which causes their death. Suramin is also used to stop the growth of bladder cancer by stopping blood flow to the tumor.
Recently it was discovered to work as an antifibrotic agent, which means it prevents scar tissue from forming. It may be helpful in promoting faster muscle healing after injury.
Studies on Sumarin for its use in muscle injuries have been done on rabbits and mice. The next step is to test Sumarin on large animals. If it's safe and effective in large animals then clinical trials will begin in humans. Approval for children will occur much later after the drug has been proven safe and effective in adults.