The company said it would rebuild lost business through a distribution agreement with Walgreens pharmacies announced on Tuesday, and said the arrangement would also help sales of products like Xifaxin for irritable bowel syndrome and Addyi, a new sexual dysfunction treatment for women. Valeant shares rose 8 percent to $118.75 in New York trading, gaining ground as Chief Executive Michael Pearson led investors through a four-hour meeting in which he defended the company’s plan to rebuild its dermatology business.