MINYANVILLE ORIGINAL It’s been a rough week for diet pill maker Vivus (NASDAQ:VVUS). After disclosing Tuesday that early sales of its new weight-loss drug Qsymia is selling slower than expected and that challenges remain the shares dropped significantly. Even with a slight recovery the shares are still down almost a quarter for the week trading at $10.81 in late morning trading Friday. The stock is down by half in just the past three months. Vivus’ drug was launched in September. The Vivus news dinged the stocks of Vivus rivals Arena Pharmaceuticals (NASDAQ:ARNA) and Orexigen Therapeutics (NASDAQ:OREX) this week as ...