Prescription drugs often have unusual names. Names like Motrin, Rogaine, Cipro, Prozac, Ventolin, Viagra...they're not ordinary words. If you notice, many new companies follow this trend as well, using exotic, made-up names to convey a feeling about the company.
Part of the reason for this is the trademark system in the United States. Almost any normal word you can think of is already trademarked. Therefore, you end up having to invent a word to get a new mark. The same thing happens with Internet domain names. By naming your drug (or company) something unique, you have a word that is available as a domain name and is unique in online search engines.
The search engine part is actually getting to be extremely important -- by making up a name, someone searching for information will find pages that deal only with your company or product. This lets people find information about your company or product much more easily.
Here are some interesting links: