Hey Jorge, sounds like we have a similar background and interest (I've done an MSc and PhD in Neuroscience now working for GSK in commercial analysis). Consultancies such as LEK, Arthur Little, Cambridge Consultants, Bridgehead all do work for pharma/biotech. That's probably the best place to start if you are sure you want to stay in the life sciences world but just to get away from the bench. Other more market/commercial research agencies with a life science focus are WoodMacKenzie, Datamonitor which produce reports on various commercial aspects of the industry and may be a stepping stone into consulting per se.
The big strategy houses (McKinsey, Boston Consulting, Bain) also work for the pharma sector, but it's harder to get in to these positions.
Most pharma companies hire scientists keen to move from the bench into commercial positions, there are quite a few people in marketing and commercial analysis at GSK with PhD's. The work is very different from doing experiments but you'll still need to know how to do market forecasting etc. I've had to teach myself this sort of thing (it's really easy once you get the hang of it). If you can get some freelance experience...even voluntary experience doing this kinda thing it will help tremendously when it comes to applying and interviewing for consulting etc as the case studies rely heavily on this sort of analysis (market sizing questions etc). Also, brush up on some maths, a lot of consulting firms I've spoken too although consider a PhD an asset, will question your mathematical ability if your a life scientist (biologist) than if your a chemist/engineer. I missed out on a job recently as I failed a pretty basic maths psychometric test with a consulting firm.....but luckily I'm getting a second chance in a few months.
Key things, figure out what direction you want to go, make some contacts, and try try try to get some experience (voluntary for now while your working...check the uni your working at for a technology transfer office, they may help). Then prepare for the case interviews by brushing cobwebs off some basic microeconomics and algebra.
Hope that helps, good luck....believe me it aint easy!