Director Steven Soderbergh's prescriptions drug-oriented dramatic thriller, Side Effects, seemingly hit a snag recently, on its way to beginning production. Megan Ellison (via her Annapurna Pictures) was previously said to have withdrawn her financial support for the project, due to concerns about actress Blake Lively serving as the film's protagonist.

A new report indicates the situation with AP is indeed "a bit shaky," but doesn't clarify whether or not the backer is actually no longer involved with Side Effects. However, there's reason to suspect the financier is still onboard, seeing how the film now has a new (confirmed) leading lady attached.

Lively has been replaced on Side Effects by Rooney Mara, who's all the hotter a prospect (yes, in all meanings of the term) thanks to her landing an Oscar nod for her performance in David Fincher's The Girl with the Dragon Tattoo. Mara has recently been courted for a number of projects involving prestigious filmmaking talent, such as Kathryn Bigelow's Osama Bin Laden thriller and Spike Lee's Oldboy re-interpretation - so, there's little surprise about her decision to join the latest flick from a decorated auteur like Soderbergh.

Deadline has the scoop on Mara joining Side Effects, which the site also says fits in well with her schedule - seeing how the actress is currently overseas promoting Dragon Tattoo. Despite the questions over funding, Side Effects remains prepped to begin principal photography by April 2012, with Soderbergh working from a script penned by Scott Z. Burns (Contagion) and produced by his go-to collaborator Greg Jacobs, along with Lorenzo di Bonaventura (Transformers, The Devil Inside).

The rest of the primary cast for Side Effects is not only (seemingly) set in stone at this point, but also composed of familiar faces from previous Soderbergh "joints." Returning to work alongside the filmmaker yet again are the likes of Oscar-winner Catherine Zeta-Jones (Traffic, Ocean's Twelve), Jude Law (Contagion), and Channing Tatum (Haywire, the upcoming Magic Mike).

Side Effects revolves around Emily Hawkins (Mara), a prescription drug-addicted woman who is attempting to cope with severe anxiety and depression. Her condition is only heightened by the impending release of her husband (Tatum) from prison, as well as an affair she has been conducting with her psychiatrist (Law). Things begin to spiral even further out of control when Emily begins taking a new drug to deal with all the stress - and eventually finds herself on trial for murder, having unknowingly (supposedly?) killed her newly-freed husband.

In someone else's hands, those plot elements could lend themselves to a pretty low-grade and soapy thriller. However, with Soderbergh sitting at the helm and Burns handling screenwriting duties, expect Side Effects to be more of a thematically-rich and dark character study that avoids its B-movie trappings - and boasts the director's trademark visual flair, to boot.

Similarly, don't be surprised if Mara delivers yet another dedicated and disturbing performance in Side Effects, following her great work in Dragon Tattoo - along with her standout part in The Social Network and solid turn in the otherwise lackluster Nightmare on Elm Street remake. The rest of the cast should turn in top-notch work as well - heck, even Tatum might be okay, in this one (hard as it may be to believe).

Soderbergh is known for working fast and efficiently, so Side Effects shouldn't take too long to make its way into theaters. In fact, the film could possibly even be finished in time for an Oscar-qualifying run in late 2012 - but don't count on that being a certainty just yet.

Source: Deadline