Love and Other Drugs, Edward Zwick, 113 mins (15)

No one would call Love and Other Drugs a great film, but as two films, they're both pretty good.

The first concerns Jamie Randall (Jake Gyllenhaal), a medical school drop-out who sells hi-fi equipment, until he's sacked for seducing the boss's wife. He's just as principled when he gets a job touting Pfizer pharmaceuticals to private clinics. Thanks to a mentor played by Oliver Platt, he learns how to bribe doctors and sweet-talk receptionists as he heaves his suitcase of samples around Pittsburgh, but all his cocksure charm can't help him shift Pfizer's anti-depressant drug, Zoloft – the Ask Jeeves to Prozac's Google. Then Pfizer develops a new pill named Viagra, and suddenly Randall is befriended by the very doctors who used to run for cover whenever they saw him coming.

Based on Hard Sell: The Evolution of a Viagra Salesman, a memoir by Jamie Reidy, Love & Other Drugs has a similar tang to Jason Reitman's Thank You for Smoking and Up in the Air. But because it's recounting the experiences of a real person working for a genuine company, it packs more of a punch than either. Presumably Pfizer had script approval, and yet its salesmen and women are painted as glib con artists who are instructed to hint at their wares' unproven benefits, and their customers (such as Hank Azaria's doctor) are shown to be every bit as jaded and mercenary. Not since Michael Moore's Sicko has a film been so critical of the US's profit-oriented healthcare system.

While we're watching this anti-corporate satire, though, a different film is getting under way: a romantic comedy with no basis in Reidy's book. It co-stars Anne Hathaway as Maggie Murdock, an artist in the early stages of Parkinson's. She doesn't want a serious relationship because she's afraid her illness will eventually destroy it, but Randall nobly consents to a no-strings, sex-only arrangement – and Viagra isn't necessary. The question is, will these two cynics grow fond of each other when they've got their clothes on, too?

We all know the answer to that one. The romcom element of Love & Other Drugs is predictable enough, what with its movie version of a struggling artist (boho loft apartment, paint-spattered dungarees), and a slobbish flatmate, Randall's brother, who looks like a permed Jack Black. However, it's far more worthwhile than most contemporary romantic comedies. Instead of the usual Kate Hudson/ Jennifer Aniston contrivances, we're presented with two intelligent adults with crackling chemistry, un-airbrushed nudity, and dialogue that moves at the ping-pong pace of vintage screwball comedy. Randall and Murdock also have properly knotty reasons for being unsure about a future together. For a change, you're interested in what happens to them.

So there we have it: Love & Other Drugs offers us one tart exposé of big-business shenanigans, and one unusually grown-up romantic comedy. Either of these strands would have been a pleasure, but they don't overlap often enough to knit together, an issue which becomes more obvious later on, when the romance comes to the fore. To sum up, Love and Other Drugs ends up concentrating on Love and abandoning the Other Drugs.

The result is a frustratingly lop-sided film. If it's meant to be about two damaged souls connecting, then what need the preamble about pharmaceuticals? And if it's supposed to be about the drugs trade, then why drop that topic long before the closing credits? Love and Other Drugs has a lot going for it, but ultimately it's not one, but two wasted opportunities.

Next Week:

Nicholas Barber reviews the bookies' favourite for this year's Best Picture Oscar, The King's Speech