Januvia (sitagliptin)The Type 2 diabetes drug Januvia (sitagliptin) has become a source of controversy after the drug’s maker, Merck, funded a letter to doctors by CVS Caremark, the pharmacy benefits manager, urging the physicians to add the drug to specific patients’ treatment regimens.

Januvia costs as much as 10 times the price of older diabetes drugs such as metformin and glipizide xl. (Note: Januvia purchased from a Canadian pharmacy costs about half as much as from a U.S. pharmacy — though it is still significantly more expensive than metformin and glipizide.)

Beyond the apparent conflict of interest in CVS Caremark’s letter, the question most important to patients is whether Januvia’s superiority over older, cheaper diabetes drugs makes it worth the additional cost.

The answer is, it depends.

Amy at Diabetes Mine points out that Merck has been pushing the drug very hard, and that while it appears to be effective, there are also concerns about safety and side effects.

If you have Type 2 diabetes and are considering Januvia, or your doctor has already recommended it to you, make sure to discuss the pros and cons thoroughly — and don’t be afraid to remind your doctor of Januvia’s additional cost. Physicians often forget to factor cost into their decisions on which drugs to prescribe, so it’s important to speak up.

And if you do end up taking Januvia, be sure to ask for free samples whenever you visit your doctor.