Nearly lost in the controversy over Glaxo’s Avandia is a strongly worded statement issued the other day by Public Citizen, the advocacy group, about Merck’s relatively new diabetes pill, which was approved last fall by the FDA. On its web site, the group cautions that Januvia shouldn’t be used for another seven years, because the drug’s long-term safety is still unknown.

“Clinical study patients who were given Januvia experienced an increase in the chemical creatinine, which is found in the blood. Increases in creatinine are often an early indicator of kidney problems. Because the drug is new, more serious adverse effects may not become apparent until the drug is used by a large number of patients. Public Citizen advises consumers not to take the drug until after it has been on the market for seven years – in this case, until 2014 – without exhibiting significant health risks.”

Of course, that’s not going to happen. Some folks may heed the advice, not wishing to become ‘guinea pigs.’ But lots of people will use Januvia, especially now that so much uncertainty surrounds Avandia, and both Avandia and Takeda’s Actos will have new black box warnings about cardiovascular risk. And Merck is pushing Januvia very hard, as one might imagine. But this also suggests that Merck may have a battle on it hands if Public Citizen digs up more evidence.

It’s going to be a long seven years.