The US Food and Drug Administration (FDA) have developed a five-category labeling system for all approved drugs in the United States. Which if the following is not a category in the mentioned system?
(A) Category A: controlled human studies indicate no apparent risk to fetus. The possibility of harm to the fetus seems remote (eg, multivitamins)
(B) Category B: Animal studies do not indicate a fetal risk or animal studies do indicate a teratogenic risk, but well-controlled human studies have failed to demonstrate a risk (eg, acetaminophen, caffeine, fentanyl, hydrocodone)
(C) Category C: studies indicate teratogenic or embryocidal risk in animals, but no controlled studies have been done in women or there are no controlled studies in animals or humans (eg, aspirin, ketorolac, codeine, gabapentin)
(D) Category D: there is positive evidence of human fetal risk, but in certain circumstances, the benefits of the drug may outweigh the risks involved (eg, amitriptyline, imipramine, diazepam, phenobarbital, phenytoin)
(E) Category E: there is positive evidence of significant fetal risk, and the risk clearly outweighs any possible benefit (eg, ergotamine)