Prescription drug plans participating in the new Medicare Part D prescription drug benefit must include "all or substantially all" antidepressant and antipsychotic medications on their preferred drug lists.

That directive came last month from the Centers for Medicare and Medicaid Services (CMS) in the "Frequently Asked Questions (FAQs)" section of its Web site in answer to the question "Why is CMS requiring `all or substantially all' of the drugs in the antidepressant, antipsychotic, anticonvulsant, anticancer, immunosuppressant and HIV/AIDS categories?"

The FAQ was posted in response to significant concerns and questions raised since January, when the agency issued its final guidance to prescription drug plans (PDPs) on the development of Part D formularies (Psychiatric News, March 4). While trying to answer some questions, however, CMS seems to have raised some new ones.

In the final guidance, CMS noted that its "expectations are that best-practice formularies contain a majority of drugs within the following classes: antidepressants, antipsychotics, anticonvulsants, antiretrovirals, immunosuppressants, and antineoplastics. Following common best practices, CMS will check to see that beneficiaries who are being treated with these classes of medications have uninterrupted access to all drugs in that class via formulary inclusion, utilization management tools, or exceptions processes. When medically necessary, beneficiaries should be permitted to continue utilizing a drug that is providing clinically beneficial outcomes."

While the FAQ suggests that patients will have access to a variety of psychiatric drugs, it has no bearing on the exclusion of benzodiazepines from Part D coverage. That exclusion is mandated by the law that created Part D, the Medicare Modernization Act of 2003. As this issue went to press, Rep. Benjamin Cardin (D-Md.) introduced HR 3151 to reverse the exclusion of benzodiazepines. More information on the bill will appear in the next issue.

After the FAQ was posted, questions quickly arose regarding its language. For example, what does "contain a majority of drugs" really mean? CMS acknowledged that in training sessions and phone calls, PDPs had asked for an explanation of how a formulary could meet the "inclusion" standard expected by CMS while continuing to make use of "utilization management tools or exceptions processes." In short, critics said, the policy appears to be contradictory.

CMS said in the FAQ that it has "consistently explained that [the policy] meant that access to all or substantially all drugs in these specific categories needed to be addressed by plan formularies."

The FAQ goes on to say that "`substantially all" in this context means that all drugs in these categories are expected to be included in plan formularies, with the "specific exceptions noted" at the end of the FAQ in the section headed "Note (Attachment I)." One of the five exceptions listed is of particular interest to the mental health community. The note states that "all formularies must include either escitalopram [Lexapro] or citalopram [Celexa]."

CMS states that the list of exceptions should not be viewed as a list of exclusions and that each PDP's Pharmacy and Therapeutics Committee will have the final say on whether the plan covers only escitalopram or citalopram, or both.

In the FAQ document posted on June 15, CMS did not explain why formularies are directed to include escitalopram or citalopram, but not both. However, a version of the FAQ posted on June 10 stated, "Either escitalopram or citalopram may be left off formularies since escitalopram is the component of citalopram that is responsible for the antidepressant effect."

Pharmacologically, the agency is correct about escitalopram's antidepressant effect. Escitalopram, which was developed by Forest Laboratories as a successor to citalopram, contains half of the active ingredient found in the older product. The active ingredient occurs as nearly identical chemical isomers, which exist as mirror images of one another. Escitalopram—designated chemically as" S-citalopram"—is the half thought to be responsible for the medication's antidepressant effect. However, citalopram is roughly half S-citalopram and half R-citalopram. The R-isomer, which does not have antidepressant effects, is thought to interfere somewhat with the S-isomer's beneficial effects. In addition, the R-isomer is thought to be responsible for many of the adverse effects of citalopram. By eliminating the R-isomer from the parent compound, Forest aimed to produce a better tolerated and more effective antidepressant.

After reviewing the FAQ posted on June 10, mental health advocacy organizations, including APA, the National Alliance for the Mentally Ill, the National Mental Health Association, and the Treatment Effectiveness Now Project, brought their concerns to CMS. They fear that PDPs will choose to cover the less-expensive generic citalopram over escitalopram, which is available only as the Lexapro brand, despite the fact that the two drugs are not interchangeable, pharmacologically or therapeutically.

The final FAQ eliminated the suggestion that the two drugs are therapeutically interchangeable and noted that all formularies had to include only one.

Overall, the policy as stated in the FAQ appears to ensure broad access to nearly all psychotropic medications through the PDPs approved by CMS to participate in Medicare Part D, noted Irvin L. "Sam" Muszynski, J.D., director of APA's Office of Healthcare Systems and Financing. The policy also appears to protect patients who are now covered under Medicaid and will transition to Part D on January 1, 2006, by ensuring that their existing medications will continue to be covered—even escitalopram.

Muszynski added, however, that it remains to be seen whether patients who are prescribed escitalopram for the first time after January 1, 2006, will be able to get it through their PDP.

"The policy expressed in the CMS guidance and clarified in the FAQ document clearly represents a major step forward in ensuring continuity of care for dual-eligible patients transitioning to the new benefit," Muszynski said. "The policy generally reaffirms the position APA and our partners... have been strongly advocating from the beginning: that [individual medications within the antidepressant and antipsychotic classes] are not therapeutically interchangeable. We remain concerned, however, about how to interpret certain parts of the guidance [that] continue to appear problematic."

Muszynski and the staff in APA's Division of Advocacy are continuing to monitor and analyze CMS's developing policies regarding the implementation of Part D.

The CMS FAQ document can be accessed online at<http://questions.cms.hhs.gov/cgi-bin/cmshhs.cfg/php/enduser/std-alp.php> by searching on the word "antidepressants." ▪