Newer antidepressant and antipsychotic medications have attained formulary status in most of the programs surveyed in this study. Although most payers provide for the coverage of at least several of the newer agents first-line, not all payers cover every newer agent without prior authorization.
The present survey shows that most payers cover at least two of the four SSRIs approved in the US for the treatment of depression (fluoxetine, paroxetine, citalopram, sertraline), and at least one other new antidepressant (venlafaxine, nefazadone, bupropion). Coverage of fluvoxamine and mirtazapine appears to be the most scant. The approval of bupropion for the treatment of smoking cessation appears to have increased the frequency of requiring prior authorization for the dispensing of this drug. Likewise, the new-generation antipsychotics (risperidone, olanzapine, quetiapine) have also achieved formulary status.
- Public Programs
Among Medicaid programs interviewed for this study, only California maintains a restricted formulary. Medi-Cal conducted a therapeutic class review of antidepressants in the mid-1990s. This review resulted in the addition of fluoxetine and paroxetine to the Medi-Cal formulary in 1996. At the same time drugs fluvoxamine, bupropion, and nefazadone were added to the formulary. The antipsychotics risperidone, olanzapine, and quetiapine were also added via petition between 1996 and 1998.
The four State Mental Health agencies interviewed all reported open formularies. Only mirtazapine and citalopram were reported as exclusions. Citalopram was approved in the 4th quarter of 1998, and therefore is likely too new to have achieved widespread formulary acceptance. The reasons for the exclusion of mirtazapine are less clear, although the lack of a clear advocacy for its inclusion cannot help its uptake.
The CHAMPUS program of the Department of Defense maintains a system wide formulary that represents the minimal set of pharmaceuticals covered for treatment within military treatment facilities (MTFs). The national formulary is generally somewhat more limited in scope than those that may be in used in individual MTFs. For example, the national formulary includes a limited selection of newer antidepressants and antipsychotics on its formulary. TCAs and haloperidol are specifically included on the national formulary. In addition, each individual military treatment facility (MTF) must include at least one SSRI on its own formulary. Although these formularies are technically closed, providers can prescribe off formulary with prior authorization. The DoD has made the addition of at least one SSRI to the national formulary a priority.
The Veteran's Administration (VA) includes one SSRI (citalopram) and one atypical antipsychotic (quetiapine) on formulary. Off-formulary prescriptions are allowed, however, pending prior authorization.
- Private Payers
The private sector has embraced the newer agents, although formularies appear to be more actively managed than in the public sector. A review of over forty managed care formularies (in addition to those MCOs interviewed for this study) found no managed care plans or PBMs who did not include at least two of the newer antidepressants on their formulary. However, few plans includedevery newer agent. Results of the survey for antidepressants are shown in Exhibit IV-3 below.
Exhibit IV-3. Formulary Status of Antidepressants in 41 Managed Care Plans
Agent Reimbursed without Qualification PA Required Not Reimbursed Higher Copay Required Total Fluoxetine 27 8 4 2 41 Paroxetine 37 2 2 41 Sertraline 28 9 3 1 41 Venlafaxine 31 8 1 1 41 Bupropion 33 7 1 41 Nefazadone 37 4 41
As can be seen in Exhibit IV-3, paroxetine (N=37) and nefazadone (N=37) are the drugs most frequently included on formulary in these 41 plans, followed by bupropion (N=33), venlafaxine (N=31), and sertraline (N=31). Fluoxetine is the drug most frequently not reimbursed (N=4), followed by sertraline, paroxetine, and venlafaxine. Again, it should be stated that in none of the formularies reviewed are newer antidepressants excluded outright. Rather, at least two SSRIs are reimbursed, together with at least one or more of the other newer agents.
Formulary coverage of newer antipsychotics is even more widespread than is that of newer antidepressants. Exhibit IV-4 shows the results of the survey of 41 health plans for antipsychotics.
Exhibit IV-4. Formulary Status of Antipsychotics in 41 Managed Care Plans
Agent Reimbursed without Qualification PA Required Not Reimbursed Higher Copay Required Total Risperidone 34 5 1 1 41 Olanzapine 32 5 2 2 41 Quetiapine 20 6 12 3 41 Clozapine 26 12 1 2 41
As shown in Exhibit IV-5, risperidone is refused reimbursement by only one plan, olanzapine by only two plans, and clozapine by only one plan. In a small minority of cases, these agents are reimbursed but require higher copayments as non-formulary drugs. Only 50% of plans surveyed covered quetiapine at the time of this survey. This likely represents the relatively recent approval date of quetiapine (4thquarter 1997) relative to the frequency of updating of published formularies. It may also represent a lack of demand for quetiapine. This lack of demand may reflect curiosities in the treatment of schizophrenia. Clozapine is utilized as a second or third line agent for the treatment of schizophrenia. Clinicians and plans may prefer to use the agents with which they are most familiar (i.e., risperidone and olanzapine) prior to switching to clozapine for treatment refractory patients, leaving quetiapine without a therapeutic niche.
The formulary status of the newer antidepressant and antipsychotic agents is consistent with the pattern observed for other classes of pharmaceutical agents. For example, Exhibit IV-5 shows the formulary status of the statin class of lipid lowering agents. This drug class is a useful comparator to psychotherapeutics because it represents a class of branded agents that, with few exceptions, has failed to differentiate themselves one from another. A clear exception is atorvastatin, which has been shown to be the most powerful of these agents. The statins have similar per day costs to the SSRIs. However, statins have no historical antecedents, as do the psychotherapeutics, and therefore comparison is not strictly parallel.
Exhibit IV-5. Formulary Status of Lipid Lowering Agents (HMG-co-A Reductase Inhibitors, i.e., Statins) in 40 Managed Care Plans
Agent Reimbursed without Qualification PA Required Not Reimbursed Higher Copay Required Total Fluvastatin 35 2 3 40 Atorvastatin 32 5 3 40 Pravastatin 31 5 3 1 40 Simvastatin 15 13 9 3 40
At first glance, it would appear that coverage of the statins is slightly more generous than that of the newer antidepressants. However, one would expect that a drug class with only four options would show a slightly higher rate of formulary inclusion of each agent than a drug class with over seven options.
- Public Programs
- Special Populations
The formulary for the New York State Department of Corrections is more limited with regard to antidepressants than antipsychotics. The antipsychotic formulary includes both risperidone and quetiapine, while excluding olanzapine. However, the antidepressant formulary excludes six of the newer agents: citalopram, paroxetine, bupropion, nefazadone, venlafaxine, and mirtazapine. Use of newer antidepressants and antipsychotics is discouraged because of the cost. Generics are used to the extent possible, if therapeutic efficacy remains unchanged as a result of use.
The Navajo Region of the Indian Health Service includes five of the newer antidepressants on its formulary: fluoxetine, sertraline, paroxetine, bupropion, and venlafaxine. The antipsychotics included on formulary are risperidone and olanzapine. Clozapine is not included on the IHS formulary because patients with treatment refractory schizophrenia will usually be referred to an outside provider and reimbursed on a fee-for-service basis.