The proportion of the entire population of heavy substance abusers that is considered to be a realistic target market for pharmacotherapy is small relative to the effective target market of pharmacotherapy for other diseases. Although there are other clinical conditions for which the market penetration of pharmacotherapy is proportionately low, the absolute magnitude of the overall market may be so large that even such small penetration of a substantially priced drug can be financially attractive to industry, as in the case of the smoking cessation market.
A combination of factors minimizes the attractiveness of the cocaine abuse market to industry, including: a relatively modest potential market (2.1 million heavy users), low proportion of users currently in treatment (250,000 enrollees on any given day), concerns about compliance in this population, and apparent market expectation of a low price point. This appears to be corroborated by the methadone market, where a relatively effective, low-priced medication in a well-established, long-standing treatment system achieves, at best, a 25 percent penetration of the small population of opiate addicts (i.e., about 125,000 patients enrolled in methadone treatment per day out of about 500,000 opiate addicts). The penetration of LAAM is less than five percent of the methadone market, i.e., less than one percent of the opiate addiction market, and the use of naltrexone for opiate addiction falls below that of LAAM. On the other hand, the market for medications to treat the 2.1 million epilepsy patients generates $400 to $500 million per year (IOM, 1995).
Drawing inferences about the potential market for a new cocaine abuse medication from the market experience of other medications for substance abuse must consider the market-limiting characteristics of the treatment systems for opiate addiction to which methadone and LAAM are subject. The market conditions for a new cocaine abuse medication would differ if it is provided via more traditional means of physician prescribing and distribution through pharmacies, rather than if it is a Schedule II or Schedule III controlled substance warranting the forms of controlled treatment delivery required for methadone and LAAM. Nevertheless, their status as medications for illegal substance abuse, similarities in the user populations, and other characteristics make methadone, LAAM, and naltrexone useful, though imperfect, market comparators for a new cocaine abuse medication. As a group, the markets for these medications more closely resemble the potential market for a cocaine abuse mediation than markets for other medications, and industry looks to these markets accordingly when assessing the market for potential cocaine abuse medications.
In comparison to other populations with clinically manifest cancer, heart disease, or other disorders, most substance abusers practice denial. Most abusers do not acknowledge a need for treatment and some even actively resist treatment. Many abusers that do acknowledge a need for treatment fail to seek or sustain treatment. Most patients that enter treatment do so under duress or coercion from legal authorities, employers, family members or friends (Institute of Medicine, 1990). Thus, social policy may be a primary driver of the proportion of cocaine addicts that can be directed to treatment in a year. However, such policies can be badly undermined when patients that do seek to enter treatment are greeted with waiting lists. Once placed on a waiting list, a patient is far less likely to be contacted and admitted when a treatment slot does open.
As noted in this report, it is estimated that there may be almost 900,000 treatment admissions or episodes per year by perhaps 800,000 cocaine addicts, although this number may be smaller due to high rates of relapse and treatment re-entry. Assuming that 800,000 users enter the system at least once during a year, this would constitute nearly 40 percent of the total number of heavy cocaine users, and might appear to be a more substantial market. However, the prospects of retaining this number of patients in ongoing treatment do not appear favorable, given the limitations of a treatment system and characteristics of a population that yield only 250,000 daily enrollees.
The uncertainty about the number of cocaine users, especially the secondary users, places a wide confidence interval around the potential size of the market for cocaine abuse treatment. For the purposes of gauging the potential market for a new pharmacotherapy for cocaine addiction, it may be optimistic to use an estimate of 250,000 current daily enrollees in treatment. Projections of market penetration must consider that some primary users and many secondary abusers may be treated for other addictions and with behavioral therapy to the exclusion of pharmacotherapy, particularly in the context of the current treatment system. Given that many cocaine addicts abuse multiple substances and have diverse health and behavioral disorders, it may be that one or a few medications for cocaine abuse will be insufficient for treating this population. To the extent that multiple medications are needed, the market potential for any one medication would be reduced.
From the standpoint of the pharmaceutical industry, the anti-depressant drug market may serve as a useful contrast in the CNS market to the cocaine market. Depression is a condition that afflicts more than 8 million Americans (Irvin 1997), and depressive disorders have a lifetime prevalence of up to 15 percent for men and 24 percent for women (Hirschfeld 1997).
The consequences of depression include patient mortality as well as direct and indirect costs to society. Those that suffer from depression are at a greater risk for suicide and other co-morbidities including substance abuse, heart disease and other medical conditions. In 1990 alone, the cost of depression was estimated to be between $26 and $43.7 billion (Henry 1997). On average, employers incur an annual cost of $4,200 per depressed employee, of which 28 percent represents treatment costs (Hirschfeld 1997).
In terms of utilization and sales of anti-depressant drugs, 98 million prescriptions were written for these drugs and $4.3 billion in total sales were recorded in 1996 alone (Scott-Levin 1996, IMS 1996). The selective serotonin re-uptake inhibitors (SSRIs) were the most prescribed anti-depressant (54 percent) and captured 89 percent of the market dollars, while the tri/tetracyclics accounted for 5.6 percent of the market dollars despite representing 32 percent of all anti-depressant prescriptions.
The vast majority of these anti-depressants are dispensed through the retail sector (IMS 1996). Retail sales (i.e., through chain stores, independent pharmacies, food stores) accounted for 86 percent of the market in 1996, while long term care, federal facilities, HMOs, non-federal hospitals, and clinics made up the remaining 14 percent of the market.