Drug research in older patients

The elderly (over 64 years old) comprise 12% of the US population and 17% of Sweden and Japan. This sector continues to grow. In the United States, it is estimated that the elderly population will grow to 14% by the year 2010 and reach 17% by 2030 (US Bureau of the Census, 1996). This, together with their known sensitivity to medications (Everitt and Avom, 1986), contributed to acceptance by industry of additional requirements for testing in the elderly. 

The US Bureau of the Census, International Database (1996) (National Center for Health Statistics, 1996) projected that, for the year 2020, the less-developed countries would contain only 16.4% of the world population compared to 27.1 % in 1996, and that by 2020 the mean age of the population in more developed countries would be 42 years, up from 36 years in 1996. In developed regions, the elderly would outnumber young children by 8 1, for example in Italy, based on current fertility and survival rates, only 2% of the population would be five years or younger, but 40% would be 65 years and older. 

There were even more startling projections by the United Nations International Population Division (1996). They projected life expectancy in the 

7 births per woman down to 1.4 in the Western world. This is below the replacement rate. For Second World regions, the rate of about 3.3 births per woman would decline to 1.6. Even in the least developed (Third World) countries, five births per woman would fall to two by 2050. Thus, the whole world would actually start to depopulate in 40 years. 

The social and healthcare impact of these demographics in the United States and across the globe will lead to an increased demand for better medicines directed at a healthy old age. This elderly population have more income than average per capita income. In the United States, 70 million baby-boomers are starting to retire to a total of 

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Some research dollars are pursuing new classes of drugs, which may supplant older therapies or create new markets in areas where there was before no effective therapy. Several companies have current research programs on drugs for Alzheimer s disease, a major cause of dementia in older people, but so far no drug can offer substantial improvements in patient functioning. (See chapter 5, box 5-E for more information on... 

Schizoid Personaiity Disorder (SPD). Again, there is very little research to guide in the selection of medications to treat the schizoid patient. If we conceptualize the symptoms of SPD as most resembling the negative symptoms of schizophrenia, the choice of agents would tend to favor the atypical antipsychotic drugs as opposed to the older typical antipsychotics. Consequently, we also recommend low doses of an atypical antipsychotic as a first-line treatment for SPD. 

As with most of the older psychotropic drug, dose-response curves for clozapine have not been developed until recently. In a blinded, controlled study, Simpson and coworkers (330) randomized patients into three doses of clozapine 100, 300, and 600 mg. These researchers found that 600 mg was more effective than 300 mg and that doses up to 400 mg/day usually produce inadequate plasma levels. Thus, the results of this dose-response study are consistent with the plasma level studies. 

The possibility of hereditary factors has been raised on many occasions. Although animal experiments suggest that such factors do exist, recent research on this subject in man is scanty. All that can be gleaned from the older literature is that the existence of any such influence remains uncertain. It is nevertheless claimed that patients with an atopic predisposition or with the lupus erythematosus diathesis are more prone to drug reactions than normal people. 

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