are given as examples. Finally, other common
drugs most likely to be used with the test drug
are recommended to be explored for possible
synergistic or antagonistic drug interactions.15.7 Industry response
A survey conducted by the FDA in 1983 (Abrams,
1993) showed that, for 11 drugs recently approved
or awaiting approval of New Drug Applications, in
seven applications 30–36% of patients were aged
over 60. In one application, a study on a drug for
prostate cancer, 76% of patients were, not surpris-
ingly, over 60 years old (Everitt and Avorn, 1986).
An additional survey by the FDA in 1988 of 20
NDAs showed similar results but, in addition, ana-
lysis by age and PK studies in the elderly were
frequently included. A survey by the Pharmaceu-
tical Research and Manufacturers of America
(PhRMA) (Tauzin, 1995) showed that 917 medi-
cines were being studied for potential use in the
elderly. These include 373 drugs targeting indica-
tions of old age, 166 for heart disease and stroke.
Aprivatesurveyof19pharmaceuticalcompanies
operating in the United States (Chaponis, 1998)
ranked cardiovascular, depression, Alzheimer
hypertension, rheumatoid arthritis, osteoarthritis
and oncology as the most important therapeutic
areas in their company. All of these are commonly
found in the elderly. Why did companies target
these therapeutic areas in the geriatric population?
This drew the response: ‘It’s a growing population,’
from 77% of respondents, and ‘increasing market
size’ from 58% of the 27 company respondents.
Companies were asked which types of geriatric-
based clinical trialsthey conducted. Safety, efficacy,
PK and drug interaction studies were quoted in that
order of frequency, which, because of the introduc-
tion of the guidelines, is to be expected. However,
the next most frequent studies were quality-of-life,
pharmacoeconomic, drug disease (outcomes) and
patient satisfaction studies. The later studies reflect
the elderly and third-party payers’ influences
(Chaponis, 1998). In its 2005 survey, PhRMA
reported that more than 600 medicines were then
being developedfor diseasesofageing. Thisreflects
the increasing importance of medicines for the
graying population of United States.15.8 Issues of diseases
in the elderlyHypertensionaffects about 50% of the elderly
population. There is also a unique form called
isolated systolic hypertension, which affects 9%
of the geriatric population and is growing as the
population ages. The challenges of doing studies in
this area increase with the age of patients admitted,
which correlates with increased concomitant med-
ications and illness and compliance, but otherwise
relates well to study designs in the younger age
group. This is a major cause of the following three
major events causing death in the elderly.
Coronary heart diseasecaused one in five deaths
in 2002 at average age of 65.8 and 70.4 for women
(American Heart Association, 2005).
Heart failureis a leading cause of hospitaliza-
tion of the elderly. About 5 million Americans
suffer from this disease, which has a high mortality
rate. Control of blood pressure, use ofb-blockers,
ACE inhibitors and now spironolactone (Pittet al.,
1999) will result in further improvement of mor-
tality which have started to fall from 117 per
110 000 in 1988 to 108 in 1995, according to the
Center for Disease Control and Prevention (CDC).
Because of its severity, patients are on many
concomitant medications apart from the aforemen-
tioned drugs, such as diuretics, digoxin, potassium
supplements, medicines to improve pulmonary
function and antibiotics to control frequent infec-
tion in edematous and often emphysematous lungs.
Measurements of heart function, and the long dura-
tion of these studies and large patient numbers
required for mild to moderate heart failure (end
point death), make these very challenging and
expensive studies.
Strokethrombotic or hemorhagic is the third
leading cause of death, killing 160 000 persons in
the United States each year, 7 out of 10 victims are
aged 65 or older. Of those that survive, one-third
will be permanently disabled. Some improvements
in these figures are hoped for, with earlier use of15.8 ISSUES OF DISEASES IN THE ELDERLY 197