In a managed healthcare setting (e.g., hospital, nursing home), a medication

therapy management program is an excellent way to reduce inappropriate

polypharmacy that would result in cost savings. The clinicians should also consider

drug-disease interactions (especially liver and kidney disorders) that may be unique

to individual patients and may require dose adjustment. A proper assessment of

polypharmacy interactions may provide insight into medications that are inappropri-

ate, ineffective, and/or unnecessary for a particular patient. Such best prescribing

practices would not only reduce the risk of clinical interactions and side effects of

medications and herbal therapies the patient may be taking but also help in adjusting

doses of interacting medications that exacerbate harmful effects.

Education of healthcare professionals is a key factor to assess the therapeutic need

of frail elderly patients, and perhaps the best education is first-hand experience to

talk to the patient and families with informed discussion of expected benefits and

potential harms of pharmacotherapy.

The aims and objectives of this article are multi-fold: namely, (1) to review the

available data on the metabolic disposition of drugs in the elderly population, and

how the metabolic changes can cause adverse drug reactions and frequent

hospitalizations and affect the quality of life in geriatric patients; (2) to address the

issues and concerns regarding drug dose adjustment in frail elderly patients; and

(3) why it is crucial to enroll elderly subjects in clinical trials to evaluate the

pharmacometabolomics, long-term safety, and efficacy as well as learning about

the optimal dose schedules of new drugs. All these efforts will be supported by good

prescribing practices and dose adjustment examples of psychotherapeutic drugs

because the antidepressant, antianxiety, and anti-insomnia medications are some of

the most frequently used classes of drugs for mitigating depressive disorders in

elderly men and women.

15.2

Modifications of Gastrointestinal (GI) Physiology in Elderly

The core functions of the GI tract are to ensure adequate digestion of foods and

absorption of nutrients involving digestive secretions and GI motility regulated by

neuronal and hormonal control. Healthy GI functions also require good dental status

for chewing and swallowing of chewed food. Quite often the masticatory function,

taste, and swallowing reflex get impaired in elderly subjects (Wyatt and Kawato

2019). Madhavan et al. (2016) have reported salivation reduction and swallowing

problems in elderly individuals aged 65 years and over. Although salivary flow rate

decreases with healthy ageing, medications with anticholinergic, psychotropic,

antihistamine, and diuretic drugs reduce salivary secretion that can adversely impact

on food digestion (Madhavan et al. 2016). Impairment of salivary and dental

functions can contribute to food avoidance, reduce food intake, and eventually

lead to poor nutritional status among elderly (Morley 2007). Reduction in esopha-

geal functions is often observed in the elderly, which can also occur in younger age

groups, about 40 years old. Deteriorated esophageal reflexes may reduce peristalsis

and increase non-propulsive contractions of the GI tract (Rayner and Horowitz

15

The Importance of Drug Dose Adjustment in Elderly Patients with Special. . .

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