admissions amongst elderly population, and nearly 4.8% of admissions in elderly are

caused by DDIs (Hines and Murphy 2011).

It has been reported that around 8.7–10% hospital admissions in older persons are

frequently related to ADRs caused by NSAIDS, beta-blockers, and polymedication.

In most cases, ADRs are preventable if the doctors are aware of prescribing the

interacting drugs and inappropriate medications to older patients (Oscanoa et al.

2017). Increased risk of bleeding, prolongation of QT interval, and hyperkalemia are

examples of the DDI consequences that expose elderly people with dementia and

cognitive impairment to unnecessary risks if drug use is not properly monitored

(Hosia-Randell et al. 2008). Many hospitalizations caused by DDIs could be avoided

by careful selection of antidepressant medications (Bogetti-Salazar et al. 2016).

Some clinically relevant interactions may result from the simultaneous intake of

antidepressant drugs with herbal remedies (St. John’s wort, Ginseng, Ginkgo biloba,

Ashwagandha) and fruit juices (grape fruit, orange, and pomegranate). Healthcare

providers should ask questions to their patients about the use of herbal remedies,

dietary supplements, and fruit juices, and discourage concomitant ingestion of

botanical products with psychotropic drugs.

Keeping in mind the scope of this review, we will focus on the DDIs targeting

more precisely on the psychotropic drugs, which are related to antidepressants. DDIs

are frequently observed in the geriatric population due to comorbidity and a wide

range of polypharmacy. The selection of these kinds of interactions is rather subjec-

tive, but we will describe the DDIs which are more serious and most frequently

observed within the elderly populations. It is worthy to note that many compounds

may produce similar pharmacological effects due to their close chemical structures,

CYP-metabolic pathways, or some other attributes mentioned in Table 15.3.

Balanced and safe prescribing is difficult to achieve in frail older adults affected

by multiple comorbid conditions, especially with renal and hepatic disorders. The

improvements in medical technologies and better nutrition and sanitation have

expanded the life span of people worldwide. At the same time, the proportion of

elderly people inflicted with multiple chronic diseases and requiring multiple drug

therapies has also increased. Unfortunately, older patients with comorbid conditions

are often excluded from clinical trials, and as a consequence the evidence coming

from diverse studies may not be generalized to this population. In addition, the

application of clinical practice guidelines, which are based on the evidence coming

from randomized trials and meta-analyses, is problematic because such studies

usually focus on specific disease and do not take into account the presence of

comorbid conditions. The problem is further exacerbated by the fact that multiple

conditions are often treated by different specialists, many of whom do not commu-

nicate with one another. As a result, the guidelines-driven therapeutic approach in

elderly patients with multiple chronic abnormalities may produce undesirable

consequences resulting from multiple drug regimens with increased risk of drug-

drug or drug-disease interactions. In view of these circumstances, the International

Association of Gerontology and Geriatrics in conjunction with WHO has suggested

that drugs which are intended to be used in older population should undergo double-

blind and randomized controlled trials in nursing homes and long-term care

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