From drugs to dry mouth: a rapid systematic review exploring health implications of dry mouth in older adults with polypharmacy
Authors: Cannon I , Ramsay S , McLellan G , Robinson-Barella A 
Published: November 2022

Abstract

Introduction
Approximately 60% of older adults complain of dry mouth which may be associated with polypharmacy, common in this population. Existing studies have reported treatment approaches to dry mouth but do not address long-term, preventative measures that would more positively benefit the health and wellbeing of older adults.1

Aim
This rapid systematic review aims to identify the implications of dry mouth on the physical and psychological wellbeing of older adults with polypharmacy to establish the importance of preventing dry mouth.

Methods
Studies reporting health implications of dry mouth, in relation to polypharmacy in older adults (&gt;65 years old), were included in this rapid systematic review. MEDLINE, EMBASE, PsycINFO and CINAHL databases were searched using Keywords such as ‘polypharmacy’, ‘dry mouth’, ‘oral health’ and ‘quality of life’ (PROSPERO: CRD42021288945). Joanna Briggs Institute critical appraisal tools were used to assess study quality. Ethical approval was not required for this project due to the methodology of this rapid systematic review.

Results
Of the 6,852 citations screened, 9 studies (cross-sectional, n = 8; longitudinal, n = 1) were included which comprised 37,459 participants (mean age range: 68.5-85.0 years). Studies were published between 2005 and 2019. Meta-analysis was not possible due to the heterogenicity of outcomes reported; instead, a narrative synthesis was undertaken. The health implications identified in this review were categorised as ‘physical’, such as tooth loss, or ‘psychological’, such as depression. The main physical health implications reported in the studies related to dental health, such as tooth loss and gingivitis, as well as functional impairments, such as chewing and swallowing difficulties. An increase in the number of medicines taken, from 0 to 5, decreased the number of natural teeth remaining from 16.35 ±8.58 to 11.74 ±7.88, respectively. Additionally, the number of dental complications increased from 1.43 ±2.1 to 2.33 ±2.2 as the number of medicines increased from 1 to &gt;3, respectively. There was a paucity of studies (n = 2) that investigated the psychological health implications of dry mouth upon older adult populations. Depression, was however, identified as a significant consequence of dry mouth in older adults with a prevalence as high as 64%.2 An additional 6 psychological health implications were identified, for example, self-consciousness.

Discussion/Conclusion
This review examined the health implications of dry mouth in relation to polypharmacy in older adults, including physical health and psychological health implications. There were limitations in this review; for example, the predominant cross-sectional study design restricted findings due to the inability to establish longitudinal associations. High levels of physical health implications of dry mouth were observed in older adults with polypharmacy and, to a lesser extent, psychological health implications. The modifiable nature of polypharmacy could pave the way for prevention strategies of dry mouth. The optimisation of medication regimens, to effectively treat chronic conditions but also limit the likelihood of dry mouth, is a practical approach to achieve this.3

References
1. Villa A, Abati S. Risk factors and symptoms associated with xerostomia: a cross-sectional study. Aust Dent J. 2011;56(3):290-5.
2. Rech RS, Neves Hugo F, Torres LHN, Hilgert JB. Factors associated with hyposalivation and xerostomia in older persons in South Brazil. Gerodontology. 2019;36(4):338-44.
3. Cheong ST, Ng TM, Tan KT. Pharmacist-initiated deprescribing in hospitalised elderly: prevalence and acceptance by physicians. Eur J Hosp Pharm. 2018;25:35-9.