Adult Patients with Difficulty Swallowing Oral Dosage Forms: A Systematic Review of the Quantitative Literature

Abstract

The aim of this systematic review was to identify and critically appraise the available evidence regarding solid oral dosage forms (SODFs), e.g., tablets, and challenges regarding the oral administration of medicine to inpatients in a variety of healthcare settings such as (1) hospitals, (2) nursing homes and (3) long-term stay units (LTSUs). A literature search was undertaken in September 2021 and repeated in June 2023 in the following databases: PubMed, EMBASE, CINAHL, Scopus, Web of Science, The Cochrane Library, PsycINFO and ProQuest. A Microsoft Excel^® spreadsheet was devised to collate the following data from each eligible study: study author and year, country, number of participants, title, duration (follow-up period), study design, inclusion and exclusion criteria, method and data collection, relevant outcomes, and key findings. A total of 3023 records were identified, with 12 articles being included in the final systematic review. Seven of the twelve studies reported on the prevalence of difficulties swallowing SODFs, which varied from 10–34.2%. Nine of the twelve studies reported the methods used to manipulate SODFs, with the most reported method being tablet crushing. Given the prevalence of swallowing difficulties and the subsequent crushing of medicines in response to this, it is evident that concerns should be raised regarding the potential for a medication administration error to occur.

Introduction

One of the most prevalent and successful ways in which to prevent, manage and cure disease and ill health is using medication [1]. However, published research has shown that despite the clear advantages of medicines in helping patients, many patients do not take their medicines as prescribed, a concept termed by healthcare professionals as non-adherence [2]. Non-adherence may be unintentional or intentional [2]. Unintentional non-adherence can occur due to a lack of capacity or resources to take medications, e.g., patients forgetting to take medication. In older adults for example, unintentional adherence may be due to cognitive or psychological problems, visual or motor impairments, or a lack of adequate support structures [3]. Intentional non-adherence is associated with a decision, which may be based upon the perceived need for the medicine and may also involve the modification of the medicine or the doses taken [4,5]. The constructs underlying intentional non-adherence are varied, but can include difficulty swallowing the medicine, amongst other reasons. There are many negative consequences of non-adherence, including disease progression for the patient and increased healthcare utilisation and cost [6]. A review of interventions to improve adherence advises that any intervention should address specific medication adherence barriers for the individual patient [7].

Medicines are most commonly administered via the oral route [8]. However, patients may have trouble taking their medicines in this way due to a diagnosed or perceived swallowing difficulty [9]. Dysphagia is the medical term for swallowing difficulties, and while patients with dysphagia (PWDs) may have problems swallowing certain foods or liquids, others may not be able to swallow at all [10]. Swallowing difficulties may be overcome using routes of administration other than oral, such as the transdermal parenteral route. However, the number of medicines suitable for administration via routes other than oral is limited and the parenteral route may not be suitable for long-term administration. Another option is to use an enteral feeding tube (EFT) for the administration of medicines, e.g., a naso-gastric (NG) or gastrostomy tube. EFTs are often inserted when the risk of the aspiration of medicines or food is high when taken via the oral route. In many instances, however, the patient may not have a formal diagnosis, but rather may find that the act of swallowing presents challenges due to sensations such as a feeling of choking, gagging, or a fear that the medicine may get stuck [11]. These patients and/or their carers may seek to overcome these challenges by modifying the tablet or capsule. This is known as solid oral dosage form (SODF) modification. In many instances, the tablet will be crushed or split, or the capsule might be opened, and the contents removed for easier administration. In healthcare settings, e.g., hospitals and nursing homes, most patients have their medications administered via a healthcare professional (HCP), where again the modification of SODF takes place to facilitate administration [12,13]. In these settings, non-adherence is not as much of a problem, but SODF modification still occurs to facilitate the administration of oral medicines to patients with a swallowing difficulty or an EFT.

Whilst SODF modification presents a pragmatic and simple solution, it does not come without its own risks and challenges. These include the fact that any modification of a SODF from its authorised form may change the absorption, distribution, metabolism and or elimination (ADME) profile of that authorised product [14]. This is particularly problematic for oral sustained-release or enteric-coated formulations, leading to unintended consequences such as therapeutic failure or toxicity [15]. Patients, carers and HCPs can be exposed to cytotoxic, hormonal or teratogenic medicines if powder aerosolisation results from the crushing process [14]. Irritation to the respiratory tract, skin or mucous membranes can also occur. Additionally, crushing SODFs is almost always outside the terms of the marketing authorisation for the medicinal product [16]. Patients without an EFT face the difficulty of ingesting a manipulated SODF, which may be unpalatable and result in the use of vehicles that are unsuitable [14]. Medication errors and non-adherence to medicine regimens is a significant cost burden to health services [6]. Whilst a significant volume of research has been conducted in the paediatric population [17,18,19], the aim of this systematic review is to identify and critically appraise the available evidence regarding oral medicine administration to adult inpatients in a variety of healthcare settings, such as (1) in hospitals, (2) nursing homes and (3) long-term stay units (LTSUs).
The objectives of the review are as follows: (i) to examine the prevalence of swallowing difficulties, (ii) to describe the medication management practices used to administer oral medicines, and (iii) to examine the prevalence and type of medication administration errors associated with solid oral dosage form (SODF) manipulation.

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Harnett, A.; Byrne, S.; O’Connor, J.; Lyons, D.; Sahm, L.J. Adult Patients with Difficulty Swallowing Oral Dosage Forms: A Systematic Review of the Quantitative Literature. Pharmacy 2023, 11, 167. https://doi.org/10.3390/pharmacy11050167

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