Writing in the Annals of Internal Medicine, US researchers find the majority of challenges centre on multivitamins or calcium supplements, with products exceeding 17 millimetres (mm) in length topping the list.
“One way to prevent swallowing problems is to modify dosage form characteristics, for example, produce smaller dosage forms or add coatings,” suggests the report, led by the US Food and Drug Administration’s (FDA) Dr Cecile Punzalan.
“Another approach is to educate patients to speak with their pharmacists or physicians about ways to address swallowing difficulties.”
While the FDA are primarily responsible for determining generic tablets and capsule size, in Europe that responsibility ultimately lies with the European Medicines Agency (EMA).
Whilst the Agency’s 2017 reflection paper ‘Pharmaceutical development of medicines for use in the older population,’ does not mention capsule length and size as such, it does discusses potential problems that elderly populations may face.
For example, the paper cites that “elderly patients are more likely to experience conditions which lead to impaired swallowing, such as stroke or Parkinson’s disease.
“This can lead to accidental under dosing, which can be managed appropriately by the development and use of formulations which are easier for such patients to swallow,” it continues.
The paper’s thoughts on tablets could well apply to supplements as the rise in layered tablets, nutrient blends and modified release methods invariably result in a larger pill form.
This in itself presents challenges with swallowing and tablet movement as the importance of good tablet design to address patient acceptability and compliance becomes more crucial than ever.
The investigation uses 10 years of data from adverse event reports submitted to the FDA Center for Food Safety and Applied Nutrition Adverse Event Reporting System (CAERS).
Here, researchers began identifying dietary supplement reports submitted to CAERS from 1 January 2006 to 31 December 2015 that involved swallowing problems (such as choking and dysphagia).
The team noted the sex, age, product, and adverse event outcomes excluding 442 reports mentioning multiple supplement products or nonsolid oral formulations like liquids or powders.
Along with colleagues from the Centers for Disease Control and Prevention (CDC) they categorised products on the basis of their ingredients or common reasons for use also measuring capsule sizes for the 10 most commonly identified dietary supplements.
Out of the 20 791 adverse event reports submitted to CAERS mentioning dietary supplements in 2006 to 2015, 3962 (19.1%) indicated swallowing problems.
These reports most commonly involved females (85.6%) and represented 25.4% of all CAERS reports among females.
Of the 64.5% of swallowing problem reports that included age data, 76.8% involved adults aged 65 years or older.
Choking was the most frequently reported swallowing problem (86.0%), followed by foreign body trauma (7.8%).
According to a CAERS medical reviewer assessment, 14.3% of swallowing problem reports cited serious adverse events, including 3 deaths attributed to supplement-induced airway obstruction or aspiration.
Most reports of swallowing difficulty (72.9%) involved multivitamins; 17.3% involved calcium supplements.
Further findings looked at the 10 most commonly reported dietary supplements that accounted for 3026 (76.4%) of swallowing problems.
The findings have a weighted mean pill length, width, and height of 19.3 mm, 9.8 mm, and 7.8 mm, respectively.
Swallowing complications from these 10 products accounted for a proportional reporting ratio of 12.7, indicating that the ratio of reports of swallowing problems to those of all problems was 12.7 times higher for these 10 products than for other dietary supplements.
Seven of the 10 products, accounting for 64.5% of all swallowing problem reports, were multivitamins marketed to older adults or calcium supplements. A single multivitamin product marketed to older women was involved in 40.6% of swallowing problem reports.
“This study had limitations,” the report points out. “Data regarding frequency of use for specific products were not available, CAERS reports may not represent the US population overall, swallowing problems may be underreported, and completeness of reports may vary.
“Therefore, patient-specific risk factors for choking could not be fully assessed. In addition, pill sizes may have changed during or after the study period.
“Nevertheless, these data identify a specific harm—choking—that may be preventable, particularly in older adults who regularly consume dietary supplements.”
CRN: Alternative, innovative delivery options are available
Commenting on the study's findings, Andrea Wong, PhD, VP of scientific & regulatory affairs for US trade organization the Council for Responsible Nutrition (CRN), said: “At CRN, consumer safety is our top priority, and we appreciate any opportunity to remind consumers of ways to safely consume dietary supplements. Choking is preventable, and there are many reasonable solutions for consumers who may have difficulty swallowing dietary supplements, as indicated in this letter. For example, adult supplement users can talk with their pharmacist or other healthcare practitioner about modifying dosage form characteristics.
"Adult supplement users can also choose alternative, innovative delivery options, including liquids, gummies, melts or effervescent powders. With three quarters of Americans taking dietary supplements each year, it is important that the task of swallowing a supplement does not get in the way of consumers’ access to good nutrition. If swallowing anything – a dietary supplement, an over-the-counter or prescription drug, or food—is a struggle, we recommend consumers seek the attention of a medical professional.”
Source: Annals of Internal Medicine
Published online: doi:10.7326/M19-0947
“Swallowing Problems and Dietary Supplements: Data From U.S. Food and Drug Administration Adverse Event Reports, 2006–2015.”
Authors: Cecile Punzalan et al.