Marta Szumilak, Hubert Cieplucha, Julia Gołąb, Jacek Owczarek

Oral administration of medicines to patients with swallowing difficulties – the case of antiparkinsonian drugs

 

2026-05-26

Study subject. Administration of solid oral dosage forms of medications indicated for Parkinson’s disease in patients with dysphagia, including the ones using enteral feeding tubes.

Study purpose. The aim of this study is to review all medicinal products registered in Poland that are indicated for the treatment of Parkinson’s disease, together with an analysis of the information provided in the Summaries of Product Characteristics and the scientific literature concerning the possibility of modifying solid oral dosage forms for safe administration to patients with dysphagia, including the ones using enteral feeding tubes. The analysis included in the paper concerns alternative routes of administration other than oral administration and the availability of reimbursed medicinal products in forms suitable for administration to patients with swallowing difficulties.

Material and methods. Review and analysis of information provided in the Summaries of Product Characteristics (176 presentations, 16 active substances); the Announcement of the Minister of Health of 17 June 2025 on the list of reimbursed medicines, special-purpose foods, and medical devices, effective as of 1 July 2025, and guidelines of scientific societies: American Society of Parenteral and Enteral Nutrition, Society of Hospital Pharmacists of Australia, British Pharmaceutical Nutrition Group, NEWT Guidelines, NHS Specialist Pharmacy Service, and Estonian Society of Hospital Pharmacists, as well as scientific literature (Embase, PubMed, Scopus, Web of Science) regarding the modification of solid oral dosage forms of medications used in the treatment of Parkinson’s disease. Literature review included full-text works (original articles and reviews) from 1995 to 2025, with emphasis on scientific reports from the last 10 years. The search strategy included Medical Subject Headings (MeSH) terms: “Parkinson’s disease”,” deglutition disorders”, “enteral nutrition”, “dosage forms”, “drug administration”, “crushing”, and “mastication”.

Results. A total of 176 presentations of medicinal products containing 16 active substances used in the treatment of Parkinson’s disease were analyzed. Most of the drugs were authorized for marketing through the centralized procedure (79).

Levodopa, as a key drug in the treatment of Parkinson’s disease, is available in the broadest range of pharmaceutical forms, including oral preparations, a gel for intestinal administration, a powder for inhalation, and a solution for infusion. It is noteworthy that no liquid dosage forms of this drug sensu stricto are registered in Poland for use in this disease. Analysis of administration instructions showed that for 57% of all evaluated products, Summaries of Product Characteristics clearly and unambiguously state that the medicine should only be taken whole (this applies to 58 prolonged-release products and 35 standard-release products). In the case of 101 standard-release preparations (tablets and capsules), no information was found in Summaries of the Products Characteristics regarding the possibility of splitting or crushing tablets or opening the capsules. However, only 9% of oral preparations can theoretically be administered to patients with dysphagia (assuming that the modification facilitating swallowing permitted in the Summary of Product Characteristics is sufficient).

A clear statement regarding the possibility of administering the medicine to patients with swallowing disorders was found exclusively in the Summary of Product Characteristics of dispersible tablets containing the levodopa/benserazide combination. In addition, two medicinal products in the form of an intestinal gel for continuous intestinal administration, containing combinations of levodopa/carbidopa/entacapone and levodopa/carbidopa have been authorized for marketing in Poland; however, they are reimbursed only under the drug program.

The analysis of scientific literature and professional guidelines revealed variable levels of detail regarding the information about the possibility of modifying solid oral dosage forms. Some sources refer to modifications of a specific medicinal product, while others refer only to its pharmaceutical form. Except for prolonged-release formulations, which must not be altered, administration procedures are described for most solid oral dosage forms used in patients with dysphagia and/or artificial enteral access, typically accompanied by a note emphasizing the healthcare professional’s responsibility due to off-label use. It is worth noting that there are few studies on the bioavailability of modified solid dosage forms.

An analysis of alternative forms of administering anti-Parkinson’s drugs has shown that they are available on the Polish market in the form of injections/infusions, the use of which can be burdensome for the patient. Moreover, some of them are not reimbursed (rotigotine in transdermal systems, apomorphine in cartridges) or are only available in the drug programe in the advanced stages of Parkinson’s disease (apomorphine, foslevodopa/foscarbidopa in subcutaneous infusions), which limits their wide availability.

Conclusions. The analysis revealed insufficient and imprecise information in Summaries of Product Characteristics of drugs indicated for the treatment of Parkinson Disease regarding their safe administration to patients with swallowing disorders, which poses a serious risk of medication errors and exposes medical staff to legal liability. Inappropriate drug administration increases the risk of complications, reduces the effectiveness of treatment and lowers patients’ quality of life. The coordinated and strategic intervention is necessary, including: requiring marketing authorization holders to provide comprehensive information in Summaries of Product Characteristics regarding the possibility of modifying (decomposing) solid oral dosage forms, based on stability and bioavailability studies; developing a publicly accessible, regularly updated Evidence-Based Medicine (EBM) database providing precise guidance on safe decomposition and administration of medicines to patients with dysphagia and/or the ones using enteral feeding tubes and implementing interdisciplinary cooperation between pharmacists, physicians and nurses to ensure the conscientious and documented medication management, minimizing the risks arising from discrepancies between official recommendations and the clinical needs of the patient.

Keywords: Parkinson disease, deglutition disorders, enteral nutrition, drug administration, dosage form, crushing, mastication, splitting.

© Farm Pol, 2025, 81(10): 609–619