Personalised Dose System (PDS): Community Pharmacy Guide

The Personalised Dose System (PDS) has become a fundamental tool in community pharmacy for optimising medication for polymedicated patients or those with management difficulties. Its correct implementation not only facilitates medication intake but also enhances therapeutic adherence and reduces the risk of errors.

What is a Personalised Dose System (PDS)?

A PDS involves organising a patient's medication into a device (usually a weekly blister pack) that groups medicines by daily doses (morning, midday, evening, night) and days of the week. The pharmacist, after an exhaustive review of the prescribed medication, prepares these packs individually, ensuring that each dose contains the correct medicines at the appropriate dose and at the indicated time. This system is especially useful for patients taking multiple medications, who have complex regimens, or who have physical or cognitive limitations in managing their treatment.

The preparation of a PDS is based on the medical prescription and is carried out under the supervision of the pharmacist. Approved devices are used to guarantee the correct storage and dispensing of medicines. The pharmacy thus becomes a key support centre for the patient, facilitating therapeutic compliance and acting as an essential link in the care chain.

Which patients are suitable for a PDS?

A PDS is especially recommended for patients who present with:

• Polymedication: Those taking five or more medicines chronically.
• Management difficulties: Patients with vision problems, limited manual dexterity (osteoarthritis, tremors), or cognitive difficulties (mild impairment, disorientation).
• Complex regimens: Treatments with multiple doses per day, medicines requiring special administration conditions (with or without food), or variable doses.
• Risk of medication errors: Patients with a history of forgotten doses, duplications, or confusion in taking their medication.
• Older people: Who often combine several pathologies and treatments.
• Patients with chronic diseases: Such as diabetes, hypertension, heart or kidney failure, which require rigorous control of their medication.

The identification of these patients is carried out through direct observation in the pharmacy, consultation of the pharmacotherapeutic history, or referral from other healthcare professionals. An individualised assessment is crucial to determine the suitability of a PDS.

PDS Preparation and Monitoring Process

The preparation of a PDS follows a series of standardised steps:

1. Request and Evaluation: The patient or their carer requests the service. The pharmacist reviews the medical prescription, the pharmacotherapeutic history, and evaluates the patient's specific needs.
2. Obtaining the Prescription: The doctor is asked for a detailed prescription of all medicines to be included in the PDS, specifying dose, regimen, and duration.
3. Blister Preparation: Using specific software or manually, the medicines are organised into the weekly blister pack, grouping them by doses and days. The compatibility of the medicines in each dose is verified.
4. Labelling and Quality Control: Each dose is clearly labelled with the necessary information (patient's name, date, time of dose, medicines included). Rigorous quality control is carried out to ensure accuracy.
5. Delivery and Training: The pharmacist delivers the blister pack to the patient or carer, explaining its use in detail, the importance of adherence, and resolving any doubts. Instructions are given on the correct storage of the medicines.
6. Continuous Monitoring: A periodic monitoring plan is established to evaluate the effectiveness of the PDS, detect possible problems (adverse effects, unforeseen interactions), and make adjustments if necessary.

This process ensures that the patient receives their medication safely and effectively, promoting autonomy and improving their quality of life. The pharmacy is positioned as an active agent in health management.

Benefits of PDS for the Patient and the Healthcare System

The adoption of PDS in community pharmacy brings multiple benefits:

• Improved Therapeutic Adherence: Facilitates compliance with regimens, especially in patients with complex treatments.
• Increased Safety: Significantly reduces the risk of medication errors, forgotten doses, duplications, or confusion in taking doses.
• Optimisation of Pharmacotherapy: Allows the pharmacist to carry out a comprehensive review of the medication, detecting possible interactions or therapeutic duplications.
• Greater Patient Autonomy: Empowers the patient or their carer in managing the treatment, fostering independence.
• Reduction of Healthcare Costs: By improving adherence and reducing errors, hospitalisations, emergency visits, and complications arising from poor therapeutic control are minimised.
• Facilitates the Carer's Work: Simplifies medication administration for family members or carers.

These benefits underscore the value of PDS as a proactive strategy in pharmaceutical care, contributing to a more rational and safer use of medicines.