[Assessing an algorithm for the therapeutic swapping of calcium antagonists]

INTRODUCTION AND OBJECTIVE: Therapeutic swapping is one of the activities a Pharmacist ascribed to a Unitary Dose area should undertake. The goal of this work is to assess the impact the definition of a clearly laid-out criteria algorithm for therapeutic swapping regarding calcium antagonists. MATERIAL AND METHODS: The study periods spanned from January to December 2000 before algorithm delivery and from January to April 2001, once the algorithm was in operation. Both the number of prescriptions received at the Pharmacy Department Unitary Dose Area and the number of pharmaceutical acts regarding drugs not included within the Pharmacotherapeutic Guidelines (MNIGFT) and belonging in the Calcium Antagonists Group were collected: direct replacements, active principle swapping, dosage / pharmaceutical formula swapping, and accepted drugs. Study variables were: a) compliance with pharmacotherapeutic guidelines during prescription, such as adjusted number of prescribed MNIGFTs per 1,000 prescriptions, and b) pharmaceutical action adequacy, such as percentage of non-proper therapeutic swaps (performed on the same active principle / dosage, but with better alternatives as defined later in the algorithm). RESULTS: After algorithm implementation a 47.1% decrease in active principles swapping, and a 7.7% decrease in MNIGFT-accepted calcium antagonists, was seen. Similarly, the number of dosage / pharmaceutical formula swaps was increased by 28.6%, and that of non-proper swaps was decreased by 48.0% when compared to the previous period. CONCLUSION: Establishing an algorithm for therapeutic swapping improves compliance with the Pharmacotherapeutic Guidelines during calcium antagonist prescription and the quality of therapeutic swapping as performed by pharmacists regarding this group of drugs.