N-of-1 tests in general practice: pharmacological considerations
- N-of-1 Hub
- Oct 28
- 2 min read
Updated: Nov 1
What is the main takeaway?
This article in the British Journal of General Practice examines the pharmacological factors that determine whether an N-of-1 trial can realistically be carried out in primary care. Diezi et al. identify seven key factors: onset of action, washout, titration rate, withdrawal or rebound potential, reversibility of effect, identifiability, and galenic formulation (how the medicine is made and delivered, for example tablet vs capsule or slow release).
Through clinical vignettes and a detailed feasibility table covering commonly prescribed drugs, the authors explain why certain treatments like duloxetine, gabapentin, melatonin, NSAIDs, and statins are suitable for N-of-1 trials, whereas drugs such as fluoxetine, long-term pregabalin, and proton pump inhibitors with rebound physiology are poor candidates. The paper gives clinicians a structured pharmacology-based filter to judge which treatments can be tested safely and efficiently at the individual level.
What is the real-world impact?
For researchers, clinical pharmacologists, and prescribers, this publication connects pharmacokinetic reasoning with practical N-of-1 trial design. It serves as a tool for determining feasibility before moving to compounding, randomisation, and data collection.
Pharmaceutical and complementary medicine developers can use these criteria to identify compounds suitable for personalised dose optimisation or tolerability testing. MedTech and digital health companies can build these parameters into automated screening tools to streamline trial setup. Clinical research organisations and universities can adapt the checklist to guide pharmacy collaboration, improve resource allocation, and reduce failed single-patient studies.
What do we think about it?
This work offers a technical advance in operationalising pharmacological logic within N-of-1 testing. It moves feasibility decisions from subjective judgment to measurable properties such as half-life, onset kinetics, and formulation compatibility.
The seven-factor checklist can be incorporated into digital N-of-1 platforms and prescribing systems, allowing primary care teams to apply pharmacological reasoning with minimal effort. Wider use of these criteria could accelerate patient-centred precision prescribing and help normalise N-of-1 testing as part of evidence-based care.
Who are the authors and where can I read the paper?
The article was written by Leonore Diezi, Marco Anastasi, Laurent Brutus, and Thierry Buclin from Lausanne University Hospital and Nantes University.
It was published in the British Journal of General Practice, March 2025.
