Pharmacology Mentor

The Concept of P-Drugs in Rational Prescribing

Main Takeaway: A P-drug is a prescriber’s personal choice of first-line medicine for a specific indication, selected through a systematic and evidence-based process. Developing and maintaining a personal formulary of P-drugs streamlines decision-making, promotes rational therapeutics, and enhances patient safety. 1. Definition and Purpose of P-Drugs A P-drug (“personal drug”) is not merely the generic name of a medicine but encompasses: P-drugs serve as a clinician’s priority choices for given indications, reducing repetitive searches in daily practice and ensuring familiarity with each drug’s effects and side effects. 2. Relation to Essential Medicines and Guidelines 3. The Six-Step Process for Rational Prescribing The WHO Guide to Good Prescribing outlines a six-step model, with P-drug selection comprising Step 3: 4. Criteria for Selecting P-Drugs (The STEP Framework) When comparing drug options, apply the STEP criteria: Example: Selecting a P-Drug for Acute Amoebic Dysentery Among nitroimidazoles, tinidazole may be preferred over metronidazole due to similar efficacy and cost but greater suitability (shorter course, once- or twice-daily dosing). 5. Benefits of a P-Drug Formulary By systematically selecting and regularly reviewing P-drugs according to these principles, prescribers establish a robust foundation for safe, effective, and cost-conscious patient care.