P-drugs & Rational Prescribing

Definitions & framing

• Rational use of medicines (WHO) — patients receive medication appropriate to their clinical needs, in doses meeting their individual requirements, for an adequate period, and at the lowest cost to them and their community. Despite the assumption that qualified doctors prescribe rationally, irrationality abounds in almost every aspect of drug use, more so in developing countries.
• P-drug (Personal drug) — the drug a prescriber has chosen in advance to prescribe regularly as a first choice for a given common condition, together with its standard dosage form, schedule and duration. The set of such pre-selected agents is the prescriber's personal formulary — a deliberately studied working subset of the thousands of marketed products, made by reasoning rather than habit or imitation.
• Why compile P-drugs — choosing a drug afresh for every encounter is impractical and error-prone; pre-selecting a small, well-justified set lets the prescriber know each drug's effects, contraindications, interactions and monitoring well, speeds the consultation and reduces irrational, inconsistent choices — "thinking before prescribing, once, so you need not re-derive it each time."
• P-drug vs P-treatment — P-treatment is the chosen management strategy for a problem and need not be a drug at all — it may be advice/reassurance, a non-pharmacological measure (physiotherapy, lifestyle change), referral or watchful waiting, or a drug. The P-drug is the specific pre-selected first-choice medicine turned to when the P-treatment is pharmacological. Thus every P-drug is a P-treatment, but many P-treatments are not P-drugs.
• Drug therapy in context — drug therapy is the most frequently chosen therapeutic option once a diagnosis is reached, but the options also include surgery, radiation, physical therapy, counselling, further consultation, and no therapy; a written prescription is the prescriber's order to prepare or dispense a specific treatment for a specific patient.