- According to the World Health Organization (WHO), the concept of rational use of medicines emphasizes the importance of prescribing medications that are well-suited to the individual patient's clinical condition.
- This involves selecting drugs that appropriately address the patient's medical needs, ensuring the correct dosage is administered for an adequate duration to achieve the desired therapeutic effect.
- Additionally, it is crucial to consider the cost-effectiveness of treatment, aiming to provide medications at the lowest possible cost without compromising quality.

- Options suggesting the exclusive use of brand-name drugs, indiscriminate prescribing of the newest medications regardless of cost, or fixed dosing without personalization are contrary to the principles of rational drug use. These practices can lead to unnecessary healthcare expenses, increased risk of adverse effects, and suboptimal patient outcomes.

Therefore, the best description of rational use of medicines is: "Prescribing medications that match the patient's clinical needs, in correct dosages, for sufficient duration, and at the lowest possible cost."

Reference: WHO Guide to Good Prescribing, Volume 1, Chapter 2