Understanding the Concept of Essential Drugs in Primary Healthcare

When a patient visits a primary health centre, they expect to receive medicines that will effectively treat their condition. But have you ever wondered how healthcare systems decide which medicines should be available at every hospital and clinic? This is where the concept of essential drugs comes into play-a foundational principle that shapes medicine policies worldwide and ensures that critical treatments reach those who need them most.

What are essential drugs? 🔗

Essential drugs are medicines that satisfy the priority health care needs of a population. These are not necessarily the newest or most expensive medications. Instead, they are carefully selected to address the most common and significant health conditions affecting communities. The selection process considers disease prevalence, public health relevance, evidence of efficacy and safety, and comparative cost-effectiveness.

According to the World Health Organization, these medicines should be available in functioning health systems at all times, in appropriate dosage forms, of assured quality, and at prices both individuals and communities can afford. This means a rural clinic treating malaria patients should have antimalarial drugs readily available, just as an urban hospital should stock essential antibiotics for common infections.

The origin and evolution of the essential medicines concept 🔗

The first WHO Model List of Essential Medicines was published in 1977, containing 208 medications. This groundbreaking initiative emerged from the recognition that having thousands of medicines available doesn’t necessarily translate to better healthcare. In fact, a focused list of carefully chosen drugs could improve treatment outcomes while reducing costs and simplifying supply chains.

The concept was reinforced during the International Conference on Primary Health Care in 1978, where the Alma-Ata Declaration reaffirmed that health is a fundamental human right. Essential medicines became integral to achieving this goal. Today, the WHO updates its Model List every two years. The 24th edition, released in September 2025, contains 523 essential medicines for adults and 374 for children. More than 150 countries have created their own national essential medicines lists based on the WHO model.

Selection criteria for essential drugs 🔗

Not every medication qualifies as essential. The selection process involves rigorous evaluation based on several key criteria.

Therapeutic effectiveness 🔗

An essential drug must demonstrate proven clinical effectiveness. This means there should be solid scientific evidence showing that the medicine works for its intended purpose. The WHO Expert Committee evaluates comparative effectiveness and safety when reviewing applications for inclusion in the list. Preference is given to medicines with the best evidence for effectiveness and safety within their pharmacological class.

Safety profile 🔗

Beyond being effective, essential medicines must have an acceptable safety profile. The potential benefits should clearly outweigh the risks. Medicines with severe side effects or those requiring complex monitoring may be classified as complementary rather than core essential medicines, as they need specialized healthcare infrastructure for safe administration.

Cost-effectiveness 🔗

Healthcare resources are limited everywhere. Essential drugs are selected with consideration for their cost-effectiveness, meaning they provide good value for money. When multiple medicines offer similar therapeutic benefits, the one available at the lowest price-based on international drug price information-is typically preferred. This approach helps stretch limited healthcare budgets further.

Disease prevalence and public health relevance 🔗

Medicines are selected based on the burden of disease they address. Priority conditions are chosen considering both current and estimated future public health relevance. A medicine treating a common condition affecting millions of people would be prioritized over one treating a rare condition affecting few individuals.

Core and complementary lists 🔗

The WHO Model List distinguishes between core and complementary medicines. Core items represent the most cost-effective options for key health problems and can be used with minimal additional healthcare resources. Complementary items, while still essential, may require specialized diagnostic or monitoring facilities, trained healthcare providers, or have higher costs.

This classification helps countries prioritize based on their healthcare capacity. A well-equipped tertiary hospital might stock both core and complementary medicines, while a primary health centre in a remote area focuses on core essential drugs that can be safely administered with basic facilities.

Rational use of essential drugs 🔗

Having essential medicines available is only half the equation. These drugs must also be used rationally to achieve optimal health outcomes. Rational use requires that patients receive medications appropriate to their clinical needs, in doses that meet their individual requirements, for an adequate period of time, and at the lowest cost to them and their community.

Unfortunately, irrational use of medicines remains a significant global challenge. The WHO estimates that more than half of all medicines worldwide are prescribed, dispensed, or sold inappropriately. Common problems include polypharmacy (using too many medicines per patient), inappropriate antibiotic use for viral infections, overuse of injections when oral formulations would suffice, and failure to follow clinical guidelines.

Consequences of irrational drug use 🔗

The impact of irrational medicine use extends beyond wasted resources. It contributes to antimicrobial resistance-now a major public health threat. When antibiotics are prescribed unnecessarily or in inadequate doses, bacteria develop resistance, making infections harder to treat. This has led to situations where chloroquine-resistant malaria exists in approximately 90% of countries, and drug-resistant tuberculosis affects healthcare systems worldwide.

WHO interventions to promote rational use 🔗

To address these challenges, the WHO advocates 12 key interventions for promoting rational medicine use. These include establishing a multidisciplinary national body to coordinate medicine use policies, developing clinical guidelines, creating national essential medicines lists, and setting up drug and therapeutics committees in hospitals and districts.

Other important measures involve including problem-based pharmacotherapy training in medical curricula, requiring continuing medical education for licensure, implementing supervision and audit systems, providing independent drug information, educating the public about medicines, avoiding perverse financial incentives that encourage overprescription, and ensuring adequate government spending on medicines and healthcare staff.

Health Action International criteria 🔗

Beyond WHO guidelines, organizations like Health Action International (HAI) have contributed to shaping essential medicines policies. HAI works alongside WHO to develop methodologies for measuring medicine prices, availability, and affordability across different healthcare sectors and regions. Their criteria emphasize medical necessity, therapeutic value, proven safety, and value for money.

The WHO/HAI methodology has been used globally to assess healthcare systems and identify gaps in essential medicine access. Studies using this approach have revealed that despite progress, essential medicines remain unavailable or unaffordable for many people in low- and middle-income countries.

The role of essential drugs in primary healthcare 🔗

Essential medicines form the backbone of primary healthcare systems. When primary health centres stock essential drugs, they can effectively manage common conditions without referring patients to higher levels of care. This reduces healthcare costs, improves access for rural and underserved populations, and strengthens the entire health system.

The basic concept is that high-priority drugs should be available as part of a functioning health system at all times. Using a limited number of well-known and cost-effective medicines leads to improved medicine supply, lower costs, better healthcare quality, and more equitable access to treatment.

Challenges and the path forward 🔗

Despite nearly five decades of progress since the first Essential Medicines List, significant challenges remain. An estimated two billion people still lack access to essential medicines. Low supply, shortages of inexpensive drugs, high prices of newer essential medicines, and weak health systems all contribute to this gap.

The WHO continues working to improve access. Recent updates to the Essential Medicines List have included new cancer treatments, diabetes medications, and medicines for conditions like cystic fibrosis and haemophilia. The organization also emphasizes strategies for improving affordability, encouraging generic competition, and making essential treatments available in primary care settings, especially in underserved areas.

Why nursing professionals should understand essential drugs 🔗

For nursing students and practitioners, understanding the essential drugs concept is crucial. Nurses play a vital role in medicine administration, patient education, and identifying potential drug-related problems. Knowledge of which medicines are considered essential helps nurses understand prescribing patterns, advocate for patients who may not be receiving appropriate treatment, and contribute to rational medicine use within their facilities.

Nurses working in primary healthcare settings often serve as the primary point of contact for patients. Their understanding of essential medicines helps ensure that patients receive appropriate treatment and that limited resources are used effectively.

What do you think? How can healthcare professionals in primary care settings contribute to promoting rational use of essential medicines in their daily practice? What role should patient education play in reducing inappropriate medicine use?

References

1. https://www.who.int/groups/expert-committee-on-selection-and-use-of-essential-medicines/essential-medicines-lists
2. https://www.who.int/initiatives/gap-f/our-portfolio/essential-medicines
3. https://en.wikipedia.org/wiki/WHO_Model_List_of_Essential_Medicines
4. https://ispub.com/IJPHARM/10/1/14081
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC6998134/
6. https://www.who.int/activities/promoting-rational-use-of-medicines
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC5345295/
8. https://joppp.biomedcentral.com/articles/10.1186/s40545-021-00339-2
9. https://en.wikipedia.org/wiki/Essential_medicines