What are the essential medicines for a basic healthcare system?

Essential Medicines for a Basic Healthcare System

The WHO Model List of Essential Medicines (EML) defines the core medicines necessary for a functioning healthcare system, addressing the most important health care needs through cost-effective, safe, and readily available medications. 1

Definition and Purpose

The WHO EML includes medications deemed necessary for a basic health care system to function effectively, addressing priority health care needs of populations. 1 These medicines are selected based on:

• Cost-effectiveness 1
• Safety profile 1
• Ready availability 1
• Evidence-based efficacy for priority health conditions 1

The list is updated biennially to reflect current medical knowledge and changing health priorities. 1

Core Categories of Essential Medicines

Antibiotics (AWaRe Classification)

The 2023 AWaRe classification provides empirical guidance on 41 essential antibiotics for over 30 clinical infections, categorized into three groups: 1

Access Group Antibiotics (first-line, narrow-spectrum):

• Amoxicillin-clavulanic acid 1
• Cloxacillin/dicloxacillin 1
• Cefalexin 1
• Clindamycin 1
• Metronidazole 1

Watch Group Antibiotics (second-line, broader-spectrum with resistance concerns):

• Ceftriaxone 1
• Piperacillin-tazobactam 1
• Vancomycin 1
• Levofloxacin 1
• Ciprofloxacin 1

Reserve Group Antibiotics (last-resort options):

• Carbapenems 1
• Polymyxins 1

Cancer Medicines

The 22nd WHO EML includes targeted and immune-modulating therapies: 1

• Trastuzumab (and biosimilars) for breast cancer 1
• Imatinib for chronic myeloid leukemia 1
• Erlotinib, gefitinib, and afatinib for non-small-cell lung cancer 1
• Nivolumab and pembrolizumab for melanoma 1

Chronic Disease Management

Antihypertensive medications (first-line agents): 2

• Thiazide or thiazide-like diuretics (particularly chlorthalidone) 2
• ACE inhibitors 2
• Angiotensin receptor blockers (ARBs) 2
• Long-acting dihydropyridine calcium channel blockers 2

Diabetes medications: 3

• Metformin (first-line for type 2 diabetes) 3
• Insulin 1

Implementation Principles

Availability Standards

Essential medicines should be available at all times to everyone within a functioning healthcare system. 1, 4 The concept emphasizes that these medicines must satisfy priority health-care needs of populations. 4

Formulary Development

National essential medicines lists should: 1

• Be country-specific based on local disease prevalence 1
• Consider local antimicrobial resistance patterns 1
• Ensure therapeutic choices are consistent and cost-effective 1
• Enable national pricing negotiations for generic medicines 1

Pediatric Considerations

The WHO Essential Medicines List for Children (EMLc), established in 2007, addresses distinct pediatric needs. 1 Key medicines for children include appropriate formulations and dosing for: 1

• Common infections 1
• Childhood cancers 1
• Chronic conditions 1

Global Disparities in Access

High-Income vs. Low-Income Countries

In high-income countries (HICs) and upper-middle-income countries (UMICs): 1

• Essential medicines are almost always available at no cost or subsidized 1
• Formulary inclusion rates exceed 90% for most essential medicines 1

In low-middle-income countries (LMICs) and low-income countries (LICs): 1

• Medicines are generally provided only at full out-of-pocket cost 1
• Generic availability in public sector ranges from 36.1% (low-income) to 44.3% (low-middle-income) 1
• Up to 90% of populations purchase medicines through out-of-pocket payments 1

Critical Access Barriers

Financial barriers: 1

• Medicines represent the largest family expenditure after food in LMICs 1
• Patients often purchase medicines daily, leading to incomplete treatment courses 1
• Pediatric formulations cost more than adult equivalents 1

Supply chain issues: 1

• Two-thirds of antibiotics sold over-the-counter without prescriptions 1
• Private pharmacies have better stock than primary healthcare clinics 1
• National EMLs include only 66% of WHO EML antibiotics on average 1

Monitoring and Surveillance

Countries should systematically monitor: 1

• Patterns of antibiotic use by AWaRe category 1
• Trends in antimicrobial resistance development 1
• Proportions of patients without access to essential antibiotics 1

The WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS) provides standardized methodology, though only 14% of countries actively report consumption data. 1

Current List Scope

The original 1977 EML included 186 drugs; the current list exceeds 300 medicines. 5 The principle of making essential medicines available to everyone is accepted by 156 countries, though implementation remains variable. 5