Which antibiotic is most commonly prescribed in primary care?

Amoxicillin is the Most Commonly Prescribed Antibiotic in Primary Care

Amoxicillin consistently emerges as the most frequently prescribed antibiotic across primary care settings globally, accounting for approximately 40% of all antibiotic prescriptions. 1, 2

Evidence from Primary Care Prescribing Studies

Multiple observational studies from different countries demonstrate amoxicillin's dominance in primary care prescribing:

• In Ireland's out-of-hours primary care services, amoxicillin represented 40% of all antibiotic prescriptions over a two-year period 1
• In UK general practice, amoxicillin was the most commonly prescribed antibiotic for all respiratory tract infections except upper respiratory tract infections (URTIs) 2
• In Iceland's out-of-hours services, amoxicillin (either alone or combined with clavulanic acid) was the predominant choice, though amoxicillin-clavulanate was more frequently prescribed than amoxicillin alone 3

Why Amoxicillin Dominates Primary Care Prescribing

The predominance of amoxicillin reflects several clinical realities:

Respiratory tract infections drive the majority of antibiotic prescribing - accounting for 46-59% of all antibiotic prescriptions in primary care 1, 4. Within respiratory infections, the most common conditions are:

• Cough symptoms (22.7%)
• Lower respiratory tract infections (17.9%)
• Sore throat (16.7%)
• Upper respiratory tract infections (14.5%)

Amoxicillin is the guideline-recommended first-line agent for most common bacterial infections in primary care, including community-acquired pneumonia, acute otitis media, and streptococcal pharyngitis 5, 6.

Important Caveats About Appropriateness

While amoxicillin is most commonly prescribed, this doesn't mean all prescribing is appropriate:

• Amoxicillin accounted for 34.5% of URTI prescriptions despite not being recommended for this viral condition 2
• 62.3% of otitis externa prescriptions were amoxicillin, even though it's not indicated for this condition 2
• Overall antibiotic prescribing rates in primary care show substantial variation between practices (median 626 prescriptions/1000 patients, IQR 543-699), suggesting overprescribing in some settings 4

Other Commonly Prescribed Antibiotics

After amoxicillin, the prescribing hierarchy in primary care typically follows:

1. Amoxicillin-clavulanate (second most common in many settings) 3
2. Macrolides (13% of prescriptions) 4
3. Tetracyclines (12% of prescriptions) 4
4. Trimethoprim (11% of prescriptions, primarily for urinary tract infections) 4

The penicillin class overall (including amoxicillin, amoxicillin-clavulanate, and other penicillins) accounts for approximately 50% of all primary care antibiotic prescriptions 4.