What are the commonly prescribed antibiotics in India, including the drug of choice, for beginners?

Commonly Prescribed Antibiotics in India: A Guide for Beginners

The most commonly prescribed antibiotics in India include amoxicillin, amoxicillin-clavulanate, cephalosporins, macrolides, and fluoroquinolones, with specific drug choices depending on the infection type, patient factors, and local resistance patterns.

Respiratory Tract Infections

Upper Respiratory Tract Infections

• Streptococcal Pharyngitis
  • First-line: Penicillin V (250 mg 2-3 times daily for children; 250 mg four times daily or 500 mg twice daily for adults) for 10 days 1
  • Alternative: Amoxicillin (50 mg/kg once daily, maximum 1000 mg) for 10 days 1
  • For penicillin allergy:
    • Cephalexin (20 mg/kg twice daily, maximum 500 mg per dose) for 10 days
    • Azithromycin (12 mg/kg once daily, maximum 500 mg) for 5 days
    • Clarithromycin (7.5 mg/kg twice daily, maximum 250 mg per dose) for 10 days 1

Lower Respiratory Tract Infections

• Community-Acquired Pneumonia

  • Children <3 years: Amoxicillin (80-100 mg/kg/day in three divided doses) for 10 days 1
  • Children >3 years:
    • For suspected pneumococcal infection: Amoxicillin (as above)
    • For suspected atypical bacteria: Macrolides (e.g., azithromycin, clarithromycin) for 14 days 1
  • Adults:
    • Mild-moderate: Amoxicillin or macrolides
    • Severe: Combination therapy with beta-lactam plus macrolide

• Aspiration Pneumonia

  • First-line: Clindamycin (600 mg IV every 8 hours for hospitalized adults; 300-450 mg orally three times daily for mild cases) 2
  • Pediatric dosing: 30-40 mg/kg/day in 3 divided doses 2
  • Duration: Until clinical and radiological resolution (typically 7-21 days) 2

Skin and Soft Tissue Infections

• MRSA Infections

  • First-line: Vancomycin (30-60 mg/kg/day IV in 2-4 divided doses) 1
  • Alternatives:
    • Linezolid (600 mg PO/IV every 12 hours for adults)
    • Clindamycin (300-450 mg orally three times daily) 2
    • Daptomycin (6 mg/kg/dose IV daily) 1

• Impetigo

  • First-line: Clindamycin (300-400 mg orally three times daily) 2

Bone and Joint Infections

• Osteomyelitis

  • First-line: Vancomycin (30-60 mg/kg/day IV in 2-4 divided doses) for >6 weeks 1
  • Alternatives:
    • Daptomycin (6 mg/kg/dose IV daily)
    • TMP-SMX (TMP 4 mg/kg/dose PO/IV every 8-12 hours) plus Rifampin (600 mg PO daily)
    • Teicoplanin (6-12 mg/kg/dose IV every 12 hours for three doses, then daily) 1

• Septic Arthritis

  • First-line: Vancomycin (30-60 mg/kg/day IV in 2-4 divided doses) for 3-4 weeks 1
  • Alternatives: Similar to osteomyelitis options 1

Central Nervous System Infections

• Meningitis
  • First-line: Vancomycin (30-60 mg/kg/day IV in 2-4 divided doses) plus TMP-SMX (TMP 600 mg PO daily or 300-450 mg PO every 12 hours) for 14 days 1
  • Alternative: Linezolid (600 mg IV/PO every 12 hours) 1

Special Considerations for Antibiotic Use in India

Resistance Patterns

• India has high rates of antimicrobial resistance, particularly with:
  • Extended-spectrum beta-lactamase (ESBL) producing organisms
  • Methicillin-resistant Staphylococcus aureus (MRSA)
  • Carbapenem-resistant Enterobacteriaceae

Prescription Practices

1. Empiric therapy is common initial practice but should be guided by:

   • Local resistance patterns
   • Patient risk factors
   • Severity of infection

2. Duration considerations:

   • Respiratory infections: 5-14 days depending on pathogen and severity
   • Skin infections: 7-10 days
   • Bone/joint infections: Minimum 3-6 weeks
   • CNS infections: 14 days to 6 weeks depending on type

Common Pitfalls in Antibiotic Prescribing

1. Overuse of broad-spectrum antibiotics when narrow-spectrum would suffice

   • Example: Using amoxicillin-clavulanate when amoxicillin alone would be effective

2. Inappropriate duration of therapy

   • Too short: Risk of treatment failure
   • Too long: Increased resistance, adverse effects, and costs

3. Failure to adjust therapy based on culture results

   • Always narrow therapy when possible based on susceptibility testing

4. Neglecting special populations

   • Pediatric dosing is weight-based and different from adult dosing
   • Avoid doxycycline in children under 8 years 1

5. Combination therapy concerns

   • Addition of gentamicin or rifampin to vancomycin is generally not recommended 1
   • Vancomycin plus piperacillin/tazobactam increases risk of acute kidney injury 3

Practical Antibiotic Selection Algorithm

1. Identify infection site and likely pathogens
2. Consider patient factors: Age, allergies, comorbidities
3. Select appropriate antibiotic:
   • For gram-positive infections: Beta-lactams, vancomycin, or clindamycin
   • For gram-negative infections: Cephalosporins, fluoroquinolones, or aminoglycosides
   • For anaerobic infections: Clindamycin, metronidazole
4. Reassess after 48-72 hours:
   • If improving: Continue or narrow therapy based on cultures
   • If not improving: Broaden coverage or consider alternative diagnosis

Remember that antibiotic stewardship is crucial to combat the rising threat of antimicrobial resistance in India. Always use the narrowest spectrum antibiotic that will effectively treat the infection.