Can you take amoxicillin (amox)/clavulanate (clav) with doxycycline?

Concurrent Use of Amoxicillin/Clavulanate with Doxycycline

Yes, amoxicillin/clavulanate can be safely taken with doxycycline, and this combination is sometimes specifically recommended for certain infections. 1

Rationale for Combination Use

Amoxicillin/clavulanate and doxycycline have different mechanisms of action and target different bacterial pathogens, making them complementary in certain clinical scenarios:

• Amoxicillin/clavulanate: Beta-lactam antibiotic that inhibits cell wall synthesis
• Doxycycline: Tetracycline antibiotic that inhibits bacterial protein synthesis

Clinical Scenarios Where Combination Is Recommended

1. Respiratory Tract Infections:

   • For penicillin-allergic patients with acute bacterial rhinosinusitis (ABRS) who fail initial therapy, a combination of clindamycin plus a third-generation cephalosporin is recommended, but doxycycline alone is also an acceptable alternative 1
   • In bronchiectasis with specific pathogens, combination therapy may be needed 1

2. Skin and Soft Tissue Infections:

   • For cellulitis with suspected mixed infections or MRSA risk, combination therapy may be appropriate 2

3. Periodontal Disease:

   • Sequential administration of amoxicillin/clavulanate and doxycycline has shown better clinical outcomes than doxycycline alone in recurrent/progressive periodontitis 3

4. Melioidosis Prophylaxis:

   • Both antibiotics have been evaluated as prophylaxis against melioidosis, though co-trimoxazole showed better efficacy than either agent alone 1

Pharmacokinetic Considerations

• Studies have shown that the pharmacokinetics of amoxicillin is not significantly affected by the presence of other agents 4
• No significant drug-drug interactions between these antibiotics have been reported that would contraindicate their concurrent use

Efficacy Comparison

When comparing these antibiotics individually:

• In acute suppurative tracheobronchitis, both doxycycline and amoxicillin/clavulanate showed similar efficacy (89% vs 91% clinical response rates) 5
• For certain infections, amoxicillin/clavulanate has demonstrated superior outcomes compared to amoxicillin alone in post-surgical interventions 6

Potential Concerns

• Adverse Effects: Both medications can cause gastrointestinal side effects, which may be additive when used together
• Resistance Development: Using multiple antibiotics should be justified by clinical need to avoid promoting antimicrobial resistance
• Duration of Therapy: For most infections, 5-10 days of therapy is sufficient, with shorter courses preferred when clinical improvement occurs 1

Clinical Recommendations

1. For Respiratory Infections:

   • If treating sinusitis and initial therapy fails, either doxycycline alone or amoxicillin/clavulanate can be used, but combination is generally not first-line 1
   • For bronchiectasis with specific pathogens like Haemophilus influenzae (beta-lactamase positive), amoxicillin/clavulanate is preferred, with doxycycline as an alternative 1

2. For Skin/Soft Tissue Infections:

   • For cellulitis with mixed flora or MRSA concerns, combination therapy may be appropriate 2

3. For Dental/Oral Infections:

   • Sequential therapy may be more effective than either agent alone for certain periodontal infections 3

While these antibiotics can be taken together, always ensure the combination is clinically indicated rather than simply doubling coverage unnecessarily. The decision should be based on suspected pathogens, local resistance patterns, and specific clinical indications.