Cephalexin Can Be Taken With Food
Cephalexin can be taken with or without food, as it is acid stable and its absorption is not significantly affected by food intake. 1 This makes it a convenient antibiotic option for patients who may experience gastrointestinal discomfort when taking medications on an empty stomach.
Pharmacokinetic Properties Supporting This Recommendation
Cephalexin has several pharmacokinetic properties that make it suitable for administration with or without food:
- It is acid stable, allowing it to pass through the stomach without degradation 1
- It is rapidly absorbed after oral administration, with peak serum levels occurring approximately 1 hour after dosing 1
- It is absorbed high in the intestinal tract rather than the stomach 2
- Over 90% of the drug is excreted unchanged in the urine within 8 hours 1
Clinical Considerations
Benefits of Taking Cephalexin with Food
Taking cephalexin with food may provide several advantages:
- May reduce potential gastrointestinal irritation
- May improve medication adherence for patients who experience stomach upset with antibiotics
- Does not significantly alter the drug's effectiveness since absorption is not impaired by food
Dosing Considerations
When prescribing cephalexin:
- Standard adult dosing is typically 250-500 mg every 6 hours, depending on the severity of infection 3
- For children, dosing is generally 50-100 mg/kg/day divided into 4 doses 3
- In patients with renal impairment (creatinine clearance <30 mL/min), dose reduction is necessary 2
Specific Clinical Applications
Cephalexin is commonly used for:
- Skin and soft tissue infections (with cure rates of 90% or higher) 4
- Upper and lower respiratory tract infections 5
- Urinary tract infections 2
It's important to note that cephalexin is ineffective for Lyme disease treatment 3 and should not be used for this indication.
Important Caveats
- First-generation cephalosporins like cephalexin are ineffective against methicillin-resistant staphylococci, most enterococci, Enterobacter species, Morganella morganii, Proteus vulgaris, Pseudomonas, and Acinetobacter 1
- Patients with a history of anaphylaxis, angioedema, or urticaria with penicillins should not receive cephalexin due to potential cross-reactivity 3
- While taking with food is acceptable, patients should be advised to maintain adequate fluid intake when taking cephalexin to support its renal excretion
Conclusion
The FDA-approved labeling for cephalexin specifically states it "may be given without regard to meals" 1, making it a flexible option for patients who prefer or need to take medications with food. This flexibility can improve patient compliance while maintaining the antibiotic's effectiveness.