Does cephalexin (antibiotic) 250/5 suspension require refrigeration?

Cephalexin 250/5 Suspension Storage Requirements

Yes, cephalexin 250/5 suspension must be refrigerated after reconstitution. According to the FDA drug label, after mixing, the suspension should be stored in the refrigerator and may be kept for 14 days without significant loss of potency. 1

Preparation and Storage Instructions

The FDA drug label provides clear instructions for the preparation and storage of cephalexin suspension:

1. Preparation process:

   • Prepare suspension at time of dispensing
   • Add the appropriate amount of water to the bottle (71 mL for 100 mL bottles or 140 mL for 200 mL bottles)
   • Tap bottle to loosen powder
   • Add water in 2 portions, shaking well after each addition

2. Storage requirements:

   • After mixing, store in refrigerator
   • The reconstituted suspension remains stable for 14 days when refrigerated
   • Refrigeration is necessary to maintain potency throughout the treatment period 1

Clinical Implications

Proper storage of cephalexin suspension is crucial for several reasons:

• Maintains antimicrobial efficacy throughout the treatment course
• Ensures proper dosing for patients, particularly important for pediatric patients who commonly use the suspension formulation
• Prevents treatment failure that could lead to increased morbidity

Common Pitfalls to Avoid

• Failure to refrigerate: Leaving the reconstituted suspension at room temperature can lead to degradation of the medication and reduced efficacy
• Using beyond 14 days: Even when refrigerated, the suspension should not be used after 14 days from reconstitution
• Improper reconstitution: Following the exact water amounts specified in the label is essential for achieving the correct concentration (125 mg/5 mL or 250 mg/5 mL)

Patient Education Points

When dispensing cephalexin suspension, patients/caregivers should be instructed to:

• Store the medication in the refrigerator (not the freezer)
• Shake well before each use
• Discard any unused portion after 14 days
• Use the measuring device provided to ensure accurate dosing

Proper storage and handling of cephalexin suspension helps ensure optimal treatment outcomes for common infections including streptococcal pharyngitis, skin and skin structure infections, and urinary tract infections for which this antibiotic is commonly prescribed.