Cephalexin is a first-generation cephalosporin used for the treatment of respiratory tract infections and dermatological infections caused by staphylococcus.

Drug classes

• Antibiotic
• Cephalosporin (first generation)
• Pregnancy Category B

Therapeutic actions

Bactericidal: Inhibits synthesis of bacterial cell wall, causing cell death.

Indications

• Respiratory tract infections caused by S. pneumoniae, group A beta-hemolytic streptococci
• Dermatologic infections caused by staphylococcus, streptococcus
• Otitis media caused by S. pneumoniae, H. influenzae, streptococcus, staphylococcus, Moraxella catarrhalis
• Bone infections caused by staphylococcus, Proteus mirabilis
• GU infections caused by Escherichia coli, P. mirabilis, Klebsiella

Contraindications

• Contraindicated with allergy to cephalosporins or penicillins.
• Use cautiously with renal failure, lactation, pregnancy.

Available forms

Capsules—250, 500 mg; tablets—250, 500 mg, 1 g; tablets for oral suspension—125, 250 mg; oral suspension—125, 250 mg/5 mL

Dosages

ADULTS

1–4 g/day in divided doses; 250 mg PO q 6 hr usual dose.

• Skin and skin-structure infections: 500 mg PO q 12 hr. Larger doses may be needed in severe cases; do not exceed 4 g/day.

PEDIATRIC PATIENTS

25–50 mg/kg/day PO in divided doses.

• Skin and skin-structure infections: Divide total daily dose, and give q 12 hr. Dosage may be doubled in severe cases.
• Otitis media: 75–100 mg/kg/day PO in four divided doses.

Adverse effects

• CNS: Headache, dizziness, lethargy, paresthesias
• GI: Nausea, vomiting,diarrhea, anorexia, abdominal pain, flatulence, pseudomembranous colitis, liver toxicity
• GU: Nephrotoxicity
• Hematologic: Bone marrowdepression
• Hypersensitivity:Ranging from rash to fever to anaphylaxis; serum sickness reaction
• Other: Superinfections

Nursing Interventions

• Arrange for culture and sensitivity tests of infection before and during therapy if infection does not resolve.
• Give drug with meals; arrange for small, frequent meals if GI complications occur.
• Refrigerate suspension, discard after 14 days.

Patient Education

• Take this drug with food. Refrigerate suspension; discard any drug after 14 days.
• Complete the full course of this drug even if you feel better.
• This drug is prescribed for this particular infection; do not self-treat any other infection.
• You may experience these side effects: Stomach upset, loss of appetite, nausea (take drug with food); diarrhea; headache, dizziness.
• Report severe diarrhea with blood, pus, or mucus; rash or hives; difficulty breathing; unusual tiredness, fatigue; unusual bleeding or bruising.