Cephalexin

Cephalexin is used to treat a wide variety of bacterial infections. This medication is known as a cephalosporin antibiotic. It works by stopping the growth of bacteria.

• Cephalexin will not work for viral infections (such as common cold, flu). Unnecessary use or misuse of any antibiotic can lead to its decreased effectiveness.
• Cephalexin is available under the following different brand names: Keflex, and Panixine Disperdose.

Dosages of Cephalexin:

Adult and Pediatric Dosage Forms and Strengths

Capsule

• 250 mg
• 500 mg
• 750 mg (adult only)

Oral suspension

• 125 mg/5mL
• 250 mg/5mL

Tablet

• 125 mg (pediatric only)
• 250 mg
• 500 mg (adult only)

Dosage Considerations – Should be Given as Follows:

Genitourinary Tract Infections

• Adult: 250 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses
• Pediatric: 25-50 mg/kg/day orally divided every 6-8 hours for 10 days; not to exceed 4 g/day

Bone Infections

• Adult: 250 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses
• Pediatric: 25-50 mg/kg/day orally divided every 6-8 hours for 10 days; not to exceed 4 g/day

Uncomplicated Cystitis

• Adult: 250 mg orally every 6 hours or 500 mg orally every 12 hours; dosage range, 1-4 g/day in divided doses
• Younger than 15 years: 25-50 mg/kg/day orally divided every 6-8 hours for 10 days; not to exceed 4 g/day
• Children older than 15 years: 250 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses

Otitis Media

• Adult: 250 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses
• Pediatric: 75-100 mg/kg/day orally divided every 6 hours for 10 days; not to exceed 4 g/day

Skin/Skin Structure Infections

• Adult: 250 mg orally every 6 hours or 500 mg orally every 12 hours; dosage range, 1-4 g/day in divided doses
• Pediatric: 25-50 mg/kg/day orally divided every 6-8 hours for 10 days; not to exceed 4 g/day

Respiratory Tract Infections

• Adult: 250 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses
• Pediatric: 25-50 mg/kg/day orally divided every 6-8 hours for 10 days; not to exceed 4 g/day

Streptococcal Pharyngitis

• Adult: 250 mg orally every 6 hours or 500 mg orally every 12 hours; dosage range, 1-4 g/day in divided doses
• Pediatric: 25-50 mg/kg orally every 12 hours for 10 days; not to exceed 500 mg every 12 hours

Cellulitis and Mastitis

• Adult: 500 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses
• Adolescents: 500 mg orally every 6 hours; dosage range, 1-4 g/day in divided doses

Renal Impairment

• CrCl less than 10 mL/min: 250-500 mg orally every 12-24 hours
• CrCl 10-50 mL/min: 500 mg orally every 8-12 hours

Beta-Hemolytic Streptococcal Infections, Pediatric

• 25-50 mg/kg/day orally divided every 6-8 hours for 10 days; not to exceed 4 g/days

Hepatic Impairment

• Not studied

Dosing Considerations

Susceptible organisms

• Gram-positive cocci, gram-negative bacilli, gram-positive bacilli, gram-negative cocci, anaerobes

Side effects associated with use of Cephalexin, include the following:

• Abdominal pain
• Agitation
• Low blood iron (anemia)
• Skin swelling
• Confusion
• Diarrhea
• Dizziness
• Indigestion
• Elevated transaminases
• Eosinophilia hemolytic
• Skin redness
• Fatigue
• Stomach pain or upset
• Genital itching
• Hallucinations
• Headache
• Hemolytic anemia
• Hypersensitivity
• Kidney problems (nephritis)
• Low white blood cell count (neutropenia)
• Pseudomembranous colitis
• Low blood platelet count (thrombocytopenia)
• Transient hepatitis
• Toxic epidermal necrolysis
• Hives
• Vaginal discharge
• Vomiting

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Severe interactions of cephalexin include:
  • None
• Serious Interactions of cephalexin include:
  • BCG vaccine live
  • cholera vaccine
  • typhoid vaccine live
• Moderate Interactions of cephalexin include:
  • bazedoxifene/conjugated estrogens
  • conjugated estrogens
  • dienogest/estradiol valerate
  • digoxin
  • estradiol
  • estrogens conjugated synthetic
  • estropipate
  • ethinylestradiol
  • flucloxacillin
  • mestranol
  • mycophenolate
  • pivmecillinam
  • probenecid
  • sodium picosulfate/magnesium oxide/anhydrous citric acid
  • temocillin
  • ticarcillin
• Cephalexin has moderate interactions with at least 56 different drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

Warnings

• This medication contains cephalexin. Do not take Keflex or Panixine Disperdose if you are allergic to cephalexin or any ingredients contained in this drug
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately

Contraindications

• Documented hypersensitivity

Effects of Drug Abuse

• No information provided

Short-Term Effects

• See "What Are Side Effects Associated with Using Cephalexin?"

Long-Term Effects

• Superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy
• Prolonged treatment may be associated with increased international normalized ratio (INR)
• Prolonged use is associated with fungal or bacterial superinfection
• See "What Are Side Effects Associated with Using Cephalexin?"

Cautions

• Endocarditis prophylaxis is appropriate only for high-risk patients, per American Heart Association guidelines
• Adjust dose in severe renal insufficiency (high doses may cause CNS toxicity)
• Superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy
• Prolonged treatment, hepatic or renal disease, or nutritional deficiency may be associated with increased international normalized ratio (INR)
• Prolonged use is associated with fungal or bacterial superinfection
• Use with caution in patients with a history of hypersensitivity to penicillin

Pregnancy and Lactation

• Cephalexin may be acceptable to use during pregnancy
• Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies are done and showed no risk
• Cephalexin is excreted in breast milk; use with caution while breastfeeding