Cephalexin

💊 What is Cephalexin used for?

• •Respiratory tract infections caused by susceptible Streptococcus pneumoniae and Streptococcus pyogenes
• •Ear infections (otitis media) caused by susceptible bacteria
• •Skin and skin structure infections caused by susceptible Staphylococcus aureus and Streptococcus pyogenes
• •Bone infections caused by susceptible Staphylococcus aureus and Proteus mirabilis
• •Genitourinary tract infections, including acute prostatitis, caused by susceptible E. coli, Proteus mirabilis, and Klebsiella pneumoniae

How it works

How it is usually taken

• •Cephalexin is taken by mouth as a capsule. The label says the dose and schedule depend on age, body weight, type and severity of infection, and kidney function, so follow the instructions from your prescriber or pharmacist. The label says treatment usually lasts 7 to 14 days depending on the infection. The label says it should be taken exactly as directed, and that skipping doses or not finishing the full course may make it less effective and raise the chance of resistant bacteria.

Comes as

• •250 mg capsules (white to off white powder; dark green cap and body)
• •333 mg capsules
• •500 mg capsules
• •750 mg capsules

⚠️ Cephalexin side effects

🛑 Who should not take Cephalexin, and who should be careful

The label says not to take it if

• 🚨You have a known allergy (hypersensitivity) to cephalexin or to other members of the cephalosporin class of antibacterial drugs. The label lists this as a contraindication.

Tell your doctor before taking it if

• •Tell your prescriber about any past allergic reactions to cephalexin, other cephalosporins, penicillins, or other beta-lactam antibiotics, or to other drugs. The label says cross-reactions among beta-lactam antibiotics may occur in up to 10% of people with a penicillin allergy.
• •Tell your prescriber if you have kidney problems. The label says dose adjustment is needed in severe and end stage kidney disease, and that seizures have been linked to cephalosporins in people with kidney impairment when the dose was not reduced.
• •Tell your prescriber if you have liver problems, poor nutrition, bleeding problems, or take an anticoagulant. The label says cephalosporins may prolong prothrombin time in these situations.
• •Tell your prescriber if you have had diarrhea after taking antibiotics before.
• •The label says antibacterial drugs, including cephalexin, do not treat viral infections such as the common cold.

🔀 Cephalexin with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •Metformin: The label says cephalexin increases metformin levels and reduces how fast the kidneys clear metformin. The label says careful monitoring and metformin dose adjustment is recommended, and to monitor for low blood sugar (hypoglycemia).
• •Probenecid: The label says probenecid slows the kidney removal of cephalexin, and co-administration is not recommended.
• •Urine glucose tests: Cephalexin may cause a false-positive result when testing urine for glucose with Benedict's or Fehling's solution.
• •Anticoagulants: The label says patients on anticoagulant therapy are at risk for prolonged prothrombin time and should be monitored.

Alcohol and food

The label does not say.

🤰 Cephalexin in pregnancy and breastfeeding

Pregnancy

The label says available data from studies and reports over several decades have not established drug-associated risks of major birth defects, miscarriage, or adverse maternal or fetal outcomes with cephalosporin use, including cephalexin. Animal studies showed no evidence of harm to the fetus. The label also says that available studies cannot definitively establish the absence of risk, and the background risk for the indicated population is unknown. Talk with your prescriber about your situation.

Breastfeeding

The label does not say.

🗓️ Storage, missed doses and taking too much

Storage

Store at 20°C to 25°C (68°F to 77°F). Short excursions to 15°C to 30°C (59°F to 86°F) are permitted, according to the label.

If a dose is missed

The label does not say.

If too much is taken

The label says symptoms of an oral overdose may include nausea, vomiting, stomach distress (epigastric distress), diarrhea, and blood in the urine (hematuria). The label says treatment is general supportive measures. It also says forced diuresis, peritoneal dialysis, hemodialysis, or charcoal hemoperfusion have not been established as beneficial for cephalexin overdose.

🗒️ Questions to ask about Cephalexin

• Is my infection the kind that cephalexin is meant to treat?
• What dose and schedule should I follow, based on my age, weight, and kidney function?
• How long do I need to take it, and what should I do if I start to feel better early?
• Do I have any past allergies to penicillins or other cephalosporins?
• Do any of my other medicines, such as metformin or probenecid, interact with cephalexin?
• What signs of a serious allergic reaction or severe diarrhea should prompt me to call for help?
• Could my kidney function affect how this medicine is dosed for me?

❓ Cephalexin: frequently asked questions