Cefalexin

What is Cefalexin?

Fig.1: Cefalexin structure

• Cefalexin (or Cephalexin) is a beta-lactum antibiotic.

What are the uses of this medicine?

• Cefalexin can be used to treat various bacterial infections, such as ear infections, upper respiratory infections, skin infections, urinary tract infections, bone infections.
• It may be used to treat strep throat and certain types of pneumonia, and can be used to prevent bacterial endocarditis.
• It cannot be used against methicillin-resistant Staphylococcus aureus (MRSA), most Enterococcus, or Pseudomonas.

How does this medicine work?

• Cefalexin is a beta-lactum antibiotic that is able to kill bacteria by disrupting the bacterial cell wall.

Who Should Not Use this medicine?

Do not use this medicine if you are allergic to cephalexin or to other cephalosporin antibiotics, such as:

• cefaclor (Ceclor, Raniclor);
• cefadroxil (Duricef);
• cefazolin (Ancef, Kefzol);
• cefdinir (Omnicef);
• cefditoren (Spectracef);
• cefpodoxime (Vantin);
• cefprozil (Cefzil);
• ceftibuten (Cedax);
• cefuroxime (Ceftin); and others

Cefalexin may be used in patients with mild allergies to penicillin, but is not recommended for those with severe allergies to penicillin.

To make sure cephalexin is safe for you, tell your doctor if you have ever had

• an allergy to any drug (especially penicillin);
• liver or kidney disease; or
• intestinal problems, such as colitis.

Is this medicine FDA approved?

• Cefalexin is an FDA-approved antibiotic.

How should this medicine be used?

• Take cephalexin exactly as prescribed by your doctor, and avoid taking more or less than prescribed amount.
• Follow all directions on your prescription label and read all medication guides or instruction sheets before taking this medication.
• Cefalexin can be taken as a tablet, liquid, or capsule to take by mouth.
• If using liquid, shake well before each use to ensure the medication is mixed evenly.
• It is usually taken with or without food every 6 or 12 hours for 7 to 14 days, depending on the condition being treated and should be taken at around the same times every day.
• Continue to take cephalexin until you finish the prescription even if you feel better.
• If you stop taking cephalexin too soon or skip doses, your infection may not be completely treated and the bacteria may become resistant to antibiotics.
• Contact your doctor or pharmacist if confused about any of the instructions.

What are the  dosage forms and brand names of this medicine?

Fig. 2: A Finnish Kefalex (cefalexin) 750 mg -medicine package and a blister pack.

• Follow the dosage prescribed by doctor because it is based on your medical condition and response to treatment. In children, the dose is also based on weight.
• Brand names include Keflex, Zartan, Keftab, Daxbia.

What side effects can this medication cause?

Common cefalexin side effects may include:

• diarrhea
• nausea, vomiting
• indigestion, stomach pain
• vaginal itching or discharge

Call your doctor at once if you have:

• severe stomach pain
• unusual tiredness, feeling light-headed or short of breath
• easy bruising, unusual bleeding, purple or red spots under your skin
• diarrhea that is watery or bloody (even if it occurs months after your last dose)
• a seizure
• pale or yellowed skin
• cold hands and feet
• dark colored urine
• fever, weakness
• pain in your side or lower back
• painful urination.

What special precautions should I follow?

• Do not take Cefalexin if you're allergic to penicillin.

• Inform your doctor if you are pregnant or breastfeeding before taking this medication.

• Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, stomach/intestinal disease (such as colitis).

• The liquid form of this product may contain sugar, so diabetics should avoid liquid form.

• Cephalexin may cause live bacterial vaccines (such as typhoid vaccine) to not work as well. Therefore, avoid any immunizations/vaccinations while using this medication unless your doctor tells you to.

What to do in case of emergency/overdose?

• In case of overdose, call the poison control helpline of your country. In the United States, call 1-800-222-1222.

• Overdose related information is also available online at poisonhelp.org/help.
• In the event that the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services. In the United States, call 911.

Can this medicine be used in pregnancy?

• Cephalexin is not expected to be harmful to an unborn baby, however inform your doctor if you are pregnant. Cephalexin can pass into breast milk, therefore, inform your doctor if you are breast-feeding a baby.

Can this medicine be used in children?

• Cefalexin can be used in children above one year old.

What should I know about storage and disposal of this medication?

Store the tablets and capsules at room temperature away from moisture, heat, and light. Store the liquid medicine in the refrigerator. Throw away any unused liquid after 14 days. Keep out of reach of children and pets.

• Dailymed label info on Cefalexin
• FDA Cefalexin