Cephalexin is used to treat infections caused by bacteria, including upper respiratory infections, ear infections, skin infections, and urinary tract infections.
Cephalexin is used for treating certain bacterial infections. Cephalexin is a cephalosporin antibiotic. It works by interfering with the bacteria’s cell wall formation. This weakens the cell wall, causing it to rupture and kill the bacteria.
Use Cephalexin as directed by your doctor.
- Take Cephalexin by mouth with or without food.
- To clear up your infection completely, buy Cephalexin for the full course of treatment. Keep taking it even if you feel better in a few days.
- If you miss a dose of Cephalexin, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use Cephalexin.
Store Cephalexin at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Cephalexin out of the reach of children and away from pets.
Important safety information
- Cephalexin may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use cephalexin with caution. Do not drive or perform other possible unsafe tasks until you know how you will react to them.
- Cephalexin may decrease the ability of your blood to clot. Avoid activities that may cause bruising or injury. Tell your doctor if you have unusual bruising or bleeding. Tell your doctor if you have dark, tarry, or bloody stools.
- Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you use the antibiotic or within several months after you stop using it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
- Be sure to use Cephalexin for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
- Cephalexin only works against bacteria; it does not treat viral infections (e.g., the common cold).
- Long-term or repeated use of cephalexin may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
- Diabetes patients: Cephalexin may cause the results of some tests for urine glucose to be wrong. Ask your doctor before you change your diet or the dose of your diabetes medicine.
- Cephalexin may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Cephalexin.
- Use cephalexin with caution in the elderly; they may be more sensitive to its effects.
- Use Cephalexin with extreme caution in children younger than 10 years who have diarrhea or an infection of the stomach or bowel.
- Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using cephalexin while you are pregnant. Cephalexin is found in breast milk. If you are or will be breast-feeding while you use Cephalexin, check with your doctor. Discuss any possible risks to your baby.
All medicines may cause side effects, but many people have no, or minor, side effects.
Check with your doctor if any of these most common side effects persist or become bothersome:
Diarrhea; dizziness; headache; indigestion; joint pain; stomach pain; tiredness.
Seek medical attention right away if any of these severe side effects occur:
- Severe allergic reactions (rash; hives; itching; difficulty breathing;
- tightness in the chest;
- swelling of the mouth, face, lips, or tongue);
- dark urine;
- decreased urination;
- red, swollen, or blistered skin;
- severe or bloody diarrhea;
- severe stomach pain or cramps;
- severe tiredness;
- unusual bruising or bleeding;
- unusual vaginal pain, odor, or discharge;
- yellowing of the eyes or skin.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.