Cephalexin, also spelled cefalexin, is an antibiotic. It belongs to a class of antibiotics known as first-generation cephalosporins, which doctors use to treat a range of bacterial infections.

A doctor may prescribe cephalexin to treat infections of the skin, middle ear, upper respiratory tract, and urinary tract. It appears on the

While cephalexin does not directly interact with alcohol, this article outlines some reasons why people may wish to avoid alcohol while undergoing antibiotic treatment.

As with other cephalosporins, the most common side effects of cephalexin are gastrointestinal problems, including:

Some less common side effects of cephalexin include:

Allergic reactions

Itchiness is a potential side effect of Cephalexin.
Itchiness is a potential side effect of cephalosporins.

Researchers estimate that of people will develop a reaction to cephalosporins.

The risk may be higher for people who are allergic to penicillin.

The authors of advise that people with a known allergy to penicillin do not take any cephalosporins before undergoing tests. These will involve taking a progressively increasing amount of one of these drugs to measure any possible reaction.

Common symptoms of an allergic reaction include:

In rare cases, a person may experience an extreme allergic reaction known as anaphylaxis. Anaphylaxis is a potentially life-threatening condition that requires urgent medical attention.

Symptoms of anaphylaxis can include:

  • difficulty breathing
  • tightness in the chest
  • swelling of the face, mouth, lips, or tongue
  • severe abdominal pain or cramps
  • red, swollen, or blistered skin
  • seizures
  • dizziness
  • fainting

Although cephalexin and alcohol are safe to use in combination, people taking the antibiotic for an active urinary tract infection (UTI) may still benefit from avoiding alcohol altogether.

Doctors usually advise people with UTIs to drink more water in an attempt to "flush out" the infection. Drinking alcohol tends to dehydrate the body, which may prolong bladder irritation.

Effects of alcohol on the immune system

Consuming alcohol can impair liver function.

Drinking alcohol while experiencing a UTI increases the strain on the liver, which will already be working hard to overcome the infection.

Alcohol may also disrupt the immune system by and causing gastrointestinal symptoms.

Each of these effects can impair the ability of the body to recover from infection, possibly prolonging recovery.