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 World Health Organization’s “List of Essential Medicines.”
While cephalexin does not directly interact with alcohol, this article outlines some reasons why people may wish to avoid alcohol while undergoing antibiotic treatment.
Although it is not the case with some other antibiotics, cephalexin and alcohol are safe to consume together. However, some people report unpleasant side effects.
The side effects of cephalexin can be similar to those of alcohol, so combining the two may exacerbate these effects.
Many people believe that consuming alcohol while taking antibiotics can be dangerous. This is true for some types of antibiotics, such as metronidazole and tinidazole, which can cause severe adverse reactions in combination with alcohol.
Additionally, some people may avoid alcohol while taking antibiotics because they fear that alcohol can render the medication ineffective.
It is possible that alcohol may reduce the effectiveness of some antibiotics, such as doxycycline. People with a history of chronic alcohol consumption or liver problems should not use this type of medicine.
As with other cephalosporins, the most common side effects of cephalexin are gastrointestinal problems, including:
Some less common side effects of cephalexin include:
Researchers estimate that 1–3 percent of people will develop a reaction to cephalosporins.
The risk may be higher for people who are allergic to penicillin.
The authors of one study 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
Cephalexin is a common antibiotic that doctors prescribe for a range of bacterial infections. However, alternative antibiotics are available for people who are hypersensitive to cephalexin and other first-generation cephalosporins.
Individuals with a known allergy to penicillin are less likely to experience an allergic reaction to newer third- or fourth-generation cephalosporins, such as:
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
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 disturbing sleep patterns and causing gastrointestinal symptoms.
Each of these effects can impair the ability of the body to recover from infection, possibly prolonging recovery.
While it is safe to consume alcohol in moderation while taking cephalexin, the two substances can cause similar side effects. Taking them in combination may make these side effects worse.
For people who have an active UTI, alcohol may increase irritation and potentially extend recovery time.
In general, moderate alcohol intake will not impact on cephalexin’s effectiveness. However, it is usually best for people who are feeling unwell to abstain from alcohol or limit their intake to allow their body to rest.