Cloxapen Side Effects

Generic name: cloxacillin

Medically reviewed by Drugs.com. Last updated on May 9, 2024.

Note: This document provides detailed information about Cloxapen Side Effects associated with cloxacillin. Some dosage forms listed on this page may not apply specifically to the brand name Cloxapen.

Applies to cloxacillin: oral capsule, oral powder for reconstitution.

Important Warnings This medicine can cause some serious health issues

Take all of the cloxacillin that has been prescribed for you even if you begin to feel better.

Your symptoms may begin to improve before the infection is completely treated.

Do not break, chew, open, or crush the capsules.

Swallow them whole.

Cloxacillin may decrease the effectiveness of birth control pills.

Use a second method of birth control while taking cloxacillin to protect against pregnancy.

If you experience any of the following serious side effects, stop taking cloxacillin (the active ingredient contained in Cloxapen) and seek emergency medical attention:

• an allergic reaction (shortness of breath; closing of your throat; hives; swelling of your lips, face, or tongue; rash; or fainting);

• seizures;

• severe watery diarrhea and abdominal cramps; or

• unusual bleeding or bruising.

Other, less serious side effects maybe more likely to occur. Continue to take cloxacillin and talk to your doctor if you experience

• mild nausea, vomiting, diarrhea, or abdominal pain;

• white patches on the tongue (thrush/yeast infection);

• itching or discharge of the vagina (vaginal yeast infection); or

• black, "hairy" tongue or sore mouth or tongue.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

For Healthcare Professionals

Applies to cloxacillin: oral capsule, oral powder for reconstitution.

Gastrointestinal

• Common gastrointestinal complaints include nausea, vomiting, and diarrhea. Rarely the use of cloxacillin (the active ingredient contained in Cloxapen) has been associated with pseudomembranous colitis.^[Ref]

Hematologic

Hematologic adverse effects include neutropenia, leukopenia, and thrombocytopenia. Neutropenia has occurred in 17% of patients and occurs most commonly with higher doses and longer durations of therapy. Neutropenia occurs most often after 14 days of therapy and is reversible upon discontinuation.^[Ref]

Hepatic

Hepatic side effects include transient increases in serum transaminases and the development of cholestatic hepatitis. Liver transaminases may take several weeks to return to normal following discontinuation of therapy. Frequent monitoring of liver function tests is recommended in patients with liver disease.^[Ref]

Hypersensitivity

Hypersensitivity reactions include rash, fever, eosinophilia, pruritus, fever, chills, and myalgias.^[Ref]

Further information

Cloxapen side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer