Skip to main content


Generic name: cycloserine [ SYE-kloe-SER-een ]
Brand name: Seromycin
Dosage form: oral capsule (250 mg)
Drug class: Streptomyces derivatives

Medically reviewed by on Aug 10, 2023. Written by Cerner Multum.

What is cycloserine?

Cycloserine is an antibiotic that is used to treat tuberculosis (TB).

Cycloserine is also used to treat bladder or kidney infections.

Cycloserine is usually given after other medications did not work or have stopped working.

Cycloserine may also be used for purposes not listed in this medication guide.

Cycloserine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Cycloserine may cause serious side effects. Call your doctor at once if you have:

Common side effects of cycloserine may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use cycloserine if you are allergic to it, or if you have:

Cycloserine is not approved for use by anyone younger than 18 years old.

Tell your doctor if you have ever had:

It is not known whether cycloserine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breast-feed while using cycloserine.

How should I take cycloserine?

Your doctor will perform a blood test to make sure cycloserine is the right treatment for your condition.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Cycloserine will not treat a viral infection such as the flu or a common cold.

You will need frequent medical tests.

Tuberculosis is often treated with a combination of medications. Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include confusion, severe drowsiness, tingly feeling, problems with muscle movement, slurred speech, seizure, or loss of consciousness.

What should I avoid while taking cycloserine?

Avoid drinking alcohol. It may increase your risk of seizures or other side effects.

Avoid driving or hazardous activity until you know how cycloserine will affect you. Your reactions could be impaired.

What other drugs will affect cycloserine?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may affect cycloserine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.