Skip to Content

Cycloserine

Generic Name: cycloserine (sye kloe SER een)
Brand Name: Seromycin

Medically reviewed on December 15, 2017

What is cycloserine?

Cycloserine is an antibiotic. It prevents tuberculous bacteria from growing in your body.

Cycloserine is used to treat tuberculosis (TB).

Cycloserine is also sometimes used to treat urinary tract and other types of infections that have not responded to other treatments.

Cycloserine may also be used for purposes other than those listed in this medication guide.

Important Information

Take all of the cycloserine 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.

Avoid alcohol while taking cycloserine. Alcohol will increase your risk of having a seizure during cycloserine treatment. Alcohol will also increase dizziness and drowsiness.

Use caution when driving, operating machinery, or performing other hazardous activities. Cycloserine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Call your doctor immediately if you experience a skin rash, mental confusion, dizziness, headache, or tremors (shaking).

Who should not take cycloserine?

You cannot take cycloserine if you

Cycloserine is in the FDA pregnancy category C. This means that it is not known whether cycloserine will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant

Cycloserine passes into breast milk, and it is not known whether cycloserine will harm a nursing baby. Do not take this medication without first talking to your doctor if you are breast-feeding a baby.

How should I take cycloserine?

Take cycloserine exactly as directed by your doctor. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass (8 ounces) of water.

Cycloserine is usually taken twice a day. Follow your doctor's instructions.

Take all of the cycloserine 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.

Cycloserine is usually combined with one or more other tuberculosis medicines.

Your doctor may also want you to take a supplemental vitamin B6 (pyridoxine) tablet daily during treatment to lessen side effects.

Store this medication at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for your next regularly scheduled dose, skip the missed dose and take the next one as directed. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a cycloserine overdose include drowsiness, confusion, headache, dizziness, irritability, numbness and tingling, difficulty speaking, paralysis, abnormal behavior, seizures, and unconsciousness.

What should I avoid while taking cycloserine?

Avoid alcohol while taking cycloserine. Alcohol will increase your risk of having a seizure during treatment with this medication. Also, alcohol will increase dizziness and drowsiness.

Use caution when driving, operating machinery, or performing other hazardous activities. Cycloserine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Cycloserine side effects

If you experience any of the following serious side effects, seek emergency medical attention or contact your doctor immediately:

  • an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);

  • seizures;

  • numbness or tingling in your hands or feet;

  • a skin rash;

  • confusion or abnormal behavior;

  • tremors (shaking);

  • headache;

  • drowsiness;

  • dizziness;

  • difficulty speaking; or

  • irritability.

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. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Cycloserine dosing information

Usual Adult Dose for Tuberculosis -- Extrapulmonary:

500 mg to 1 g orally per day, in 1 or 2 divided doses (10 to 15 mg/kg/day).

Duration: Treatment should continue until permanent bacteriological conversion and maximal clinical improvement have occurred, generally, 18 to 24 months.

Usual Adult Dose for Tuberculosis -- Active:

500 mg to 1 g orally per day, in 1 or 2 divided doses (10 to 15 mg/kg/day).

Duration: Treatment should continue until permanent bacteriological conversion and maximal clinical improvement have occurred, generally, 18 to 24 months.

Usual Pediatric Dose for Tuberculosis -- Extrapulmonary:

Children: 10 to 15 mg/kg/day in 2 divided doses

Maximum dose: 1 g/day

Usual Pediatric Dose for Tuberculosis -- Active:

Children: 10 to 15 mg/kg/day in 2 divided doses

Maximum dose: 1 g/day

What other drugs will affect cycloserine?

Before taking cycloserine, tell your doctor if you are taking

You may require a dosage adjustment or special monitoring if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with cycloserine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Further information

  • Your pharmacist has additional information about cycloserine written for health professionals that you may read.

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.

Hide