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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.

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What are the possible side effects of cycloserine?

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.

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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.

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What is the most important information I should know about cycloserine?
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.

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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.

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What other drugs will affect cycloserine?
Before taking cycloserine, tell your doctor if you are taking ethionamide (Trecator-SC), or isoniazid (Nydrazid). 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.

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Cycloserine has been assigned to pregnancy category C by the FDA. Animal studies with high doses have not revealed evidence of teratogenicity. Cycloserine crosses the placenta and may achieve fetal blood levels similar to those in maternal blood. The Collaborative Perinatal Project found no adverse effects in 3 mother-child pairs who were exposed to cycloserine during the first trimester. Cycloserine is only recommended for use during pregnancy when there are no alternatives and benefit outweighs risk.

Cycloserine is excreted into human milk in concentrations that may approach maternal serum levels. Cycloserine is considered compatible with breast-feeding by the American Academy of Pediatrics. The manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

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What does my medication look like?
Cycloserine is available with a prescription under the brand name Seromycin. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you. Seromycin 250 mg--red and gray capsules

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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.

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Who should not take cycloserine?
You cannot take cycloserine if you have epilepsy, suffer from depression, have an anxiety disorder, have a psychotic or psychiatric disorder, have kidney disease, or drink alcohol on a daily basis. 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.

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Can I stop taking the medication if I feel better?
If you have been diagnosed with a disease for which an antibiotic is needed, you must complete the prescribed course of treatment. Even if you start to feel better, do not skip any doses and remember to take the medication until it is all gone.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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