Cycloserine (Oral)

Cycloserine is an antibiotic that works by reversing the growth of microorganisms that cause infections such as TB.


Cycloserine, whose brand name is Seromycin, treats TB as part of a broader regimen involving other medications. It is a proper medical prescription for various forms of TB, including active tuberculosis, tuberculosis meningitis, and tuberculosis affecting the lungs.

A doctor may recommend the cycloserine medication for other conditions as necessary. As such, it may also treat a urinary tract infection as a result of the E. coli bacteria or even Enterobacter cloacae. The medication does not work when it comes to remedying viral diseases, for example, flu and the common cold, because it is only an antibiotic.

Cycloserine is a prescription-only drug that is available in the form of a capsule. A patient takes it orally (through the mouth), and they must use their entire prescription regardless of treatment outcomes unless their doctor recommends otherwise. Quitting this medication prematurely or consistently skipping doses allows the TB bacteria to keep growing. In turn, the infection may come back, with the bacteria developing resistance and making future treatment using this medication difficult.

Conditions treated

  • style="font-weight: 400;">Tuberculosis
  • E. coli bacteria urinary tract infection
  • Enterobacter cloacae urinary tract infection

Type of medicine

  • Antitubercular

Side effects

It is possible for cycloserine to produce unwanted results in a patient using it to treat TB or a urinary tract infection. However, the doctor prescribes this medication after assessing that its therapeutic benefits outweigh any possible side effects. Nonetheless, the majority of patients taking this drug complete their treatment without encountering any severe unpleasant results.

Some of the likely cycloserine side effects include a headache, dizziness, sleepiness, or even tremors. Such conditions do not usually persist or escalate, but if they do, the patient must report them to their doctor right away.

Typically, most patients on cycloserine for TB never experience serious side effects like weakness, convulsions, and numbing of the skin. It is also rare for mental disturbances or mood fluctuations in the form of agitation, depression, vivid/strange dreams, or suicidal thoughts to occur as a result of an individual using this medication. These treatments outcomes are dire, nonetheless, and require reporting to the doctor once they occur.

Cycloserine is not likely to cause swelling of ankles or feet, abnormal heart rates, paleness of the skin, or unusual fatigue levels. Those conditions may still occur, requiring immediate medical attention.

In rare occasions, some patients have severe allergic reactions when taking cycloserine. Possible such outcomes include breathing difficulty, severe lightheadedness, or even rashes/ itching/swelling affecting body parts like the tongue, face, or throat. If left untreated, such conditions may escalate and threaten the life and overall wellness of the patient.

Other possible cycloserine side effects include:

  • Numb or tingling hands or feet
  • Anxiety
  • Difficulty speaking
  • Increased irritability

To be on the safe side, the patient should always consult their doctor over any strange, unfavorable outcomes they experience while using cycloserine. The healthcare giver may be able to advise them on how to manage, prevent, or cope with such medication side effects.

Dosage information

Every patient has their appropriate cycloserine dosage requirements for treating TB or urinary tract infections. That is why the doctor bases a prescription on the specific diagnosis their patient gets. Likewise, the weight and cycloserine blood levels of the victim determine their dosing specifications. Of course, the doctor may later adjust a dose depending on how their patient responds to treatment.

The initial dosage for treating tuberculosis in adults and teenagers is 250 milligrams (mg) of cycloserine twice per day. The dosage may gradually increase to 250 milligrams thrice or four times per day. To treat TB, the patient uses this medication along with other prescribed drugs.

Only a doctor can decide the right dosage for minors with TB. In some instances, a physician may order from 10 to 20 milligrams of cycloserine for every kilogram a minor weighs. The dosage translates to 4.5 to 9.1 milligrams for every pound of body weight. Again, a child must use this drug along with other prescribed TB medicines.

The patient must avoid skipping this medication and giving their bacterial infection an opportunity to multiply and come back stronger. In case of a missed dose, they should take it at their earliest chance. Nonetheless, if the next medication intake as per the usual dosing plan is almost due, the patient should just wait for it and forego the late one. They should avoid overdosing or taking two doses at the same time or too close to each other.

Recommendations for optimizing cycloserine's treatment benefits:

A patient may be unable to stick to their dosage plan if it sometimes causes them a stomach upset. To avoid that issue, the victim should use cycloserine after eating. It is also imperative that they take the medication at uniform time intervals to get the best out of their treatment. For instance, two doses per day require spacing of about 12 hours between each. The best strategy would be to use the drug at the same time or times each day.

To make sure that their TB or urinary tract infection goes away and never returns, the patient should continue using cycloserine for the entire duration of treatment, regardless of any evident recovery signs. Some victims have to take the medication (along with other medical prescriptions) for up to two years. The patient is free to consult their doctor about planning their dosage if they are encountering difficulties concerning it.

Major drug interactions

Just like other drugs, cycloserine may have interactions with other medicines. Such chemical interferences could affect the efficacy of the antibiotic as well as the other medications that the patient is using. Informing the doctor about all other prescription and nonprescription treatments the victim is on helps the medic devise a regimen that mitigates all risks. Necessary precautions may include dosage adjustments.

For example, healthcare professionals do not usually give cycloserine together with ethionamide, but they may have to if its benefits outweigh any risks. In such a case, the doctor may alter the dosage or frequency for using one or both drugs.

Combining cycloserine with particular foods and beverages may also pose significant risks to the patient. Any patient that seeks treatment for TB or a urinary tract infection while using alcohol or tobacco has to tell their doctor about it. The physician may help avert a potential health problem by recommending a change of dosing, medication, or lifestyle habits.

Doctors do not prescribe cycloserine for patients using substances that contain ethanol. If that is an issue, the medic may decide not to give the antibiotic. They could also provide "custom"directives for how the patient may use the substance safely.

Healthcare experts name cycloserine among antibiotics that have possible adverse reactions with liquor. Potential interaction outcomes include a faster heart rate, a sharp rise in blood pressure, and stomach upsets. A headache, nausea and vomiting, red patches on the face, as well as liver damage are also likely severe interactions between the anti-TB drug and alcohol.

Equally critical, the patient should reveal if they have other health conditions as these may impact the application of cycloserine. The doctor has to know if the victim has a record of alcohol addiction, whether in the past or currently. Liquor users that suffer convulsions or epilepsy should be wary that cycloserine may trigger such incidences.

The body gets rid of cycloserine through the kidney, and if this organ has an infection, the doctor may change the dosage or discontinue the medication. The anti-TB drug may cause mental disorders, so an individual with a history of anxiety, depression, or psychosis should take the right precautions before receiving this treatment.


  • The dosage for cycloserine may require adjustments based on response to therapy, making it vital that the patient undergoes regular medical checkups.
  • The abuse of cycloserine can decrease its effectiveness as bacteria develop resistance to the treatment. Misuse includes taking the medication as an over-the-counter remedy without a prescription.
  • Treatment benefits should be evident within two to three weeks, failure to which, or if symptoms escalate, the patient must see their doctor right away.
  • Cycloserine may cause lightheadedness, sleepiness, or loss of alertness. If a patient notices such side effects when taking the medication, they should be careful about taking up responsibilities that require excellent concentration levels and a sound state of mind, including driving or operating machines. The patient should see their healthcare giver about such side effects once they become too much to bear day to day.
  • The combination of liquor and cycloserine is inappropriate considering that it can cause severe complications like seizures and even cardiac problems.
  • If a pregnant woman has concerns about using the anti-TB treatment, they should discuss that with their doctor. So far, there are no specific risks or assurances available regarding the potential impact of cycloserine on unborn human babies.
  • According to research, cycloserine may cause little harm to a breastfeeding child while their mother is using the treatment.
  • Patients with a history of allergies to cycloserine or other drugs need to reveal those to their doctor. Precautions are also necessary when it comes to allergies to foods, additives, dyes, or animal products.
  • A patient should never use more than 1000 milligrams of cycloserine in a day.


Cycloserine requires excellent storage for maximum effectiveness as well as the safety of the patient and kids. The most fundamental rule is to store it in a sealed prescription container, box, or cabinet, making sure children cannot access it.

If a patient has any expired cycloserine or dosage that is no longer in use, they should discard it safely. Their doctor may give directions for how to dispose of unwanted medication without posing any threat to the environment or other users.

Other conditions that cycloserine storage must avoid are:

  • Heat
  • Freezing temperature
  • Wetness/water
  • Direct light


Cycloserine is a capsule that treats tuberculosis and various urinary tract infections. The oral antibiotic subverts the growth of bacteria that cause such complications. However, the drug does not treat diseases resulting from viral attacks, including flu and the common cold. A patient has to avoid misusing this drug because that may lead to their infection becoming resistant to the medication.

The patient has to continue taking cycloserine to full treatment and avoid skipping doses to guarantee that their infection may go away permanently. They should keep going to their doctor for checkups to ensure that the treatment is working. A gradual dosing increase may become necessary at some point.

Cycloserine has potential interactions with drugs and substances, such as alcohol, ethanol, and ethionamide. A patient using those items needs to reveal it to their doctor for medical advice and necessary safety precautions. It is also vital for the healthcare practitioner to know about other health conditions a candidate for this treatment may have.

Overall, cycloserine can treat TB without producing severe side effects. A patient only needs to follow instructions from their doctor for using this medication to get the most out of it.