Cycloserine for tuberculosis

Cycloserine is one of several medicines you will need to take to treat tuberculosis (TB).

You will need to have regular blood tests while you are taking these capsules.

Continue to take cycloserine unless your doctor tells you to stop. It is important that you take your doses regularly.

About cycloserine

Type of medicine Antituberculosis medicine
Used for Tuberculosis (TB)
Available as Capsules

Cycloserine is used to treat tuberculosis (TB). TB is a bacterial infection which mostly affects the lungs, but which can affect any part of your body. TB is treatable with a course of medicines which usually lasts for six months. You will need to take several medicines to treat TB - cycloserine is one of the medicines used, particularly when other antituberculosis medicines are not suitable.

Cycloserine works by acting on the cell walls of the bacteria responsible for the TB. The cell walls do not form correctly which causes them to break, killing the bacteria.

Before taking cycloserine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking cycloserine it is important that your doctor or pharmacist knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you drink large amounts of alcohol.
  • If you have any mental health problems, such as anxiety, depression or psychosis.
  • If you have liver or kidney problems.
  • If you have a condition that causes fits, such as epilepsy.
  • If you have porphyria (this is a rare inherited blood disorder).
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine.

How to take cycloserine

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about cycloserine and a full list of side-effects which you may experience from taking it.
  • Take the capsules exactly as your doctor tells you to. As a guide, it is usual to begin with to be prescribed one capsule twice daily (morning and evening). After two weeks, your dose may be increased up to two capsules twice daily, depending on the result of a blood test. If cycloserine has been prescribed for a child, carefully follow the directions your doctor gives to you, as the dose will depend upon your child's age.
  • Try to take cycloserine at the same times each day, as this will help you to remember to take your doses. You can take the capsules before or after meals.
  • If you forget to take a dose, take it as soon as you remember. If it is almost time to take your next dose when you remember, skip the missed dose and take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • It is important that you keep your regular appointments with your doctor. This is so your doctor can check on your progress. Your doctor will want you to have blood tests during this treatment, to make sure you have just the right amount of the medicine in your bloodstream. For some people, these tests may be as regular as once a week.
  • Continue to take cycloserine regularly unless your doctor tells you to stop. This is because it is important for you to complete the course of this medicine so that the infection does not come back. Your treatment will last for several months.
  • Do not to drink alcohol while you are on cycloserine. Cycloserine causes drowsiness and drinking alcohol will increase the chance that you experience this side-effect. It will also increase the risk of more serious side-effects, such as convulsions (fits).
  • This medicine may stop the oral typhoid vaccine from working. If you are having any vaccinations, make sure the person treating you knows that you are taking this medicine. Also, if you are having an operation or dental treatment, you should tell the person carrying out the treatment that you are taking cycloserine.
  • If you buy any medicines, check with a pharmacist first that they are suitable for you to take with your other medicines.

Can cycloserine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common cycloserine side-effects
What can I do if I experience this?
Headache Ask your pharmacist to recommend a suitable painkiller. Let your doctor know if the headache continues
Feeling dizzy or sleepy, vertigo (a spinning sensation) Do not drive or use tools or machines. Do not drink alcohol
Shakiness, fits, feeling confused, mood or character changes, skin rashes Let your doctor know if you experience any of these

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store cycloserine

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.