cycloserine
Cycloserine (Seromycin) is an antibiotic that's used to treat tuberculosis (TB) and urinary tract infections (UTIs) in adults. It's usually only used for treating drug-resistant infections (when typical antibiotics don't work). This medication is a capsule that's taken by mouth. At higher doses, it can cause side effects, including sleepiness, headache, confusion, changes in personality, and even seizures. Treatment requires frequent monitoring of medication levels in the blood to prevent side effects.
What is Cycloserine (Seromycin)?
What is Cycloserine (Seromycin) used for?
- Tuberculosis (TB) that's hard to treat with first-choice antibiotics
- Urinary tract infections (UTIs), after first-choice options haven't worked
How Cycloserine (Seromycin) works
Cycloserine (Seromycin) is an antibiotic. It kills bacteria by preventing them from making their cell walls, which are important "shields" that bacteria use to protect themselves.
Drug facts
Side effects of Cycloserine (Seromycin)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Side effects are more likely to happen at doses greater than 500 mg per day.
- Sleepiness
- Headache
- Tremor (shakiness)
- Trouble speaking or slurred speech
- Feeling like your surroundings are spinning (vertigo)
- Confusion
- Memory problems
- Changes in mood, thoughts, or behaviors
Less Common Side Effects
- Skin rash
Cycloserine (Seromycin) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Seizures
- Heart failure: shortness of breath, swelling in the stomach or legs, sudden weight gain, tiredness, dizziness
- Allergic reaction: rash, hives, trouble breathing, swelling of the face
The following Cycloserine (Seromycin) side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
confusion
dizziness
drowsiness
increased irritability
increased restlessness
mental depression
muscle twitching or trembling
nervousness
nightmares
other mood or mental changes
speech problems
thoughts of suicide
Less common
Convulsions (seizures)
numbness, tingling, burning pain, or weakness in the hands or feet
skin rash
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Headache
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
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Pros and cons of Cycloserine (Seromycin)
Pros
- Might be useful for hard-to-treat TB infections
- Doesn't typically cause liver damage like most anti-TB antibiotics
- Fewer drug interactions than other anti-TB antibiotics
Cons
- Not a first-choice option for treating infections
- Requires frequent blood tests to monitor medication levels in the body
- Not a good option for people who have seizures or mental health problems
Pharmacist tips for Cycloserine (Seromycin)
- Before you start taking cycloserine (Seromycin), make sure your provider and pharmacist have a full list of your medications and medical history. Certain medical conditions and medications can raise your risk of nerve problems and unwanted side effects.
- Cycloserine (Seromycin) might make you feel dizzy and tired. Avoid driving and doing tasks that require you to be alert until you know how the medication affects you.
- Don't drink alcohol while you're taking cycloserine (Seromycin). This medication has a risk of seizures at higher doses, and drinking a lot of alcohol can raise your risk even more.
- It's important to remember to take all your doses of cycloserine (Seromycin) on time. Missing or skipping doses can make the antibiotic work less well against the bacteria, which can then make the infection harder to treat. Take cycloserine (Seromycin) exactly as prescribed, finish your treatment course, and don't stop taking the antibiotic unless instructed by your provider.
- Cycloserine (Seromycin) is usually prescribed with other antibiotics when it's used to treat TB to prevent drug resistance. Make sure you know which medications are part of your anti-TB treatment plan so you can start them all at the same time.
Common questions about Cycloserine (Seromycin)
Penicillin and cycloserine (Seromycin) are both antibiotics that fight certain bacterial infections. They both stop bacteria from making strong cell walls, which bacteria use to "shield" themselves from harm. But how exactly the two medications do this is a little different — they block different proteins that bacteria use to make their cell walls.
There isn't a set amount of time that you can take cycloserine (Seromycin) for. But if you're taking the antibiotic for TB, treatment typically lasts for many months. Your provider will determine how long you need to take cycloserine (Seromycin) for based on how your body responds to treatment and whether you have side effects from the medication (e.g., nervous system problems). It's important to take cycloserine (Seromycin) and your other anti-TB medications exactly as prescribed. Don't stop taking them unless instructed by your provider. This helps prevent drug-resistant TB, which can be even harder to treat. Speak with your provider about how long you need to take cycloserine (Seromycin) for.
It's possible for people who take cycloserine (Seromycin) to develop psychosis, which include hallucinations and delusions. The risk for psychosis is higher if you're taking this antibiotic at doses higher than 500 mg per day. Speak with your provider if you have concerns about this side effect. And get medical help as soon as possible if you or your loved ones notice that you start hearing or seeing things that aren't real or having delusional thinking. Your dose might need to be lowered or your treatment plan might need to change.
It's best to avoid alcohol while you're taking cycloserine (Seromycin). This medication can cause serious side effects, like seizures. And the risk for seizures happening while you're taking this medication is higher if you drink large amounts of alcohol on a regular basis. Speak with your provider about your drinking habits while you're taking cycloserine (Seromycin). Your provider can discuss with you about ways to stop drinking altogether.
While cyclosporine and cycloserine (Seromycin) sound alike, they're two completely different medications. Cyclosporine is used to treat or prevent rejection after someone gets an organ transplant; it works by lowering the activity of the immune system. On the other hand, cycloserine (Seromycin) is an antibiotic that helps fight tuberculosis (TB) and urinary tract infections (UTIs) that are very hard to treat; it works by killing bacteria.
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Risks and warnings for Cycloserine (Seromycin)
Cycloserine (Seromycin) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Nervous system problems
- Risk factors: Taking over 500 mg of cycloserine (Seromycin) per day | Heavy alcohol use | Kidney problems | Also taking Trecator (ethionamide) or isoniazid
Cycloserine (Seromycin) can cause sleepiness, headache, tremor, balance problems, muscle weakness, and confusion. This medication can also cause more serious problems like seizures, depression, anxiety, psychosis, and other changes in mood or behavior.
These problems are more likely to happen if you're taking cycloserine (Seromycin) at doses higher than 500 mg per day. You're also at risk if you have kidney problems; the body can't get rid of the medication properly from the system and the medication builds up in the body. In addition, drinking large amounts of alcohol also raises the risk for seizures.
You'll need to get lab work done often so your provider can check the medication levels in your blood and monitor you for side effects. Call your provider if you have any symptoms of nervous system problems. Get medical help right away if you have a seizure while you're taking this medication.
Heart failure when used at very high doses
Some people who took cycloserine (Seromycin) at very high doses (1 to 1.5 grams per day) suddenly had heart failure. This condition happens when the heart isn't able to pump as well as it should. Contact your provider right away if you notice symptoms of heart failure, such as shortness of breath that's worse with activity or when lying down, swelling in the stomach or legs, sudden weight gain, tiredness, or dizziness.
Low vitamin B12 and folic acid levels
Some people who took cycloserine (Seromycin) developed low vitamin B12 levels and low folic acid levels. This can lead to anemia (low red blood cell counts). Your provider will check your vitamin levels and blood cell counts during treatment. Make sure to let your provider know if you notice any symptoms of anemia, such as tiredness, pale skin, shortness of breath, or lightheadedness.
Cycloserine (Seromycin) dosage
Capsule| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 250mg | 30 capsules | $1,331.22 | $44.37 |
Typical dosage for Cycloserine (Seromycin)
The typical starting dose is 250 mg by mouth every 12 hours for the first 2 weeks. Your provider will adjust your dose based on the levels of cycloserine (Seromycin) in your blood. The usual dose ranges from 500 mg to 1 gram per day, separated into smaller doses throughout the day.
Interactions between Cycloserine (Seromycin) and other drugs
More on Cycloserine (Seromycin) interactions
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Ethionamide
How much does Cycloserine (Seromycin) cost?
$1,331.22
Cycloserine (Seromycin) contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Cycloserine (Seromycin) will not be safe for you to take.
