Detailed instructions for taking cycloserine for patients

1. Indications

Cycloserine (Cycloserine) is an antibiotic mainly used to treat infections caused by Mycobacterium tuberculosis (Mycobacterium tuberculosis () caused by tuberculosis (TB), especially multidrug-resistant tuberculosis (MDR-TB) that is resistant to conventional first-line drugs such as isoniazid and rifampicin. In addition, cycloserine can also be used to treat other drug-resistant non-tuberculous mycobacteria (NTM) infections.

2. Mechanism of action

Cycloserine competitively inhibits two key enzymes in bacterial cell wall synthesis——alanine lysinase (alanine racemase) and D-alanine-D-alanine synthase (D-alanine-D-alanine ligase), interfere with the synthesis of peptidoglycan, thereby inhibiting the growth and reproduction of bacteria. Damage to the bacterial cell wall will cause bacterial cell lysis in a high osmotic pressure environment, thereby inhibiting or killing the bacteria.

3. Pharmacology

Pharmacokinetics: Cycloserine is well absorbed after oral administration, and its bioavailability is approximately70-90%. The drug is widely distributed in the body and can penetrate into body fluids such as cerebrospinal fluid, pleural effusion, and ascites. The liver metabolizes less and is mainly excreted by the kidneys. About 65% of it is excreted in the urine in its original form. The half-life is approximately 10 hours.

Pharmacodynamics: Cycloserine has a significant inhibitory effect on Mycobacterium tuberculosis and some drug-resistant non-tuberculous mycobacteria.

4. Dosage and usage

Adult dosage: The usual dose is 500-1000mg daily taken in two divided doses. Each interval is approximately12 hours. The initial dose is usually 250 mg per day and gradually increased to the target dose to reduce adverse reactions.

Children's dosage: The dosage should be adjusted according to body weight. The usual dosage is 10-20mg/kg per day, taken in two divided doses. The specific dosage should be adjusted by the doctor according to the condition.

How to take: Cycloserine capsules can be taken with food or on an empty stomach. To reduce gastrointestinal discomfort, it is recommended to take it with food and a full glass of water.

5. Side Effects

1.Common side effects: include headache, dizziness, insomnia, irritability, depression, ataxia (coordination disorder), tremor, seizures, and psychiatric symptoms (such as hallucinations, delusions).

2.Gastrointestinal reactions: such as nausea, vomiting and abdominal pain.

3.Allergic reactions: such as rash, itching and urticaria.

4.Others: such as blood system abnormalities (anemia, leukopenia), abnormal liver function and renal function damage.

6. Warnings and Precautions

1.Psychiatric symptoms: Cycloserine can cause severe psychiatric symptoms, including depression, psychosis, and suicidal tendencies. Patients should closely monitor their mental status during treatment and notify the doctor promptly if any abnormalities occur.

2.Nervous system reaction: Patients should avoid driving and operating machinery until the effect of the drug on themselves is confirmed.

3. Liver and renal function: Liver and renal function should be monitored regularly during treatment, especially in patients who use cycloserine for a long time.

4.Drug dependence: Long-term use may lead to drug dependence, and the dosage should be gradually reduced when discontinuing the drug.

7. Contraindications

1.Patients allergic to cycloserine or its components.

2.Patients with a history of severe mental disorder or epilepsy.

3.Patients with severe liver and kidney dysfunction.

8. Drug interactions

1.Other anti-tuberculosis drugs: When cycloserine is used in combination with other anti-tuberculosis drugs, liver function and nervous system response should be monitored to avoid aggravation of side effects caused by drug interactions.

2. Central nervous system depressants: such as alcohol, barbiturates, etc., combined use may aggravate the central nervous system depressant effect, and simultaneous use should be avoided.

3.Anti-epileptic drugs: such as phenytoin and cycloserine may reduce their blood concentration, and the dose needs to be adjusted.

9. Medication for Special Populations

1.Pregnant and lactating women: Cycloserine should be used with caution in pregnant women and only when the benefits clearly outweigh the risks. Breast-feeding women should suspend breastfeeding when taking the drug.

2.Children: The dose should be adjusted according to body weight and used under the guidance of a doctor.

3.Elderly patients: Elderly patients may be more sensitive to drugs and need to adjust the dose according to liver and kidney function and closely monitor adverse reactions.

4.Patients with liver and kidney dysfunction: The dose needs to be adjusted according to liver and kidney function, and liver and kidney function should be monitored regularly.

Cycloserine is an effective antibiotic used to treat multidrug-resistant tuberculosis. Patients should strictly follow the doctor's instructions while taking cycloserine, take the medicine on time and in the right amount, and conduct regular health monitoring. Understanding the indications, mechanism of action, pharmacology, dosage and usage, side effects, warnings and precautions, contraindications, drug interactions, and medication use by special groups can help improve treatment effects, reduce adverse reactions, and ensure safe medication use.