Common side effects of cycloserine and how long they last

Cycloserine (Cycloserine), as a synthetic broad-spectrum antibiotic, is mainly used for the treatment of multidrug-resistant tuberculosis (MDR-TB) or non-tuberculous mycobacterial infections. It works by inhibiting the formation of bacterial cell walls, but because it can cross the blood-brain barrier, it has a significant impact on the central nervous system, so side effects are mostly related to the neuropsychiatric system. The most common side effects include anxiety, insomnia, depression, mood swings, memory loss, headache, and possibly seizures, hallucinations, or psychotic-like manifestations at high doses or with long-term use. Some patients may also experience slurred speech, tremors, decreased concentration and even abnormal behavior. These adverse reactions are often the main reasons that limit its widespread use.

The onset time and duration of side effects vary from person to person, but generally appear within days to weeks after starting medication, with anxiety and sleep disturbance being one of the earliest manifestations. Without timely intervention, these symptoms may gradually worsen as the cumulative dose increases. Literature shows that about 20%-30% of patients will experience varying degrees of central nervous system side effects during treatment. Some of these symptoms may be relieved within a few days to weeks after stopping the drug, but there are also individual patients who experience persistent or irreversible neurobehavioral changes after long-term use.

The mechanism leading to these neuropsychiatric side effects is mainly related to the effect of cycloserine on the γ-aminobutyric acid (GABA) energy system in the brain. GABA is the main inhibitory neurotransmitter, involved in regulating emotions and nervous stability. Interference of cycloserine with its receptors will cause increased excitability of the nervous system and increase the risk of epilepsy and anxiety. Therefore, patients especially need to be monitored regularly while taking the medication, especially those with a history of mental illness, epilepsy, or alcohol dependence, who are high-risk groups and must be carefully evaluated for use.

Reference materials:https://en.wikipedia.org/wiki/Cycloserine