Which antitubercular medication should be used cautiously in patients with seizure disorders?

The reason to use caution with Cycloserine and high-dose Isoniazid in patients with seizure disorders is due to the central nervous system (CNS) effects of these medications. Cycloserine has been associated with neurotoxicity, which can lead to seizures, particularly in patients who are predisposed to seizure disorders. Similarly, high doses of Isoniazid can lower the seizure threshold, especially when not adequately supplemented with pyridoxine (vitamin B6), which is a common preventive measure against this side effect.

When these two drugs are used together, the risk of seizures can be significantly heightened, necessitating close monitoring and possible adjustment of the therapy. Understanding the side effect profile of these medications is crucial for effectively managing patients with a history of seizures, ensuring both the effectiveness of tuberculosis treatment and the safety of the overall treatment plan. This careful approach is not as critical with the other combinations listed, where either the medications have a lesser association with seizures or are less likely to exacerbate existing seizure conditions.