In a patient with multidrug-resistant tuberculosis, which medication should be avoided due to potential seizure exacerbation?

In the context of multidrug-resistant tuberculosis (MDR-TB), both cycloserine and high doses of isoniazid are associated with neurological side effects that can include seizure exacerbation.

Cycloserine is known to have a direct neurotoxic effect, and it has been documented to cause seizures, especially in individuals with a history of epilepsy or those who are susceptible to seizures. The risk of seizures is particularly relevant in patients with underlying conditions or those on high doses, necessitating close monitoring.

High doses of isoniazid can also lead to seizures due to its effects on the nervous system. In some cases, high levels can induce seizures in susceptible individuals, especially when considering isoniazid's role in inhibiting the synthesis of GABA, an important inhibitory neurotransmitter in the brain.

Given these associations, it is important to avoid both medications in patients who are at high risk for seizures or who have a history of seizure disorders when managing MDR-TB. Thus, the preference for avoiding both drugs due to their potential to exacerbate seizures aligns with best practices in treating patients with this condition.