Tuberculosis Management - Treatment Relapse

Treatment Relapse

A patient is said to relapse if he improves while on treatment, but becomes ill again after stopping treatment. Patients who experience only a transient improvement while on treatment, or who never respond to treatment are said to have failed treatment and are discussed above.

There is a small relapse rate associated with all treatment regimens, even if the treatment has been taken religiously with 100% compliance (the standard regimen 2HREZ/4HR has a relapse rate of 2 to 3%). The majority of relapses occur within 6 months of finishing treatment. Patients who are more likely to relapse are those who took their medication in an unreliable and irregular fashion.

The probability of resistance is higher in those patients who relapse and every effort must be made to obtain a specimen that can be cultured for sensitivities. That said, most patients who relapse do so with a fully sensitive strain and it is possible that these patients have not relapsed, but have instead been re-infected; these patients can be re-treated with the same regimen as before (no drugs need to be added to the regimen and the duration need not be any longer).

The WHO recommends a regimen of 2SHREZ/6HRE when microbiology is not available (the majority of countries where TB is highly endemic). This regimen was designed to provide optimal treatment for fully sensitive TB (the most common finding in patients who have relapsed) as well as to cover the possibility of INH-resistant TB (the most common form of resistance found).

Because of the lifelong risk of relapse, all patients should be warned of the symptoms of TB relapse upon finishing treatment and given strict instructions to return to their doctor if symptoms recur.