Sustiva can linger in the body of people with a certain genetic makeup for at least eight weeks after treatment is stopped, and persistent low levels of the drug can allow HIV to develop defenses against it, British researchers warn. Writing in the October 15 edition of the journal AIDS, they report a case study of an African woman with a rare genotype'CYPB26'who had stopped Sustiva treatment but still maintained blood-based drug levels sufficient to control HIV four weeks later. However, the drug persisted in her body for another four weeks at suboptimal levels, during which time she developed a viral mutation conveying resistance to the medication.
Although most HIVers who stop taking Sustiva usually replace it with another potent anti-HIV medication, the case study could indicate that treatment interruptions where all anti-HIV drugs are stopped could result in the development of drug resistance for Sustiva users.
