"Self-managed", inadequate "adherence" to antiretroviral therapy, limited to one half of standard dosages, followed by an unexpected, sustained virological and immunological success
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KeywordsRitonavir Therapeutic Drug Monitoring Indinavir Single Daily Dosage Half Dosage
Antiretroviral adherence issues are essential for successful and sustained efficacy, and viral resistance prevention.
One exceptional case regards an ex-IVDA patient (p) with HIV infection known since 1985. Due to a severe HIV-related immunosuppression (CD4: 37 cells/μL), in 1997 3TC, d4T, and indinavir was effectively started, achieving after 3 months undetectable viremia and a CD4 count of 315 cells/μL, but recurring urolithiasis recommended a therapeutic shift. Since April 1997,3TC, d4T, and ritonavir were suggested for 5 years, followed by 3TC, d4T, and lopinavir-ritonavir (10 months), and 3TC, AZT, and lopinavir-ritonavir (6 years). However, all proposed regimens were voluntarily taken by our p (whose body weight was 75-80 Kg) at half-dose, as a single daily dosage, against any recommendation, although our p always maintained his "adherence" to his self-made regimen, as assessed by monthly visits, direct drug distribution-accountabilty, and adherence questionnaires. Surprisingly, viremia remained for 12 years at non-detectable values (save one single detection of 1,260 HIV-RNA copies/μL), so that a genotypic resistance testing was never feasible, while CD4 count ranged from a nadir of 382 cells/μL (year 2001), to 525-794 cells/μL since 2003.
A second male p with a body weight of 69-73 Kg, since 2002 took all combined antiretroviral therapy at half dosage (3TC 150 mg/day, AZT 300 mg/day, and lopinavir-ritonavir 2 cp/day for 7 years, as a single daily dose), without showing detectable viremias, and CD4 counts >500 cells/μL. A third 48-y-old male, after two changes of antiretroviral regimens due to dysmetabolism, started the fixed dose AZT-3TC-abacavir combination at half dosage (one pill/day), and since 2003 had a persistingly negative viremia, and a CD4 count always >650 cells/μL. In both these last 2 p, genotypic resistance testing was not feasible (undetectable viremia).
Although recognizing the limitation of anecdotal observations, and our impossibility to resort to resistance testing and therapeutic drug monitoring, however the long-term maintenance of an excellent virologic-immunological situation in 3 p with an adherence voluntarily limited to 50% of recommended dosages depite all counselling, deserves discussion. A 50% compliance is considered absolutely inadequate in HIV disease treatment. Anyway, all our 3 p are somewhat "adherent" to their 50% dosage regimens, and are re-enforced in their wrong consideration by checking every 3 months their excellent clinical-laboratory situation, and by their long-term, unchanged therapy response. Health care professionals are embarrassed in discussing this inappropriate mode of antiretroviral seld-administration, but lack of supporting elements to opposite to the strongloy radicated p's thoughts.
This article is published under license to BioMed Central Ltd.