"Self-managed", inadequate "adherence" to antiretroviral therapy, limited to one half of standard dosages, followed by an unexpected, sustained virological and immunological success
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.
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