Methods: This was a prospective observational study of routine TDM for protease inhibitors (PIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and integrase inhibitors (IIs) in combination antiretroviral therapy (cART) treated HIV-infected children. Voluntary informed consent was required. Outcome measures included the proportion of serum antiretroviral medication (ARV) levels in the therapeutic range and correlation of levels with virologic control, adherence and toxicity.
Results: Forty-eight of 64 cART treated children in the clinic were recruited (75%). Their median age, viral load (VL) and CD4 percent were 13 (3-18) years, <40 (<40-124) copies/mL and 37.4% (8.4-47.9%), respectively; 45.8% were female. VL was <40 copies/mL in 91.7%. Adherence was assessed as excellent (>95%) in 95.8%. Fifty baseline trough serum levels were taken, including 19 (38%) for PIs, 27 (54%) for NNRTIs, and 4 (8%) for IIs. Sixty-eight percent (n=34) of levels were within the therapeutic range, 10% (n=5) were subtherapeutic, and 22% (n=11) were supratherapeutic. The highest proportion of therapeutic levels were within the NNRTI class (77.8%) followed by PIs (52.6%) and IIs (50%) (p=0.047). There was no statistically significant correlation between serum ARV levels and demographic data, VL, CD4%, adverse event scores, or adherence. Only one dose adjustment was made for subtherapeutic raltegravir levels due to a presumed interaction with ritonavir.
Conclusion: This study does not support routine use of TDM in generally healthy, well-controlled cART-treated HIV-infected children, which is consistent with current DHHS guidelines. A more targeted strategy, such as when adherence is questioned or when there are suspected drug interactions, may be more appropriate.
C. Arneson, None
G. Macdougall, None
D. Louch, None
S. Read, None
A. Bitnun, None
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