HIV Drug Resistance (HIVDR) in Antiretroviral Therapy-Naïve Patients in Tanzania Not Eligible for WHO Threshold HIVDR Survey Is Dramatically High

The World Health Organization (WHO) has recommended guidelines for a HIV drug resistance (HIVDR) survey for resource-limited countries. Eligibility criteria for patients include age below 25 years in order to focus on the prevalence of transmitted HIVDR (tHIVDR) in newly-infected individuals. Most of the participating sites across Africa have so far reported tHIVDR prevalences of below 5%. In this study we investigated whether the rate of HIVDR in patients <25 years is representative for HIVDR in the rest of the therapy-naïve population. HIVDR was determined in 88 sequentially enrolled ART-naïve patients from Mwanza, Tanzania (mean age 35.4 years). Twenty patients were aged <25 years and 68 patients were aged 25-63 years. The frequency of HIVDR in the study population was 14.8% (95%; CI 0.072-0.223) and independent of NVP-resistance induced by prevention of mother-to-child transmission programs. Patients >25 years had a significantly higher HIVDR frequency than younger patients (19.1%; 95% CI 0.095-0.28) versus 0%, P = 0.0344). In 2 out of the 16 patients with HIVDR we found traces of antiretrovirals (ARVs) in plasma. ART-naïve patients aged over 25 years exhibited significantly higher HIVDR than younger patients. Detection of traces of ARVs in individuals with HIVDR suggests that besides transmission, undisclosed misuse of ARVs may constitute a significant factor in the generation of the observed high HIVDR rate. The current WHO tHIVDR survey that is solely focused on the transmission of HIVDR and that excludes patients over 25 years of age may therefore result in substantial underestimation of the prevalence of HIVDR in the therapy-naïve population. Similar studies should be performed also in other areas to test whether the so far reported optimistic picture of low HIVDR prevalence in young individuals is really representative for the rest of the ART-naïve HIV-infected population

Pharmacokinetics of chewed vs. swallowed raltegravir in a patient with AIDS and MAI infection: some new conflicting data

Background: While HIV, AIDS and atypical Mycobacterium infections are closely linked, the use of Integrase-Inhibitor based cART, notably raltegravir-based regimens is more widespread. RAL should be double-dosed to 800 mg semi-daily in situation of rifampicin co-medication, because RAL is more rapidly metabolized due to rifampicin-induced Uridine-5'-diphosph-gluronosyl-transferase (UGT1A1). Recently, it was speculated that chewed RAL might lead to increased absorption, which might compensate the inductive effect of rifampicin-rapid metabolized RAL, as part of cost-saving effects in countries with high-tuberculosis prevalence and less economic power. Methods: We report measurement of raltegravir pharmacokinetics in a 34-year AIDS-patient suffering from disseminated Mycobacterium avium infection with necessity of parenteral rifampicin treatment. RAL levels were measured with HPLC (internal standard: carbamazepine, LLQ 11 ng/ml, validation with Valistat 2.0 program (Arvecon, Germany)). For statistical analysis, a two-sided Wilcoxon signed rank test for paired samples was used. Results: High intra-personal variability in raltegravir serum levels was seen. Comparable C$_{max}$ concentrations were found for 800 mg chewed and swallowed RAL, as well as for 400 mg chewed and swallowed RAL. While C$_{max}$ seems to be more dependent from overall RAL dosing than from swallowed or chewed tablets, increased AUC(12) is clearly linked to higher RAL dosages per administration. Anyway, chewed raltegravir showed a rapid decrease in serum levels. Conclusions: We found no evidence that chewed 400 mg semi-daily raltegravir in rifampicin co-medication leads to optimized pharmacokinetics. There is need for more data from randomized trials for further recommendations