Urine levels of rifampicin & isoniazid in asymptomatic HIV-positive individuals.
OBJECTIVE
AIDS and its associated gastrointestinal complications may impair the absorption of anti-tuberculosis (TB) drugs. Impaired absorption of anti-TB drugs could lead to low drug exposure, which might contribute to acquired drug resistance and reduced effectiveness of anti-TB treatment. The aim of this study was to obtain information on the status of absorption of rifampicin (RMP) and isoniazid (INH) in asymptomatic HIV- positive individuals, who are less immunocompromised. The D-xylose absorption test was also carried out to assess the absorptive capacity of intestive.


METHODS
The absorption of RMP, INH and D-xylose was studied in 15 asymptomatic HIV-positive individuals with CD4 cell counts>350 cells/mm3 and 16 healthy volunteers, after oral administration of single doses of RMP (450 mg), INH (300 mg) and D-xylose (5 g). Urine was collected up to 8 h after drug administration. Percentage dose of the drugs and their metabolites and D-xylose excreted in urine were calculated.


RESULTS
A significant reduction in the urinary excretion of INH and D-xylose in HIV-positive persons compared to healthy volunteers was observed. The per cent dose of RMP and its metabolite, desacetyl RMP was also lower in HIV-positive persons compared to healthy volunteers, but this difference was not statistically significant.


CONCLUSIONS
Decreased urinary excretion of D-xylose and INH are suggestive of intestinal malabsorption in HIV-positive individuals. HIV infection could cause malabsorption of anti-TB drugs even at an early stage of the disease. The clinical implications of these findings need to be confirmed in larger studies.
Ramachandran
Geetha
G
Tuberculosis Research Centre (ICMR), Chennai, India.
Hemanth Kumar
A K
AK
Sarala
K
K
Padmapriyadarsini
C
C
Anitha
S
S
Tharani
C B
CB
Kumaraswami
V
V
Swaminathan
Soumya
S
D000328:Adult; D000995:Antitubercular Agents / Q000652:urine*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D004334:Drug Administration Schedule; D004351:Drug Resistance; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy*; D006679:HIV Seropositivity; D006801:Humans; D016867:Immunocompromised Host; D007538:Isoniazid / Q000652:urine*; D008875:Middle Aged; D008954:Models, Biological; D012293:Rifampin / Q000652:urine*; D014376:Tuberculosis / Q000150:complications* / Q000188:drug therapy*; D014994:Xylose / Q000737:chemistry
D000995:Antitubercular Agents; D014994:Xylose; D007538:Isoniazid; D012293:Rifampin