Bioavailability of Chinese rifapentine during a clinical trial in Hong Kong.
METHODS
A clinical trial of rifapentine in Hong Kong.


OBJECTIVE
Assessment of the bioavailability of the Chinese rifapentine used in the trial.


METHODS
The content of rifapentine in serum samples taken from 287 patients during the administration of four batches of the drug was measured by microbiological assay.


RESULTS
An initial comparison of areas under curve obtained in a random allocation to 40 patients of rifapentine either of Western or Chinese origin indicated that the bioavailability of the Chinese drug was 74% of the Western drug. The bioavailability of the second batch was found to be about 66% of the Western drug. The dose of the last two batches of rifapentine was therefore increased from the planned 600 mg to 750 mg, or briefly to 900 mg; serum concentrations were then similar to those obtained with the Western drug. Bioavailability did not change during the use of each drug batch.


CONCLUSIONS
A comparison of the results obtained in the trial with the initial two batches and the final batches will estimate the effects of rifapentine dose size on its efficacy and toxicity.
Tam
C M
CM
Hong Kong Department of Health, Wanchai Polyclinic, Hong Kong.
Chan
S L
SL
Lam
C W
CW
Dickinson
J M
JM
Mitchison
D A
DA
D000328:Adult; D000995:Antitubercular Agents / Q000097:blood* / Q000627:therapeutic use; D019540:Area Under Curve; D001682:Biological Availability; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D015195:Drug Design; D004355:Drug Stability; D005260:Female; D006723:Hong Kong; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012293:Rifampin / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D016896:Treatment Outcome; D014376:Tuberculosis / Q000188:drug therapy*
D000995:Antitubercular Agents; D012293:Rifampin; C018421:rifapentine