title: A direct HPLC method to estimate streptomycin and its putative ototoxic derivative, streptidine, in blood serum: application to streptomycin-treated humans.
abstract: Streptomycin is an aminoglycoside antibiotic with a well-known antituberculosis activity; it is commonly used in clinical practice because it is effective and cheap. However, streptomycin has severe ototoxic effects. The delayed and gradual onset may suggest that a metabolic derivative of the antibiotic could be a potential contributor to ototoxicity. As in a rat experimental model this compound was found to be streptidine, we investigated whether this ototoxic metabolite was also present in the blood of streptomycin-treated patients. To this end, we implemented and optimized a direct reverse-phase HPLC technique to identify and estimate streptomycin and streptidine in serum of streptomycin-treated patients. All criteria for validation of the method were implemented in standard curves in serum of healthy non-treated volunteers by addition of increasing concentration of both compounds and their determination in a trichloroacetic acid deproteinized extract. We found that recovery of streptomycin or streptidine was > or =91.5%. Linearity was r(2)> or =0.99. The intraday and interday precisions were < or =9.7 and < or =10.6%, respectively. The relative intraday and interday error ranged from -9.0 to 8.3% for both compounds in human serum. Studies in patients included five male individuals treated from 35 to 90 days with 1g/day of streptomycin, presenting inner ear malfunction from mild to severe, in whose serum streptidine was always present, and could be successfully separated from streptomycin. Therefore, the validated method used can be a valuable tool to measure and follow these compounds in serum of streptomycin-treated patients.
authors.affiliation: Departamento de Neurociencias. Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Apdo. Postal 70-253, 04510 México D.F., Mexico.
authors.forename: Omar
authors.initials: O
authors.lastname: Granados
authors.forename: Graciela
authors.initials: G
authors.lastname: Meza
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000097:blood*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D016903:Drug Monitoring / Q000379:methods; D006146:Guanidines / Q000009:adverse effects / Q000097:blood* / Q000378:metabolism; D006595:Hexosamines / Q000009:adverse effects / Q000097:blood* / Q000378:metabolism; D006801:Humans; D007759:Labyrinth Diseases / Q000097:blood* / Q000139:chemically induced; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013307:Streptomycin / Q000009:adverse effects / Q000097:blood* / Q000378:metabolism; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D006146:Guanidines; D006595:Hexosamines; C005733:streptidine; D013307:Streptomycin