Undernutrition and tetracycline half life.

The plasma half life of tetracycline hydrochloride was determined in groups of well-nourished and undernourished subjects employing two dosage schedules and two routes of administration, namely oral and parenteral. Protein binding of the drug was estimated and relative volume distribution was calculated. The results indicated that in undernourished subjects, the half life of tetracycline hydrochloride, protein binding and relative volume distribution were all significantly low as compared to well-nourished subjects. The elimination rate was considerably higher in the undernourished groups, which accounted for the shorter half life. These data suggest that to maintain adequate serum concentrations of the drug in undernourished subjects, tetracycline needs to be given at more frequent intervals.