Clinical pharmacology of the tetracycline antibiotics

Abstract

Some of the relevant features of the clinical pharmacology of the tetracycline antibiotics are reviewed, and, in particular, the absorption, excretion, and disposition in the body of the four homologues that are currently available for clinical use are compared. The relatively minor differences in the chemical structure of these drugs are accompanied by significant differences in some of their physical properties and by some quantitative differences in their absorption, excretion, and distribution in the body, their activity against different bacteria, and their clinical toxicity.

Quantitation of Antibiotics Using High-Pressure Liquid Chromatography: Tetracycline

“…Six samples of each concentration were extracted separately and determined on the same day. As shown in Table 2, this method had a satisfactory precision in the range of serum concentrations obtained with the doses of tetracycline used in clinical practice (11). At tetracycline concentrations of 2 and 7 ,ug/ml, the variation coefficients were 3.45 and 1.50%, respectively.…”

“…The precision of the method was determined for two concentrations of tetracycline in serum within the therapeutic range, i.e., 2 and 7 ,ug/ml (11). Six samples of each concentration were extracted separately and determined on the same day.…”

Complications of Tetracycline Therapy

“…1,3 Third, the demethyl derivative (Declomycin) has one known disadvantage, photosensitization,6,T and one pos¬ sible one, an increased incidence of anaphylactoid reactions,5 which mitigate against its replacing tetra¬ cycline as the analogue of choice in the group.…”

Interaction between phenytoin and antacids.

“…We cannot say which of the constituents is responsible for the interaction and there are several possible mechanisms. Aluminium ions can chelate tetracyclines (Waisbren & Hueckel, 1950) as can ferrous and magnesium ions (Kunin & Finland, 1961) but in vitro studies with phenytoin have shown that chelate formation does not occur with magnesium, ferrous and calcium ions, although it does with copper (Glazko & Chang, 1972). Aluminium hydroxide and magnesium trisilicate form gels in the gastrointestinal tract and adsorption on the surface of these could explain the reduced phenytoin absorption.…”