Thiazine, Antibiotic, Bilirubin Adducts

Abstract

1. Electron charge transfer interactions of some phenothiazine derivatives with aminoglycoside antibiotics, β-lactams and penicillin-related antibiotics and bilirubin were investigated with alternating current titrations.

2. Neither the β-lactams nor penicillin-related drugs interacted.

3. However, the aminoglycoside antibiotics formed complexes with the phenothiazines.

4. Tobramycin and gentamicin each formed 1 :2 adducts with carbenicillin.

5. The phenothiazines interacted with bilirubin forming concentration-dependent micellar adducts which were exciplexes. This may explain the appearance of xanthomata in patients medicated with phenothiazines.