Very little is known about drug kinetics in pinnipeds.  At the California Marine Mammal Center we have begun examining the kinetics of selected therapeutic drugs.

Theophylline is used frequently in the treatment of respiratory distress in neonatal animals at CMMC.  It has a low therapeutic index.  We have seen toxic effects which were found to be associated with higher than predicted serum levels.  Therefore theophylline was selected as the first drug to be evaluated.

The purpose of this study was to determine the bioavailability, half-life, alpha and beta elimination rates, peak serum level, and the apparent volume of distribution in harbor seal pups.

Four clinically normal harbor seal (Phoca vitulina) pups were used in this study. Blood was drawn for a CBC, SMA-18, SGPT, and GGT, to evaluate their liver and kidney status. All the pups were five to six months old.

Oral theophylline was given.  Timed blood samples were drawn.  The serum drug levels were determined using high-pressure liquid chromatography.

The results of this study will be discussed.  Our study of theophylline kinetics in neonatal harbor seals (if completed), and the status of other drug studies will be presented.