Table 1

Search terms used for the literature research

CaffeineTheophylline
Caffeine horseTheophylline horse
Caffeine horse urineTheophylline horse doping
Caffeine horse serumTheophylline horse urine
Caffeine horse pharmacokineticsTheophylline horse plasma
Caffeine horse intoxicationTheophylline feed horse
Caffeine horse feedTheophylline intoxication horse
Caffeine horse dopingTheophylline horse pharmacokinetics
Koffein pferdTheophyllin pferd