May block epinephrine ... Bradycardia with catecholamine-depleting drugs. Antagonized by NSAIDs, barbiturates, rifampin, phenytoin. May increase cardiac effects of calcium channel blockers ...

Stimulants - these banned substances, such as caffeine, cocaine, amphetamines and ephedrine, can increase ... drugs help a performer to keep calm by blocking the effect of the hormone adrenaline.