Reference no: EM132441439

A therapeutic dose for a human of 0.4 µg/kg body weight results in a plasma concentration of 0.300 µg/L. Cattle may be given up to 5 mg/kg body weight. Pharmacokinetics are unknown for this dosage, but one study found 1% of clenbuterol was retained in muscle tissue 48 hours after this dose. Phil was found to have a plasma concentration of 57 pg/mL on the first day he tested positive, 34 pg/mL the following day, and 29 pg/mL the third day which was final day of Tour of Austria.

Step 1: Clenbuterol is used illegally in livestock. Estimated dosages for the anabolic effect in livestock are low, in the range of mg/kg body weight (1 to 5 mg/kg body weight). It is likely the final dose is several days to two weeks before slaughter, but two days is a reasonable starting point. Calculate the amount present per kg of muscle after two days.

Step 2: How much does a hamburger weigh? If Phil ate a Quarter Pounder from McDonald's, about how many grams of meat is this? How much clenbuterol would Phil have ingested in this amount of meat?