Final answer:
The phlebotomist should draw the blood at 1200, which is one hour after the physician ordered the Tobramycin to be administered at 1100.
Step-by-step explanation:
The correct action the phlebotomist should take if a physician ordered a Tobramycin level to be drawn one hour after the dose, which has been ordered for 1100, is to draw the blood one hour after the medication has been administered. Therefore, the phlebotomist would need to draw the blood at 1200, not at the time the medication is ordered to be given (1100). It is important for the accuracy of the pharmacokinetic measurement that the sample is taken at the specific post-dosage time requested by the physician. If there is confusion or a discrepancy in orders, the phlebotomist may need to check with the nurse caring for the patient or contact the laboratory for clarification before proceeding.