<unk>  (CDR) is a medical testing protocol in which a medicine or drug is administered, withdrawn, then re-administered, while being monitored for adverse effects at each stage. The protocol is used when statistical testing is inappropriate due to an idiosyncratic reaction by a specific individual, or a lack of sufficient test subjects and unit of analysis is the individual. During the<unk>  (withdrawal) phase, the medication is allowed to wash out of the system in order to determine what effect the medication is having on an individual.
Challenge–dechallenge–rechallenge
Allergy test
Benadryl challenge
Patch test
Skin allergy test
Booster dose
Immunoadsorption
Freeze spray