This code system http://hl7.org/fhir/medication-admin-status defines the following codes:

CodeDisplayDefinition
in-progressIn ProgressThe administration has started but has not yet completed.
on-holdOn HoldActions implied by the administration have been temporarily halted, but are expected to continue later. May also be called "suspended".
completedCompletedAll actions that are implied by the administration have occurred.
entered-in-errorEntered in ErrorThe administration was entered in error and therefore nullified.
stoppedStoppedActions implied by the administration have been permanently halted, before all of them occurred.
unknownUnknownThe authoring system does not know which of the status values currently applies for this request. Note: This concept is not to be used for "other" - one of the listed statuses is presumed to apply, it's just not known which one.