Arithrazine
From Star Trek : Freedom's Wiki
Arithrazine is a medication used for the most extreme cases of theta radiation poisoning. According to Starfleet Medical protocols, a doctor has to monitor the patient who has received arithrazine during treatment.
When the USS Voyager encountered the Omega molecule in the Delta Quadrant, Captain Janeway went out to destroy the molecule after receiving arithrazine by The Doctor. As he could not monitor her, he initially refused to give the medication, but she overruled him with the Omega Directive. (VOY: "The Omega Directive")