Dear Colleagues,
I have an MRO question and would appreciate some feedback:
Someone came in for a pre-placement physical (in a patient care role) and the drug screen came back positive for phenobarbital. She denies use of any barbiturate and none of the medications that she is on should cause a positive barbiturate
screen. However, she called me back a day later to say that she had a colonoscopy on 9/9 and her gastroenterologist told her that might have caused the positive test. The drug test was done 20 days after the colonoscopy on 9/29 and as far as I know, you
don’t typically get a barbiturate during a colonoscopy.
I asked her to have the anesthesiologist’s report sent to me so I could see what was administered.
The t ½ of phenobarbital is 53-140 hours (per Up to Date). Since it takes about 5 half-lives to eliminate something, it could take from 265-700 hours. She had the procedure on 9/9 and the drug test on 9/29 which is 480 hours. So if
she was given phenobarbital during the procedure, it actually might have been in her system.
Has anyone ever dealt with anything like this? What are your thoughts?
Sincerely,
Claudine Holt, MD, MPH
Staff Physician, Occupational Health Services
Temple University Hospital
Basement, Rock Pavilion
215-707-8151 (phone)
215-707-5751 (fax)