Can you take a muscle relaxer and pass a drug test?

If you have a Rx, it won't be a problem even if it is drug tested for or you come up positive from it. Generally No (most don't include controlled substances ) but sometimes benzodiazepines (schedule IV controlled substance) like Valium (diazepam), Ativan (lorazepam), Rivotril (clonazepam), Klonopin are used as muscle relaxers and you may be tested for/ fail positive (depend on the test panels - 5 panel drug test or some 8,10, 12 panel test).