Hyperkalemia is a common side effect of these medications. GI disturbances, including nausea, vomiting, diarrhea, anorexia can occur. Triamterene and spironolactone have been known to cause impotence and sexual dysfunction. Spironolactone may precipitate gynecomastia or an SLE-like syndrome.
Flexeril has a half life of 18 hours. So 5x18 is 90 hours. Or just under 4 days. Of course, it is not that easy. This varies on how much and how long the drug was taken and it can vary from person to person. That being said I cannot image any way that flexeril would be detectable 30 days after the last dose.
Flexeril, a generic variety of the medication cyclobenzaprine, is a muscle relaxer that is usually prescribed for the short-term relief of muscle spasms. Flexeril is also sometimes used for long-term conditions such as chronic fatigue syndrome and fibromyalgia. Flexeril users commonly experience drowsiness, fatigue, nausea, muscle weakness, dry throat or mouth, appetite loss, diarrhea and gas while taking the medication.