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.
The half-life of a drug is the time it takes your body to metabolize and excrete the medication, so that half of it is removed from your body. Generally speaking, it takes five half-lives to fully eliminate a drug from your blood or urine. Flexeril has a half-life of 18 hours. The drug stays active for about 5 half-lives. Therefore, the time to metabolise will be 5 times 18 hours. So it will take 90 hours before nearly all of it is out of your system. This equates to 3.75 days for it to clear out of your body completely. This half-life time can vary from person to person, and will depend on how much of a dosage was ingested, and both the personâs weight and metabolism.