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.
Responses (4) Fexeril is a muscle relaxer & my doc prescribes it twice a day, but it doesn't always last that long. My hubby takes it too, & he can take it every 6 hours if needed. It usualyy takes a good 20 to 30 minutes to get going in your system where your muscles spasms will relax a bit, also put a heating pad where you are having th spasms. Pleas read the link below... https://www.drugs.com/flexeril.html.