frameshift mutation / frame-shift mutation; frameshift. A frameshift mutation is a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read. A DNA sequence is a chain of many smaller molecules called nucleotides.
As for Flexeril (cyclobenzaprine) is is not a controlled substance under US, Canadian, or international law. Some drugs used as muscle relaxants ARE controlled substances like Valium and many US states and countries have listed Soma (carisoprodol) as a controlled substance (or prohibited it).
How and When Flexeril is Taken (and Not Taken) As with any medication take Flexeril or cyclobenzaprine according to your doctor's or pharmacist's instructions. It's meant to be used for about 2-3 weeks, i.e. not for the long term. Generally, Flexeril or cyclobenzaprine is taken three times per day in tablet form.