Baclofen
"Last time I had really bad cramps, several months ago, doctor prescribed 10mg, 3 x's a day, for 10 days. I remembered I was a 'low doser' so I took only half a tablet for 6 days. Result was wonderful! Spasms in diaphragm, bilateral waistline, bilateral buttocks, back, shoulders, neck, hands, legs, feet, lowest abdomen, all ceased and desisted in two and a half days. This time, a couple of days ago, I called for a new prescription and then forgot to take half a pill--took a whole 10mg, 3x's a day for two days, as prescribed, and got treated to a whole bunch of weird side effects--intense sleepiness, hallucinations, very shallow breathing, edema, but no cessation of spasms and pain.  So now I'll wait several days and try half a pill again."