DMPS question

HI ... My doctor wants me to do one dose 250mg of DMPS once every month... is this ok. if not what dose should I suggest? I have heard 50mg every eight hours, but for how long? three days? and then what is the brake time. Also should I start with a lower dose and work up? I have done 4 rounds of dmsa at 12.5mg and then went to 16mg with ALA, but he says DMPS has worked better for his patients and wants me to go for the DMPS. He is open to any suggenstions and will work with me. He wants to doa 250mg DMPS urine challange... is this ok?

thank you,
healing