There's a lot of factors to add in when asking questions like this.... like age, weight, do you excersize regularly, do you use other drugs, are you male or female, have you eaten, etc.
I wouldn't even consider giving advice on dosage without a little basic info, definitely not reducing harm in any way. I took a 30 mg IR at work around 3:30pm and still was very stimulated around 3:30 Am.
So figuring fuck it, I'm up tonight I snorted another 30 and ate another (60 MG's total redose). Coming on very beautifully, pretty stoned as well lol. I'm very experienced with amps and all other drugs, a guy, in my late twenties, about 5'7" 160lbs, smoke cigarettes & weed daily, excersize every so often, haven't eaten since 2:30 pm, & definitely wouldn't recommend a high dose like this 'til you get a feel for what you're in for. I wouldn't exceed 30 personally...