So I have pretty moderate acne and I was prescribed Tretinoin (.05%) and Aczone (5%). I was advised to use the Aczone twice a day and Aczone on top of tretinoin every night. Ive been doing some research about the combination of the two medications and I've seen varying different answers, some say use Aczone on top of Tretinoin but others say use Tretinoin on top of Aczone so Im not sure what to do. Im also unsure of when/how to incorporate my moisturizer in this process. My dermatologist suggested Aczone on top of Tretinoin so that is what I did tonight (my first time using it). Please let me know the best possible combination of these two medications and also when/how to use my moisturizer. Thank you!
I also have the same combo, along with Bactrim orally twice a day (but only for 2 months--this stuff is strong and I think not great in the long term). My routine:
Morning: just the Aczone (dapzone)--only a pea-sized amount. Also a TINY bit of spot treatment if I feel that the spreading the pea-sized amount didn't get to everything. I wait about 30 minutes and then I put on a heavy moisturizer (I live in a midwest climate that causes dry skin). Some moisturizers that work for me and don't make me break out are Aveeno Skin Relief moisture repair and Pond's dry skin cream. They both go on REALLY thick though, so if you have oily skin you might want something lighter like Cetaphil.
Night: Wash face with a benzoyl peroxide wash 2.5% (dime-sized amount). My doc recommended 5% but like i said earlier, I suffer from dry skin on the regular. i would recommend staying away from the 10% bp wash for at least the first 3 months of topical meds to avoid irritation. After my shower, I do the pea-sized amount of retin-a (tretinoin). Wait at least 30 min for it to fully absorb. Then do the aczone, then after at least 30 minutes you must moisturize. If I'm very dry I'll do rosehip oil before moisturizing.
I'm a life-long acne sufferer (currently 30 yrs old)--on and off with different meds, natural remedies, diet, etc. I've been through clear years and not-so-clear years, and I really think stress is the major culprit. And diet to a certain extent (although technically not officially proven, but those of us who have tried the dairy-free/gluten-free lifestyle know what works for us).This is the first time I'm using this combo, and after 5 weeks I am seeing great results. But I will say that you can totally avoid a bad purge if you moisturize heavily and avoid slathering everything on at once.
I just want to update here--the purge definitely happened 
but it occurred at 8 weeks. I was very surprised because in the past I purged much earlier, so I thought I could truly avoid it. But the purge was somewhat controlled--i think because of the dapsone and good moisturizing. I'm at week eleven and my face is definitely looking clearer--I'm hoping by week 13 I'll be zit free. I've read that week 16 is the true test with this medication combo.