acne help!

hey, lately i'm having acne on both sides of my face above the cheeks...they aren't so much but they hurt and they're red ,shall i'm thinking of taking retin A or deffirin but in what dosages?
i also have blackheads on my nose .... as well as lots and lots of pimples on my back that hurt a lot there aren't as much pimples on my face than there are on my back does retin A work on the back as well?? i remember using eretheromicine before but the application is annoying  what shall i do???

[loiloi]

Hi. Synthetic topical retinoids like Differin (adapalene 0.1%) are effective and generally well tolerated. They should be applied once daily before bed as applying retinoids in the daytime can lead to sunburn.
Topical retinoids can also be used on the chest and back, but if you have large areas of acne consider using oral antibiotics instead of or in conjunction with topical treatment. An 8-12 week course of Erythromycin, Lymecycline or Oxytetracycline should clear acne. You may require further courses if your tendency to acne continues.
Hope this is helpful.
Eloise.