Both doxycycline and minocycline are oral types of antibiotics. They act on the P. acne bacteria that cause inflammatory acne. They also do have anti-inflammation properties and are helpful in reducing the inflamed papules and cysts of acne.
Tretinoin is a vitamin D analogue. This is in the active ingredient in creams such as Retin-A and Retacnyl. The main action of tretinoin is its comedolytic action, ie. it is good for clearance of comedones like blackheads and whiteheads.
5 Fluorouracil is a cream that is often used for the treatment of actinic keratosis. It is not usually indicated for acne treatment.
