Hello. Thank you for writing to us at healthcaremagic You seem to have inflammatory acne. Red, nodular, pustular and painful acne classify as inflammatory acne. Oral antibiotics like Doxycycline, Azithromycin, Minocycline are effective in inflammatory acne because they are antinflammatory as well as antibacterial in action. Repeated courses of oral antibiotics may be required in acne because acne may last for months or even years. Oral antibiotics may continued for weeks or months depending on the severity of acne and response to treatment but in those in whom antibiotics benefit only as long as they are administered, Isotretinoin is a better option. Isotretinoin is a very effective antiacne drug specially in those whose acne is inflammatory and in those in whom acne relapses quickly once oral and topical treatment is stopped. It is specially a favored treatment in those in whom acne is not adequately responding to traditional antiacne treatment Or acne associated with scaring tendancy. Oral retinoids are very safe too, apart from causing minor side effects like dryness of lips and skin. They are however contraindicated in pregnancy and therefore doctors should be more careful with isotretinoin in females of reproductive age group. Regards