Dec 1, - So she gave me Ampicillin mg twice a day. . be able to afford this and will run out of the first tube I buy before I finish the treatment llin mg and clindamycin topical lotion 1% - Adult acne. Antibiotics are moderately effective for acne and are frequently used for acne treatment. They are often prescribed for months or years, because acne is a Missing: ampicillin | Must include: ampicillin.