Severe acne usually indicates the necessity of prescription medication to treat the pimples. Prescription medications used to treat acne and pimples include isotretinoin , which is a retinoid . Historically, antibiotics such as tetracyclines and erythromycin were prescribed. While they were more effective than topical applications of benzoyl peroxide, the bacteria eventually grew resistant to the antibiotics and the treatments became less and less effective. Also, antibiotics had more side effects than topical applications, such as stomach cramps and severe discoloration of teeth. Common antibiotics prescribed by dermatologists include doxycycline and minocycline.  For more severe cases of acne dermatologists might recommend accutane , a retinoid that is the most potent of acne treatments. However, accutane can cause various side effects including vomiting, diarrhea, and birth defects if taken during pregnancy.
For large cysts that don’t respond to other treatments, a drug called isotretinoin may be prescribed. This treatment reduces the size of the oil glands and is very effective, resulting in permanent improvement in about 85 percent of people with severe acne. However, it is also riskier because it can cause potentially severe side effects, including liver problems and severe depression . Due to the risk to the fetus, women must avoid becoming pregnant during and immediately after treatment. Therapy usually lasts 4-5 months. Patients should follow up regularly with their dermatologists during this time.