context: Are over-the-counter acne products not cutting it? The good news is that there are highly effective medicines for tougher teen acne cases. According to the American Academy of Dermatology, virtually anyone's acne, no matter how severe, can be treated. But the prospect of taking a daily prescription medicine - especially as a teenager -- can raise some concerns for teens and their parents. Will it really work? How long will it be necessary? What are the side effects? Exactly what causes acne? Acne develops when cells and natural oils block tiny hair follicles in the skin. Bacteria work their way into the plugged-up follicles and start multiplying. When the body's immune cells move in to attack the bacteria, the results of the battle are the classic symptoms of acne -- swelling, redness, and pimples. Acne medications help by interrupting this process in different ways. Some over-the-counter and prescription acne creams help by unplugging the follicles. Others, such as antibiotics, kill the bacteria that move into the follicles. The pill isotretinoin reduces oil production, unplugs the follicles, and targets inflammation and acne-causing bacteria. There is no best acne treatment. Some people do fine using one acne product, although many need a combination to control their teen acne. For mild to severe acne, a doctor might recommend prescription treatments that are "topical," which means they go on your skin. These treatments might also be used for more severe acne in combination with other medicines. Topical treatments for teenage acne come in different forms, including creams, lotions, foams, gels and pads. Some types include: Topical antibiotics. These acne medicines can kill some of the bacteria on the skin and reduce redness and inflammation. Examples of antibiotics include clindamycin ( Cleocin T, Clinda- Derm) and erythromycin ( Dapsone gel, Erythrocin). Topical retinoids. Retinoid creams are made from vitamin A. They work by unplugging the follicles, which also allows other medicines like topical antibiotics to work better. Examples include adapalene ( Differin), tazarotene ( Tazorac), and tretinoin ( Avita, Retin- A), and Other topical medicines. Some of the medicines that you can find over the counter are available in more potent forms by prescription. These include azelaic acid, benzoyl peroxide, and sulfur-based treatments. They help by reducing swelling and blocking the growth of bacteria. Some prescription creams include two or more active ingredients. The typical side effects from these treatments are mild and confined to the skin. They include stinging, redness, irritation, and peeling. Retinoid creams can make skin more sensitive to sunlight. So when using these treatments, it's important to limit sun exposure, especially between the hours of 10 a.m. and 2 p.m., and apply sunscreen regularly. Protect exposed skin with a long-sleeved shirt, pants, and a large-brimmed hat. Make sure not to get any topical retinoids in your mouth, nose, or eyes. For moderate to severe cases, a dermatologist might recommend prescription acne medications taken by mouth instead of -- or in addition to -- topical treatments. Here are some of the types used. Oral antibiotics. For more severe teen acne, daily antibiotics can help kill bacteria and reduce swelling. These drugs are typically prescribed for periods of six months or less. Over time, the bacteria may become resistant to a specific antibiotic. When that happens, the doctor may switch to a different drug. The side effects of oral antibiotics depend on the medication, but they can cause problems like upset stomach, dizziness, skin color changes, and sun sensitivity. Tetracycline ( Sumycin) can yellow the teeth and affect bone formation, so it's not recommended for children under 14 or pregnant women. However, the newly approved tetracycline derivative sarecycline ( Almirall, Seysara) can be used in children from age 9 and above and you can take it once daily Doxycycline ( Acticlate, Monodox, Vibra- Tabs, Vibramycin) and minocycline ( Dynacin, Minocin) are also not recommended for children under 14 or pregnant women. Isotretinoin. This is a powerful drug in the retinoid group. It's used for severe or moderate acne that can't be controlled with other treatments. It reduces the amount of oil made by glands in the skin. It also curbs inflammation and reduces clogged hair follicles. Taking it for several months, once or twice a day, can clear most cases of acne. The most common side effects are dryness of the skin, eyes, mouth, lips, and nose. Other side effects include nosebleeds, achiness, diminished night vision, sun sensitivity, and changes in triglyceride levels and liver function. Severe side effects of isotretinoin are very rare. Since it can cause serious birth defects, women should use two different forms of birth control when taking isotretinoin. People using isotretinoin might need periodic blood tests. Many teens and their parents are concerned about the possible psychological effects of isotretinoin. What's the connection? Experts say that there have been a number of people using isotretinoin who had severe depression and attempted suicide. But no one knows whether the medicine was really the cause. The fact is that depression is more common in people with acne, regardless of the treatment. Parents, if you notice that your son or daughter is having mood swings, seeming down or angry, or losing interest in friends or the things that he or she usually enjoys, schedule an appointment with the doctor. Hormonal treatments. Some teen girls have acne that's linked to hormones called androgens. To treat this sort of acne, a doctor might recommend birth control pills or spironolactone ( Aldactone). Side effects of hormonal treatments for acne include irregular periods, tender breasts, headaches, blood clots, high blood pressure, and fatigue. Take the acne treatment as prescribed. It's important to stick to the doctor's acne treatment. Make it a part of the daily routine. Leave the medicine out where you can see it, instead of tucking it away in a medicine cabinet. If it helps, use notes or alarms as reminders. Stop using other acne treatments. If a doctor has prescribed an acne treatment, don't also use other treatments or home remedies. They're unlikely to help and they could even make the acne worse. Stick with it. Acne treatment won't work immediately. It can take six to eight weeks before you see some benefit. It may take as long as six months to clear the skin altogether. Do your part. Follow the doctor's skin care advice, particularly when it comes to cleansing and using moisturizer. Avoid oil-based makeup and hair products, since they can plug up the pores and aggravate acne. And though it can be hard, resist the temptation to pop zits or pick at them - it can lead to infection and scarring. Work with a doctor. If treatment isn't working, don't give up. It may take some time to hit on the right approach. Schedule an appointment with a doctor to discuss other options. Remember: With the right treatment, almost every case of acne can be cured.