Common Oral Treatments for Acne
Oral treatments are usually considered when acne is moderate to severe, there is acne scarring, significant psychosocial impact, or failure to respond to topical therapies. Systemic therapy should ideally be combined with topical therapy for maximum efficacy. Commonly used oral medications include antibiotics, hormonal therapy, as well as oral isotretinoin.
Oral antibiotics are the initial choice for the management of moderate to severe inflammatory acne. Commonly used antibiotics include tetracycline class antibiotics (e.g doxycycline, minocycline, tetracycline), clindamycin, and erythromycin. Acne is not a classical bacterial infection and antibiotics used for treatment act largely through effects independent of their antibacterial actions. Tetracycline antibiotics improve acne via their anti-inflammatory properties by reducing pro-inflammatory mediators ( e.g. TNF-a, IL-1, IL-6). Antibiotics also inhibit the growth of C. acnes within the pilosebaceous unit.
Antibiotics need to be taken for a minimum two months, and are usually continued until there is no further improvement for at least six months. Most antibiotics need to be taken for a month before improvement of acne severity is seen.
Tetracycline class antibiotics can sometimes cause gastrointestinal distress ( bloating, heartburn, nausea), it is advisable to take your medication with a full glass of water and with meals. Some patients may also have some sun-sensitivity, sun-protective behaviour is advised with taking these medications.
Hormonal therapy is typically given as a component of a therapeutic regimen that combines other acne therapies with a hormonal agent.
Androgens are an important contributing factor to the formation of acne. They promote excess sebum production from the sebaceous glands. The accumulation of sebum and keratinous material in the pilosebaceous follicles leads to obstruction, resulting in comedone formation. Sebum also acts as a growth medium for C. acnes bacterium which contribute to the inflammatory acne. Most patients with acne have normal serum (blood levels) androgens. It is proposed that the increased sensitivity of sebaceous glands to androgens as the mechanism for acne development. The goal of hormonal therapy is thus to minimize acne via the reduction of androgen action on the pilosebaceous unit.
Oral contraceptives can help female patients who have acne. Oestrogens in the pill supress sebaceous gland activity and decrease formation of ovarian and adrenal androgens. They may also be combined with an androgen blocker cyproterone ( e.g. Dianette 35/ Estelle 35). It usually takes 3-4 months for the benefits to show. In addition, the pills are useful as a contraceptive.
Common side effects of the pill include nausea, cyclical weight gain, breast tenderness, mood swings, increased risk of blood clots. The pill may not be suitable for you if are a smoker > 35 years old, have high blood pressure, heart disease, migraines, and have a personal or family history of blood clots.
The mini-pill (progesterone only pill) does not contain oestrogen and may worsen acne, you should avoid this preparation and switch to the pill if you have no contraindications to oestrogen-containing preparations.
Spironolactone is an androgen receptor blocker that can be used for acne treatment in female patients. The drug competitively inhibits binding of androgens to androgen receptors. This medication is often given in conjunction with an oral contraceptive as the drug may cause irregular menstrual periods. As with other hormonal therapies, response may take up to 3 months of continuous treatment before benefit is seen. After starting spironolactone, it may be advisable to do a blood test to monitor potassium levels in the blood.
Hormonal therapies are unsuitable for male patients as their mainstay of action is mostly anti-androgenic ( male hormones including testosterone).
Isotretinoin is a synthetic vitamin A analogue that is a powerful highly effective treatment for acne. It is usually indicated when there is nodulocystic acne, moderate to severe recalcitrant acne, severe scarring, and psychosocial distress due to acne. It is the only treatment that has effect on all major pathogenic factors involved in acne. Isotretinoin decreases the size and secretion of sebaceous glands, normalises follicular keratinization preventing comedone formation, inhibits C. acnes growth, and has anti-inflammatory effects.
A course of isotretinoin is calculated based on body weight. The course duration depends on the maximum tolerated daily dose and can last from 4 months up to 2 years. It is a fat soluble medication. Hence, absorption is best when taken with food. You may experience an early flare of acne within the first month of starting isotretinoin, but this usually improves with continued treatment. Due to its potential effect on serum cholesterol and liver enzymes, most patients should have a pre-treatment blood test as well as one 6-8 weeks after treatment for monitoring. Heavy alcohol intake should also be avoided when on treatment.
Common side effects of isotretinoin include dry eyes (resulting in blepharoconjunctivitis), dry lips cheilitis(dry lips), xerosis(dry skin) causing skin irritation, nosebleeds, and photosensitivity. These side effects are usually dose dependent, and can by managed with moisturisers and lip salves. Some patients may experience difficulties wearing contact lenses due to eye dryness, you may need switch to glasses when on treatment. There are also concerns that isotretinoin may affect your mood, but acne itself often makes people feel depressed. The link between isotretinoin treatment and depression is still controversial.
Isotretinoin is teratogenic (can harm an unborn child), women undergoing treatment need to be on at least one form of contraception. If you have been sexually active, your doctor may suggest a pregnancy test before embarking on a course of treatment. Pregnancy is only advised > 5 weeks after the cessation of treatment.
It should be emphasised that many patients have benefitted from the effectiveness of isotretinoin for acne treatment without serious side effects.