When to add oral antibiotics
When topical treatment does not produce the desired result or cannot be tolerated, oral antibiotics may be introduced, either as an addition or replacement. Like topicals, oral antibiotics have both antimicrobial and anti-inflammatory properties.
Tetracycline antibiotics (ie, doxycycline and minocycline) are first-line oral therapy.21 Minocycline has been found to be the most potent agent in this drug class; tetracycline is the least.22 Tetracyclines can cause tooth discoloration and inhibit skeletal growth, and are contraindicated for children younger than 10 years and pregnant women.
Photosensitivity is an adverse effect of tetracycline antibiotics, so patients should be advised to cover up and avoid sun exposure. Other adverse effects, particularly of minocycline, include dizziness, lupus-like syndrome, pseudotumor cerebri, skin and mucosal pigmentation, serum sickness, and hepatitis. If the patient is taking an oral contraceptive pill (OCP) concurrently for family planning, she should be advised that oral antibiotics have the potential to reduce the efficacy of the OCP.
Other oral antibiotics sometimes used to treat acne include erythromycin, trimethoprim-sulfamethoxazole, amoxicillin, and azithromycin, but data on their efficacy are limited. Erythromycin has similar potency to tetracycline, but may need to be taken 2 to 4 times a day and may cause more gastrointestinal disturbances. Cephalosporins, fluoroquinolones, aminoglycosides, chloramphenicol, sulfonamides/sulfur, and gyrase inhibitors should not be used for acne because of a lack of efficacy.6
Diagnostic challenge: Is it acne?
No, it isn’t. Pustules on the face, like those on the patient pictured here, are a common manifestation of acne. But facial lesions alone are not sufficient for a definitive diagnosis. In fact, the pustules that this 59-year-old woman sought treatment for were correctly diagnosed as perioral dermatitis. The tip-off? The lack of comedones and the distribution of the lesions, which were concentrated around the mouth.
Regardless of the type of oral antibiotic prescribed, it should be tried for about 3 months (8-16 weeks) and discontinued once improvement occurs. If no improvement is seen within 3 months, consider changing antibiotics due to resistance or adding antifungal therapy for Pityrosporum and Malassezia species.6
Initiating isotretinoin therapy: An evidence-based approach
Oral isotretinoin is the only potential cure for acne vulgaris. The cure rate is about 30% to 40% (with about 20% of patients developing a recurrence that requires retreatment within one to 3 years).25
Isotretinoin is FDA approved for severe nodulocystic acne, but several organizations, including the AAD and the Global Alliance to Improve Outcomes in Acne, recommend its use for milder cases.25,26 It is also an excellent treatment for other forms of severe acne, such as acne fulminans and acne conglobata. Accutane is no longer available, but 5 other formulations of isotretinoin are on the market.
Because isotretinoin is a category X teratogen, all providers and patients must register with iPLEDGE (www.ipledgeprogram.com), an FDA-approved mandatory risk management program. Before starting to take isotretinoin, females of childbearing age are required to undergo 2 pregnancy tests; they must also agree to use 2 forms of program-approved birth control and submit to monthly pregnancy tests.
Patients on isotretinoin also need to be monitored for depression.27 Other potential adverse effects include hepatitis, hypertriglyceridemia, arthralgia, myalgias, and inflammatory bowel disease.28,29 Dry skin and mucosa are the most common adverse effects, and patients should be advised to use moisturizers regularly.
A better dosing regimen?
The standard starting dose of isotretinoin is 0.25 to 1 mg/kg/d, divided and taken twice a day, then titrated upward monthly to a maximum daily dose of 2 mg/kg. The goal is for the total intake of isotretinoin to be 120 to 150 mg/kg. So, for example, the goal for a patient weighing 60 kg might be a cumulative intake of 7200 mg (120 mg/kg × 60 kg), taken in doses of 20 mg BID (40 mg/d) for 180 days.
The medication should be taken with food (especially with fatty food) for better absorption. Treatment duration has typically been 16 to 32 weeks, with an average of 20 weeks, with the daily dose lowered in patients requiring treatment for a longer period of time. Continuous use of isotretinoin is more effective than taking it intermittently.26
Lower dosages? While that standard regimen has been adequate in the management of acne vulgaris, emerging evidence suggests that dosages of isotretinoin as low as 5 mg/d are equally effective and have significantly fewer adverse effects.30 Relapse continues to be a problem. Risk factors for relapse include a macrocomedonal pattern of acne, smoking, and age, with patients <14 years and >25 years at higher risk.30 While lower dosing was previously thought to be associated with greater risk of relapse, this appears to be related less to the cumulative dose of 120 to 150 mg/kg and more to the duration of sebaceous gland suppression.30