Medicine for acne: Isotretinoin Therapy (2)

Isotretinoin therapy.
Patients are seen frequently during the course of therapy (e.g., every 4 weeks). Isotretinoin is given in two divided doses daily, preferably with meals. Many patients experience a moderate to severe flare of acne during the initial weeks of treatment. This adverse reaction can be minimized by starting at 10 to 20 mg twice each day and gradually increasing the dosage during the first 4 to 6 weeks. Treatment is discontinued at the end of 16 to 20 weeks, and the patient is observed for 2 to 5 months. Those with persistently severe acne may receive a second course of treatment after the posttreatment observation period.
Response to therapy.
At dosages of 1 mg/kg/day, sebum production decreases to approximately 10% of pretreatment values and the sebaceous glands decrease in size. Maximum inhibition is reached by the third or fourth week. Within a week, patients normally notice drying and chapping of facial skin and skin oiliness disappears quickly. These effects persist for an indefinite period when therapy is discontinued.
During the first month, there is usually a reduction in superficial lesions such as papules and pustules. New cysts evolve and disappear quickly. A significant reduction in the number of cysts normally takes at least 8 weeks. Facial lesions respond faster than trunk lesions.
Resistant patients.
Younger patients (14 to 19 years of age) and those who have severe acne relapse more often. [acne relapses more often than facial acne. A return of the reduced sebum excretion rate to within 10% of the pretreatment level is a poor prognostic factor. with microcystic acne (whiteheads) and women with gyneco-endocrinologic problems are resistant to treatment. Women who do not clear after a total cumulative dose of 150 mg/kg need laboratory and clinical evaluation of their endocrinologic status. They may benefit from antiandrogen therapy.
Psychosocial implications.
Patients successfully treated with isotretinoin have significant posttreatment gains in social assertiveness and self-esteem. There is also a significant reduction in anxiety and depression.
Patients with minimal facial acne but with symptoms of dysmorphophobia (inappropriate depression and/or anxiety response to mild acne) are often treated with long-term antibiotic therapy with no perceived improvement. These patients respond to isotretinoin in that they are satisfied with the cosmetic results achieved. The incidence of relapse is greater than that of other acne patients and often requires additional therapy in the form of antibiotics or further isotretinoin.
Laboratory studies.
Pregnancy tests, triglyceride tests, complete blood counts, and liver function tests are performed on patients taking isotretinoin.