Oral isotretinoin, or 13-cis-retinoic acid, is currently the best
oral retinoid and the best drug to combat severe acne. It has
been in use for acne treatment for more than 20 years. It significantly
reduces sebum secretion, comedone formation and propionibacterium
or P. acnes on the skin and it also has anti-inflammatory properties.
Patients with severe acne that resists treatment with combined
oral and topical therapy are the proper subjects for oral isotretinoin
therapy. However, clinical experience has shown that oral isotretinoin
can also be used with success in mild or moderate acne which is
resistant to long-term oral or topical treatment. It can also
be used in acne cases where there are severe scarring and psychological
problems. Isotreinoin should never be used during pregnancy, lactation
and in people with hepatic and renal disorders.
Before starting isotretinoin therapy, the severity of the disease
should be well assessed. The assessment should include the likely
effect of acne on the patient such as the potential for scarring.
Isotretinoin acts in four ways. It reduces the size and secretions
of the sebaceous glands, secondarily it inhibits the growth of
P. acnes and the resulting inflammation, and prevents comedogenesis
through normalization of the differentiation of the follicular
keratinocytes. Isotretinoin thus affects all four pathogenic factors
of acne and is the only drug that does so, revolutionizing the
treatment of severe acne. This explains its nearly universal efficacy
during active therapy. Moreover, it is the only treatment which
can lead to permanent remission.
In isotretinoin therapy the dosage must be decided after considering
the risk factor of the patient. Generally, 50% reduction of pustules
is observed after 2 to 4 weeks of treatment. For the majority
of patients, 6-month treatment duration is enough, but to get
optimal results a low dosage treatment should be continued. Improvement
continues during this post treatment period. Approximately 40%
of patients remain free of acne after one course of treatment,
40% have a recurrence of low severity that responds to medications
to which the acne had been previously been resistant and 20% will
need repeated treatment with isotretinoin at a future time.
Relapses may occur after one six-month treatment course. Patients
younger than 16 years, those with severe acne on the trunk and
adult women are more likely than others to have a relapse. These
first two groups may require multiple courses of isotretinoin
over the duration of their acne prone years. Relapses, requiring
repeated treatment, are higher among patients with severe acne
who receive a low dosage treatment, compared to those receiving
higher dosages of isotretinoin. The chance of a prolonged remission
is greater when a total dose of 120mg to 150mg per kg of body
weight is achieved. Most patients can be started on a dose of
20mg to 40mg per day with an increase to 40mg to 80mg over several
Systemic isotretinoin therapy has numerous side effects. The
two most important ones are related to isotretinoin teratogenecity
and psychological effects.
Isotretinoin is a potent teratogen. In pregnancies affected by
isotretinoin, 50% end up as spontaneous abortions and another
25% have neonatal cardiovascular or bone related abnormalities.
Such abnormalities have been reported after a single dose. Women
of childbearing age should be closely monitored for pregnancy
prevention. They should test negative for pregnancy before starting
treatment and the dermatologist should ensure that they are on
effective contraception 1 month before the start, throughout and
up to 6 weeks after discontinuation of isotretinoin treatment.
The psychological status of the patient should also be monitored
carefully. Psychological disorders like depression, irritability
and suicidal tendencies have been reported during and after
isotretinoin therapy. Although studies have not confirmed any
association between the use of isotretinoin and these psychological
disorders, such events should be expected and the patient should
have physicians and counselors at hand for immediate help. These
disorders tend to disappear after stoppage of treatment, but
recur with the resumption of treatment.
Mucocutaneous side effects are most common. These include dryness
of the lips which affects all isotretinoin users, dry skin affecting
50%, nasal passages affecting 30% to 35% and dry eyes affecting
20%. To cure dryness moisturizers and lip balms are used.
The drug, however, has serious opthamalogic and gastro-intestinal
side effect potential. Isotretinoin may cause hypertriglyceridemia
and to a lesser extent affect cholesterol levels.
Side effects of therapy may be limited with reduced doses or
by dietary changes over an extended period, allowing treatment
to continue. However, reduction of dosage may cause relapse. Most
side effects are tolerable and treatable.