How oral retinoid drugs can be used to treat acne

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.

Advantages:

1) Reduces sebum secretion
2) Reducescomedone formation
3) Reduces incidence of propionibacterium or P. acnes infection
4) has anti-inflammatory properties

Indications:

1) Patients with severe acne that resists treatment with combined oral and topical therapy
2) Mild or moderate acne which is resistant to long-term oral or topical treatment
3) In acne cases where there are severe scarring and psychological problems.

Absolute Contraindications:

1) pregnancy
2) lactation
3) people with hepatic
4) people with renal disorders

Mechanism of action:

Isotretinoin acts in four ways.

1) It reduces the size and secretions of the sebaceous glands
2) It inhibits the growth of P. acnes
3) It is anti-inflammatory
4) It prevents formation of comedones by preventing the proliferation and differentiation of the follicular keratinocytes, thus preventing blockage of hair follicles.

Thus Isoretinoin affects all four pathogenic factors of acne and is the only drug that does so. This explains its nearly universal efficacy during active therapy and the only treatment that can lead to permanent remission.

Prognosis:

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 with worse prognosis include:

1) Patients younger than 16 years
2) Patients with severe acne on the trunk
3) Adult women These first two groups may require multiple courses of isotretinoin over the duration of their acne prone years.

Relapses:

- 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 months.

Side effects

The two most important side effects are isotretinoin teratogenecity (i.e. capable of causing congenital deformities in pregnant women) and psychological effects.

1) Teratogenicity: Isotretinoin is a potent teratogen and abnormalities have been reported after a single dose.. In pregnancies affected by isotretinoin, 50% end up as spontaneous abortions and 25% have neonatal cardiovascular or bone related abnormalities. 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.

2) Psychological effects: Psychological disorders like depression, irritability and suicidal tendencies have been reported during and after isotretinoin therapy. The psychological status of the patient should be monitored carefully. and the patient should have physicians and counselors at hand for immediate help should such effects occur. These disorders tend to disappear after stoppage of treatment, but recur with the resumption of treatment.

3) Mucocutaneous side effects are most common. These include dryness of the lips (100%), dry skin (50%), nasal passages (30-35%) and dry eyes (20%). To cure dryness moisturizers and lip balms are used.

4) Other side effects: The drug has serious opthamalogic and gastro-intestinal side effects. It can also cause hypertriglyceridemia and to a lesser extent affect cholesterol levels (i.e. increase fat content in blood).

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.