I. Imiquimod: A Wonder Drug in Dermatology

What is imiquimod? (Aldara, Zyclara)

Imiquimod is a topical cream with many uses in dermatology. It works by activating the body’s immune system to get rid of pre-cancerous, cancerous, and virally-infected cells.

Imiquimod does not destroy these cells by itself. It focuses the immune cells of the body to locate and destroy the undesirable cells. Cancer cells survive by escaping normal body surveillance mechanisms. Imiquimod allows some of these mechanisms to be restored, stimulates the production of interferon (an important immune mediator), and pushes surveillance cells to attack pre-cancerous, cancerous, and virally-infected cells.

If this sounds like a wonder drug, it most certainly is. Imiquimod has changed many aspects of dermatology practice. Besides being an effective anti-wart treatment, it allows treatment of some skin cancers (basal and squamous cell carcinomas) without surgery.

Does imiquimod work for warts?

Imiquimod is currently approved for treatment of genital warts, but not warts on other parts of the body. This does not mean that it only works for warts on the genitals. In fact, I have been using imiquimod to treat warts everywhere on the body and find it very effective. Warts on genital skin are covered with a very thin epidermis (top layer of the skin). That allows for imiquimod’s easy penetration into the skin. Warts on other skin surfaces (feet, hands, fingers, etc) are often covered with thick epidermis. Hence, imiquimod does not penetrate into the skin and has no chance to work. But the way around it lies in trying to thin the epidermis down with salicylic acid, tazarotene cream, or by filing. Once the top layer of the skin is no longer thick, imiquimod penetrates the skin and works quite nicely. The time for warts to go away differs from patient to patient. One person may use imiquimod for a week and his or her warts melt right away. Another person may have to apply the cream for many

Is imiquimod effective for pre-cancerous growths (actinic keratoses)?

These pre-cancerous lesions respond very well to imiquimod. The treatment is usually accompanied by some redness, scaling, or crusting. If you have an important event coming up, it may be reasonable to postpone imiquimod use until after the big day. The approved way of treating actinic keratoses is twice weekly for 16 weeks. I usually do not stick to this regimen. It is simply too long for most patients. I usually see patients every two weeks and increase the imiquimod dose until significant inflammatory response is seen. That reduces the treatment duration to approximately 4 or 6 weeks.

Does imiquimod work for skin cancers, such as basal cell carcinoma?

Imiquimod is approved for treatment of superficial basal cell carcinomas (BCCs). In this type of BCC, cancerous cells are located close to the top layer of the skin. The cure rate for imiquimod use in superficial BCCs is reported to be around 80%. I use imiquimod in superficial and small nodular (deeper) BCCs. Since an 80% cure rate leaves 20% of cancer recurrence, this treatment has been modified to increase the cure rate. I usually start imiquimod treatment (5 times per week for 6 weeks) after curettage (scraping) of BCCs. As a rule, the BCC site becomes very irritated and crusted as the treatment progresses. No pain is observed. After 6 weeks imiquimod is discontinued, and the treatment site is left to heal. The recurrence rate is minimal. Cosmetic results after this therapy are usually quite good.

Can it be used for squamous cell carcinoma treatment?

Imiquimod is not approved by the FDA for treatment of squamous cell carcinoma (SCC). Yet, in our practice, just like in many other dermatology practices, imiquimod became a routine treatment for small and superficial SCCs. Just like for BCCs, we prescribe imiquimod for SCCs after the initial curettage of the tumor. Results of the treatment are similar for BCCs and small SCCs.

It is clear that the treatment with imiquimod is not for every BCC and SCC. Large or deeply invasive tumors should not be treated with this modality. The final decision of whether this treatment is appropriate for a particular tumor needs to be made in consultation with your dermatologist.

II. Isotretionoin

What can be done for acne when treatments fail?

What is isotretinoin?

Isotretionoin (Accutane, Sotret, Amnesteem, Claravis) is the “atom bomb” for acne. It is the most potent anti-acne medicine available. The absolute majority of patients treated with isotretinoin are completely clear at the end of the course. Up to three quarters of patients treated with this drug never have acne again.

Isotretinoin is a derivative of vitamin A. It reduces oil (sebum) production by reducing sebaceous gland size, reducing the plugging of hair follicles, and reducing P. acne on the skin.

Does it have side effects?

Multiple side effects limit the use of isotretinoin. Almost all patients experience dry lips and dry skin. Less common side effects include hair thinning, blurry vision, skin infection, abdominal pain, bone and joint pain, headache, bone spurs, mood swings, and depression. The list of side effects is very long. Yet, most of the serious side effects are very rare. Patients treated with isotretinion should be on the lookout for anything unusual (headaches lasting for many days, depressed mood, abdominal pain, etc). If something out of the ordinary happens, the treatment should be stopped. Most side effects are temporary and reversible.

Isotretinoin may cause severe birth defects in babies born to women who were on the drug during pregnancy. This is the reason (and the only reason) why isotretinoin is controlled by the government to a much higher degree than other medicines. The distribution of isotretinoin is governed by Ipledge program. This program requires the doctor, pharmacist, and patient to take several required steps to prevent pregnancies. If any of the steps are not fulfilled, the patient cannot receive isotretinoin. All women of child-bearing age are required to either be abstinent during isotretinoin treatment, or use two forms of contraception (for example, birth control pills and a condom). The requirements for men and women who cannot become pregnant are minimal. They include the prohibition to share the drug with anyone, or to donate blood while on the medicine.

Is isotretinoin bad for the body?

The fact that a special program for isotretinoin distribution has been put in place does not in any way mean that the drug is toxic. The drug does not damage the liver, kidneys, or other internal organs. Isotretinoin is not a dangerous medicine. It has been on the market for several decades. Its side effects are well known and manageable.

What kinds of acne are treated with isotretinoin?

Because of multiple side effects, isotretinoin use is reserved for severe cystic acne, or lesser degrees of acne that are treatment-resistant. Acne with scarring, or acne causing psychological distress may also be treated with isotretinoin.

By Dr. Alexander Doctoroff