Patients' Responses to Imiquimod Vary
Studies find different doses can be
safe and effective
In 2004, the U.S. Food and Drug
Administration (FDA) approved imiquimod for the treatment of actinic
keratoses (ak-'tin-nik ker-e-'to-ses), also called AKs, on the face
and scalp. The recommended dosage for this cream is 2 times per week
for up to 16 weeks.
Clinical trials conducted to obtain FDA approval determined the
recommended dosage. During the trials, 436 patients who had four (4)
to eight (8) AKs on their face or scalp were randomly assigned to
receive either 5% imiquimod cream or a cream that resembled
imiquimod but lacked the active ingredient. Patients were instructed
to apply the cream they received 2 times per week.
The patients’ responses indicated that applying imiquimod twice a
week was safe and effective. Almost half, 45.1%, of the patients
applying imiquimod had complete clearing of their treated AKs within
16 weeks. More than half, 59.1%, of the patients applying imiquimod
twice a week for 16 weeks had 75% or more of their AKs clear.
Expected side effects, such as redness, flaking/scaling/dryness, and
scabbing/crusting, were tolerable.
Recently, researchers conducted clinical trials to find out if
applying imiquimod three (3) times per week instead of two (2) times
per week for 16 weeks would increase AK clearance and still be well
tolerated. Here’s what they discovered:
Clearance increases when imiquimod is
used three (3) times per week; however, the gain is slight.
The percentage of patients who achieved complete clearance increased
by 3.2%. Patients experiencing a clearance rate of 75% or more
within 16 weeks grew by 4.9%. These increases were much less than
More patients report local skin
reactions when imiquimod is applied three (3) times per week to
In this study, 40.9% of the patients applying imiquimod 3 times per
week required a rest period. In other words, they had to stop using
imiquimod for a period of time during the 16 weeks due to skin
About 13% of patients completely
discontinued using imiquimod due to skin reactions when they applied
it 3 times per week.
Overall, applying 5% imiquimod cream 3
times per week for 16 weeks proves safe and effective.
However, when used 3 times per week, patients may experience more
skin reactions and need a rest period from imiquimod during the 16
Individual Response Varies
These clinical trials indicate that individual responses to
imiquimod will vary and that some AKs do not clear with imiquimod.
Many factors, including overall sun damage and how the patient’s
immune system behaves, influence how a person responds. However, it
is not yet known which factors can help predict how a patient will
The researchers concluded that this study and others suggest the
amount of imiquimod to be applied and the frequency may need to be
Is imiquimod right for you?
No one treatment is appropriate for every patient. If you believe
that imiquimod may be right for you, speak with a dermatologist.
There are many factors that a dermatologist considers before
prescribing treatment for AKs. These include the size, number, and
location of the AKs as well as the patient’s age and medical
history. The patient’s willingness to avoid sun exposure, not use
artificial tanning devices, and use the medication as directed at
home also must be considered.
Korman, N et al. “Dosing with 5% Imiquimod Cream 3 Times per Week
for the Treatment of Actinic Keratosis.” Archives of Dermatology.
Lebwohl, M et al. “Imiquimod 5% cream for the treatment of actinic
keratoses: Results from two phase III, randomized, double-blind,
parallel group, vehicle-controlled trials.” Journal of the American
Academy of Dermatology. 2004 May;50(5):714-21.
content solely developed by the American Academy of Dermatology
Imiquimod is an innovative
treatment option for AKs.
What makes imiquimod unique
is that it stimulates the patient's own immune system to
attack the AK cells. Signs that the patient's immune
system is responding include redness, swelling, and
scabbing/crusting of the skin treated with imiquimod.