How does this medication work? What will it do for me?

Imiquimod cream belongs to a group of medications called immune response modifiers. It works by stimulating the body's defenses to fight certain types of skin conditions. Imiquimod cream is used to treat external genital and perianal warts caused by the human papillomavirus (HPV) in adults. The external genital area includes skin surfaces on and around the vagina or penis. The perianal area includes skin surfaces surrounding the anus (the opening through which stool is passed).

Imiquimod cream is also used to treat actinic keratosis (AK) on the face or balding scalp in adults. AK is a skin condition that could turn into skin cancer (symptoms include rough, red, scaly patches or lesions, or crusts) that is caused by chronic sun exposure. Imiquimod is also used under certain conditions to treat primary superficial basal cell carcinoma (sBCC), a type of skin cancer.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are being given this medication, speak to your doctor. Do not stop using this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to use this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each gram of off-white, oil-in-water cream contains imiquimod 50 mg (5%). Nonmedicinal ingredients: benzyl alcohol, cetyl alcohol, glycerin, isostearic acid, methylparaben, polysorbate 60, propylparaben, purified water, sorbitan monostearate, stearyl alcohol, white petrolatum, and xanthan gum. Supplied as single-use packets containing 250 mg of cream or a pump container which delivers 235 mg of cream with each actuation.

How should I use this medication?

External genital and perianal warts: Before applying the cream, wash your hands with soap and water, and gently wash the treatment area with mild soap and water and allow the skin to dry thoroughly. Apply imiquimod cream to the affected skin area 3 times a week just before going to bed. (Examples of a 3-times weekly schedule include Monday/Wednesday/Friday and Tuesday/Thursday/Saturday.) Apply a thin layer of this medication onto the clean, dry wart area and rub gently into the skin until the cream is absorbed. Do not use the cream in your vagina. Wash your hands after using the medication. Do not apply an occlusive dressing (made of airtight material) over this medication.

Leave the medication on the skin area for 6 to 10 hours, and then remove it by washing the treated area with mild soap and water. Continue to use this medication until the warts have completely cleared, but do not use it for longer than 16 weeks. A rest period from medication for several days may be taken depending on your discomfort and the severity of skin reactions, as directed by your doctor.

Actinic keratosis (AK): Before applying the cream, wash your hands with soap and water, and gently wash the treatment area with mild soap and water and allow the skin to dry thoroughly. Apply imiquimod cream to the affected skin area 2 times a week just before going to bed. (Examples of a 2-times weekly schedule include Monday/Thursday and Tuesday/Friday.) Apply a thin layer of this medication onto the clean, dry AK lesion and rub gently into the skin until the cream is absorbed. Avoid contact with eyes, lips, and nostrils. If the cream gets in your eyes, rinse them with large amounts of water. Wash your hands after using the medication. Do not apply an occlusive dressing (made of airtight material) over this medication.

Leave the medication on the skin area for approximately 8 hours, and then remove it by washing the treated area with mild soap and water. Continue to use this medication for a total of 16 weeks, or as directed by your doctor. A rest period from medication for several days may be taken depending on your discomfort and the severity of skin reactions, as directed by your doctor.

Superficial basal cell carcinoma (sBCC): Before applying the cream, wash your hands with soap and water, gently wash the treatment area with mild soap and water and allow the skin to dry thoroughly. Apply the cream to the affected area 5 times a week just before going to bed. Apply a thin layer of this medication onto the affected area, making sure that the cream covers the entire area and at least 1 cm beyond the edges of the affected area. Apply a thin layer of the cream and gently rub into the skin until the cream is absorbed. Wash your hands after using the medication. Do not apply an occlusive dressing (made of airtight material) over this medication. Leave the medication on the skin area for approximately 8 hours, and then remove it by washing the treated area with mild soap and water. Treatment usually continues for 6 weeks. You should expect some skin irritation, but contact your physician if symptoms affect your ability to perform daily tasks. A rest period from medication for several days may be taken depending on your discomfort and the severity of skin reactions, as directed by your doctor.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are using the medication without consulting your doctor.

Use a new packet for each application. Your doctor will tell you the amount of cream you need to use. It may not be a full packet or the full amount of cream delivered by one actuation of the pump. Throw away the remainder of an opened packet each time. Remaining cream from one full actuation of the pump should also be discarded if you are using a smaller amount.  

This medication is for external use only. Do not take it by mouth.

It is important that this medication be used exactly as prescribed by your doctor. If you miss a dose, skip the missed dose and apply the cream at bedtime the next night. Do not apply a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, prevent it from freezing, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not use imiquimod cream if you:

  • are allergic to imiquimod or any ingredients of the medication.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is used in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • blistering on skin
  • burning or stinging of skin (mild)
  • diarrhea
  • dizziness
  • fatigue
  • flaking or peeling of skin
  • hair loss
  • hardening of skin
  • headache
  • heartburn
  • lightened or darkened skin colour where skin is treated
  • nausea
  • pain at the site of application
  • redness of skin (mild)
  • scabbing, crusted skin
  • skin itching
  • swelling of skin (mild)
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • any sign or symptom in the treatment area that makes daily activity difficult or impossible
  • difficulty urinating
  • increased blood pressure
  • open sores or scabs on skin
  • painful, swollen joints
  • rash
  • symptoms of an infection (e.g., coughing, fever, runny nose, sore throat, swollen glands)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • chest pain
  • signs of an allergic reaction (such as difficulty breathing, hives, or swelling of the face or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Exposure to sunlight: You should avoid or minimize any exposure to sunlight (including sunlamps) and use protective clothing (such as long sleeves and a hat) during treatment with imiquimod cream due to an increased risk of sunburn. If you get a sunburn, stop using the medication until you are fully recovered.

Immunosuppressed individuals: The safety and effectiveness of imiquimod cream has not been determined for people with medical conditions that affect the immune system (e.g., HIV/AIDS, lupus, psoriasis) or for people who take medications that reduce the effectiveness of the immune system. If you have any condition affecting the immune system, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

New genital warts or actinic keratosis (AK) lesions: During treatment with imiquimod cream, new genital warts or AK lesions may develop, but may clear with treatment. Even though initial genital warts or AK lesions disappear with treatment, new lesions may develop in the future and will require further treatment. Keep in mind that genital warts and AK are considered chronic conditions, and imiquimod cream is not a cure.

Sexual contact: If you are applying this medication to the external genital area, avoid sexual contact while the cream is on your skin. The effect of this medication on the transmission of genital warts is unknown. Wash the medication off before sexual contact and reapply afterwards. This medication may weaken condoms and vaginal diaphragms; therefore, wash off this medication prior to using these barrier methods of birth control.

Skin colour changes: Some people using imiquimod cream notice that the area where the cream was applied has become lighter or darker. Sometimes the change in skin colour is permanent.

Skin conditions: This medication may worsen inflammatory skin conditions including a condition called chronic graft versus host disease.

Skin reactions: If you experience a severe skin reaction to this cream, wash the area with mild soap and water. Once the reaction has cleared, start using the cream again, unless your doctor has told you to stop using it.

Superficial basal cell skin cancer: The safety and effectiveness of this medication have not been established for basal cell skin cancer of the face, head, hands, feet, or anal and genital areas.

Uncircumcised men: If you use this medication to treat warts under the penis foreskin, you should pull back the foreskin and clean the area each morning.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if imiquimod passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children less than 18 years of age.

What other drugs could interact with this medication?

There may be an interaction between imiquimod and any of the following:

  • corticosteroids (e.g., prednisone)
  • denosumab
  • echinacea
  • leflunomide
  • live vaccines (e.g., BCG, yellow fever)
  • medications that suppress the immune system (such as medications for cancer or organ transplants, e.g., tacrolimus, cyclosporine, methotrexate)
  • natalizumab
  • other medications applied to the skin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.