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Cantharidin/Salicylic Acid/Podophyllin - Topical

Pronunciation: kan-THAR-i-din/SAL-i-SIL-ik AS-id/POD-o-FIL-in

Common Brand Name(s): Canthacur-PS

Important: How To Use This Information

This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.


This combination product is used on the skin to remove warts. It is also used to treat a certain viral skin infection (molluscum contagiosum). Cantharidin is known as a vesicant and is a substance that comes from blister beetles. Cantharidin works by causing a blister to form under the wart. The blister cuts off the blood supply to the wart, leading to its destruction, usually without scarring. Salicylic acid causes the treated skin to be shed naturally. Podophyllin prevents the wart from growing.

How To Use

You should not self-treat your warts at home with this medication. This is a highly toxic material that should be applied only by a healthcare professional in a doctor's office or clinic.

Your doctor should limit the number of warts and the amount of skin treated to prevent great discomfort and possible absorption of the medication through the skin.

Care should be taken when applying this medication because it can irritate normal skin around the application site. If this medication gets on surrounding skin, wipe off right away using nail polish remover (acetone) or alcohol. Then wash the area with warm soapy water and rinse well.

Avoid contact with the eyes, nose, mouth, and genitals. If contact occurs, flush or soak the area with cool water for at least 10-15 minutes.

Depending on the type of warts being treated, it may be necessary to repeat treatments with this medication during return visits to your doctor's office or clinic. Keep all medical appointments while being treated with this medication.

Inform your doctor if the treated warts persist or new warts appear.

Side Effects

The blister that forms under the treated skin may become itchy, painful, or swollen, and you may see small amounts of blood. For the pain, your doctor may recommend aspirin or acetaminophen. Sometimes a stronger pain reliever may be needed. If the pain or any other effects persist or worsen, notify your doctor or pharmacist promptly.

Most often, there is a temporary color change in the treated skin, with no scarring. Notify your doctor right away if you notice a long-lasting color change in the treated skin.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if any of these rare but very serious side effects occur:

  • chills
  • high fever
  • swollen glands

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include:

  • rash
  • itching/swelling (especially of the face/tongue/throat)
  • severe dizziness
  • trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.


Before receiving treatment with cantharidin/salicylic acid/podophyllin, tell your doctor or pharmacist if you are allergic to any of these drugs; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

This medication should not be used if you have certain medical conditions. Before receiving treatment with this medicine, consult your doctor or pharmacist if you have:

  • diabetes
  • poor blood circulation

This medication should not be applied to moles, birthmarks, or unusual warts with hair growing from them.

Do not drink any alcoholic beverages for several hours after this medication is applied.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using this product. This product may harm an unborn baby. If you become pregnant while using this product, talk to your doctor right away about its risk and benefits.

It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Your healthcare professionals (such as your doctor or pharmacist) may already be aware of any possible drug interactions and may be monitoring you for it. Do not start, stop or change the dosage of any medicine before checking with them first.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of:

  • topical salicylic acid plaster

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.


If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center. This medicine may be harmful if swallowed, leading to symptoms such as: burning of the mouth, nausea, painful swallowing, painful/bloody urine, change in the amount of urine, bloody vomit, or vomit that looks like coffee grounds.


Do not share this medication with others.

Missed Dose

Not applicable.


Store at room temperature away from open flame and heat. Keep the bottle tightly closed. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.