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Generic name: Cantharidin [ kan-THAR-e-din ]

Medically reviewed by Last updated on Mar 18, 2023.

Uses of Cantharidin:

What do I need to tell my doctor BEFORE I take Cantharidin?

  • If you have an allergy to cantharidin or any other part of cantharidin.
  • If you are allergic to cantharidin; any part of cantharidin; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have a type of wart called mosaic wart.
  • If skin around the treated area is swollen or irritated.
  • If you have any blood flow problems, talk with your doctor.
  • If you have high blood sugar (diabetes).
  • If your skin has birthmarks, moles, bleeding warts, or warts with hair growth. Do not use cantharidin on these areas.
  • If you drink alcohol. You must avoid drinking alcohol for several hours after treatment.
  • If you are pregnant or may be pregnant. Do not use cantharidin if you are pregnant.
  • If you are breast-feeding. Do not take cantharidin if you are breast-feeding.

This is not a list of all drugs or health problems that interact with cantharidin.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take cantharidin with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Cantharidin?

  • Tell all of your health care providers that you take cantharidin. This includes your doctors, nurses, pharmacists, and dentists.
  • Talk with your doctor before you drink alcohol.
  • Talk with your doctor before you use other drugs or products on your skin.

How is this medicine (Cantharidin) best taken?

Use cantharidin as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • Your doctor or other healthcare provider will put on the skin.
  • Follow what your doctor has told you to do.

What do I do if I miss a dose?

  • Call the doctor for an office visit.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Very bad skin irritation.

What are some other side effects of Cantharidin?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Skin irritation.
  • Blistering.
  • Short-term pain after use.
  • Change in color of skin where drug is used.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Cantharidin?

  • This medicine will be given in a hospital or doctor's office. You will not store it at home.

Consumer Information Use and Disclaimer

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about cantharidin, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.