Cantharidin Topical

Cantharidin Topical is a prescription medication indicated for the topical treatment of molluscum contagiosum in adult and pediatric patients 2 years of age and older.

• Cantharidin Topical is available under the following different brand names: Ycanth

Common side effects of Cantharidin Topical include:

• blistering
• erythema
• pain
• bleeding
• ring warts
• post-inflammatory hyperpigmentation
• lymphangitis
• secondary bacterial cellulitis
• scarring and varicelliform vesicular dermatitis

Serious side effects of Cantharidin Topical include:

• skin irritation
• blistering
• short-term pain after use
• change in color of skin at the application site
• eye contact reactions include ulcers or small holes in the eyes, irritation, scarring, severe eye pain, redness, and permanent eye injury including blindness

Rare side effects of Cantharidin Topical include:

• none

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Topical solution

• 0.7% (7 mg/mL)
• Each sealed glass ampule contains approximately 0.45 mL
• Break tool is packaged as 2 units/carton of applicators

Molluscum contagiosum

Adult dosage

• Apply topically to cover each lesion by clinician every 3 weeks or as needed; not to exceed 2 cantharidin applicators during a single session

Pediatric dosage

• Children younger than 2 years: Safety and efficacy not established
• Children aged 2 years and older: Apply topically to cover each lesion every 3 weeks or as needed; not to exceed 2 cantharidin applicators during a single session

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, healthcare provider, or pharmacist first.

• Cantharidin Topical has no noted severe interactions with any other drugs.
• Cantharidin Topical has no noted serious interactions with any other drugs.
• Cantharidin Topical has no noted moderate interactions with any other drugs.
• Cantharidin Topical has no noted minor interactions with any other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Cantharidin Topical?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Cantharidin Topical?”

Cautions

• Toxicities associated with inappropriate administration
• Life-threatening or fatal toxicities can occur if administered orally
• Avoid contact with the treatment area, including oral contact, after treatment
• Oral ingestion may result in renal failure, blistering and severe damage to the gastrointestinal tract, coagulopathy, seizures, and flaccid paralysis
• Ocular toxicity can occur if cantharidin encounters the eyes; if this occurs, flush your eyes with water for at least 15 minutes
• Contact with eyes can result in corneal necrosis, ocular perforation, and deep ocular injuries
• Advise patients and/or caregivers to avoid oral and eye contact as well as touching lesions after treatment; seek medical attention immediately if accidentally ingested
• Local skin reactions
  • Application site reactions reported, including vesiculation, pruritus, pain, discoloration, and erythema
  • Avoid application near eyes or mucosal tissue and on healthy skin
  • Immediately remove the solution by wiping with a cotton swab or gauze if contact with the unintended surface or healthy skin occurs
  • Avoid applying other topical products (eg, creams, lotions, sunscreen) on treated areas for 24 hours after treatment or until washing
  • Application of other topical products could spread cantharidin and cause blistering or other adverse reactions to healthy skin
  • If severe blistering, pain, or other adverse reactions occur, remove cantharidin before the recommended 24-hour treatment period by washing it with soap and water
  • Flammability
  • Cantharidin Topical solution is flammable, even after drying
  • Avoid fire, flame, or smoking near lesion(s) during treatment and after application until removed

Pregnancy and Lactation

• There are no available data on the use of cantharidin in pregnant women to evaluate drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes
• Animal reproduction studies have not been conducted
• Systemic exposure following topical cantharidin administration is low; maternal use of the drug is not expected to result in fetal exposure
• Lactation
  • Avoid application to areas with increased risk for potential ingestion by or ocular exposure to the breastfeeding child
  • There are no data on the presence of cantharidin in either human or animal milk and its effects on breastfed infants or milk production
  • Breastfeeding is not expected to result in cantharidin exposure to the child owing to low systemic absorption following topical administration
  • Consider the developmental and health benefits of breastfeeding along with the clinical need for Cantharidin and any potential adverse effects on breastfeeding children from cantharidin or any underlying maternal condition