Capsaicin

(cap-say-sin)

Trade/other name(s): Capsagel, Capsin, Capzasin-P, Dolorac, No-Pain, Qutenza, Salonpas-Hot, Zostrix, Zostrix HP, and others

Why would this drug be used?

Capsaicin cream or gel is used to help control neuropathic pain (numbness, tingling, burning, shooting, or electric-shock-like pain), such as post-herpetic neuralgia (pain in areas affected by shingles). You can buy creams or gels over the counter, without a prescription. The capsaicin patch is more potent, and requires a prescription.

How does this drug work?

Capsaicin is made from hot pepper extract. It appears to work by using up "substance P," which transits pain signals from the nerve endings. This interferes with the nerves' ability to send pain signals.

Before taking this medicine

Tell your doctor…

• If you are allergic to anything, including medicines, dyes, additives, or foods, especially if you have had a problem with foods, plants, or adhesives.
• If you have broken, inflamed, burned or irritated skin in the affected area. These products should not be used on broken skin.
• If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. No studies have been done in pregnant women.
• If you are breast-feeding. It is not known whether this drug can pass into breast milk and affect the baby.
• About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

Do not use other creams or gels on the affected area without talking to your doctor or pharmacist.

Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

The prescription patch: Your doctor or nurse will prepare, place, and remove the patch. Usually this means numbing your skin before putting on the patch, which is left in place for an hour. Do not touch the patch. After removing it, the doctor or nurse will clean your skin to remove any capsaicin that is left. If you touch the patch by accident, let the doctor know right away so that your hand or arm can be cleaned too. If you still have pain, the patch treatment can be repeated in 3 months.

Creams and gels: A thin film of capsaicin cream or gel is applied to the painful area 3 or 4 times a day. To avoid getting it in the eyes or nose, some recommend wearing disposable plastic gloves to apply it. Wash your hands thoroughly after handling. Capsaicin also comes in a roll-on form, which is applied like roll-on deodorant to the painful area.

Take this drug exactly as directed by your doctor, or follow the directions on the label. If you do not understand the instructions, your doctor or nurse can explain them to you. Keep the medicine in a tightly closed container away from children and pets. Do not refrigerate or freeze.

Precautions

Avoid touching your eyes, nose, or other mucous membranes while this medicine is on your hands. It can cause severe pain.

It is common for the skin to feel warm and sting or burn a little just after the cream or gel is applied. If the burning is painful or unbearable, wash it off with soap and cool or lukewarm water. Hot water can worsen the problem. Call your doctor if the skin gets irritated, red, blistered, or keeps burning where the capsaicin was applied.

Don't wrap or bandage the area after applying the gel or cream. If a covering is required, be sure it isn't tight on the skin. Never use heat on the skin after capsaicin is applied.

It takes 2 to 4 weeks of regular applications for the drug to work. If you stop using the drug, pain may return.

Do not use the cream (or go to the doctor for a patch) right after bathing, swimming, using a hot tub or sauna, or other exposure to heat.

The area treated with the patch may be sensitive to heat (hot showers, sauna, baths, direct sunlight, and even exercise) for a few days after treatment.

Rarely, allergies to capsaicin can occur. Call your doctor if you notice intense itching or if you develop a cough. Get emergency help if you notice skin welts, trouble breathing, dizziness, or swelling of the face, mouth, or throat.

Possible side effects

You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.

Common

• Burning or stinging of the skin
• Redness of the skin (after the patch treatment)
• Feeling of warmth after applying

Rare

• Skin breakdown
• Cough*
• Serious allergic reaction*

*See "Precautions" section for more detailed information.

There are other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

The prescription patch was first approved by the FDA in 2009. Some (non-prescription) forms of this drug appear to pre-date the current FDA approval process, which would mean they were not required to get formal FDA approval.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.