Capsaicin

Capsaicin is a topical cream that has been found to help relieve pain from some arthritic conditions such as osteoarthritis and rheumatoid arthritis and neuralgic pain. Neuralgia is a severe pain which can be severe that comes from the nerve endings near the surface of your skin.

Capsaicin is available as a 0.025% or 0.075% strength cream in 45g tube. The trade name is Zostrix® or Zostrix-HP®.

How does capsaicin work?

Capsaicin is the purified extracted alkaloid from red chilli peppers (capsicums). This is the substance that makes chilli peppers hot. The purified form capsaicin has been found to relieve pain by reducing substance P, which is found at nerve endings and is involved in transmitting neuralgic and arthritic pain signals to the brain. Pain relief is not instantaneous after application as it is the cumulative depletion of substance P over a period of weeks that brings the full effect.

What is capsaicin used for?

Capsaicin is approved for use for the symptomatic relief of pain associated with osteoarthritis (pain experienced in and around the joints when they are being used).

However, it has been used to treat many other types of neuralgic pain including:

• Post-herpetic neuralgia: mild to severe pain on the surface of the skin in patients who have just had shingles (herpes zoster). This pain occurs in about 20% of people and can persist for one month or more after the shingles rash heals.
• Trigeminal neuralgia: disorder of the trigeminal nerve that causes episodes of intense, stabbing, electric shock-like pain in the areas of the face where the nerve endings reach (lips, eyes, nose, scalp, forehead, upper jaw, and lower jaw).
• Atypical facial pain: facial pain, often described as burning, aching or cramping that occurs on one side of the face, and can extend into the upper neck or back of the scalp.
• Brachioradial pruritus: an itchy condition of the arms localized to skin near the elbows.
• Nodular prurigo: a chronic conditions characterised by intensely itchy lumps.

How to use capsaicin cream

Capsaicin cream can be purchased over-the-counter from pharmacies. Before using the cream you should carefully read any precautions on the label or package insert. Also, if you have experienced any unusual side affects or allergic reaction to red chilli peppers, then you should alert your health professional.

Capsaicin should be used as follows.

• Apply a small amount of cream with fingers and rub it well into the affected area 3 or 4 times daily or as directed by your doctor.
• Wash hands after application if hands are not the treatment sites or if you are applying the cream to someone else. If using for arthritis in your hands, do not wash your hands for at least 30 minutes after applying the cream.
• If using for treatment of post-herpetic neuralgia, only apply capsaicin after the shingles sores have healed.
• Capsaicin must be used regularly every day as directed. Immediate pain relief is not to be expected, depending on the type of pain you have it may take from 1 week to as long as 6 weeks to obtain the full effect.
• Continue to use it regularly even after you begin to feel pain relief. If you stop using capsaicin and pain returns, begin using it again.

If condition does not improve after a month of treatment or at any time if the condition worsens, see your doctor.

Precautions

Do not use capsaicin cream on broken or infected skin. Seek medical advice first.

Avoid use near eyes or other sensitive areas of the body. If capsaicin gets into your eyes, flush eyes with water. Wash other sensitive areas with warm soapy water.

Tight bandages should not be applied on top of capsaicin cream.

If you experience any unusual side effects stop the treatment and consult your doctor.

Side effects

The most common side effect of capsaicin use is a feeling of warmth and stinging, or a sensation of burning after application. This sensation is related to the action of capsaicin on the skin and is to be expected. Approximately 50% of patients will experience some mild to moderate stinging or burning. This sensation usually diminishes after the first few days of application and in most cases will disappear with time and continued use.

Methods used to reduce this sensation include:

• Avoid taking a hot bath or shower just before or after applying capsaicin cream.
• Try to keep cool, do not wear tight clothing or become too warm as heat may increase the sensation.
• Maintain your recommended or prescribed dosing schedule as reducing the number of doses you use each day will not lessen the sensation and may lengthen the period of time that you get the sensation.