Capsaicin

 Action May deplete and prevent reaccumulation of substance P, principal transmitter of pain impulses, from periphery to CNS.

 Indications Temporary relief of pain from rheumatoid arthritis and osteoarthritis; relief of neuralgias (eg, pain after shingles, diabetic neuropathy). Unlabeled use(s): Temporary relief of pain of psoriasis, vitiligo, intractable pruritus, postmastectomy and postamputation neuroma (phantom limb syndrome), vulvar vestibulitis, apocrine chromidrosis, reflex sympathetic dystrophy.

 Contraindications Standard considerations.

 Route/Dosage

ADULTS & CHILDREN ³ 2 YR: Apply to affected area no more than 3 to 4 times/day. Wash hands immediately after application.

 Interactions None well documented.

 Lab Test Interferences None well documented.

 Adverse Reactions

DERM: Burning; stinging; erythema. RESP: Cough; respiratory irritation.

 Precautions

Pregnancy: Safety undetermined. Lactation: Undetermined. Capsaicin is for external use only.

 Administration/Storage

• Wear gloves during application and avoid contact with eyes and broken or irritated skin.
• If bandage is needed, apply loosely to application area.
• Store at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Note that transient burning may occur during initial course of therapy but will decrease in a few days. Burning is more common when medication is applied > 3 times/day.
• Assess location and intensity of pain periodically throughout therapy.

 Patient/Family Education

• Remind patient that this medication is for external use only.
• Teach patient correct method of application: Wear gloves, avoid contact with eyes and broken or irritated skin, and wash hands immediately after application.
• Caution patient to use care when handling contact lenses after application.
• Advise patient to keep bandage placed loosely over application area.
• Emphasize that following prescribed regimen reduces transient burning associated with infrequent administration. Remind patient not to apply medication > 3 times/day.
• Instruct patient to discontinue treatment and notify physician if pain persists 14 to 28 days or returns a few days after initiation of therapy, or if signs of infection occur.
• Counsel patient to notify physician if persistent cough accompanies therapy.