HERBS: Capsaicin

Scientific name
Other names
Brand name
Food sources
Purported uses
Warnings
Adverse reactions
Drug interactions
References

Capsaicin

Scientific name

Capsicum frutescens, Capsicum annuum. Family: Solanaceae

Other names

Cayenne, chili pepper, capsaicin, African chilies, green bell pepper, red pepper, tabasco pepper

Brand name

Zostrix� cream 0.025% & 0.075%

Food sources

Cayenne pepper

Purported uses

To improve circulation in the extremities: Laboratory studies have found that capsaicin inhibits dilation of blood vessels in the skin, which would not help improve circulation to the hands and feet. Its clinical benefit has yet to be examined in large clinical trials
To relieve pain of neuropathy associated with diseases such as diabetes and herpes zoster (shingles): Clinical trials show conflicting results regarding the use of capsaicin for neuropathies; cancer patients with post-surgical neuropathies benefited from capsaicin cream, while patients with HIV-related distal symmetrical peripheral neuropathy did not.
To relieve muscle pain and muscle spasms: Laboratory data show that capsaicin blocks pain fibers, but there is no proof from clinical trials that capsaicin can be used to treat muscle pain or spasms.
To treat osteoarthritis and rheumatoid arthritis: Several clinical trials support this use, with the results more positive for osteoarthritis than for rheumatoid arthritis.
To treat toothaches: No scientific evidence supports this use.
To treat psoriasis: One clinical trial supports this use.

Warnings

Capsaicin can be extremely irritating to the mucous membranes and to the eyes. Avoid contact with eyes and irritated or broken skin. Use gloves when applying topically.

Adverse reactions

Common (topical): Burning, urticaria, contact dermatitis.

Drug interactions

Oral ingestion of Capsaicin is not recommended. However, oral use in theory may potentially cause the following interactions.

ACE inhibitors: Capsaicin can increase the incidence of cough that is associated with ACE inhibitors.
Sedatives: Capsaicin may increase sedation.
Theophylline: Concurrent administration with capsaicin may increase absorption.
Monamine-oxidase inhibitors: Capsaicin may increase catecholamine secretion.
Antihypertensives: Capsaicin may increase catecholamine secretion and antagonize hypotensive effects

References

1. Ellison N, et al. Phase III placebo-controlled trial of capsaicin cream in the management of surgical neuropathic pain in cancer patients. J Clin Oncol 1997;15:2974-80.

2. Paice JA, et al. Topical capsaicin in the management of HIV-associated peripheral neuropathy. J Pain Symptom Manage 2000;19:45-52

3. McCarthy GM, et al. Effect of topical capsaicin in the therapy of painful osteoarthritis of the hands. J Rheumatol 1992;19:604-7.

4. Deal CL, et al. Treatment of arthritis with topical capsaicin: a double-blind trial. Clin Ther 1991;13:383-95.

5. Biesbroeck R, Bril V, Hollander P, Kabadi U, Schwartz S, Singh SP et al. A double-blind comparison of topical capsaicin and oral amitriptyline in painful diabetic neuropathy. Adv.Ther. 1995;12:111-20.

6. Stander S, Luger T, Metze D. Treatment of prurigo nodularis with topical capsaicin. J Am Acad.Dermatol 2001;44:471-8.

7. Dasgupta P, et al. Chilies: from antiquity to urology. Br J Urol 1997;80:845-52.

8. Fusco BM, Marabini S, Maggi CA, Fiore G, Geppetti P. Preventative effect of repeated nasal applications of capsaicin in cluster headache. Pain 1994;59:321-5.

9. Newall CA, et al. Herbal Medicines: A Guide for Health Care Professionals. London: Pharmaceutical Press; 1996.

10. Park KK, Chun KS, Yook JI, Surh YJ. Lack of tumor promoting activity of capsaicin, a principal pungent ingredient of red pepper, in mouse skin carcinogenesis. Anticancer Research 1998;18:4201-5.

11. Lynn B. Capsaicin: actions on nociceptive C-fibres and therapeutic potential. Pain 1990;41:61-9.

12. Marsh SJ, Stansfeld CE, Brown DA, Davey R, McCarthy D. The mechanism of action of capsaicin on sensory C-type neurons and their axons in vitro. Neuroscience 1987;23:275-89.

13. Nolano M, Simone DA, Wendelschafer-Crabb G, Johnson T, Hazen E, Kennedy WR. Topical capsaicin in humans: parallel loss of epidermal nerve fibers and pain sensation. Pain 1999;81:135-45.

14. Brinker F. Herb Contraindications and Drug Interactions, 2nd ed. Sandy (OR): Eclectic Med Publications; 1998.