capsaicin
Place in Therapy
Scientists believe that substance P, an endogenous peptide, is thought to initiate the pain often felt by patients with arthritis.1 Furthermore, due to the accumulation of substance P, it is thought that capsaicin, a substance P depleter, would be beneficial as a topical agent.1 Capsaicin is a chemical found within chilli peppers that give them their characteristic hotness.2 Recent developments of using capsaicin as a topical analgesic have emerged for those that are unresponsive to other therapies such as acetaminophen, NSAIDs, or prescription opiates.2 The use of topical capsaicin for osteoarthritis has a variety of recommendations that often do not correspond with one another. The American College of Rheumatology (ACR) recommends the conditional use of topical capsaicin in those suffering only from hand osteoarthritis.3 Furthermore, ACR recommends that topical capsaicin should not be used for knee osteoarthritis and does not comment on hip osteoarthritis.3 On the contrary, OARSI recommends the use of topical capsaicin as an adjunctive or alternative therapy to oral medications for knee osteoarthritis.4 The 2003 EULAR recommendations also notes that topical capsaicin may have clinical efficacy in knee osteoarthritis.5 It should be noted however, that the ACR recommendations are the most current to date.3,4,5 Furthermore, only the ACR and OARSI incorporated researchers from Canada resulting in recommendations that would be beneficial for treating patients within our community.3,4
A double-blind study conducted for 12 weeks in 113 patients including both men and women between the ages of 18 to 86 who were diagnosed with primary (idiopathic) or posttraumatic (secondary) osteoarthritis of the knee, elbow, ankle, shoulder, or wrist were randomly assigned to two treatment groups; either capsaicin 0.025% as monotherapy or a vehicle (placebo).1 A washout period was conducted prior to beginning the study to ensure that the patient was only receiving benefit, if any, from the capsaicin cream.1 At the end of 12 weeks, 53% of patients treated with topical capsaicin reported a reduction in pain compared to 27% of patients being treated with the vehicle.1 Some side effects were noted by patients in the treatment group such as mild to moderate burning or stinging when applying the capsaicin cream which decreased over time.1 It is suggested by this study that topical capsaicin be considered for first line therapy in osteoarthritis.1 Based on the guideline recommendations and the double-blind study, it can be suggested that topical capsaicin be used in the treatment of osteoarthritis if the patient is unable to experience pain relief from other oral or topical treatments. Topical capsaicin is relatively safe to use with the noted side effect of burning and stinging when applying the cream.1 However, there have been reports of coughing when using a concentration of 0.075% capsaicin.6 Patients should be advised to use a concentration of capsaicin that works for them and apply it in a thin layer over the affected area four times daily.1,2,4,7
References:
1. Altman RD, Aven A, Holmburg CE, Pfeifer LM, Sack M, Young GT. Capsaicin cream 0.025% as monotherapy for osteoarthritis: a double-blind study. Semin Arthritis Rheu. 1994; 23(6): 25-33.
2. Zhang WY, Li Wan Po A. The effectiveness of topically applied capsaicin: a meta-analysis. Eur J Clin Pharmacol. 1994; 46: 517-522.
3. Hochberg MC, Altman RD, April KT, et al. American college of rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthrit Care Res. 2012; 64(4): 465-474.
4. Zhang W, Moskowitz RW, Nuki G, et al. OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based expert consensus guidelines. Osteoarthr Cartilage. 2008; 16: 137-162.
5. Jordan KM, Arden NK, Doherty M, et al. EULAR Recommendations 2003: an evidence based approach to the management of knee osteoarthritis: Report of a Task Force if the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT). Ann Rheum Dis. 2003; 62: 1145–1155.
6. Mason L, Moore RA, Derry S, Edwards JE, McQuay HJ. Systematic review of topical capsaicin for the treatment of chronic pain. BMJ. 2004; 1-5. doi: 10.1136/bmj.38042.506748.EE
7. Altman RD, Barthel HR. Topical Therapies for Osteoarthritis. Drugs. 2011; 71(10): 1259-1279.
A double-blind study conducted for 12 weeks in 113 patients including both men and women between the ages of 18 to 86 who were diagnosed with primary (idiopathic) or posttraumatic (secondary) osteoarthritis of the knee, elbow, ankle, shoulder, or wrist were randomly assigned to two treatment groups; either capsaicin 0.025% as monotherapy or a vehicle (placebo).1 A washout period was conducted prior to beginning the study to ensure that the patient was only receiving benefit, if any, from the capsaicin cream.1 At the end of 12 weeks, 53% of patients treated with topical capsaicin reported a reduction in pain compared to 27% of patients being treated with the vehicle.1 Some side effects were noted by patients in the treatment group such as mild to moderate burning or stinging when applying the capsaicin cream which decreased over time.1 It is suggested by this study that topical capsaicin be considered for first line therapy in osteoarthritis.1 Based on the guideline recommendations and the double-blind study, it can be suggested that topical capsaicin be used in the treatment of osteoarthritis if the patient is unable to experience pain relief from other oral or topical treatments. Topical capsaicin is relatively safe to use with the noted side effect of burning and stinging when applying the cream.1 However, there have been reports of coughing when using a concentration of 0.075% capsaicin.6 Patients should be advised to use a concentration of capsaicin that works for them and apply it in a thin layer over the affected area four times daily.1,2,4,7
References:
1. Altman RD, Aven A, Holmburg CE, Pfeifer LM, Sack M, Young GT. Capsaicin cream 0.025% as monotherapy for osteoarthritis: a double-blind study. Semin Arthritis Rheu. 1994; 23(6): 25-33.
2. Zhang WY, Li Wan Po A. The effectiveness of topically applied capsaicin: a meta-analysis. Eur J Clin Pharmacol. 1994; 46: 517-522.
3. Hochberg MC, Altman RD, April KT, et al. American college of rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthrit Care Res. 2012; 64(4): 465-474.
4. Zhang W, Moskowitz RW, Nuki G, et al. OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based expert consensus guidelines. Osteoarthr Cartilage. 2008; 16: 137-162.
5. Jordan KM, Arden NK, Doherty M, et al. EULAR Recommendations 2003: an evidence based approach to the management of knee osteoarthritis: Report of a Task Force if the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT). Ann Rheum Dis. 2003; 62: 1145–1155.
6. Mason L, Moore RA, Derry S, Edwards JE, McQuay HJ. Systematic review of topical capsaicin for the treatment of chronic pain. BMJ. 2004; 1-5. doi: 10.1136/bmj.38042.506748.EE
7. Altman RD, Barthel HR. Topical Therapies for Osteoarthritis. Drugs. 2011; 71(10): 1259-1279.