Herbal and Supplement Use in Pain Management

Capsicum

• • Class: analgesic and anti-inflammatory agent.
• • Mechanism of action: repeated use of capsaicin depletes substance p, which decreases the neuronal transmission of pain.¹
• • Use: osteoarthritis, fibromyalgia.
• • Dosing:

о Fibromyalgia:

- Topical: apply 0.025% or 0.075% capsaicin cream three or four times daily for 4-6 weeks modestly to reduce pain at tender points.² Long-term benefits are not

known, and more studies are needed in order to further assess capsaicin as a longterm therapy in the symptom management of fibromyalgia.¹

• • Adverse effects: gastrointestinal, burning of mucosal membranes if rubbed on by mistake.
• • Drug interactions: moderate theoretical risk with anticoagulants/antiplatelet warfarin, antidiabetic, antihypertensive, cefazolin, aspirin.
• • Fifty-two minor interactions (e.g., ACE-inhibitor induced cough may be induced or exacerbated).
• • Cautions: none known.

Cat’s Claw

• • Class: analgesic and anti-inflammatory agent.
• • Mechanism of action: according to in vitro and clinical research, the anti-inflammatory properties of Uncaria guianensis and Uncaria tomentosa may result from their ability to inhibit TNF-alpha and, to a lesser extent, prostaglandin E2 (PGE2) production. In vitro, cat’s claw was a potent inhibitor of TNF-alpha production.³
• • Use: osteoarthritis, rheumatoid arthritis.
• • Dosing:

о Osteoarthritis: 100 mg by mouth once daily.⁴

° Rheumatoid arthritis: 20 mg three times daily.⁵

• • Adverse effects: generally, well-tolerated.
• • Contraindications: hypersensitivity to cat’s claw or its components.
• • Drug interactions:

° Anticoagulant/antiplatelet drugs: cat’s claw contains rhynchophylline and isorhyncho- phylline. Research suggests that concurrent use of cat’s claw and anticoagulant/antiplatelet drugs can reduce platelet aggregation and cause an increased risk of bleeding in some patients.⁶

° Antihypertensive drugs: cat’s claw contains rhynchophylline and isorhynchophyl- line. Concurrent use of cat’s claw and antihypertensive drugs may increase the risk of hypotension.⁷

° Calcium channel blockers “moderate risk": animal research suggests that the various alkaloids in cat’s claw can lower blood pressure by acting as a calcium channel blocker—(TRC Natural Medicines).

=> CYP P450 3A4 substrates: cat’s claw inhibits 3A4 and may increase levels of drugs metabolized by CYP3A4, including ketoconazole, itraconzole, fexofenadine, and triazolam.⁸

° Immunosuppressants: cat’s claw may interfere with immunosuppressants due to the immunostimulating activity of cat’s claw. It stimulates phagocytosis and increases respiratory cellular activity and the mobility of leukocytes.³

=> Protease Inhibitors: cat’s claw may increase levels of protease inhibitors because cat’s claw inhibits CYP 3A4. Use with caution.⁹

• Cautions:

° Do not use in pregnancy. There is concern that it may be unsafe due to its traditional use as a contraceptive.¹⁰

° Do not use in lactation due to insufficient evidence of safety.¹⁰

DEVIL'S CLAW

• • Class: analgesic and anti-inflammatory agent.
• • Mechanism of action: the iridoid glycoside constituents of devil’s claw seem to have an anti-inflammatory effect. Some preliminary research suggests that harpagoside inhibits both the cyclooxygenase (COX) and lipoxygenase inflammatory pathways."
• • Use: osteoarthritis, back pain, rheumatoid arthritis.

• Dosing:

о Back pain:

- (Doloteffin, ardeypharm) 2400 mg taken in three divided doses daily for up to 1 year has been used.¹²

° (WS 1531) 600-1200mg of harpagophytum extract twice daily for 4 weeks.¹³ => Osteoarthritis:

• - 670-800 mg three times daily up to 2 months.
• - (Doloteffin, ardeypharm) 2400 mg taken in three divided doses daily for up to 1 year has been used.¹²
• • Adverse effects: gastrointestinal pain, allergic skin reactions, dysmenorrhea, throbbing frontal headache, tinnitus, anorexia, loss of taste, anxiety, somnolence, and insomnia, but most of these are rare and overall devil’s claw is well-tolerated.¹²
• • Contraindications: hypersensitivity to devil’s claw and its components.
• • Drug Interactions:

° CYP 2C19, 2C9, 3A4 substrates: devil’s claw inhibits these CYP enzymes and can increase levels of these substrates.¹⁴

=> H2 blockers and proton pump inhibitors: minor interaction that devil’s claw may increase stomach acid and decrease the effectiveness of H2 blockers and PPIs.¹⁵¹⁶ => Warfarin: concurrent use of warfarin and devil’s claw' may increase risk of bleeding and warfarin—dose adjustments may be necessary.¹⁷

• Cautions:

° Do not use in pregnancy. Data suggest that devil’s claw' has oxytocic effects and can induce contractions of uterine muscle.¹⁸ ° Insufficient evidence for lactation. Do not use when breastfeeding.¹⁸

Ginger

• • Class: analgesic and anti-inflammatory agent.
• • Mechanism of action: anti-inflammatory effects through the inhibition of arachidonic acid and inhibition of prostaglandin and leukotriene synthesis.
• • Use: osteoarthritis, dysmenorrhea, migraine headache, rheumatoid arthritis (further studies needed to evaluate effectiveness and dosing), post-operative recovery (further studies needed to evaluate effectiveness and dosing).
• • Dosing:

о Osteoarthritis:

• - Orally: 1000 mg daily for 4 weeks or 170 mg three times daily for 3 weeks has been used.¹⁹
• - Topically: ginger and plai 4% by weight—4 grams/day in four divided doses for 6 weeks has been applied.²⁰

° Dysmenorrhea: 250 mg four times daily orally for 3 days from the start of the menstrual period or until pain relief.²¹

° Migraine headache: 250 mg orally as a single dose at the onset of the migraine.²²

• • Adverse effects: generally-well tolerated, but in doses higher than 5 g per day may have side effects such as abdominal discomfort, heartburn. Encapsulated ginger opposed to ginger pow'der yields less abdominal discomfort.²³
• • Contraindications: hypersensitivity to ginger and its components.
• • Drug interactions:

° Anticoagulant/antiplatelet drugs: moderate interaction due to inhibition of thromboxane synthetase and decreased platelet aggregation leading to an increased risk of bleeding.²⁴ => Diabetic drugs: ginger may increase insulin levels and/or decrease blood glucose levels, leading to an additive effect w'ith blood glucose-lowering drugs and a higher risk of hypoglycemia.²⁵

=> Antihypertensive drugs: ginger may have hypotensive effects leading to an additive effect with calcium channel blocker and other antihypertensive medications.²⁶

° Cyclosporine: ginger may reduce the maximum concentration and AUC of cyclosporine by 51.4% and 40.3%, respectively, as found in a study. A decrease in the effectiveness of cyclosporine has been observed when ginger is taken before cyclosporine and this should be avoided.²⁷

=> Metronidazole: ginger may increase the absorption and plasma half-life of metronidazole. Also, the elimination rate of metronidazole may be reduced with co-administra- tion with ginger.²⁸

• Cautions: none reported.