- 1 Dosage Range
- 2 Toxicity
- 3 Adverse Reactions
- 4 Significant Interactions
- 5 Contraindications and Precautions
- 6 Pregnancy Use
- 7 Practice Points / Patient Counselling
- 8 Answers to Patients’ Frequently Asked Questions
• Liquid extract (1:2): 6-12 mL/day.
• Tincture (1:5): 2-4 mL three times daily.
It is suggested that devil’s claw extracts with at least 50 mg harpagoside in the daily dosage should be recommended for the treatment of pain.
DIGESTIVE CONDITIONS (e.g. DYSPEPSIA)
• Dosages equivalent to 1.5 g/day dried herb are used. It is suggested that devil’s claw preparations be administered between meals, when gastric activity is reduced.
The acute LD50 of devil’s claw was more than 13.5 g/kg according to one study.
Diarrhoea was reported in one clinical study.
Devil’s claw has been found to moderately inhibit cytochrome P450 enzymes in vitro, however, the clinical relevance of this is yet to be determined.
Rare case reports suggest that devil’s claw may potentiate the effects of warfarin, requiring caution and possible dose adjustments; however, clinical testing is required to confirm this — use caution in patients receiving warfarin.
Theoretical interaction exists when the herb is used in high doses; however, clinical testing is required to determine significance — observe patients taking concurrent antiarrythmics.
Contraindications and Precautions
Suspend use of concentrated devil’s claw preparations 1 week before major surgery to avoid increased risk of bleeding.
Devil’s claw is not recommended in pregnancy, as it has exhibited oxytocic activity in animals.
Practice Points / Patient Counselling
• The anti-inflammatory action appears to be different to that of NSAIDs and has not been fully elucidated. There is also preliminary evidence of a chondroprotective effect.
• Preliminary research suggests that it is best to take devil’s claw between meals, on an empty stomach.
Answers to Patients’ Frequently Asked Questions
What will this herb do for me?
When will it start to work?
Results from studies suggest that pain-relieving effects will start within 4-12 weeks.
Are there any safety issues?
Devil’s claw should be used cautiously by people with gallstones, diarrhea, stomach ulcers and those taking the drug warfarin. It is also not recommended in pregnancy.