Herb | Interaction | Potential Effects |
---|---|---|
Chamomile Chamomilla recutita |
Anticonvulsants. Barbiturates & Sedatives. Benzodiazepines |
Increase in bruising and bleeding. Drowsiness. |
Devils Claw Harpagophytum procumbens |
Warfarin. Antiarrythmic drugs. Aspirin. |
Increase in bruising and bleeding. May increase arrythmia |
Dong Quai Angelica sinensis |
Warfarin. Oestrogen/HRT. Hormone-sensitive tumours. Pregnancy. |
Increase in bruising and bleeding. Potential excess of oestrogen. May cause uterine contractions |
Echinacea spp. |
Hepato-toxic agents (e.g. Methotrexate). Immune suppressant medication. |
Possible liver toxicity. Counteracts effect of immune suppressants. |
Feverfew Tanacetum parthenium |
Anticoagulants e.g. Warfarin. Pregnancy. |
Increased risk of bleeding, bruising and haemorrhage. |
Garlic Allium sativum |
NSAIDs – Non-steroidal anti-inflammatory drugs. Saquinivir. Anticoagulats. Antiplatelet drugs. Antihypertensive drugs. Bleeding abnormalities. |
Decreases efficacy of saquinavir. May increase bleeding. |
Ginger Zingiber officialis |
Warfarin. Antiplatelet drugs. High doses in pregnancy. |
Risk of post-operative bleeding, haemorrhage. |
Ginkgo Ginkgo biloba (circulatory stimulant) |
Anticoagulants (warfarin). NSAIDs. Anticonvulsants (phenytoin). Monoamine oxidase inhibitors (MAOIs). |
May increase bleeding. Reduced efficacy of anticonvulsants. Intensify effects of MAOIs increasing side effects |
Ginseng (Siberian) Eleutherococcus senticosus |
Anticoagulants (warfarin). NSAIDs. Estrogen replacement therapy. MAOIs. |
May decrease effectiveness. Increase heart rate or blood pressure. May cause bleeding in women post-menopause. Increase side effects of MAOIs Caffeine-like palpitations, tremors, insomnia |
Ginseng (Korean) Panax ginseng |
Stimulants e.g. caffeine Hypertensives |
Insomnia, anxiety, irritability, increase high blood pressure, tremor, hysteria, mania, headaches, palpitations, diarrhoea, skin eruptions, menstrual abnormalities |
Guarana Paulinia cupana (contains caffeine) |
Anti-anxiety agents. Anti-hypertensives. Sedatives/hypnotics/tranquilisers. |
Counteract effects of these medicines. |
Liquorice Glycyrrhiza glabra |
Antihypertensives. Prednisolone. Hydrocortisone. Diuretics. Cardiac glycosides, e.g. Digitalis/Digoxin |
Increased levels of steroids (reduced clearance). Loss of potassium. Increased sensitivity to digitalis glycosides. |
Passionflower Passiflora incarnata |
Benzodiazepines. Barbiturates. Alcohol. Antipsychotics. Antidepressants. |
Excess sedation, coma |
Rosemary Rosmarinus officinalis |
Pregnancy. | Anti-implantation effect, possibly abortifacient. |
Saw palmetto Serenoa serrulata |
Oestrogen replacement therapy and oral contraceptives. Pregnancy. |
Hormonal effects. |
St John’s Wort Hypericum perforatum |
Antidepressants. Anticonvulsants. HIV protease inhibitors. Oral contraceptive pill. |
Serotonin excess. Increased frequency. Decreased serum levels. Mid-cycle bleeding. |
Valerian Valariana officinalis |
Observe with sedatives. | Possible excess sedation. |
Wormwood | Anticonvulsants. | Insomnia, nightmares, convulsions, neurotoxic in high doses, or if taken over long periods, do not take regularly |