Natural Products

Passionflower

Passiflora incarnata

Efficacy

• Indications with proven efficacy:
  Mild sleeping problems Nervous unrest
  
• Indications with possible, but poorly documented efficacy - the use of this product cannot be recommended:
  Opiate withdrawal
• Also used for these other indications, but with no proof of efficacy:
  Attention deficit disorder in children
  Cardiac rhythm abnormalities
  Hemorrhoids (topical)
  Hypertension
  Menopause symptoms
  Nervous tachycardia
  Neuralgia
  Pain
  Seizures

Security

• Risk of Drug Interactions: Moderate
• Adverse Effects: Not Frequent

What is it?

Because of its great beauty, passionflower is a very popular plant. People use it as an ornamental plant in their garden around the world. It is found in all the Americas. When talking about passionflower, people usually refer to Passiflora incarnata used for its medicinal properties. Interestingly, there is more than 400 different species in the genus Passiflora. The applicable parts of passionflower are the aboveground parts (leaves and stems, fresh or dried) which contain flavonoids, cyanogenic glycosides, alcaloids (harmans), maltol, coumarins and several other substances. Passionflower's properties are usually attributed to its active flavonoids and alcaloids. Passionflower appears to have antidepressant activity due to its inhibition of monoamine oxydase (MAO). American herborists pretend that passionflower is one of the best "tranquilizers" found in nature.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) or homeopathic medicine number (DIN-HM) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plants content varies naturally from plant to plant – just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

Does it work?

There is evidence that passionflower effectively helps to control nervous unrest and mild insomnia. Moreover it could be used in opiate withdrawal in which it may be of some benefit.

• Nervous unrest:
  The typical dose is 250 mg to 2 g of dried aboveground parts, 3 to 4 times a day. Average doses range from 4 to 8 grams daily.
• Mild insomnia:
  Even though passionflower has been proven effective in this indication, no dosage recommendations can be found in literature.
• Opiate withdrawal:
  To attenuate withdrawal symptoms, 60 drops of liquid extract in combination with 0.8 mg of clonidine has been used daily. It could reduce anxiety, irritability, insomnia and agitation.
  

There is insufficient reliable information to conclude that passionflower is effective in any other indication.

Is it safe?

• Passionflower is not associated with any severe toxicity; when recommended doses are used, it should not be a health risk. In fact, it has been used for centuries with no reports of specific problems. Adverse reactions include dizziness, confusion and loss of coordination. People should avoid large amounts since passionflower could depress (slow) the central nervous system. Passionflower is usually not associated with allergic reactions.
• Passionflower is contraindicated in pregnant women because it may cause uterine stimulation. There is insufficient reliable data concerning breast-feeding to support its use. Pregnant and lactating women should thus avoid this product.
• Because of its inhibitory effect on MAO, it could alter the effect of antidepressants such as MAOI. Taking it in combination with barbiturates, sedatives or tranquilizers may increase its sedative effect… Before taking passionflower, check with your pharmacist to make sure that there are no interactions with your regular medication.

Clinical notes

• Passionflower appears to have significant sedative and antianxiety properties with minimal toxicity. It is often found in combination with other plants (most often valerian).

References

1. Blumethal M et al. The Complete German Commission E monographs, 1998
2. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2007
3. Lininger S. et Al. The Natural Pharmacy, Prima Health, 1998
4. Peirce, Andrea. Practical Guide to Natural Medicines, APha, 1999
5. Facts & Comparisons, The Lawrence review of natural products, 1998
6. Passeportsanté.net. Passiflore. http://www.passeportsante.net
7. Barnes J. et Al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002
8. Rotblatt M. et Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002