Passionflower (Passiflora incarnata) was used in traditional herbal remedies for anxiety, insomnia, and convulsion. During the early twentieth century, this plant was a popular sedative and calmative, and it continues to be used that way. While there is anecdotal evidence of the plant's medicinal uses, it is no longer contained in over-the-counter preparations in the United States today. In Britain, however, passionflower is used more frequently than any other ingredient in herbal sedatives, and in Germany, it is an approved tranquilizer.

Native to the tropical regions of North America, passionflower is now grown throughout Europe. It is a perennial climbing vine with herbaceous shoots and a sturdy woody stem that grows to a length of nearly 10 meters. Each flower has petals varying in color from white to pale red. Inside the petals are wreaths that form rays and surround the axis of the flower. According to folklore, the passionflower was given its name because its corona resembles the crown of thorns worn by Jesus during the crucifixion.

The passionflower's ripe fruit is an orange-colored, multi-seeded, egg-shaped berry containing an edible, sweetish yellow pulp.

The following parts of the passionflower are used:

• Flowers
• Leaves
• Stems
• Above-ground (aerial) parts

Passionflower is primarily used to treat the following:

• Anxiety
• Insomnia
• Nervous gastrointestinal conditions

Passionflower is also traditionally used as a sedative, hypnotic, antispasmodic, and pain reliever for a variety of ailments, including nervous agitation, attention deficit/hyperactivity disorder, insomnia, hysteria, diarrhea, dysentery, neuralgia (pain along a nerve), generalized seizures, nervous tachycardia (abnormally high heart rate), spasmodic asthma, dysmennorhea (painful menstruation), and externally for hemorrhoids. This plant is also incorporated into homeopathic preparations.

Passionflower preparations are made from fresh or dried flowers and other above-ground parts. Both whole and cut raw plant materials are used. Flowering shoots, growing 10 to 15 cm above the ground, are harvested after the first fruits have matured and then either air-dried or hay-dried. Available forms include the following:

• Infusions
• Teas
• Liquid extracts
• Tinctures

Pediatric

• Adjust the recommended adult dose to account for the child's weight. Most herbal dosages for adults are calculated on the basis of a 150 lb (70 kg) adult. Therefore, if the child weighs 50 lb (20 to 25 kg), the appropriate dose of passionflower for this child would be 1/3 of the adult dosage.

Adult

The following are recommended adult doses for passionflower:

• Infusion: 2 to 5 g dried herb three times a day
• Fluid extract (1:1 in 25% alcohol): 0.5 to 1.0 mL three times a day
• Tincture (1:5 in 45% alcohol): 0.5 to 2.0 mL three times a day

Passionflower should not be consumed in quantities higher than recommended doses. Taking too much passionflower could make you sleepy. Do not take it if you are pregnant or breastfeeding.

An animal study has demonstrated that passionflower enhances the effects of pentobarbital, a medication used to promote sleep. Caution is advised when taking passionflower with sedatives because the herb may increase the effects of these substances. Examples of medications with sedative properties include most antihistamines and therapies for anxiety and insomnia.

Aoyagi N, Kimura R, Murata T. Studies on Passiflora incarnata dry extract. I. Isolation of maltol and pharmacological action of maltol and ethyl maltol. Chem Pharm Bull. 1974;22:1008-1013.

Blumenthal M, ed. The Complete German Commission E Monographs. Boston, Mass: Integrative Medicine Communications; 1998: 179-180.

Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, Ore: Eclectic Medical; 1998:109-110.

Capasso A, Pinto A. Experimental investigations of the synergistic-sedative effect of passiflora and kava. Acta Therapeutica. 1995;21:127-140

Dorland's Illustrated Medical Dictionary. 25th ed. Philadelphia, Pa: WB Saunders; 1974.

Grieve M. A Modern Herbal. Vol. II. New York, NY: Dover; 1971:618.

Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company; 1998:1015-1016.

Kimura R, et al. Central depressant effects of maltol analogs in mice. Chem Pharm Bull. 1980;28:2570-2579.

Mabberley DJ. The Plant-Book: A Portable Dictionary of the Higher Plants. England: Cambridge University Press; 1987:434.

Newall C, Anderson L, Phillipson J. Herbal Medicines: A Guide for Health-care Professionals. London, England: Pharmaceutical Press; 1996: 206-207.

Nicholls JM, et al. Passicol, an antibacterial and antifungal agent produced by Passiflora plant species: qualitative and quantitative range of activity. Antimicrob Agents Chemother. 1973;3:110-117.

Soulimani R, Younos C, Jarmouni S, Bousta D, Misslin R, Mortier F. Behavioural effects of Passiflora incarnata L. and its indole alkaloid and flavonoid derivatives and maltol in the mouse. J Ethnopharmacol. 1997;57(1):11-20.

Speroni E, Minghetti A. Neuropharmacological activity of extracts from Passiflora incarnata.Planta Medica. 1988;54:488-491.

Tyler V. Herbs of Choice:The Therapeutic Use of Phytomedicinals. Binghamton, NY: Pharmaceutical Products Press; 1994:119.

Tyler V. The Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed. New York, NY: Pharmaceutical Products Press; 1993:237-238.

White L, Mavor S. Kids, Herbs, Health. Loveland, Colo: Interweave Press; 1998:22, 38.