Passionflower (Passiflora incarnata) was used in traditional remedies as a "calming" herb for anxiety, insomnia, seizures, and hysteria. During the early twentieth century, this herb was included in many over-the-counter sedatives and sleep aids. In 1978, the U.S. Food and Drug Administration (FDA) banned these preparations due to a lack of proven effectiveness. In Germany, however, passionflower is available as an over-the-counter sedative (in combination with other calming herbs such as valerian and lemon balm). It is also used in German homeopathic medicine to treat pain, insomnia, and nervous restlessness. Today, professional herbalists use passionflower (often in combination with other calming herbs) to help treat insomnia, tension, and other health problems related to anxiety and nervousness.

Native to the southeastern 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 above-ground parts (flowers, leaves, and stems) of the passionflower are used for medicinal purposes.

Although the safety and effectiveness of passionflower have not been thoroughly investigated in scientific studies, many professional herbalists report that this herb is effective in relieving anxiety, insomnia, and related nervous disorders. Also, there are some over the counter remedies for attention deficit hyperactivity disorder (ADHD) that contain passionflower along with valerian, kava, and lemon balm. The safety and effectiveness for these combination remedies for ADHD is not known, particularly since there have been case reports of hepatitis from kava.

One recent study including 36 men and women with generalized anxiety disorder found that passionflower was as effective as a leading anti-anxiety medication when taken for one month. A second study including 91 people with anxiety symptoms revealed that an herbal European product containing passionflower and other herbal sedatives significantly reduced symptoms compared to placebo. An earlier study, however, failed to detect any benefits from an herbal tablet containing passionflower, valerian, and other sedative herbs.

Passionflower may also relieve anxiety in people who are recovering from heroin addiction. In a recent study including 65 heroin addicts, those who received passionflower in addition to a standard detoxification medication experienced significantly fewer feelings of anxiety than those who received the medication alone.

Passionflower preparations are made from fresh or dried flowers and other above-ground parts of the plant. 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 grams of dried herb three times a day
• Fluid extract (1:1 in 25% alcohol): 10 to 30 drops, three times a day
• Tincture (1:5 in 45% alcohol): 10 to 60 drops, three times a day

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain active substances that can trigger side effects and that can interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care, preferably under the supervision of a practitioner knowledgeable in the field of botanical medicine.

In general, passionflower is considered to be safe and nontoxic. However, there are isolated reports of adverse reactions associated with this herb. Nausea, vomiting, drowsiness, and rapid heartbeat are among some of the adverse reactions reported.

Do not take passionflower if you are pregnant or breastfeeding.

Sedatives
An animal study has demonstrated that passionflower enhances the effects of pentobarbital, a medication used to promote sleep and for seizure disorders. Caution is advised when taking passionflower with sedatives because the herb may increase the effects of these substances. Additional examples of medications with sedative properties include certain antihistamines, such as diphenhydramine and hydroxyzine; drugs for anxiety, like a class called benzodiazipines including diazepam and lorazepam; and other medications used to treat insomnia. Interestingly, passionflower appears to work similarly to benzodiazipines.

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