Botanical name: 

The root and stem-base of Passiflora incarnata, Linné (Nat. Ord. Passifloraceae). Southern United States. Dose, 5 to 120 grains.
Common Names: Passion Flower, May Pop.

Principal Constituent.—Traces of an alkaloid.
Preparation.—Specific Medicine Passiflora. Dose, 1 to 120 drops.

Specific Indications.—Irritation of brain and nervous system, with atony; insomnia from worry or overwork, or from febrile excitement; sleeplessness in the young and the aged; convulsive movements; hysteria; infantile nervous irritability; dyspnea palpitation of the heart from excitement or shock.

Action and Therapy.—Passiflora is used chiefly in spasmodic affections and as a rest-producing agent. While somewhat hypnotic but acting slowly, it is better as a nerve calmative, rest resulting from its quieting influence, and sleep following in consequence of this rest rather than through any narcotic effect of the drug. It is one of the best agents we possess to allay restlessness and overcome wakefulness, when the result of exhaustion, with cerebral fullness, or due to the nervous excitement of debility. It is admirably adapted to young children and old persons to promote rest and sleep, and it acts similarly when sleeplessness is caused by worry, overwork-physical and mental-or due to the exhaustion of fevers. Few remedies are better to produce sleep during typhoid fever. The sleep induced by the restful influence of passiflora is a quiet, peaceful slumber, undisturbed by any unpleasantness, and the patient awakens calm and refreshed. Our experience with passiflora has shown it to be slow in producing sleep, and usually more effective in the second twenty-four hours than the first. Even small doses of it may cause nausea and vomiting. When this occurs its use should be discontinued. For the nervous phenomena and unrest accompanying la grippe, passiflora is a safe and often effectual remedy.

When due to atony, passiflora may relieve pain though its anodyne properties are not marked. It is occasionally useful in nervous forms of headache due to debility, and in certain neuralgic pains associated with the process of menstruation. Reflex pains during pregnancy and the menopause may be relieved by it.

Passiflora is antispasmodic. If given when the aura is felt it may ward off or mitigate an attack of epilepsy, but is of no value when the seizure takes place. It is a better remedy to limit spasms of childhood, and has thus been successfully exhibited in trismus nascentium, and convulsions from dentition, or the presence of worms. It may be used with some degree of success in preventing spasm during meningeal disorders, in chorea, and hysterical convulsions. While more or less effectual in most varieties of spasm when established, except in epilepsy, it is a far better agent for intercurrent use to control the irritability which precedes and often provokes the convulsive explosions. It has been greatly lauded in tetanus, but little reliance should be placed upon so feeble an agent in so grave a condition. Whooping-cough is often mitigated by passiflora, and for spasmodic asthma it frequently proves one of the most effective of remedies.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.