This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Pink Root, Spigelia Marilandica. Official only in the U. S. An efficient anthelmintic against the round worm or lumbricoid worm; it acts much as does santonin. Toxic doses slow and weaken the heart's action and depress the motor spinal cord and the respiratory center (Wilcox). This drug is in too common lay use, since many parents give it to their children in ignorance of its toxic action, and it makes the little ones drowsy and may even occasion convulsions.
The most satisfactory way to give the drug is to combine one part fl. senna with 2 parts fl. spigelia, the adult dose of the mixture being 2 fluidrachms for an adult and less for children. Repeat every four hours until effect. The average dose fl. spigelia is 1 fluidrachm.