a. Pyrantel Pamoate (Antiminth). Pyrantel pamoate is the drug of choice in
the treatment of Ascaris lumbricoides (roundworm) and Enterobius vermicularis
(pinworm) infestations. This drug acts to paralyze the worms. Once paralyzed, the
worms are expelled from the gastrointestinal tract. Purges (that is, use of laxatives) are
not used after the administration of this drug.
(1) This drug should be used with caution in patients who suffer from liver
dysfunction. Adverse effects associated with this agent include anorexia, nausea,
vomiting, abdominal cramps, and drowsiness.
(2) The caramel-flavored suspension contains 50 milligrams of pyrantel
base per milliliter. For the treatment of pinworms and round worms, a single oral dose
of 11 milligrams of pyrantel pamoate per kilogram of body weight is given. The
maximum dose is 1 gram of pyrantel base. This corresponds to a dosage of 1 milliliter
of pyrantel pamoate per 10 pounds of body weight (1 teaspoonful = 5 milliliters).
Treatment may be given before or after meals. For pinworm infestations, the dose
should be repeated in 2 weeks. For roundworm infestations, the dose should be
repeated only if ova (eggs) are still found in the feces 2 weeks after the initial treatment.
b. Mebendazole (Vermox) Chewable Tablets. Mebendazole is the broadest
spectrum anthelmintic agent. It is used in the treatment of Trichuris trichiura
(whipworm), Enterobius vermicularis (pinworm), Ascaris lumbricoides (roundworm),
Ancylostoma duodenale (Old World hookworm), and Necator americanus (New World
hookworm). Vermox exerts its' anthelmintic effect by blocking glucose uptake by the
susceptible worms, thereby depleting the worms' energy level until they cannot survive.
(1) This agent is contraindicated in pregnant women, and it should be used
with caution with children under 2 years of age. Adverse reactions associated with this
agent include transient abdominal pain and diarrhea. No pre or post-treatment purging
is used with Vermox. The 100 milligram chewable tablets should be chewed before
they are swallowed.
(2) The dosage is the same for children and adults: 100 milligrams taken
twice daily for three days for whipworms, hookworms, and roundworms. Then a stool
sample should be examined for parasite ova in 2 to 3 weeks to determine if a second
course of treatment is necessary. In a pinworm infestation, the dose is 100 milligrams
taken one time only, this dose should be repeated in 2 weeks.