b. Usual Dosage. The usual oral dose is 0.5- to 1.0-gram daily, given in a
single dose or divided doses after meals. Administration after a fatty meal increases its
absorption. Treatment must be continued 3 to 6 weeks for skin infections, and up to 6
months if hair or nails are involved.
c. Adverse Reactions. Griseofulvin is a relatively safe drug although some
allergic type reactions (rashes, serum sickness) have been reported. Photosensitivity,
headache, and mental and neurologic problems have been seen in some clients.
d. Cautions and Warnings.
(1) Griseofulvin is ineffective in treating Candida, tinea versicolor, and
bacterial infections. If a mixed infection is present, a second agent must also be
(2) This drug should not be used unless laboratory findings indicate a
(3) In severe cases, concomitant administration of a topical antifungal
(tolnaftate) may be needed.
Griseofulvin may increase the rate of metabolism of oral anticoagulants.
Contraindicated in clients with acute porphyria or with a history of the
e. Supply. The drug is available as 0.5-gram tablets, compressed from
microsized powder to allow maximum absorption.
6-12. TOLNAFTATE SOLUTION
a. Indications. Tolnaftate (Tinactin) is a topical antifungal useful in athlete's
foot, ringworm, and other fungal infections. However, if the scalp, nails, palms, or soles
are infected, an oral preparation such as griseofulvin is indicated.
b. Usual Dosage.
One to 2 drops of solution are rubbed into the lesion twice a day for 2 to
Tinea versicolor: Rub in sufficient amount of solution to cover the area,
twice a day.