terbinafine_Hydrochloride: profile and news

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Other information

Indication
For the treatment of interdigital tinea infections

Pharmacology
Terbinafine is an allylamine antifungal agent and acts by inhibiting squalene epoxidase, thus blocking the biosynthesis of ergosterol, an essential component of fungal cell membranes. in vitro, mammalian squalene epoxidase is only inhibited at higher (4000 fold) concentrations than is needed for inhibition of the dermatophyte enzyme. Depending on the concentration of the drug and the fungal species test in vitro, Terbinafine may be fungicidal. However, the clinical significance of in vitro data is unknown.

Mechanism Of Action
Terbinafine is hypothesized to act by inhibiting squalene epoxidase, thus blocking the biosynthesis of ergosterol, an essential component of fungal cell membranes.

Drug Category
Trypanocidal Agents; Antifungals; Allylamines; ATC:D01AE15; ATC:D01BA02

Brand Names/Synonyms
Bramazil; Lamasil; Lamisil; Lamisil At; Terbina; Terbinafine; Terbinafine Hcl; Terbinafine Hydrochloride; Ternbinafine Hcl

Dosage Forms
TABLET; CREAM; SPRAY

Absorption
Readily absorbed from gastrointestinal tract.

Interactions
-->Interactions for Terbinafine:

In vitro studies with human liver microsomes showed that terbinafine does not inhibit the metabolism of tolbutamide, ethinylestradiol, ethoxycoumarin, and cyclosporine. In vitro studies have also shown that terbinafine inhibits CYP2D6-mediated metabolism. This may be of clinical relevance for compounds predominantly metabolized by this enzyme, such as tricyclic antidepressants, ß-blockers, selective serotonin reuptake inhibitors (SSRIs), and monoamine oxidase inhibitors (MAO-Is) Type B, if they have a narrow therapeutic window.

In vivo drug-drug interaction studies conducted in normal volunteer subjects showed that terbinafine does not affect the clearance of antipyrine or digoxin. Terbinafine decreases the clearance of caffeine by 19%. Terbinafine increases the clearance of cyclosporine by 15%.

There have been spontaneous reports of increase or decrease in prothrombin times in patients concomitantly taking oral terbinafine and warfarin, however, a causal relationship between LAMISIL^® Tablets and these changes has not been established.

Terbinafine clearance is increased 100% by rifampin, a CyP450 enzyme inducer, and decreased 33% by cimetidine, a CyP450 enzyme inhibitor. Terbinafine clearance is unaffected by cyclosporine.

There is no information available from adequate drug-drug interaction studies with the following classes of drugs: oral contraceptives, hormone replacement therapies, hypoglycemics, theophyllines, phenytoins, thiazide diuretics, beta blockers, and calcium channel blockers.

Chemical IUPAC Name
N,6,6-trimethyl-N-(naphthalen-1-ylmethyl)hept-2-en-4-yn-1-amine

Chemical Formula
C21H25N

Half Life
36 hours

Drug Type
Approved Drug

# Accession No
APRD00508

CAS Registry Number
91161-71-6