Terbinafine

Terbinafine (TDT 067) is an antifungal medication used to treat fungal infections. It is a potent non-competitive inhibitor of squalene epoxidase from Candida with a Ki of 30 nM.

Signaling Pathways >> Anti-infection >> Fungal

Research Areas >> Infection

Ki: 30 nM (squalene epoxidase)[1]

Terbinafine has a primary fungicidal action in vitro against most fungal pathogens, including dermatophytes, and dimorphic and filamentous fungi. Terbinafine specifically inhibits fungal ergosterol biosynthesis at the point of squalene epoxidation. The treated fungal cells rapidly accumulate tlic intermediate squalene and become deficient in the end-product of the pathway, ergosterol[1].

Terbinafine is not only active after topical application but is very effective in experimental dermatophytoses following oral administration. In fungi infected guinea-pigs, the skin temperature dropps dramatically after the fourth treatment of terbinafine[2].

Guinea-pigs: The backs (lumbar regions) of guinea-pigs, which have been mechanically depilated, are infected with 0.1 mL Sabouraud's dextrose 2% broth containing 106 c.f.u. of Truhophyton mentagrophytes. The treatments commence 48 h post-inoculation. The test compounds (Terbinafine) are suspended in 2% tylose and Tween 80 and administered via a stomach tube once daily on 9 consecutive days, or dissolved in a mixture of polyethylene glycol 400 and etbanol and spread on the infected part ot the body in a volume of 0.4 mL with a Hrigalski spatula once daily for 1-7 consecutive days[2].

[1]. Ryder NS, et al. Terbinafine: mode of action and properties of the squalene epoxidase inhibition. Br J Dermatol. 1992 Feb;126 Suppl 39:2-7.

[2]. Mieth H, et al. Preclinical evaluation of terbinafine in vivo. Clin Exp Dermatol. 1989 Mar;14(2):104-7.

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MOLECULAR FORMULA :

C21-H25-N

MOLECULAR WEIGHT :

291.47

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - woman

DOSE/DURATION :

210 mg/kg/6W-I

TOXIC EFFECTS :

Sense Organs and Special Senses (Taste) - change in function

REFERENCE :

LANCAO Lancet. (7 Adam St., London WC2N 6AD, UK) V.1- 1823- Volume(issue)/page/year: 340,728,1992

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - man

DOSE/DURATION :

3918 ug/kg

TOXIC EFFECTS :

Gastrointestinal - other changes

REFERENCE :

KSRNAM Kiso to Rinsho. Clinical Report. (Yubunsha Co., Ltd., 1-5, Kanda Suda-Cho, Chiyoda-ku, KS Bldg., Tokyo 101, Japan) V.1- 1960- Volume(issue)/page/year: 27,6087,1993

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Human - woman

DOSE/DURATION :

200 mg/kg/40D-I

TOXIC EFFECTS :

Behavioral - anorexia (human) Liver - jaundice, cholestatic Skin and Appendages - dermatitis, other (after systemic exposure)

REFERENCE :

JOHEEC Journal of Hepathology. (Elsevier Science, 655 Avenue of the Americas, New York, NY 10010) V.1- 1985- Volume(issue)/page/year: 24,753,1996

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

4 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

DRFUD4 Drugs of the Future. (J.R. Prous, S.A., Apartado de Correos 540, 08080 Barcelona, Spain) V.1- 1975/76- Volume(issue)/page/year: 9,427,1984

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

213 mg/kg

TOXIC EFFECTS :

Behavioral - somnolence (general depressed activity) Behavioral - ataxia Lungs, Thorax, or Respiration - dyspnea

REFERENCE :

53XPA8 "Proceedings of the International Congress of Chemotherapy, 13th, Vienna, 1983," Spitzy, K.H., and K. Karrer, eds., 18 vols., Vienna, Austria, Verlag H. Egermann, 1983 Volume(issue)/page/year: 6,116/52,1983

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

4 gm/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

DRFUD4 Drugs of the Future. (J.R. Prous, S.A., Apartado de Correos 540, 08080 Barcelona, Spain) V.1- 1975/76- Volume(issue)/page/year: 9,427,1984

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

393 mg/kg

TOXIC EFFECTS :

Behavioral - somnolence (general depressed activity) Behavioral - ataxia Lungs, Thorax, or Respiration - dyspnea

REFERENCE :

53XPA8 "Proceedings of the International Congress of Chemotherapy, 13th, Vienna, 1983," Spitzy, K.H., and K. Karrer, eds., 18 vols., Vienna, Austria, Verlag H. Egermann, 1983 Volume(issue)/page/year: 6,116/52,1983