Systemic Pharmacology Flashcards
Examples of Oral Antifungals
Griseofulvin
Terbinafine (Lamisil)
Itraconazole (Sporonox)
What do oral antifungals treat?
Scalp & nail fungal disorders
Medications to Treat Scalp Fungal Infections
1st: Griseofulvin
2nd: Terbinafine (Lamisil)
Medications to Treat Nail Fungal Infections
1st: Terbinafine (Lamisil)
2nd: itraconazole (Sporanox)
MOA of Griseofulvin
Inhibits fungal cell division
Binds to keratin making it resistant to fungal invasion
Administration of Griseofulvin
Take with a fatty meal: increases absorption, lessens GI upset
Distribution of Griseofulvin
Deposited in the keratin layer of skin, hair, & nails
Concentrates in liver, fat, & skeletal muscles
Where is griseofulvin metabolized?
Hepatically
2 Formulations of Griseofulvin
Microsize
Ultramicrosize
Contraindications with Griseofulvin
Liver failure Porphyria Pregnancy (Cat. X) Caution with penicillin allergy Breast feeding
SE of Griseofulvin
Photosensitivity SJS Toxic epidermal necrolysis Erythema multiforme Jaundice Elevated liver enzymes Granulocytopenia Dizziness Headache Fatigue N/V Drug induced lupus like syndrome
Drug Interactions with Griseofulvin
Multiple Warfarin Oral contraceptives Alcohol Barbiturates Cyclosporine
Monitoring with Griseofulvin
LFTs: liver failure
CBC: granulocytopenia
Renal function tests
MOA of Terbinafine (Lamisil)
Creates ergesterol deficiency within the fungal cell wall leading to cell death
Distribution of Terbinafine (Lamisil)
Sebum & skin
How is terbinafine (Lamisil) metabolized?
Hepatically
Drug Reactions with Terbinafine (Lamisil)
Many
Inhibit CYP450 enzymes
Terbinafine (Lamisil) SE
Headache
Diarrhea
Elevated liver enzymes
Monitoring for Terbinafine (Lamisil)
AST/ALT prior to initiation
CBC
Assess taste/smell disturbances
What is terbinafine used for?
Treat tinea capitis, and onychomycosis
Reasons to Treat Onychomycosis
Cosmetic reasons
DM & onychomycosis
Hx of lower extremity cellulitis & ipsilateral onychomycosis
Pain/discomfort secondary to infection
Black Box Warning for Itraconazole (Sporanox)
Negative inotropic effects have been observed following IV administration
Discontinue or reassess if S/S of HF occur during treatment
Contradictions for Itraconazole (Sporanox)
Ventricular dysfunction
CHF
Pregnancy
Concomitant use of other CYP450 drugs
How is itraconazole (Sporanox) metabolized?
Hepatically
Drug Interactions with Itraconazole (Sporanox)
PPIs Anxiolytics Pain medications Antiplatelet agents Antihypertensives Statins
Itraconazole (Sporanox) SE
Nausea Diarrhea Edema Headache Rash Abnormal LFTs Heart failure Arrhythmia Hearing loss Many others
Monitoring with Itraconazole (Sporanox)
Baseline LFTs
Monthly LFTs
Serum contraindications
5-Alpha-Reductase Inhibitor Medication for Fungal Infections
Finasteride (Propecia)