C/4. Antifungal Agents Flashcards
Drugs need to know in this topic (9)
Amphotericin B Nystatin Clotrimazole Fluconazole Itraconazole Voriconazole Flucytosine (5-FC) Caspofungin Terbinafine
Amphotericin B
Both polar and nonpolar structures
Interacts with ergosterol in fungal membrane and form pores which disrupt membrane permeability
Fungicidal effect
Broadest antifungal spectrum
Systemic fungal infection: Against aspergillus, Blastomyces, Candida, Cryptococcus, Histoplasma, Mucor, Sporothrix
Oral(poor bioavailability)
IV
Topical
Poor CNS penetration (intrathecal injection is required against Cryptococcal or Candida meningitis)
Clearance via hepatic metabolism and renal elimination
Fever, chill, muscle spasm
Dose dependent : nephrotoxicity, CNS toxicity, Anemia
Nystatin
Both polar and nonpolar structures
Interacts with ergosterol in fungal membrane and form pores which disrupt membrane permeability
Fungicidal effect
Topical for Candidiasis
Clotrimazole
Tx for dermatophytes, superficial candidiasis, vaginal candidiasis
OTC drug
Can cross BBB(ketoconazole can’t penetrate)
Hepatic metabolism
Renal elimination
Inhibitors of CYP450 enzymes
GI symptom, skin rash
Decreased synthesis of steroid hormones(mainly cortisol and testosteron): decreased libido, gynecomasia, menstrual irregularity
Visual disturbances
Fluconazole
Oropharyngeal, genital candidiasis
Coccidiodes infection
Cryptococcus meningitis
Hepato metabolism
Renal elimination
Inhibitor of CYP450 enzymes
GI symptom, skin rash
Decreased synthesis of steroid hormones(mainly cortisol and testosteron): decreased libido, gynecomasia, menstrual irregularity
Visual disturbances
Itraconazole
Balstomyces and sporothrix infections
2nd line agent for Aspergillus, coccidiodes, Cryptococcus, Histoplasma
Hepato metabolism
Renal elimination
Inhibitor of CYP450 enzymes
GI symptom, skin rash
Decreased synthesis of steroid hormones(mainly cortisol and testosteron): decreased libido, gynecomasia, menstrual irregularity
Visual disturbances
Voriconazole
2nd generation
Against Aspergillus, invasice candida infection
Hepato metabolism
Renal elimination
Inhibitor of CYP450 enzymes
GI symptom, skin rash
Decreased synthesis of steroid hormones(mainly cortisol and testosteron): decreased libido, gynecomasia, menstrual irregularity
Visual disturbances
Flucytosine (5-FC)
Activated by fungal cytosine deaminase to 5-FU which incoporates into fungal RNA
Inhibits DNA synthesis
Narrow spectrum
Combination with amphtericin B or triazole to tx Cryptococcal meningitis and invasive candidiasis
Oral
Can penetrate BBB
Renal elimination
BM suppression
Alopecia
Liver dysfunction
Caspofungin
Inhibits the synthesis of beta(1-3)-glucan, a critical component of fungal cell wall
Candida infections failed to respond to amphotericin B
Mucar infeciton
Aspergillus infection
IV
Hepatic metalism
GI distress
Fever, Headache, skin rash
Terbinafine
Inhibits squalene epoxidase, interfering with ergosterol synthesis
Fungicidal effect
Systemic drigs for Superficial fungal infections
Onychomycosis
Dermatophytosis ofr the skin hair
Topical (OTC drug)
Oral(prescription drug)
GI distress
Headache, rash