Most common nail disorder Toenails >>> fingernails

Onychomycosis Lecture Flashcards by Beth Cocker

Onychomycosis

Most common nail disorder

Toenails&raquo_space;> fingernails

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Dermatophytes

Trichophyton rubrum

Trichophyton mentagrophytes

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Yeast

Candida albicans

Candida parapsilosis

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Nondermatophytes

Aspergillus

Scopulariopsis

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Why treat?

Quality of life
Physiological stress
Pain
Inflammation
Peripheral circulation
Foot ware
Infection potential

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Types of onychomycosis

DISTAL SUBUNGUAL ONYCHOMYCOSIS
White superficial onychomycosis
Proximal subungual onychomycosis
Candida Onychomycosis

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Distal Subungual Onychomycosis

Most common
Infection begins in the distal area of the nail bed (tip of the toe)
THICK toenail

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White superficial

Toe nail infection only
Involves the surface of the nail –> not a thicker nail
Nail is soft, dry, and easily scraped off

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Proximal Subungual Onychomycosis

Infection that beings at the nail bed and moves out

Leads to separation from nail bed

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Dystrophic

Nail deformities

- Increased risk of infection in immunocompromised and diabetic patients

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Candida Onychomycosis

Immunocompromised
Seen in dishwashers
Nails appear opaque and does not crumple
Yellow-brown in collor
FINGER NAILS

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Differential diagnosis

Psoriasis
Pseudomonal infections
Medications
Exzema
Dermatitis
Trauma
Ischemic conditions (poor blood flow)

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People at risk

Diabetes
Immunosuppressant and systemic antibiotics
HIV/AIDS: younger age –> proximal subungual onychomycosis
Geriatrics >60
Institutional living
Athletes
Health clubs

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Clinical presentation/symptoms

Hyperkeratosis (thickening of the nail)
Discoloration of the nail (white or brown)
Brittleness
Onycholysis (separation of the nail from the bed
Paronychial inflammation
Recurrent tinea pedis
Pain

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Diagnosis

History/clinical symptoms
KOH prep of nail clippings
Fungal culture
Nail biopsies
- Need test as well as physical observations

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Ideal agents

Good concentration in the nail bed
High clinical/mycologic cure rate
Low rate of relapse
Short term therapy
Few ADR's and interactions
Cost effective

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Treatment options

Nail removal
Topiocal therapy (ineffective)
Griseofulvin
Ketaconazole (DO NOT USE)
Itraconazole
Fluconazole
Terbinafine

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Topical Nail Therapy

Nail lacquers (ciclopirox- PenLac)
Antifungal agents: solutions or creams (clotrimazole, tolnaftate, terbinafine) or powders (tolnaftate
– Low cure rate and high relapse rate

History of high transaminase levels or have liver disease and want something for fungal infections?

PenLac bc others raise transaminase levels

Cons of Topical Nail therapy

Cannot penetrate harden nail mass
Requires multiple daily applications and long duration of therapy
- Can be used with other oral treatments

Griseofulvin

First oral agent; Fungistatic
Microsize: need to take with a fatty meal to increase adsorption
Ultramicrosize: Increased absorption
- Monitor Baseline AST, ALT, and CBC and repeat AST and ALT if treatment last >6 wks

Dosage of Griseofulvin

500 mg QD-BID

Griseofulvin Disadvantages

High rate of resistance, high rate of relapse, low cure rate, long duration, intolerable adverse drug reactions
ADR’s: skin rashes, urticaria, GI, photosensitivity, toxic epidermal necrolysis (sore throat, fever, rash)
- Potential cross reactive with penicillin

Griseofulvin Drug Interactions

Anticoagulants, oral contraceptives, cyclosporine and salicylates
Phenobarbital decrease serum concentrations

Fluconazole (Diflucan)

Fungistatic --> inhibits the synthesis of ergosterol | Toe nails

Fluconazole (Diflucan) Advantages

Good nail bed and matrix penetration Detect in toenails 6 months after Good absorption not influence by gastric acid, food, antacids or H2 blockers

Fluconazole (Diflucan) Disadvantages

Lacks indication | Not extensively studied

Fluconazole (Diflucan) Dosage

150, 300, or 450 mg week for 3 months 3-12 months of treatment 80% excreted unchanged via urine

Fluconazole (Diflucan) Monitor & Interaction

Baseline AST, ALT, CBC; remonitor >6 wk therapy Increases the effects of warfarin, cyclosporine, theophyline, phenytoin, sulfonylureas QT prolongation and decreases oral contraceptives

Fluconazole (Diflucan)ADR's

GI- nausea, diarrhea and ab pain, elevated liver enzymes | Pulse dosing decrease incidence

Intraconzaole (Sporanox)

Fungistatic- inhibits the synthesis of ergosterol For onychomycosis; good concentration in nail matrix and bed Detectable for 6 months after

Intraconzaole (Sporanox) Dosage

Toenails: 200 mg daily for 12 weeks Fingernails: 200 mg BID for 3 days per month for 2 months (separated by 3 weeks)

Intraconzaole (Sporanox) Monitor

Baseline AST, ALT, CBC; recheck monthly

Intraconzaole (Sporanox) Drug Interactions

Warfarin, H2 blockers, PPI, DDI, Ritonavir, Indiavir, Benzodiazepines, Lovastatin, Simvastatin, Cyclosporine, Tacrolimus, Phenytoin, Phenobarbital, carbamazepine, rifamycins

Intraconzaole (Sporanox) ADR's

``` GI- nausea, vomiting, diarrhea, ab pain Headache Dizziness Rash ELEVATED LIVER ENZYMES ```

Intraconzaole (Sporanox) FDA Warnings

Hepatoxicity CHF, cardiac dysfunction or a history of CHF - Discontinue if signs or symptoms of CHF

Intraconzaole (Sporanox) Disadvantages

Drug interactions Expensive Must be taken with full meal Acidic environment for absorption - no antacids, H2 blockers, PPIs; need achlorhydria - soda increases adsorption

Terbinafine (Lamisil)

First line therapy FDA indicaiton More effective than itraconzaole Fungicidals

Terbinafine (Lamisil) Dosage

Fingernail: 250 mg QD for 6 weeks Toenails: 250 mg QD for 12 weeks

Terbinafine (Lamisil) FDA warnings

Hepatotocicity (rare) - Liver failure and death - Not indicated for chronic or active hepatic disease * **NO LIVER DISEASE PATIENTS***

Terbinafine (Lamisil) Monitor and interactions

Baseline AST, ALT, CBC; recheck after >6 wk of treatment Tricyclic antidepressants, SSRI's (fluoxetine, paroxetine) Venlafaxine and cyclosporine

Terbinafine (Lamisil) ADRs

GI- diarrhea, ab pain, nausea, and flaulence Rash TASTE DISTRUBANCES ELEVATED LIVER ENZYMES

Terbinafine (Lamisil) Advantages

Fewer drug interactions, fewer ADR's, fungicidal activity, pregnancy category B

Therapeutic considerations

``` Concomitant disease states (don't treat liver disease patients) Drug interactions (azoles) ADR's (terbinafine and fluconazole = better tolerated) How much they cost ```