1
Q
First and second line oral antifungals for scalp and nail disorders?
A
scalp:
1st line: griseofulvin
2nd: terbinafine (lamisil)
Nails:
1st line: terbinafine (lamisil)
2nd: itraconazole (sporanox)
2
Q
Use of griseofulvin: MOA and administration?
A
- 8 wks for tinea capitis
- MOA: fungistatic, binds to human keratin making it resistant to fungal invasion
- admin:
taken with fatty meal helps to increase absorption, take with food in general to lessen GI upset
3
Q
Griseofulvin:
Half life, absorption, distribution and metabolism?
A
- half life: 9-24 hrs (erratic)
- absorption: microsize is variable (25-70% of an oral dose) - enhanced by ingestion of a fatty meal.
GI absorption of ultramicrosize is 1.5x that of microsize - distribution: deposited in keratin layer of skin, hair and nails, concentrates in liver, fat, and skeletal muscles
- metabolism: extensive hepatic
4
Q
What are the 2 formulations for griseofulvin?
A
- smaller the particle size the greater the bioavailability
- dosing:
microsize: suspension, grifulvin V tabs: 20-25 mg/kg/day
ultramicrosize: Gris-PEG tabs - 10-15 mg/kg/day
5
Q
CIs and precautions with admin of griseofulvin?
A
- liver failure
- porphyria (defect in enzyme for heme synth)
- preg category x
- use with caution if hx of PCN allergy as potential for cross reactivity
- breast feeding not recommended (can use in kids though)
6
Q
Adverse rxns of griseofulvin?
A
- skin: photosensitivity, SJS, toxic epidermal necrolysis, erythema multiforme
- liver: jaundice, elevated liver enzymes
- bone marrow: granulocytopenia
- neuro: dizziness, HA, fatigue
- GI: N/V (MC)
- drug induced lupus like syndrome
7
Q
Drug interactions,monitoring - griseofulvin?
A
- multiple
- metabolized through CYP1A2, CYP2C9, and CYP3A4
- beware of warfarin, OCPs, alcohol, barbiturates, cyclosporine (just a few)
- monitoring: CBC, renal and liver fxns if long term therapy (beyond 8 wks)
8
Q
MOA of Terbinafine (lamisil)?
A
- systemic allylamine antifungal
- MOA: creates ergesterol deficiency w/in the fungal cell wall leading to cell death
9
Q
Comparison of griseofulvin and terbinafine?
A
- terbinafine was superior for tx of infections from Trichophton species
- griseofulvin was superior for tx of infections due to Microsporum
- have failure with one drug after tx - switch to the other (don’t know what species you are targeting)
10
Q
Pharmacokinetics/dynamics of terbinafine?
A
- half life: 36 hrs
- distribution to sebum and skin
- metabolized hepatically
- inhibition of CYP450 enzymes: mult drug interactions including metoprolol and tramadol
11
Q
MC terbinafine SEs?
Monitoring tests?
A
- HA
- diarrhea
- elevated liver enzymes
- monitoring tests:
AST/ALT prior to initiation
repeat if used for greater than 6 wks
CBC
assess for taste and/or smell disturbance
12
Q
Use of terbinafine for tinea captious? Formulations?
A
- approved for use in 4 and over
formulations avail: - granules (sprinkle on top of non-acidic foods)
- tablets
13
Q
Use of terbinafine for onychomycosis?
A
- greater efficacy and fewer SEs than others
- cure rate is 76%
pts who need tx:
- cosmetic reasons
- diabetes and onychoycosis
- hx of lower extremity cellulitis and ipsilateral onychomycosis
- pain or discomfort secondary to infection
14
Q
Dosing of terbinafine?
A
-fingernails:
250 mg daily x 6 wks
- toenails:
250 mg daily x 12 wks
15
Q
Cure rate for Itraconazole (sporanox) for oncyhomycosis? BBW?
A
- cure rate 63% for pulse therapy and 59% for continuous therapy
- BBW:
negative inotropic effects have been observed following IV admin. D/C or reassess use if signs or sxs of heart failure occur during tx
16
Q
CIs for itraconazole?
A
- ventricular dysfxn
- pregnancy
- CHF
- concomitant use of other drugs that inhibit the CYP450 system
17
Q
Half life, metabolism of itraconazole?
A
- half life: 21 hours
- metabolized by liver
- better absorbed with food (capsules) but take the soln on an empty stomach
18
Q
Drug interactions of itraconazole?
A
- PPIs, anxiolytics, pain meds, antiplatelet agents, antihypertensives, statins
- drug interaction check is a MUST for this drug and other azole antifungals
(alot of times benefits of tx fungal infections don’t outweigh the risks esp in older pt - use lamisol)
19
Q
Adverse effects of itraconazole?
A
- Nausea, diarrhea
- edema
- HA
- rash
- abnormal LFTs
- heart failure
- arrhythmia
- hearing loss
- many others
20
Q
Monitoring while on itraconazole?
A
- baseline LFTs
- monthly LFTs if long term therapy
- serum concentrations:
draw 2 wks after starting therapy, draw w/o regard to when last dose was taken
21
Q
Itraconazole dosing for onychomycosis?
A
- fixed dosage:
fingernails - 200 mg po qdx 6 wks
toenails - 200 mg po qd x 12 wks
(continue longer if no signs of clearing) - pulse therapy:
fingernails - 200 mg po BID x 1 wk/month x 2 month
toenails - 200 mg po BID x 1 wk/month x 3 months
22
Q
What is Finasteride (propecia) used for?
A
- 1st line therapy for tx of androgenic alopecia in men
- 5-alpha reductase inhibitor: ultimately inhibits the conversion of testosterone to dihydrotestosterone
- same as Proscar (but lower dose) - used for tx of BPH
23
Q
How does Propecia affect PSA values? Monitoring?
A
- PSA monitoring: reduce PSA by 50%
- pts tx for 6 or more months the PSA should be doubled when comparing to normal ranges in untx pts
- baseline PSA is needed, then recheck in 6 months
- if PSA increases on this med refer to urology
- if PSA didn’t change (go down about 50%) after 6 months of therapy then this may indicate an increased risk for prostate cancer
24
Q
Efficacy of Finasteride?
A
- after 2 yrs of therapy hair counts may increase by about 25%
- have to stay on med to keep up efficacy
25
SEs of Finasteride (Propecia)?
```
- sexual dysfxn (may continue post d/c of meds):
decreased libido, ED, ejaculatory dysfxn
- gynecomastia
- testicular pain
- depression
```
```
- more common SEs:
orthostatic hypotension
dizziness
weakness
sexual dysfxn
```
26
What pop is Finasteride hazardous to?
- women - teratogenic
| - women should avoid contact with crushed or broken tabs
27
Metabolism and dosing of Finasteride?
- hepatic metabolism: caution for drug interactions and don't use in liver failure
- dose: 1 mg po daily
- continuous dosing for a min of 1 yr b/f assessment of efficacy
- max results at 2 yrs
28
What are common abxs used in derm?
- cephalexin (keflex)
- TCN: doxy, minocycline, tetracycline
- clindamycin
- mupirocin (bactroban)
29
Cephalexin:
| Drug class, derm indications, and distribution?
- PO
- 1st gen cephalosporin
- a b-lactam abx
- derm indications: skin and skin infections - cellulitis but not effective against MRSA
- distribution: widely distributed to all body tissues except doesn't penetrate CNS very well
30
Adult dosing for cephalexin?
- capsules, tabs, suspension
- skin and skin structure infections 500 mg PO q 6 hrs
- furunculosis and skin abscess 250 mg PO q6 hrs
- bugs it covers: Staph (not MRSA) and strep
31
MOA of cephalexin?
- inhibits bacterial cell wall synthesis by binding to one or more of the pcn binding proteins (PBPs) which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis
- preg B
- decrease dose for severe renal impairment (CrCl less than 10 ml/min)
32
Indications for Mupirocin (Bactroban)?
- impetigo due to S. aureus and S. pyogenes: ointment TID for 3-5 days
- tx of secondarily infected lesions due to staph and strep: cream TID for 10 days
- intranasal: used to eradicate nasal colonization of MRSA, BID for 5 days
- topical med:
use Intranasal formula for nares and use ointment (more potent) for impetigo and cream for other skin infections
33
MOA of Mupirocin (Bactroban)?
- inhibits protein synthesis by binding to bacterial isoleucyl transfer RNA synthetase
- absorption:
topical ointment and cream: penetrates outer layers of skin with some minimal systemic absorption
Intranasal: about 3% of what is applied is systemically absorbed in adults, can be significant in neonates
34
Mupirocin sizes and formulations?
- cream: 15 g tubes (Rx needs to say external cream)
- ointment: 22-30 g tubes (Rx needs to say external ointment)
- intranasal ointment: 1 g (Rx needs to say intranasal ointment)
35
MOA, distribution, SEs of tetracyclines?
- doxy, minocycline
- MOA: inhibition of protein synthesis - bind to 30S and possible 50S of susceptible bacteria, may also cause alterations in cytoplasmic membrane
- distribution: good distribution in the body tissue and fluids but poor CNS penetration
- SE: all cause photosensitivity
- all are preg D and not generally used in kids (esp younger than 9)
- have direct anti-inflammatory effects (COPD, and asthma pts can benefit from this when resp infections)
36
Doxy - dosing, SEs, absorption?
- oral: tabs, capsules, delayed release capsules and suspension
- usually BID dosing (50-100 mg BID)
- IV
- SE: nausea on empty stomach: esophagitis if not taken with fluids**
- absorption may be delayed with antacids (achlorydia) - very high pH
37
Doxycycline derm indications?
- tickborne rickettsial infections
- acne
- rosacea
- off label use when 1st line derm therapy is unavailable:
animal and human bites
cellulitis secondary to MRSA
skin and soft tissue infections
38
Indications for Minocycline (minocin)? SEs?
- acne
- off label: MRSA cellulitis
- capsule, tab, IV
- SE: vertigo esp at higher doses, esophagitis if not taken with water, GI upset if taken on empty stomach
39
What are ways we can reduce abx resistance when tx acne? Most resistance is assoc with?
- most assoc with erythromycin
- before abx therapy give benzoyl peroxide for 5 days and continue during abx
- if benzoyl peroxide isn't an option - note increased efficacy if using topical retinoid plus oral abx therapy
- try to limit abx to 12-18 wks
- don't change therapy too quickly (eval after 6-8 wks)
- don't give topical plus same oral abx
40
Clindamycin:
indications in derm?
Most common form?
- topical and oral formulations
- indications: acne and rosacea
- avoid oral for tx of acne due to risk of C diff
- commmonly used topically alone or in conjuction with benzoyl peroxide (combo product)
- gel, lotion, foam, swabs: most common is gel (clinda-gel or cleocin-T)
41
Retinoic acid derivative?
- Isotrentinoin (accutane)
(Absorica)
(Amnesteem)
- have derm rx this!
42
Indications for Isotrentinoin?
- tx of severe, recalcitrant, nodular acne (have derm rx this!)
- acne with many inflammatory nodules (greater than 5 mm) that is unresponsive to conventional therapy - including systemic abx
43
MOA of Isotrentionoin?
- shrinks sebaceous glands
- decreases sebum production
- decreases number of sebum dependent bacteria Propionibacterium acnes
44
Efficacy of Isotrentinoin?
- only acne med that can permanently alter natural course of this disorder
- 39% of pts are cured
- 61% still reqr topical or systemic acne tx
- after tx - better response rates to traditional topical and systemic acne therapies
45
Isotrentinoin has extremely high risk of what? What needs to be done to prevent this?
- high risk for birth defects
- need to have 2 forms of birth control started at least 1 month prior to tx
- 2 negative pregnancy tests prior to initial Rx
- pregnancy test and counseling once monthly
- need to be registered presriber in iPledge program and document expertise in rx isotrentinoin per FDA regs
46
Mucocutaneous SEs of Isotrentinoin?
- cheilitis
- dry skin and mucous membranes
- epistaxis
- desquamation
- photosenstivity (worse than tetracyclines)
- pruritus
- ocular sxs related to dysfxn of meibomian glands within conjunctiva - eye is really dry - corneal abrasion
- cutaneous staph infections: paronychia, pyogenic granulomas
- temporary diffuse alopecia, or nail brittleness
47
More SEs of Isotrentinoin?
- depression
- hyperTG: up to 45% of pts, ETOH may potentiate this rxn
- elevated total and LDL cholesterol: up to 30%
- usually resolves after d/c of drug
48
Monitoring of Isotrentinoin? When would you d/c drug based on labs?
- CBC, fasting lipid profile, and LFTs at baseline
and repeat them after 4 and 8 wks of therapy
- if these test results are normal and the dose of isotretinoin remains stable - can d/c lab monitoring other than pregnancy tests if applicable
- monthly preg. test during admin of drug and one month after d/c of therapy
- d/c if:
TG greater than 800
LFTs 3x upper limit of normal
49
What are the topical calcineurin inhibitors used in derm? Indications?
- Tacrolimus (Protopic 0.03%, 0.1%)
- Pimecrolimus (Elidel) 1%
- indications:
atopic dermatitis
lichen planus
vitiligo
psoriasis
50
BBW for topical calcineurin inhibitors?
- assoc with rare cases of malignancy (including skin and lymphoma); therefore, it should be limited to short-term and intermittent tx using minimum amt necessary for control of sxs and only on involved areas
51
CIs (recommendations against use) of topical calcineurin inhibitors?
- not recommended for use under age of 2
- don't admin. with systemic immune suppressants (cyclosporine)
- don't use in immunocompromised pts
52
MOA of topical calcineurin inhibitors?
suppresses cellular immunity (inhibits T lymphocyte activation)
- binds to intracellular protein, FKBP-12 and complexes with calcineurin dependent proteins to inhibit calcineurin phosphatase activity
53
What is recommended when taking topical calcineurin inhibitors? What does concomitant alcohol ingestion cause?
- sun protection is recommended with use
- don't use under an occlusive dressing
- concomitant alcohol ingestion can cause redness and flushing
54
SEs of Tacroliumus? 2 strengths?
- HA (20%)
- skin burning at application site (58%)
- pruritus (46%)
- erythema (28%)
- ointment: 2 strengths - 0.03% (kids) and 0.1%
55
Why is pimecrolimus better tolerated than tacroliumus?
- less burning than tacroliumus
- it's a cream
- 1 strength
56
Presentation of Drug induced lupus like syndrome? Tx?
- pts usually present with some combo of arthralgia, myalgia, malaise, fever, rash, and or serositis
- usually are on the drug for month or more
- mult drugs can be responsible for this (grisefulvin)
- usually have spontaneous resolution of disease, typically within several weeks to months after offending agent has been d/c
- hydroxychlorquine if sxs don't resolve w/in 4-8 wks
- systemic corticosteroids for severe sxs or if quick relief is needed (pleurisy or pericarditis)
- maintay of therapy is d/c of drug and sx tx with NSAIDs
Dermatology
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