Term
| Exanthem (rash, eruption); may be maculopapular, morbilliform, erythematous |
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Definition
most common drug eruption
occurs 2-3 days after drug admin
treat with antihistamines, wet dressing or systemic corticosteroids if severe reaction occurs
: reaction disappears after drug termination (2-4 days)
Type 4 |
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Term
| Urticarial Eruptions (Hives) |
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Definition
: acute or intermediate reaction
: lesions (hives) raised from a few mm to larger (cm)
: treat with H1 & H2 blockers
: systemic corticosteroids in severe cases
: symptoms clear in 1-2 days
Drug culprits commonly involved
e.g. heparin, penicillin, or codeine |
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Term
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Definition
: oval lesion with dusky red-blue appearance
: lesion can reoccur 30min - 8hr after rechallenge (any site, but oral mucosa and genitalia most common locations)
: Drug treatment may not be very effective (anti-H & steroids)
: lesion typically heals 7-10 days after drug termination |
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Term
| Photosensitive (thought to be mostly non-immune in nature) |
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Definition
skin becomes sensitive to
sun exposure
: either phototoxic – effect
seen within hrs of exposure
or photoallergic – response
within 1-2 days
: treatment – discontinue drug use
Culprits: topical corticosteroids; |
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Term
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Definition
often a toxic reaction
interfere with normal growth phases of the hair
Drug culprits:
e.g. – warfarin, heparin, chemotherapy drugs |
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Term
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Definition
acne like lesions, usually on neck, chest or back
- 2-4 week time to onset
- uniform size and symmetrical distribution
Culprits: e.g. – ACTH, oral contraceptives, corticosteroids (“steroid acne”), iodide, lithium |
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Term
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Definition
red painful nodules
: treatment – discontinue drug use
: heals over 2-3 wks after drug termination
Culprits: oral contraceptive, iodides & bromides, penicillin |
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Term
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Definition
: may be severe, with erythema and abundant flaky desquamation (skin sloughs; 20-30 g/day?)
: loss of fluid
: treat with fluids, steroids, pain meds, antibiotics
Culprits: barbs, phenytoin, penicillin, carbamazepine |
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Term
Toxic Epidermal Necrolysis
(TEN) |
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Definition
: life threatening
: mediated by
Cytotoxic T-lymphocytes
: 30% mortality due to 2nd
infections
: Treatment – discontinue drug use;
: treat with corticosteroids, antihistamines,
fluids, antibiotics |
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Term
|
Definition
Life threatening
: mediated by Cytotoxic T cells
: mortality rate 5-18%
Symptoms: maculopapular bullae, vesicles, hemorrhagic lesions on mucus membranes of mouth, lips and conjunctiva |
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Term
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Definition
Action on microtubule system to disrupt mitosis in certain fungal cells
Not used systemically any more and topical use is reducing |
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Term
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Definition
Often used PO; well-absorbed, but suffers 40% loss due to first-pass effect in liver; 99% protein bound so expect displacement and ΔPK of other meds; accumulates in skin/nails/fat so long T1/2
Avoid use in presence of hepatic or renal failure due to potential large increases in plasma drug concentration
Inhibits conversion of squalene to lanosterol by squalene epoxidase; thus squalene accumulates and ergosterol synthesis is decreased - cell membrane damage results
Drug interactions: Rifampin decreases and Cimetidine increases plasma concentrations of Terbinafine via effects on P450
Tox issues: Hepatoxicity is a major concern |
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Term
| Azoles - Imidazoles and Triazoles |
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Definition
Imidazoles: 2 nitrogens in 5-membered azole ring
Triazoles: 3 N's in 5-mem ring
Both groups share the same MOA. Triazoles are now preferred in therapy, with fluconazole and itraconazole receiving more common use in therapy of dermatological conditions |
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Term
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Definition
Blocks fungal P450-dependent synthesis of ergosterol
Step of the pathway affected is the demethylation of lanosterol; enzyme is 14-α-sterol-demethylase (ERG11)
Blockade of ergosterol formation disrupts cell membranes ; ↓ATPase and ↓electron transport enzymes
Can also inhibit gonadal and adrenal steroid synthesis in humans, thus suppressing testosterone and cortisol formation
Triazoles have less effects on human P450-dependent steroid synthetic pathways (less enzyme affinity) and a broader spectrum of fungal activity
Triazoles often are preferred clinically for those reasons
Azoles should not be used in pregnancy |
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Term
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Definition
Low cure rate and High relapse rate
Cannot penetrate harden nail mass
Requires multiple daily applications and long duration of therapy
May use as adjunctive therapy with oral antifungal agents |
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Term
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Definition
Disadvantages
High rate of resistance
High rate of relapse
Low cure rate
Long duration of therapy 6-18 months of therapy
Intolerable adverse drug reactions
cross rxtvty wit penicillin
ADRs- fotosenstvty. Phenobarbital decr griseofulvin serum conc. |
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Term
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Definition
Not effective
Risk of drug interactions and hepatoxicity |
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Term
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Definition
Fungistatic - inhibits the synthesis of ergosterol
Advantages
Good nail bed and matrix penetration
Can be detected in toenails 6 months after D/C
Good absorption that is not influenced by gastric acid, food, antacids or H2 blocker
Disadvantages
Lacks indication
150 mg q week x 3 months with re-evaluation at 3 months
Treatment duration range 3 to 12 months
80% of Fluconazole is excreted unchanged in the urine
parameters- Base line AST,ALT and CBC. Consider AST and ALT monthly if therapy is longer than 6 weeks.
Drug Interactions- incr effects of warfarin and decr effects of oral contraceptives |
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Term
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Definition
First line therapy in private practice
FDA indication
Studies show this agent is more effective than Itraconazole
Fungicidal
Advantages
Fewer drug interactions
Fewer adverse drug interactions
Fungicidal activity
Pregnancy Category B |
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