Complications of Antiepileptic Drugs - Block 1 Flashcards
What are the types of Dermatologic Drug Reactions?
Irritant: topical
Allergic: topical or systemic route
What kind of hypersensitivity is SJS/TEN?
Type 4: Delayed cell-mediated
What are the types of drug eruptions?
What are Severe Cutaneous Adverse Reactions to Drugs (SCARs)? Types?
Skin reactions accompanied by fever are generally more serious systemic disorders:
1. Dress
2. SJS
3. TEN
What is DRESS?
S/s
characterized by an extensive skin rash and fever
S/S: 2-8 weeks
- mortality rate is very high
What causes DRESS?
Exact pathogenesis is still unknown:
1. Mutations in genes encoding drug detox enzymes have a higher risk of DRESS
2. Reactivation of human herpes virus (Epstein barr and HHV6 and 7)
3. Ethnic predisposition with certain human leukocyte antigen (HLA) alleles
What is the proposed diagnostic marker for DRESS?
HHV-6
What is the relationship between carbamazepine and DRESS?
Chinese, Koreans, Japanese, & Europeans who express the HLA serotype (HLA-A*3101) have a higher risk of developing DRESS
What are presentation of DRESS?
Latency: later onset of fever, malaise, lymphadenopathy
Cutaneous and mucosal: maculopapular eruption -> coalescing erythema
* Target-like lesions
* Facial edema
* > half BSA
(50% of patients have mucosal involvement, but it is mild in comparison to SJS/TEN)
What are the lab presentation of DRESS?
- Fever ≥101.3
- Lymphadenopathy
- Hematologic abnormalities (Eosinophilia, leukocytosis, lymphocytosis, atypical lymphocytes)
- Liver, kidney, lung, heart abnormalities
What is the diagnostic approach to DRESS?
- New drug treatment (especially high-risk drugs/AEDs) within the last 2-8 weeks
- Presenting with systemic involvement
What are we looking for in DRESS through the assessment of drug causality?
- Prolonged latency
- Drugs that have been stopped can still be suspected
- Exposure to high-risk drugs
- Unlikely culprit if drug was taken for less than 2 weeks or more than 3 months
- Risk for drug accumulation can increase risk for DRESS (RENAL DOSING!)
What are the high risk drugs that cause DRESS?
Aromatic AED:
1. Carbamazepine
2. Phenytoin
3. Lamotrigine
4. Oxcarbazepine
5. Phenobarbital
1.
What is the tx goals for DRESS?
Identify and dc causative drug
What is the tx for DRESS?
ID and withdrawal of causative drug
* Avoid introduction of new drugs like aromatice drugs)
Supportive: Fluid, electrolyte, nutritional support, gentile skin care
What are examples of nonaromatic agents?
- VA
- Topiramate
- Gabapentin
- Keppra