Acute intermittent porphyria: Difference between revisions
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==Triggers== | ==Triggers== | ||
*Infection, metabolic stress | |||
*Carbohydrate deficiency | |||
*Tobacco, EtOH | *Tobacco, EtOH | ||
Revision as of 22:15, 23 September 2015
Background
- Related to defect(s) in heme synthesis causing a buildup of porphyrins
- Autosomal dominant, but poor penetrance
Clinical Features
Differential Diagnosis
Triggers
- Infection, metabolic stress
- Carbohydrate deficiency
- Tobacco, EtOH
Diagnosis
- Unlikely to diagnose first episode in ED given rarity of disease
- Can check spot urine porphobilinogen (PBG) - sendout at most hospitals
Management
- Analgesia
- Avoid offending meds
- Most seizure meds contraindicated. Benzodiazepines, gabapentin, levetiracetam, and vigabatrin OK
- Avoid reglan
- Glucose load
- Decreases porphyrin production
- Typical protocol is D10W 3-4 liters daily x 4 days
- Risk of hyponatremia given significant free water load
- Hemin
- Decreases porphyrin production, significantly more potent than glucose
- Recommended for most cases requiring hospitalization, or any with neurologic symptoms
- 3-4 mg/kg daily for 4 days
- Can cause significant infusion site phlebitis - minimize by reconstituting in 25% albumin; consider central venous administration
- Very expensive - around $8000 per 313 mg vial
Disposition
See Also
External Links
http://www.porphyriafoundation.com/