eMedicine Specialties > Dermatology > Metabolic Diseases
Erythropoietic Protoporphyria: Treatment & Medication
Updated: Feb 23, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Treatment
Medical Care
For protoporphyria uncomplicated by hepatobiliary disease, the major problem is lifelong cutaneous photosensitivity. Anemia, if present, typically is mild and rarely requires specific therapy. Cholelithiasis is managed surgically. Liver dysfunction is an ominous development for which medical remedies are not consistently effective. Progressive intractable liver insufficiency is an indication for liver transplantation.15,17,30
- Shield skin from sunlight by using protective clothing and lifestyle adjustments.
- Because the wavelengths of light causing porphyrin-sensitized phototoxicity are chiefly in the visible spectrum, window glass is not an effective barrier. Plastic films that attenuate transmission of portions of the visible light and long UV spectra are available and can be applied to window or windshield glass.31
- Topical sunscreens are not effective unless transmission of long UV and visible light rays is reduced by their use. Sun-blocking formulations containing zinc oxide or titanium dioxide reflect visible light and may be helpful.31
- Topical sunless tanning gels or creams containing dihydroxyacetone produce superficial pigmentation that blocks some of the offending wavelengths.31
- Induction of endogenous melanin by exposure of skin to broad- or narrow-band UV-B lamps or to UV-A in conjunction with a psoralen UV-A photosensitizer also may increase tolerance to natural sunlight.32
- Afamelanotide, an alpha-melanocyte–stimulating hormone analogue that increases melanin production in the skin, is a novel injectable photoprotective agent currently in clinical trials in Australia and several European countries.
- Oral beta-carotene reduces photosensitivity in some, but not all, patients.3,33,34
- Attenuation of photosensitivity using oral cysteine35 or pyridoxine36 has been reported but not widely confirmed.
- H1-receptor antagonists can mitigate histamine-mediated components of the acute reaction, but they rarely suppress all signs and symptoms.37 Suppression of heme synthesis by inhibition of cytochrome P-450 formation and of heme oxygenase activity is a mechanism proposed for transient improvement of isolated cases of various porphyrias after H2-receptor antagonist use, but it remains unproven.38
- Although adverse reactions to porphyrinogenic drugs known to exacerbate acute hepatic porphyrias are not characteristic of protoporphyria, avoid or administer with caution drugs with cholestatic properties, such as estrogenic hormones. Assess the risk-to-benefit ratio for each individual with protoporphyria when considering use of cholestatic therapies.
- Medical approaches to reversing protoporphyric liver dysfunction are not well established, owing to inconsistent or uncertain efficacy and experience in relatively few cases.
- Orally administered cationic exchange resins or activated charcoal aimed at reducing enterohepatic recirculation of porphyrin and/or bile acids to enhance hepatic porphyrin excretion may have some level of efficacy in selected patients.23,39,40
- Hypertransfusion to slow erythropoiesis41 and intravenous infusion of heme analogues to repress endogenous porphyrin production42,43 have been beneficial in some cases.
- Administration of iron with the rationale of enhancing protoporphyrin conversion to heme appeared beneficial in one case,44 but it aggravated the disease in others.45
- Reduction in erythrocyte protoporphyrin levels and improved liver function followed administration of vitamin E to a protoporphyric patient with cirrhosis.46
- Plasmapheresis43 or exchange transfusion47 to reduce the circulating protoporphyrin burden appeared helpful in a small number of advanced cases.
- Medical regimens are often used in combination or rapid sequence in rapidly deteriorating patients and are best instituted by experts in a referral center for advanced liver disease.
Surgical Care
Surgical removal of gallstones usually poses no more risk for individuals with protoporphyria than for the general population, although phototoxic sequelae from high-intensity operating room lighting is a theoretical possibility. Adverse reactions to anesthetic agents problematic in acute hepatic porphyrias are not characteristic of protoporphyria. Failure of medical reversal of protoporphyrin-induced hepatic decompensation warrants liver transplantation. Operating room lamps have caused acute phototoxic damage to skin and internal organs during transplantation.48,49 Preoperative exchange transfusions, plasmapheresis, and/or infusion of a heme analogue may lower the circulating burden of protoporphyrin in the blood, reducing intraoperative phototoxic potential.50 These treatments may also aid postoperatively in retarding the development of protoporphyrin hepatotoxicity in the engrafted liver.42,43
Consultations
- Consultation with a hematologist should be sought for management of anemia or if hypertransfusion, exchange transfusion, or plasmapheresis is considered. Rarely, bone marrow transplantation may have a role in the management of selected patients with severe manifestations.19,27
- Referral to specialists at a comprehensive liver center should be arranged at the earliest signs of liver decompensation for assistance in evaluation and management of progressive liver dysfunction. If liver transplantation becomes necessary, a successful outcome is more likely if the procedure is performed before the patient is gravely debilitated.
- Referral to a medical geneticist can aid in counseling patients and families about risks of inheriting or transmitting the mutations and polymorphisms associated with the disease.51,52
- Preoperative consultation with anesthesiologists and biomedical engineers concerning operating room lighting is essential. The intense visible light emitted by surgical lamps can cause intraoperative burns of the skin and internal organs due to the massive protoporphyrin tissue accumulations that result from failure of hepatic excretory mechanisms.48,49 Filtering operating room lamps appropriately can block the most harmful portions of the visible light spectrum.50
Diet
Do not severely curtail carbohydrate intake; a beneficial glucose effect may be modulating abnormal heme synthesis.53 Limit use of ethanol; alcohol excess has been implicated in fatal protoporphyria associated with liver failure.54
Activity
Sunlight avoidance is mandatory. Recommend adjustment of outdoor activities to avoid midday sunlight. Stylish and comfortable sun-protective clothing is commercially available that can reduce time constraints on many outdoor sports or activities. Specialized programs for photosensitive children can be found that offer safe and healthy recreational experiences, even a summer camp organized by the Xeroderma Pigmentosum Society. See Camp Sundown.
Medication
The only oral photoprotective agent approved by the US Food and Drug Administration and widely used for the treatment of protoporphyria is a synthetic beta-carotene formulation now available over the counter as Lumitene. Cysteine has shown benefit in clinical trials. Pyridoxine was reported effective in 2 cases. H1-receptor blockade may reduce symptoms due to mast cell histamine release during acute phototoxic reactions if established prior to exposure. Whether H2-receptor antagonists reproducibly slow porphyrin production in various porphyrias remains unproven.
Liver dysfunction warrants individualized design of therapeutic regimens that may include the administration of enteric sorbents to promote protoporphyrin excretion, bile acids to enhance porphyrin clearance from the liver, and hematin to repress porphyrin production. Combinations of these and other adjunctive agents and modalities may moderate the urgency presented by a failing organ, allowing orderly preparation for an optimal transplantation.
Photoprotectants
Beta-carotene is a scavenger of singlet-exited oxygen and is believed to interfere with the efficiency of porphyrin-sensitized photoxidative damage in the skin. Ingestion of beta-carotene at recommended doses produces carotenodermia after several weeks. Increasing tolerance of sunlight develops during this loading period. Tolerance diminishes over several weeks when treatment is stopped.
Beta-carotene (Lumitene)
Exact mechanism of action not completely elucidated. Patient must become carotenemic before effects are observed. More than one internal light screen may be responsible for effects. May provide a limited level of photoprotection. Causes yellowing of skin (carotenoderma). Any photoprotection afforded increases slowly over 4- to 6-wk period after drug is commenced. When discontinued, skin color and benefit fade over several weeks.
Adult
120-300 mg/d PO in divided doses
Pediatric
30-120 mg PO in divided doses
Coadministration with vitamin A may result in additive toxic effects
Documented hypersensitivity; use by tobacco smokers may further increase risk of lung cancer
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Caution in patients with renal or hepatic impairment; may increase risk for lung cancer in heavy smokers; may cause orange stools and diarrhea or loose stools at onset of therapy that tend to resolve with continued use
Antihistamines
H1-receptor antagonists modulate effects of histamine in skin. If taken prior to anticipated strong sunlight exposure that cannot be avoided, acute reactions may be attenuated to some extent; minimal benefit is expected if taken afterward.
Fexofenadine (Allegra)
Nonsedating second-generation medication with fewer adverse effects than first-generation medications. Competes with histamine for H1 receptors on GI tract, blood vessels, and respiratory tract, reducing hypersensitivity reactions. Does not sedate. Available in qd and bid preparations.
Adult
180 mg PO 2-3 h prior to sunlight exposure
Pediatric
<6 years: Not recommended
6-11 years: 30-60 mg PO 2-3 h prior to sunlight exposure
>12 years: Administer as in adults
Toxicity increases with coadministration of erythromycin and ketoconazole
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
No data available on use while breastfeeding; reduce dose in renal insufficiency
Enteric adsorbents
Agents that bind protoporphyrin in the intestinal lumen promote its excretion by interrupting enterohepatic recirculation, thereby reducing the porphyrin load presented to the liver for clearance.
Cholestyramine (Questran)
Polymeric resin that binds bile acids, porphyrins, and other molecules to form nonabsorbable complexes that are excreted unchanged in feces. Adsorbs many drugs and nutrients; long-term use requires proper timing of oral drugs and may warrant supplementation of vitamins D, E, A, and K.
Adult
4 g PO tid ac; may increase to 24 g/d PO in divided doses
Pediatric
<6 years: Not established
>6 years: 2 g PO bid initially; may increase up to 8 g/d PO divided tid/qid
Inhibits absorption of numerous drugs, including warfarin, thyroid hormone, amiodarone, NSAIDs, methotrexate, digitalis glycosides, glipizide, phenytoin, imipramine, niacin, methyldopa, tetracyclines, clofibrate, hydrocortisone, and penicillin G
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Caution in constipation and phenylketonuria
Activated charcoal (Actidose)
Prevents absorption by adsorbing porphyrin in intestine. Multidose charcoal may interrupt enterohepatic recirculation and enhance elimination by enterocapillary exsorption. Does not dissolve in water. Adsorbs many medications and nutrients; long-term use requires proper timing of oral drugs and may warrant supplementation of vitamins D, E, A, and K.
Adult
25-100 g or 1 g/kg PO susp in 4-8 oz of water
Pediatric
<1 year: Not recommended
>1 year: Administer as in adults
Effectiveness of other medications decreases with coadministration; do not mix charcoal with sherbet, milk, or ice cream (decreases absorptive properties)
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Administer supplemental vitamins D, E, A, and K with long-term use
Antihistamines, H2 blocker
Produce blockade of H2 receptors.
Cimetidine (Tagamet)
H2 antagonist, which, when combined with an H1-type, may be useful in treating itching and flushing in urticaria. Porphyria-specific usage for inhibiting overproduction of porphyrins is experimental.
Adult
Experimental doses reported for inhibiting heme synthesis: 400 mg PO bid to 800 mg PO qid; not to exceed 2400 mg/d (recommended)
Pediatric
Not established for experimental use in porphyrias
Can increase blood levels of theophylline, warfarin, TCAs, triamterene, phenytoin, quinidine, propranolol, metronidazole, procainamide, and lidocaine
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Elderly patients may experience confusional states; may cause impotence and gynecomastia in young males; may increase levels of many drugs; adjust dose or discontinue treatment if changes in renal function occur
Gallstone dissolution agents
Increasing bile flow enhances secretion of protoporphyrin by the liver into the enteric tract and clearance from the body.
Ursodiol (Actigall)
Shown to promote bile flow in cholestatic conditions associated with a patent extrahepatic biliary system. Decreases cholesterol content of bile, therefore reduces bile stone and sludge formation.
Adult
10-15 mg/kg/d PO divided bid
Pediatric
20-30 mg/kg/d PO divided bid
Decreased effect with aluminum-containing antacids, cholestyramine, colestipol, clofibrate, and oral contraceptives
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Caution in patients with a nonvisualizing gallbladder
Heme analogues
Intravenous infusion of a heme analogue may repress heme synthesis in liver and bone marrow cells, thereby reducing rate of protoporphyrin overproduction.
Hemin (Panhematin)
Enzyme inhibitor derived from processed red blood cells and is an iron-containing metalloporphyrin. Previously known as hematin, a term used to describe the chemical reaction product of hemin and sodium carbonate solution.
Has anticoagulant effect and may cause thrombophlebitis at infusion site. Must be reconstituted from lyophilized powder. Reconstitute with human serum albumin 25% (132 mL of 25% human serum albumin to 1 vial of hemin [301 mg heme]).
Adult
Dosing levels and intervals must be individualized based on clinical criteria
1-4 mg/kg/d IV over 10-15 min qd or qwk (or longer intervals); in severe cases, may repeat no earlier than q12h, not to exceed 6 mg/kg/24h; if given in conjunction with plasmapheresis, infuse after plasma exchange is complete
Pediatric
Not established
May further increase effect of anticoagulants
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Asymptomatic and reversible renal shutdown, oliguria, and increased nitrogen retention have occurred; no worsening of renal function observed with recommended dosages; infusion into a large vein or central venous catheter recommended to reduce risk of phlebitis; because reconstituted hematin is not transparent and particulate matter may not be visible, a 0.45-µm or smaller terminal filter should be placed in infusion line
Heme arginate
A heme analogue not available in the United States that would have similar uses to hemin as described above.
Adult
3-4 mg/kg/d IV; dosing schedule individualized by clinical criteria over 3-4 d or longer or at longer intervals
Pediatric
Not established
May further increase effect of anticoagulants
Documented hypersensitivity
Pregnancy
Precautions
Not effective in repairing neuronal damage
More on Erythropoietic Protoporphyria |
| Overview: Erythropoietic Protoporphyria |
| Differential Diagnoses & Workup: Erythropoietic Protoporphyria |
 Treatment & Medication: Erythropoietic Protoporphyria |
| Follow-up: Erythropoietic Protoporphyria |
| References |
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Further Reading
Keywords
erythropoietic protoporphyria, erythrohepatic protoporphyria, congenital erythropoietic protoporphyria, protoporphyria, porphyria, light sensitivity, photoprotection, end-stage liver disease, endstage liver disease, ESLD, ferrochelatase, FECH
