Causal therapy does not exist for both acute and cutaneous forms of porphyria because the genetic defect is genetic.
Therapeutic Targets
- Symptom relief
- Avoidance of triggering factors (exposure prophylaxis).
Therapy recommendations
- Analgesia according to WHO staging scheme until definitive therapy when diagnosis is confirmed:
- Non-opioid analgesic: paracetamol, first-line agent for acute abdominal pain.
- Low-potency opioid analgesic (e.g., tramadol) + non-opioid analgesic.
- High-potency opioid analgesic (eg, morphine) + non-opioid analgesic.
- Acute porphyrias:
- Administration of high amounts of carbohydrates:
- Glucose (oral) → decrease in hepatic ALA synthase (ALAS1) → improvement in symptoms.
- For vomiting, intravenous administration: 3 l of 10% glucose solution via central venous catheter over 24 h (125 ml/h); to prevent hyperhydration (overhydration) with subsequent dilutional hyponatremia (“dilutional sodium deficiency”), 1 l of 50% dextrose solution may be administered alternatively
- Long-term use is not recommended due to the increased risk of obesity and tooth decay.
- Glucose (oral) → decrease in hepatic ALA synthase (ALAS1) → improvement in symptoms.
- In severe cases, neurological symptoms (eg, muscle weakness) or electrolyte imbalance:
- I.v. heme or hemin-arginate (diluted in 5% dextrose or half or a quarter of normal saline) → 3 mg/kg bw i.v. 1 x/day for 4 days → improvement of symptoms within 3-4 days.
- Side effects: Venous thrombosis, thrombophlebitis (inflammation of superficial veins with secondary formation of thrombosis).
- For constipation (constipation): laxative therapy (see below constipation).
- If necessary, intensive medical monitoring → respiratory paralysis!
- Administration of high amounts of carbohydrates:
- Cutaneous porphyrias:
- Use special sunscreens → based on titanium dioxide and zinc oxide, so protection from UVA and UVB rays and visible (blue) light is possible; Note: Normal sunscreens are unsuitable, as they do not absorb the blue portion of visible light!
- Severe courses: chloroquine → binds porphyrin.
- Make sufferers helps taking beta-carotene, which acts as a free radical scavenger in the skin.
- Afamelanotide: stimulates skin tanning; this allows the affected person to stay longer in the sun (not yet approved in Germany / as of August 2019).
- Due to photosensitivity, the vitamin D status of the affected person must be monitored regularly and, if necessary, the vitamin must be substituted.
- Protoporphyria (secondary (acquired) porphyria):
- In cases of critical liver involvement, administration of red cell concentrates may help. Subsequently, erythropoiesis (hematopoiesis) is suppressed and the accumulation of protoporphyrin is decreased, ultimately relieving the liver.
