Acute Intermittent Porphyria Treatment & Management

Updated: Jan 13, 2023
  • Author: Thomas G DeLoughery, MD; Chief Editor: Emmanuel C Besa, MD  more...
  • Print
Treatment

Approach Considerations

The treatment goal for acute attacks of acute intermittent porphyria (AIP) is to decrease heme synthesis and reduce the production of porphyrin precursors. High doses of glucose can inhibit heme synthesis and are useful for treatment of mild attacks. United Kingdom guidelines recommend administering 5% glucose in 0.9% sodium chloride solution, infused intravenously at a rate of 2 L/24 h. Intravenous solutions of glucose in water (eg, dextrose 5% or 10% [D5W, D10W]) should be avoided as they may aggravate hyponatremia. [19]

Patients experiencing severe attacks, especially those with severe neurologic symptoms, should be treated with hematin in a dose of 4 mg/kg/d for 4 days. Once hematin is initiated, glucose therapy no longer has a role. [19]

Pain can be remarkably severe, and pain control is best achieved with narcotics. Laxatives and stool softeners should be administered with the narcotics to avert exacerbating existing constipation.

Symptomatic treatment also includes the use of beta-blockers to control tachycardia and prevent arrhythmia; beta- blockers, clonidine, or other recommended antihypertensives can also be used to treat hypertensive crisis. Nausea and vomiting can be controlled with olanzapine, lorazepam, or prochlorperazine. [20]

Treat seizures with gabapentin. Most classic antiseizure medicines are contraindicated, as they can lead to acute porphyria attacks.

A minority of patients with AIP experience recurrent attacks. In addition to avoidance of precipitating factors, treatment options that may be considered in those cases include gonadotrophin-releasing hormone analogues (for women with attacks related to their menstrual cycles) and prophylactic hematin infusions. [19]

Givosiran (Givlaari) is approved by the US Food and Drug Administration (FDA) for adults with acute hepatic porphyrias, in which attacks are caused by induction of the enzyme 5-aminolevulinic acid synthase 1 (ALAS1). Givosiran is a small-interfering RNA that causes degradation of aminolevulinate synthase 1 (ALAS1) messenger RNA (mRNA) in hepatocytes through RNA interference, reducing the elevated levels of liver ALAS1 mRNA. It is given monthly by subcutaneous injection. [21] Reported adverse reactions include injection-site reaction, fatigue, nausea, chronic kidney disease, and increased alanine aminotransferase. [2] In rare instances, drug-induced liver injury may develop, mandating cessation of givosiran. [22]

Rarely, liver transplantation may be indicated for patients with intractable recurrent attacks that are life-threatening or severely affect quality of life. Liver transplantation cures AIP. [19]

A comprehensive rehabilitation program, overseen by a physiatrist, can help patients regain functional independence after attacks of AIP. [23]

Gene therapy for AIP is currently under investigation.  A phase I trial using intravenous delivery of normal PBGD genes to hepatocytes using an adeno-associated virus vector confirmed the safety and tolerability of this approach, but demonstrated the need for higher doses and/or more efficient vectors in order to achieve full clinical benefit. [24]  In an animal model, improved vector efficiency has been accomplished by insertion into the promoter of a short enhancer element that can induce transgene expression during exposure to endogenous and exogenous stimuli that can trigger attacks. [25]

Next:

Diet

The patient should receive a high-carbohydrate diet during the attack. If the patient is unable to eat, intravenous glucose should be administered. Between attacks, eating a balanced diet is more important than eating one rich in glucose.

Previous