What is acute intermittent porphyria (AIP)?

About 12 years ago, I was diagnosed with AIP (acute intermittent porphyria). In all of these years I still haven’t received much information of this disease. Can you explain it to me in lay terms? I have several pages from medical journals, which I have found to be more confusing that anything else. It is my understanding that it is a genetic defect and there are no known treatments for it. The doctor that first diagnosed me has since died, and there just aren’t very many people who know anything about this condition. Any advice or information would be most helpful.

Acute intermittent porphyria (AIP) is the most common member of a group of inherited diseases that all involve defects in one of the seven metabolic steps necessary to produce heme. The heme is part of hemoglobin, the pigment that makes blood red and transports oxygen to our tissues.

Doc’s Advice: Why are my feet swelling, and what can I do?

Although AIP is the most common of this group of diseases, they are all rare, and many doctors, including me, have never seen a case and would have to read up on the condition to be able to discuss it. The diagnosis is therefore often missed. AIP occurs when a person inherits one mutated or defective gene from a parent. Since normal functioning of the pathway to heme requires two genes, the person’s ability to carry through the complete synthesis is cut in half, and if something stimulates the heme pathway, abnormal products start to build up, which leads to the symptoms of the disease. Most people with AIP are able to function pretty well with their one normal gene unless the pathway is stimulated, which leads to the intermittent nature of the symptoms.

In AIP, the defect is present in liver cells, which are also responsible for metabolizing or detoxifying many chemicals and drugs. Therefore, many drugs stimulate the heme pathway and produce the symptoms. Most of the symptoms are produced by interference with nerve function. These symptoms include vague abdominal pains, usually steady, often with nausea, vomiting, rapid heart beat, pains in the limbs, muscle weakness, and mental symptoms, such as anxiety, depression, hallucinations, and paranoia. Attacks develop rapidly, over a period of hours, and with treatment can often be terminated in a matter of days.

The most important treatment is to avoid stimulating an attack. Attacks are rare before puberty and may be stimulated by dieting, hormones — including the natural female sex hormones of the menstrual cycle — and many drugs. Drugs that commonly are implicated include sulfa drugs, barbiturates, alcohol, and many anti-convulsants including phenytoin (Dilantin). Important drugs that do not stimulate attacks include narcotics, aspirin, Tylenol, penicillins, cortisone and similar drugs, and insulin.

Treatment of acute attacks includes narcotics for pain, tranquilizers if mental symptoms are prominent, IV fluids, and heme given intravenously. Giving heme tends to turn off the heme synthesis pathway, thus reducing the buildup of the heme precursors that cause the symptoms.

Since a person with AIP has one normal and one abnormal gene, 50 percent of his or her children, on the average, will have the disease.

The information contained in or made available through This Site cannot replace or substitute for the services of trained professionals in the medical field. We do not recommend any treatment, drug, food or supplement. You should regularly consult a doctor in all matters relating to physical or mental health, particularly concerning any symptoms that may require diagnosis or medical attention.

Subscribe Scroll to Top