Acute porphyria FAQs

Acute attacks almost always start with severe pain which is usually in the abdomen but may also be felt in the back or thighs. Nausea, vomiting and constipation are common. Some people may become very confused during an acute attack and behave in ways that are unusual for them. They may later find it difficult to remember details of their illness. Convulsions and muscular weakness, which may lead to paralysis, are less common symptoms. Pulse rate and blood pressure may increase but rarely to dangerous levels. An acute attack usually lasts for no longer than one or two weeks. If paralysis occurs, recovery is gradual but slow.

To identify an acute attack of porphyria, the first urgent test, urine porphobilinogen (PBG), can usually be done in your local hospital. To identify the presence and type of porphyria, samples of urine, blood and stools (faeces) need to be tested in a laboratory which specialises in porphyria. The tests measure the concentration of porphyrins and related chemicals which will be high in a patient with an acute porphyria.  It is important that these tests are carried out as soon as possible after the start of the illness, as an accurate diagnosis may be difficult after recovery from an acute attack, especially after several months or years.

In a patient who is known to have inherited acute porphyria, it may be difficult to decide whether an illness is an attack of acute porphyria or something else. In this situation, urinary PBG can sometimes help your doctor to decide whether you are suffering from an acute attack of porphyria or some other illness. It is important that people with porphyria do not assume that all of their illnesses are porphyria related, as common but potentially serious conditions, such as appendicitis, may be overlooked.

Acute attacks are often provoked by controllable or avoidable factors such as drugs, alcohol or fasting, although some may be triggered by hormonal changes, for example, those associated with the menstrual cycle. Acute attacks can usually be reduced by avoiding any triggers.

Triggers include:

• Numerous drugs, including prescribed, over-the-counter or herbal remedies
• Alcohol
• Fasting – including dieting and gastric infections 
• Hormones
• Infections and stressful situations

Drugs: People with AIP must take great care with medication, as many medicines and chemical agents are capable of inducing an acute attack. It is important ALWAYS to check the safety of any medicine or remedy. This includes prescription medicines as well as over-the-counter treatments, tonics and herbal remedies, some of which have been known to cause attacks. It is advised to avoid all herbal remedies unless you are sure of their safety. While many drugs are considered suspect, there are many other drugs available and good alternatives can almost always be found.

• Even people who have never had an acute attack should be cautious when taking medicines. A combination of drugs with other factors such as stress, infection or poor nutrition may increase the risk of an acute attack.
• Though acute attacks are very rare before puberty, it is also best if children with the gene take only safe drugs.
• Also, it is very important for those who are suspected of having acute porphyria (or are in the process of undergoing tests to eliminate the possibility) to be extremely cautious with drugs.

The response of people with porphyria to unsafe drugs is unpredictable. A reaction does not follow in every case. However, if there is a porphyria reaction, it will take the form of an acute attack, which normally develops within days of taking the unsafe drug.

Reactions such as dizziness, feeling faint, allergies or short-lived skin rashes (which may occur immediately or very soon after taking the drug) are common after taking drugs and rarely have anything to do with porphyria. Side effects of abdominal pain or sickness may occur with some medicines, but will not always indicate an acute attack. However, if this happens, it is important to contact your doctor/porphyria specialist.

The UK Porphyria Medicines Information Service (UKPMIS, formerly the Welsh Medicines Information Centre – WMIC) has compiled a list of SAFE drugs for easy reference. AIP patients should keep an up-to-date copy with them. The SAFE list is updated annually using information collated internationally on drug safety over the previous year. This means that new drugs are sometimes added and at other times, drugs are removed following reports of adverse events. Please contact UKPMIS to be added to their database to receive your new copy each year. Patients or their doctors can call UKPMIS for advice on drug options on 029 2074 3877. Drugs not on the safe list should only be taken after obtaining expert advice from UKPMIS or a porphyria specialist.

The European Porphyria Initiative (EPI) website www.porphyria-europe.com contains further detailed information on prescribing in acute porphyria, including common prescribing problems (pain relief, anaesthesia, hormonal contraception).

Some people with porphyria may occasionally need a drug, perhaps for a serious illness, that carries some risk of provoking an acute attack or which has been introduced so recently that there is little information about its effect on porphyria. In this situation, your doctor, after fully discussing and explaining the risks, may decide to prescribe the drug for you.

Please also see our Drugs and porphyria leaflet for further information.

Alcohol: This is a common trigger for attacks, especially binge drinking. While many porphyria specialists strongly recommend absolute avoidance of alcohol, some people may find this recommendation difficult to follow. Experience has shown that people who have experienced an acute attack greatly reduce the risk of further attacks if they become teetotal for life. For those shown by testing to have inherited the gene responsible for one of the acute porphyrias, but who have not experienced an acute attack, it is best that they avoid alcohol. However, if this proves difficult a reasonable compromise is to keep intake as low as practicable and, in particular, to avoid heavy red wines, brandy and other liqueurs. , so the best advice is don’t drink. If you do drink, keep intake low.

Diet/fasting: Low calorie diets, or prolonged periods with little food, may provoke an acute attack. It is therefore important to keep to a normal diet with regular meals, eating enough to maintain a desirable body weight. Enough should be eaten to maintain a normal body weight with a suggested 55- 60% of the total food energy intake coming from carbohydrate.  Some people may find it easier to eat small meals every three hours rather than three normal-sized meals.

Hormones: Women are at least three times more likely than men to experience an acute attack, mostly due to female hormones, particularly progesterone. Women with acute porphyria should avoid oral contraceptives and HRT preparations containing progesterone or related compounds (progestogens), if at all possible. Injectable and implantable long-term hormone preparations are very dangerous and must always be avoided. See contraception in acute porphyria.

In special circumstances, where risk is low and the benefits high, your doctor may consider (after discussion with your porphyria specialist) the use of hormone-containing preparations. Replacement doses, given through the skin from patches, are preferred as they can be rapidly removed.

Pre-menstrual symptoms: In some women, particularly for those with AIP, attacks occur just before periods. One possible treatment is to suppress periods for up to two years. If you do need this sort of treatment, it needs to be done under close supervision by a porphyria specialist and will need regular monitoring.

Pregnancy:  Though nearly all pregnancies are uneventful, there is a small increased risk of having an acute attack during or after pregnancy. It is therefore very important for the doctors providing care during pregnancy to know that you have acute porphyria. See pregnancy in acute porphyria.

Anaesthetics and surgical operations: You must tell your surgeon and anaesthetist in advance that you have porphyria. Safe local and general anaesthetics, sedatives, antibiotics and pain relief must be used.

Dentist: You must also tell your dentist that you have an acute porphyria. Dentists often use local anaesthetic agents and a safe one must be chosen.

Contraceptives and HRT: Women with acute porphyria should avoid oral contraceptives and HRT preparations containing progesterone or progestogens, if at all possible. Injectable and implantable long-term hormone preparations are very dangerous and must always be avoided. The copper or Mirena coils are considered to be safe.

In special circumstances, where risk is low and the benefits high, hormone-containing preparations may be considered (after discussion with your porphyria specialist or UKPMIS). Replacement doses, given through the skin from patches, are preferred as they can be rapidly removed.

Early recognition of an acute attack allows early treatment. The early symptoms are often easily recognised by those who have previously experienced an attack. An immediate increase in carbohydrate intake (sweet or starchy food and drinks) may help to reduce the severity of the symptoms. 

If symptoms are severe, or don’t settle within 24 hours, you should contact your doctor, as you may need to be admitted to hospital. This will allow for:  confirmation of the acute attack by measuring PBG in urine; early start of specific treatment: for example, with haem arginate (Normosang); treatment for the various symptoms accompanying the attack, such as drugs to relieve pain and nausea, or actions to maintain an adequate intake of calories. 

Your doctor should contact the National Acute Porphyria Service (NAPS) who will give advice about treatment and provide haem arginate if needed. 

NAPS provides clinical advice and haem arginate where appropriate for patients having either one-off acute attacks or recurrent attacks of porphyria. There are two full NAPS centres and two associate centres: Kings College Hospital, London; University Hospital of Wales, Cardiff; Salford Royal Hospital, Salford; and St James University Hospital, Leeds.

Initially, your doctor would need to contact the emergency number at the University Hospital of Wales: 029 2074 7747. This 24/7 number should be used at all times for new patients, and out of working hours for existing NAPS patients.

Early recognition is more difficult for those people who have inherited an acute porphyria but who have never experienced an acute attack. As a consequence, there is often considerable apprehension about pains that usually turn out to be due to causes other than acute porphyria. It must be noted that people with porphyria commonly experience abdominal discomfort, just like those who do not have the condition, and a doctor will need to consider other medical conditions that may cause abdominal pain. These conditions include a range of bowel disturbances, urinary infections and, sometimes, other urgent medical problems such as appendicitis. In this situation, the diagnosis of acute porphyria can usually be established or excluded by testing the urine for porphobilinogen (PBG), one of the precursors of porphyrins.

For people who require hospital admission, intravenous haem arginate, which helps to overcome the relative deficiency of haem in the liver and which takes away the body’s desire to increase the supply of the chemicals needed for haem production, may need to be given.

Other treatments are likely to include the use of drugs to relieve pain and nausea and to provide sedation. It is also important to maintain an adequate intake of calories and this may require feeding intravenously or through a naso-gastric tube.

Not all people who inherit a gene mutation for one of the acute porphyrias will develop an acute attack. It is estimated that at least three-quarters of people who inherit an acute porphyria gene will never experience an acute attack of porphyria. In those who do become ill, it appears that additional factors are usually required for an attack to occur. Our knowledge of these factors is incomplete, but among the most important are a number of drugs, some of which are widely used, and alcohol. However acute attacks do occasionally occur in the absence of any identifiable provoking factor. Experience over many years has shown that if people who have inherited one of the acute porphyrias are careful to avoid certain drugs, alcohol and other known factors that may provoke an acute attack, their chance of becoming ill is much reduced.

Some people with porphyria may occasionally need a drug, perhaps for a serious illness, that carries some risk of triggering an acute attack or which has been introduced so recently that there is little information about its effect on porphyria. In this situation, your doctor (after discussing the risks with a porphyria specialist) may decide to prescribe the drug for you with special follow-up.

When prescribing in acute porphyria, the benefit from using the ideal drug should always be assessed against the risk of provoking an acute attack, and the likely consequences of not using it. A drug should never be withheld if it is judged to be essential for optimum treatment (e.g. chemotherapy for cancer). Support in deciding the best alternative can be obtained by telephoning UKPMIS on 029 2074 3877), or going to their website
www.wmic.wales.nhs.uk/specialist-services/drugs-in-porphyria/.

Some people may have used an unsafe drug without problems, even for many years, before being found – usually through family screening – to have latent porphyria. After discussion of the risk, these people may wish to continue on the drug and this is often allowed. However, if an additional drug needs to be prescribed, the possible risk of provoking an acute attack needs to be carefully considered and a change to a safer combination may be required. Note: even those who have taken an unsafe drug without problems in the past, could suffer an acute attack if they take it again. All individuals starting therapy should be advised to report any adverse reaction (e.g. abdominal pain or dark urine), immediately.

A portacath (also known as port-a-cath, port or implanted port) is a small medical device inserted under the skin. It provides direct access to a central vein.

A portacath may be considered if you need frequent access to veins for blood, injections, medical treatment(s). Or because of problems with access to smaller veins.

Portacaths are therefore considered for acute porphyria patients who need repeated intravenous treatment. Especially haem arginate – which needs to be given via a large vein. This avoids inflammation, pain and possibly long-term damage to smaller (peripheral) veins.

To read more, please download our portacath factsheet.