eMedicine Specialties > Hematology > Heme Synthesis and Disorders
Porphyria, Acute Intermittent
Updated: Jun 30, 2006
Introduction
Background
Acute intermittent porphyria (AIP) is one of the porphyrias, a group of diseases involving defects in heme metabolism and that results in excessive secretion of porphyrins and porphyrin precursors. AIP manifests itself by abdomen pain, neuropathies, and constipation, but, unlike most types of porphyria, patients with AIP do not have a rash.
Pathophysiology
AIP is an autosomal dominant disease that results from defects in the enzyme porphobilinogen-deaminase. This enzyme speeds the conversion of porphobilinogen to hydroxymethylbilane. In AIP, the porphyrin precursors, porphobilinogen and amino-levulinic acid (ALA), accumulate. The predominant problem appears to be neurologic damage that leads to peripheral and autonomic neuropathies and psychiatric manifestations.
Although patients with acute attacks always have elevations of porphobilinogen and ALA, how this leads to the symptomatic disease is still unclear because most patients with the genetic defect have excessive porphyrin secretion but no symptoms.
Frequency
United States
Estimates vary from 1-5 cases per 100,000 population.
International
Prevalence can be as high as 60-100 cases per 100,000 population in northern Sweden.
Sex
In most series, AIP affects women more than men, with a ratio of 1.5-2:1.
Age
Most patients become symptomatic at age 18-40 years. Attacks occurring before puberty or after age 40 years are unusual unless a major provocation, such as new use of phenobarbital or estrogens, had occurred.
Clinical
History
The sequence of events in attacks usually is (1) abdominal pain, (2) psychiatric symptoms, such as hysteria, and (3) peripheral neuropathies, mainly motor neuropathies.
- Most patients are completely free of symptoms between attacks. How the porphyrin precursors lead to these symptoms is unknown.
- AIP displays neurovisceral symptoms but no skin manifestations.
- The neurovisceral symptoms consist of autonomic neuropathies (eg, constipation, colicky abdominal pain, vomiting, hypertension), peripheral neuropathy, seizures, delirium, coma, and depression.
- The abdominal pain is severe and lasts for several days. Severe abdomen pain of short ( <1 d) duration or chronic abdominal pain is unusual.
- AIP patients may have central nervous system signs consisting of seizures, mental status changes, cortical blindness, and coma.
- Patients often experience peripheral neuropathies that are predominantly motor and can mimic Guillain-Barré syndrome. The weakness usually starts in the lower limbs and ascends, but neuropathies can be observed in any nerve distribution.
- Diffuse pain, especially in the upper body, can be observed.
- Patients may develop autonomic neuropathies, such as hypertension and tachycardia.
- Patients may have very severe abdominal pain lasting several days.
- Pain of short duration (minutes) or chronic abdominal pain is not observed in AIP.
- The pain often is epigastric and colicky in nature.
- Patients often are free of pain between attacks.
- Constipation is common and can be very severe.
- Frequently, nausea and vomiting are present.
- Patients can have a wide variety of psychiatric symptoms.
- Usually, patients have concurrent neurologic or abdominal symptoms.
- Depression is very common.
Physical
- Vital signs
- From 30-80% of patients have tachycardia.
- Fever can be present in some patients.
- Hypertension is observed in half of patients and may persist between attacks.
- Neurological manifestations
- Usually, the neuropathy is a motor neuropathy that is more predominant in the lower limbs.
- Areflexia often is present on examination.
- Any nerve can be involved, and cranial neuropathies also are observed.
- Patients also may have cortical blindness.
- Abdominal examination: Despite the intense pain, the findings on abdominal examination often are nonspecific.
- Skin examination: Unlike many other porphyrias, AIP is not associated with a skin rash.
Causes
Acute intermittent porphyria (AIP) is due to a combination of a genetic enzyme defect and acquired causes that become symptomatic only in some patients. In patients with AIP, the function of porphobilinogen-deaminase is only 40-60% of normal. With the advent of molecular technique, the genetic defect clearly is more common than symptomatic AIP. On average, out of 100 patients with the genetic defect, perhaps 10-20 secrete excess porphyrin precursors and only 1-2 have symptoms.
The classic inducers of porphyria are chemicals or situations that boost heme synthesis. This includes fasting and many medications. Although very large lists of "safe" and "unsafe" drugs exist, many of these are based on anecdotes or laboratory evidence and do not meet strict criteria. In general, drugs that lead to increased activity of the hepatic P450 system, such as phenobarbital, sulfonamides, estrogens, and alcohol, are associated with porphyria.
A large and detailed list is available on the University of Queensland, Department of Medicine Web site.
Fasting for several days also can trigger an attack. However, many attacks occur without any obvious provocation.
Table 1. Drugs Thought Safe in Porphyria*
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Table
| Acetazolamide acetylcholine Actinomycin D Acyclovir Adenosine monophosphate Adrenaline Alclofenac Allopurinol Alpha tocopheryl Acetate Amethocaine Amiloride Aminocaproic acid Aminoglycosides Amoxicillin Amphotericin Ampicillin Ascorbic acid Aspirin Atenolol Atropine Azathioprine Beclomethasone Benzhexol HCl Beta-carotene Biguanides [Bromazepam] Bromides Buflomedil HCl Bumetanide Bupivacaine Buprenorphine Buserelin Butacaine SO4 Canthaxanthin Carbimazole [Carpipramine HCl] Chloral hydrate [Chlormethiazole] [Chloroquine] [Chlorothiazide] Chlorpheniramine Chlorpromazine Ciprofloxacin Cisapride Cisplatin Clavulanic acid Clofibrate Clomiphene Cloxacillin Co-codamol Codeine phosphate Colchicine [Corticosteroids] Corticotrophin (adrenocorticotropic hormone [ACTH]) | Coumarins Cyclizine Cyclopenthiazide Cyclopropane [Cyproterone acetate] Danthron Desferrioxamine Dexamethasone [Dextromoramide] Dextrose Diamorphine Diazoxide Dicyclomine HCl Diflunisal Digoxin Dihydrocodeine Dimercaprol Dimethicone Dinoprost Diphenoxylate HCl Dipyridamole [Disopyramide] Domperidone Doxorubicin HCl Droperidol [Estazolam] Ethacrynic acid Ethambutol [Ethinyl oestradiol] Ethoheptazine citrate Etoposide Famotidine Fenbufen [Fenofibrate] Fenoprofen Fentanyl Flucytosine Flumazenil Fluoxetine HCl Flurbiprofen Fluvoxamine Maleate Folic acid Fructose Fusidic acid Follicle-stimulating hormone Gentamicin Glafenine Glucagon Glucose Glyceryl trinitrate Goserelin Guanethidine Guanfacine HCl Haem arginate [Haloperidol] Heparin Heptaminol HCl Hexamine [Hydrocortisone] Ibuprofen Indomethacin Insulin Iron Josamycin [Ketamine] | Ketoprofen Ketotifen Labetalol Luteinizing hormone–releasing hormone Liquorice Lithium Salts lofepramine Loperamide [Lorazepam] Magnesium-sulphate [Mebendazole] Mecamylamine Meclofenoxate HCl Meclozine Mefloquine HCl [Melphalan] Meptazinol Mequitazine Metformin Methadone [Methotrimeprazine] Methylphenidate Methyluracil Metipropranolol Metopimazine Metoprolol [Metronidazole] [Midazolam] Minaprine HCl Minaxolone Morphine Nadolol Naftidrofuryl Oxalate [Naproxen sodium] Natamycin Nefopam HCl Neostigmine Netilmicin Niflumic acid Nitrous oxide Norfloxacin Ofloxacin Oxolinic acid Oxybuprocaine [Oxyphenbutazone] Oxytocin [Pancuronium bromide] Paracetamol Paraldehyde Parapenzolate Br Penicillamine Penicillin Pentolinium Pericyazine Pethidine Phenformin Phenoperidine Phentolamine mesylate Pipotiazine | Palmitate Piracetam Pirbuterol Pirenzepine Pizotifen [Prazosin] [Prednisolone] Primaquine Probucol Procainamide HCl Procaine Prochlorperazine Proguanil HCl Promazine Propantheline Br Propofol Propranolol Propylthiouracil [Proxymetacaine] Pseudoephedrine HCl Pyridoxine [Pyrimethamine] Quinidine Quinine [Ranitidine] Reserpine Resorcinol Salbutamol Senna Sodium bromide Sodium ethylenediaminetetraacetic acid Sodium fusidate Sorbitol Streptomycin Sulbutiamine Sulindac Sulfadoxine Suxamethonium Talampicillin Temazepam Tetracaine [Tetracyclines] Thiouracils Thyroxine Tiaprofenic acid Ticarcillin Tienilic acid Timolol maleate Tolazoline Tranexamic acid Triacetyloleandomycin Triamterene Triazolam [Trichlormethiazide] Trifluoperazine Trimeprazine Tartrate Trimetazidine HCl Tripelennamine Tubocurarine Vancomycin [Vincristine] Vitamins Warfarin sodium Zidovudine Zinc Preparations |
| Acetazolamide acetylcholine Actinomycin D Acyclovir Adenosine monophosphate Adrenaline Alclofenac Allopurinol Alpha tocopheryl Acetate Amethocaine Amiloride Aminocaproic acid Aminoglycosides Amoxicillin Amphotericin Ampicillin Ascorbic acid Aspirin Atenolol Atropine Azathioprine Beclomethasone Benzhexol HCl Beta-carotene Biguanides [Bromazepam] Bromides Buflomedil HCl Bumetanide Bupivacaine Buprenorphine Buserelin Butacaine SO4 Canthaxanthin Carbimazole [Carpipramine HCl] Chloral hydrate [Chlormethiazole] [Chloroquine] [Chlorothiazide] Chlorpheniramine Chlorpromazine Ciprofloxacin Cisapride Cisplatin Clavulanic acid Clofibrate Clomiphene Cloxacillin Co-codamol Codeine phosphate Colchicine [Corticosteroids] Corticotrophin (adrenocorticotropic hormone [ACTH]) | Coumarins Cyclizine Cyclopenthiazide Cyclopropane [Cyproterone acetate] Danthron Desferrioxamine Dexamethasone [Dextromoramide] Dextrose Diamorphine Diazoxide Dicyclomine HCl Diflunisal Digoxin Dihydrocodeine Dimercaprol Dimethicone Dinoprost Diphenoxylate HCl Dipyridamole [Disopyramide] Domperidone Doxorubicin HCl Droperidol [Estazolam] Ethacrynic acid Ethambutol [Ethinyl oestradiol] Ethoheptazine citrate Etoposide Famotidine Fenbufen [Fenofibrate] Fenoprofen Fentanyl Flucytosine Flumazenil Fluoxetine HCl Flurbiprofen Fluvoxamine Maleate Folic acid Fructose Fusidic acid Follicle-stimulating hormone Gentamicin Glafenine Glucagon Glucose Glyceryl trinitrate Goserelin Guanethidine Guanfacine HCl Haem arginate [Haloperidol] Heparin Heptaminol HCl Hexamine [Hydrocortisone] Ibuprofen Indomethacin Insulin Iron Josamycin [Ketamine] | Ketoprofen Ketotifen Labetalol Luteinizing hormone–releasing hormone Liquorice Lithium Salts lofepramine Loperamide [Lorazepam] Magnesium-sulphate [Mebendazole] Mecamylamine Meclofenoxate HCl Meclozine Mefloquine HCl [Melphalan] Meptazinol Mequitazine Metformin Methadone [Methotrimeprazine] Methylphenidate Methyluracil Metipropranolol Metopimazine Metoprolol [Metronidazole] [Midazolam] Minaprine HCl Minaxolone Morphine Nadolol Naftidrofuryl Oxalate [Naproxen sodium] Natamycin Nefopam HCl Neostigmine Netilmicin Niflumic acid Nitrous oxide Norfloxacin Ofloxacin Oxolinic acid Oxybuprocaine [Oxyphenbutazone] Oxytocin [Pancuronium bromide] Paracetamol Paraldehyde Parapenzolate Br Penicillamine Penicillin Pentolinium Pericyazine Pethidine Phenformin Phenoperidine Phentolamine mesylate Pipotiazine | Palmitate Piracetam Pirbuterol Pirenzepine Pizotifen [Prazosin] [Prednisolone] Primaquine Probucol Procainamide HCl Procaine Prochlorperazine Proguanil HCl Promazine Propantheline Br Propofol Propranolol Propylthiouracil [Proxymetacaine] Pseudoephedrine HCl Pyridoxine [Pyrimethamine] Quinidine Quinine [Ranitidine] Reserpine Resorcinol Salbutamol Senna Sodium bromide Sodium ethylenediaminetetraacetic acid Sodium fusidate Sorbitol Streptomycin Sulbutiamine Sulindac Sulfadoxine Suxamethonium Talampicillin Temazepam Tetracaine [Tetracyclines] Thiouracils Thyroxine Tiaprofenic acid Ticarcillin Tienilic acid Timolol maleate Tolazoline Tranexamic acid Triacetyloleandomycin Triamterene Triazolam [Trichlormethiazide] Trifluoperazine Trimeprazine Tartrate Trimetazidine HCl Tripelennamine Tubocurarine Vancomycin [Vincristine] Vitamins Warfarin sodium Zidovudine Zinc Preparations |
*Bracketed [ ] drugs are those in which experimental evidence of porphyrin genicity is conflicting.
Table 2. Drugs Thought Unsafe in Porphyria†
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Table
| Alcuronium *Alphaxalone Alphadolone Alprazolam Aluminium Preparations Amidopyrine Aminoglutethimide Aminophylline Amiodarone *Amitriptyline [Amphetamines] *Amylobarbitone Antipyrine *Auranofin *Aurothiomalate Azapropazone Baclofen *Barbiturates *Bemegride Bendrofluazide Benoxaprofen Benzbromarone [Benzylthiouracil] [Bepridil] Bromocriptine Busulphan *Butylscopolamine Captopril *Carbamazepine *Carbromal *Carisoprodol [Cefuroxime] [Cephalexin] [Cephalosporins] [Cephradine] [Chlorambucil] *Chloramphenicol *Chlordiazepoxide *Chlormezanone Chloroform *Chlorpropamide Cinnarizine Clemastine [Clobazam] [Clomipramine HCl] [Clonazepam] Clonidine HCl *Clorazepate Cocaine [Colistin] Co-trimoxazole | Cyclophosphamide Cycloserine Cyclosporin Danazol *Dapsone Dexfenfluramine Dextropropoxyphene Diazepam *Dichloralphenazone *Diclofenac Na Dienoestrol Diethylpropion Dihydralazine *Dihydroergotamine Diltiazem *Dimenhydrinate *Diphenhydramine [Dothiepin HCl] Doxycycline *Dydrogesterone *Econazole NO3 *Enalapril Enflurane *Ergot compounds Ergometrine maleate Ergotamine tartrate *Erythromycin *Estramustine Ethamsylate *Ethanol Ethionamide *Ethosuximide *Ethotoin Etidocaine Etomidate Fenfluramine *Flucloxacillin *Flufenamic acid Flunitrazepam Flupenthixol Flurazepam *Frusemide *Glibenclamide *Glutethimide *Glipizide Gramicidin *Griseofulvin [Haloperidol] *Halothane *Hydantoins *Hydralazine *Hydrochlorothiazide *Hydroxyzine Hyoscine *Imipramine Iproniazid Isometheptene mucate [Isoniazid] Kebuzone Ketoconazole *Levonorgestrel Lignocaine *Lisinopril Loprazolam Loxapine *Lynestrenol Lysuride | Maleate Maprotiline HCl Mebeverine HCl *Mecillinam *Medroxyprogesterone [Mefenamic acid] Megestrol acetate *Mephenytoin Mepivacaine *Meprobamate Mercaptopurine Mercury compounds Mestranol [Metapramine HCl] Methamphetamine Methohexitone Methotrexate Methoxyflurane Methsuximide *Methyldopa *Methylsulphonal *Methyprylone Methysergide *Metoclopramide Metyrapone Mianserin HCl Miconazole [Mifepristone] Minoxidil *Nandrolone *Nalidixic acid Natamycin *Nandrolone [Nicergoline] *Nifedipine *Nikethamide Nitrazepam *Nitrofurantoin Nordazepam Norethynodrel *Norethisterone [Nortriptyline] Novobiocin *Oral contraceptives *Orphenadrine Oxanamide [Oxazepam] Oxybutynin HCl Oxycodone *Oxymetazoline *Oxyphenbutazone Oxytetracycline Paramethadione Pargyline *Pentazocine Perhexiline Phenacetin Phenelzine *Phenobarbitone Phenoxybenzamine *Phensuximide *Phenylbutazone Phenylhydrazine *Phenytoin Pipebuzone Pipemidic Acid Piritramide *Piroxicam | *Pivampicillin *Pivmecillinam Prazepam Prenylamine *Prilocaine *Primidone [Probenecid] *Progesterone Progabide Promethazine [Propanidid] *Pyrazinamide Pyrrocaine Quinalbarbitone Rifampicin Simvastatin Sodium aurothiomalate Sodium oxybate [Sodium valproate] *Spironolactone Stanozolol Succinimides *Sulfacetamide *Sulfadiazine *Sulfadimidine *Sulfadoxine *Sulfamethoxazole *Sulfasalazine *Sulfonylureas Sulfinpyrazone Sulpiride Sulthiame Sultopride *Tamoxifen *Terfenadine Tetrazepam *Theophylline *Thiopentone Na Thioridazine Tilidate Tinidazole *Tolazamide *Tolbutamide Tranylcypromine Trazodone HCl Trimethoprim [Trimipramine] Troxidone Valproate Valpromide Veralipride *Verapamil *Vibramycin Viloxazine HCl [Vinblastine] [Vincristine] Zuclopenthixol |
| Alcuronium *Alphaxalone Alphadolone Alprazolam Aluminium Preparations Amidopyrine Aminoglutethimide Aminophylline Amiodarone *Amitriptyline [Amphetamines] *Amylobarbitone Antipyrine *Auranofin *Aurothiomalate Azapropazone Baclofen *Barbiturates *Bemegride Bendrofluazide Benoxaprofen Benzbromarone [Benzylthiouracil] [Bepridil] Bromocriptine Busulphan *Butylscopolamine Captopril *Carbamazepine *Carbromal *Carisoprodol [Cefuroxime] [Cephalexin] [Cephalosporins] [Cephradine] [Chlorambucil] *Chloramphenicol *Chlordiazepoxide *Chlormezanone Chloroform *Chlorpropamide Cinnarizine Clemastine [Clobazam] [Clomipramine HCl] [Clonazepam] Clonidine HCl *Clorazepate Cocaine [Colistin] Co-trimoxazole | Cyclophosphamide Cycloserine Cyclosporin Danazol *Dapsone Dexfenfluramine Dextropropoxyphene Diazepam *Dichloralphenazone *Diclofenac Na Dienoestrol Diethylpropion Dihydralazine *Dihydroergotamine Diltiazem *Dimenhydrinate *Diphenhydramine [Dothiepin HCl] Doxycycline *Dydrogesterone *Econazole NO3 *Enalapril Enflurane *Ergot compounds Ergometrine maleate Ergotamine tartrate *Erythromycin *Estramustine Ethamsylate *Ethanol Ethionamide *Ethosuximide *Ethotoin Etidocaine Etomidate Fenfluramine *Flucloxacillin *Flufenamic acid Flunitrazepam Flupenthixol Flurazepam *Frusemide *Glibenclamide *Glutethimide *Glipizide Gramicidin *Griseofulvin [Haloperidol] *Halothane *Hydantoins *Hydralazine *Hydrochlorothiazide *Hydroxyzine Hyoscine *Imipramine Iproniazid Isometheptene mucate [Isoniazid] Kebuzone Ketoconazole *Levonorgestrel Lignocaine *Lisinopril Loprazolam Loxapine *Lynestrenol Lysuride | Maleate Maprotiline HCl Mebeverine HCl *Mecillinam *Medroxyprogesterone [Mefenamic acid] Megestrol acetate *Mephenytoin Mepivacaine *Meprobamate Mercaptopurine Mercury compounds Mestranol [Metapramine HCl] Methamphetamine Methohexitone Methotrexate Methoxyflurane Methsuximide *Methyldopa *Methylsulphonal *Methyprylone Methysergide *Metoclopramide Metyrapone Mianserin HCl Miconazole [Mifepristone] Minoxidil *Nandrolone *Nalidixic acid Natamycin *Nandrolone [Nicergoline] *Nifedipine *Nikethamide Nitrazepam *Nitrofurantoin Nordazepam Norethynodrel *Norethisterone [Nortriptyline] Novobiocin *Oral contraceptives *Orphenadrine Oxanamide [Oxazepam] Oxybutynin HCl Oxycodone *Oxymetazoline *Oxyphenbutazone Oxytetracycline Paramethadione Pargyline *Pentazocine Perhexiline Phenacetin Phenelzine *Phenobarbitone Phenoxybenzamine *Phensuximide *Phenylbutazone Phenylhydrazine *Phenytoin Pipebuzone Pipemidic Acid Piritramide *Piroxicam | *Pivampicillin *Pivmecillinam Prazepam Prenylamine *Prilocaine *Primidone [Probenecid] *Progesterone Progabide Promethazine [Propanidid] *Pyrazinamide Pyrrocaine Quinalbarbitone Rifampicin Simvastatin Sodium aurothiomalate Sodium oxybate [Sodium valproate] *Spironolactone Stanozolol Succinimides *Sulfacetamide *Sulfadiazine *Sulfadimidine *Sulfadoxine *Sulfamethoxazole *Sulfasalazine *Sulfonylureas Sulfinpyrazone Sulpiride Sulthiame Sultopride *Tamoxifen *Terfenadine Tetrazepam *Theophylline *Thiopentone Na Thioridazine Tilidate Tinidazole *Tolazamide *Tolbutamide Tranylcypromine Trazodone HCl Trimethoprim [Trimipramine] Troxidone Valproate Valpromide Veralipride *Verapamil *Vibramycin Viloxazine HCl [Vinblastine] [Vincristine] Zuclopenthixol |
*These drugs have been associated with acute attacks of porphyria.
†Bracketed [ ] drugs are those in which experimental evidence of porphyringenicity is conflicting.
More on Porphyria, Acute Intermittent |
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| Treatment & Medication: Porphyria, Acute Intermittent |
| Follow-up: Porphyria, Acute Intermittent |
| References |
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References
Anderson KE, Bloomer JR, Bonkovsky HL, et al. Recommendations for the diagnosis and treatment of the acute porphyrias. Ann Intern Med. Mar 15 2005;142(6):439-50. [Medline].
Bonkovsky HL, Barnard GF. Diagnosis of porphyric syndromes: a practical approach in the era of molecular biology. Semin Liver Dis. 1998;18(1):57-65. [Medline].
Daniell WE, Stockbridge HL, Labbe RF, et al. Environmental chemical exposures and disturbances of heme synthesis. Environ Health Perspect. Feb 1997;105 Suppl 1:37-53. [Medline].
Elder GH, Smith SG, Smyth SJ. Laboratory investigation of the porphyrias. Ann Clin Biochem. Sep 1990;27 ( Pt 5):395-412. [Medline].
Gorchein A. Drug treatment in acute porphyria. Br J Clin Pharmacol. Nov 1997;44(5):427-34. [Medline].
Hahn M, Bonkovsky HL. Multiple chemical sensitivity syndrome and porphyria. A note of caution and concern. Arch Intern Med. Feb 10 1997;157(3):281-5. [Medline].
Kalman DR, Bonkovsky HL. Management of acute attacks in the porphyrias. Clin Dermatol. Mar-Apr 1998;16(2):299-306. [Medline].
Kauppinen R, Mustajoki P. Prognosis of acute porphyria: occurrence of acute attacks, precipitating factors, and associated diseases. Medicine (Baltimore). Jan 1992;71(1):1-13. [Medline].
Laiwah AC, McColl KE. Management of attacks of acute porphyria. Drugs. Nov 1987;34(5):604-16. [Medline].
Massey EW. Neuropsychiatric manifestations of porphyria. J Clin Psychiatry. Jun 1980;41(6):208-13. [Medline].
Mattern SE, Tefferi A. Acute porphyria: the cost of suspicion. Am J Med. Dec 1999;107(6):621-3. [Medline].
Moore MR. The biochemistry of heme synthesis in porphyria and in the porphyrinurias. Clin Dermatol. Mar-Apr 1998;16(2):203-23. [Medline].
Murphy GM. The cutaneous porphyrias: a review. The British Photodermatology Group. Br J Dermatol. Apr 1999;140(4):573-81. [Medline].
Peters TJ, Sarkany R. Porphyria for the general physician. Clin Med. May-Jun 2005;5(3):275-81. [Medline].
Poh-Fitzpatrick MB. Clinical features of the porphyrias. Clin Dermatol. Mar-Apr 1998;16(2):251-64. [Medline].
Tefferi A, Colgan JP, Solberg LA Jr. Acute porphyrias: diagnosis and management. Mayo Clin Proc. Oct 1994;69(10):991-5. [Medline].
Zaider E, Bickers DR. Clinical laboratory methods for diagnosis of the porphyrias. Clin Dermatol. Mar-Apr 1998;16(2):277-93. [Medline].
Further Reading
Keywords
acute intermittent porphyria, AIP, defects in heme metabolism, increased secretion of porphobilinogen, abdominal pain, psychiatric problems, hysteria, peripheral neuropathies, abdominal pain, neuropathy, constipation
