Recognizing Acute
Intermittent Porphyria (AIP)

Acute intermittent porphyria (AIP) is a rare inherited disease caused by a partial deficiency of the enzyme porphobilinogen (PBG) deaminase in the heme biosynthetic pathway. PBG deficiency disrupts normal heme production, leading to overproduction of porphyrin precursors that cause diverse pathologic changes.1 The most common symptom is severe abdominal pain.2

Symptoms

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Recognize the signs and symptoms of AIP

There is wide variability in the clinical features of an acute AIP attack.3 Gastrointestinal, urinary, neurologic, and cardiovascular symptoms commonly occur.2

ABDOMINAL PAIN, which is neuropathic in origin, is the most common AIP symptom.2

An accurate, timely diagnosis of AIP is critical

Delayed treatment can result in serious consequences, including neurologic damage or even death. AIP should be considered in any patient with symptoms that are prominent for AIP, particularly abdominal pain, when initial clinical evaluation does not support another cause.2

Review diagnostic testing guidance

Incidence of Common AIP Symptoms*2

Precipitating Factors

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Patient characteristics and precipitating factors

In differentiating AIP from other conditions with these common symptoms, certain patient characteristics and possible precipitating factors should heighten the suspicion of AIP.

AIP Patient Profile: Women of reproductive age

Acute AIP attacks are most common in women of reproductive age (most commonly in their 30s) during the luteal phase of their menstrual cycles.2-4

Exacerbating factors in AIP attacks

The enzymatic deficiency of AIP “predisposes” patients to the effects of precipitating factors that can increase the demand for hepatic heme and induce ALA synthase.2 Thus, attacks are usually due to the additive effects of several exacerbating factors, including:

  1. Endogenous steroid hormones, particularly estrogen and progesterone4
  2. Use of certain prescription drugs, especially barbiturates, hydantoins, rifampin, and sulfonamides,4 and often newly prescribed drugs5
  3. Use of alcohol or illicit drugs such as amphetamines, cocaine, and derivatives6
  1. Fasting4 or crash dieting2
  2. Cigarette smoking2,3
  3. Metabolic stress induced by infections or surgery2
  4. Psychological stress1

Family History

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Family history of AIP

Having family members with diagnosed AIP is highly indicative, yet one-third of patients have no family history of AIP.1

Although AIP is a genetic disease, it is an autosomal dominant condition with low penetrance. Therefore, 80%-90% of individuals who have inherited the enzyme deficiency never have symptomatic disease and are considered to be "latent porphyrics." 1

Review genetic testing information

Although AIP is the most common and severe form of the four acute porphyrias in the US, it is still a rare disease.1 The combined prevalence of the acute porphyrias is estimated to be approximately 5 cases per 100,000 people in the US.2

Potential Consequences

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Possible serious consequences of not recognizing AIP

Individuals with undiagnosed or inappropriately treated AIP attacks may suffer serious, potentially fatal, consequences, including:2


  • Peripheral neuropathy
  • Paresis
  • Respiratory and bulbar paralysis
  • Hepatocellular carcinoma
  • Chronic liver damage
  • Chronic neuropathic pain
  • Chronic arterial hypertension
  • Renal impairment
  • Death resulting from cardiac arrhythmia or paralysis during an attack

AIP should be considered in any patient with symptoms that are prominent for AIP, particularly abdominal pain, when initial clinical evaluation does not support another cause.2

Diagnosing and Managing AIP Review diagnostic testing guidance
About PANHEMATIN Review efficacy and safety data