Hy's law

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Hy's law is a rule of thumb that a patient is at high risk of a fatal drug-induced liver injury if given a medication that causes hepatocellular injury (not Hepatobiliary injury) with jaundice. [1] The law is based on observations by Hy Zimmerman, a major scholar of drug-induced liver injury. [2] [3] [4] Some have suggested the principle be called a hypothesis or observation. [5]

Hy's Law cases have three components: [2]

In Zimmerman's analysis of 116 patients with hepatocellular injury and jaundice due to drug exposure, 76% went on to either require a liver transplant or died. [6] Other studies have reported a lower but still significant mortality of 10%. [7] [8]

Related Research Articles

<span class="mw-page-title-main">Jaundice</span> Abnormal pigmentation symptom for disease of the liver

Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaundice in adults is rare, while jaundice in babies is common, with an estimated 80% affected during their first week of life. The most commonly associated symptoms of jaundice are itchiness, pale feces, and dark urine.

<span class="mw-page-title-main">Bilirubin</span> Chemical compound

Bilirubin (BR) is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from the destruction of aged or abnormal red blood cells. In the first step of bilirubin synthesis, the heme molecule is stripped from the hemoglobin molecule. Heme then passes through various processes of porphyrin catabolism, which varies according to the region of the body in which the breakdown occurs. For example, the molecules excreted in the urine differ from those in the feces. The production of biliverdin from heme is the first major step in the catabolic pathway, after which the enzyme biliverdin reductase performs the second step, producing bilirubin from biliverdin.

Liver function tests, also referred to as a hepatic panel, are groups of blood tests that provide information about the state of a patient's liver. These tests include prothrombin time (PT/INR), activated partial thromboplastin time (aPTT), albumin, bilirubin, and others. The liver transaminases aspartate transaminase and alanine transaminase are useful biomarkers of liver injury in a patient with some degree of intact liver function.

<span class="mw-page-title-main">Alcoholic liver disease</span> Medical condition

Alcoholic liver disease (ALD), also called alcohol-related liver disease (ARLD), is a term that encompasses the liver manifestations of alcohol overconsumption, including fatty liver, alcoholic hepatitis, and chronic hepatitis with liver fibrosis or cirrhosis.

<span class="mw-page-title-main">Hepatotoxicity</span> Liver damage caused by a drug or chemical

Hepatotoxicity implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn from the market after approval.

<span class="mw-page-title-main">Alcoholic hepatitis</span> Medical condition

Alcoholic hepatitis is hepatitis due to excessive intake of alcohol. Patients typically have a history of at least 10 years of heavy alcohol intake, typically 8-10 drinks per day. It is usually found in association with fatty liver, an early stage of alcoholic liver disease, and may contribute to the progression of fibrosis, leading to cirrhosis. Symptoms may present acutely after a large amount of alcoholic intake in a short time period, or after years of excess alcohol intake. Signs and symptoms of alcoholic hepatitis include jaundice, ascites, fatigue and hepatic encephalopathy. Mild cases are self-limiting, but severe cases have a high risk of death. Severe cases may be treated with glucocorticoids. The condition often comes on suddenly and may progress in severity very rapidly.

<span class="mw-page-title-main">Autoimmune hepatitis</span> Chronic, autoimmune disease of the liver

Autoimmune hepatitis, formerly known as lupoid hepatitis, plasma cell hepatitis, or autoimmune chronic active hepatitis, is a chronic, autoimmune disease of the liver that occurs when the body's immune system attacks liver cells, causing the liver to be inflamed. Common initial symptoms may include fatigue, nausea, muscle aches, or weight loss or signs of acute liver inflammation including fever, jaundice, and right upper quadrant abdominal pain. Individuals with autoimmune hepatitis often have no initial symptoms and the disease may be detected by abnormal liver function tests and increased protein levels during routine bloodwork or the observation of an abnormal-looking liver during abdominal surgery.

<span class="mw-page-title-main">Primary biliary cholangitis</span> Autoimmune disease of the liver

Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build up in the liver, a condition called cholestasis. Further slow damage to the liver tissue can lead to scarring, fibrosis, and eventually cirrhosis.

<span class="mw-page-title-main">Aagenaes syndrome</span> Medical condition

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<span class="mw-page-title-main">Liver biopsy</span>

Liver biopsy is the biopsy from the liver. It is a medical test that is done to aid diagnosis of liver disease, to assess the severity of known liver disease, and to monitor the progress of treatment.

<span class="mw-page-title-main">Cholestasis</span> Medical condition

Cholestasis is a condition where the flow of bile from the liver to the duodenum is impaired. The two basic distinctions are:

<span class="mw-page-title-main">Crigler–Najjar syndrome</span> Rare inherited disorder affecting the metabolism of bilirubin

Crigler–Najjar syndrome is a rare inherited disorder affecting the metabolism of bilirubin, a chemical formed from the breakdown of the heme in red blood cells. The disorder results in a form of nonhemolytic jaundice, which results in high levels of unconjugated bilirubin and often leads to brain damage in infants. The disorder is inherited in an autosomal recessive manner. The annual incidence is estimated at 1 in 1,000,000.

<span class="mw-page-title-main">Rotor syndrome</span> Medical condition

Rotor syndrome is a rare cause of mixed direct (conjugated) and indirect (unconjugated) hyperbilirubinemia, relatively benign, autosomal recessive bilirubin disorder characterized by non-hemolytic jaundice due to the chronic elevation of predominantly conjugated bilirubin.

Neonatal cholestasis refers to elevated levels of conjugated bilirubin identified in newborn infants within the first few months of life. Conjugated hyperbilirubinemia is clinically defined as >20% of total serum bilirubin or conjugated bilirubin concentration greater than 1.0 mg/dL regardless of total serum bilirubin concentration. The differential diagnosis for neonatal cholestasis can vary extensively. However, the underlying disease pathology is caused by improper transport and/or defects in excretion of bile from hepatocytes leading to an accumulation of conjugated bilirubin in the body. Generally, symptoms associated with neonatal cholestasis can vary based on the underlying cause of the disease. However, most infants affected will present with jaundice, scleral icterus, failure to thrive, acholic or pale stools, and dark urine.

<span class="mw-page-title-main">Bentazepam</span> Chemical compound

Bentazepam is a thienodiazepine which is a benzodiazepine analog.

In medicine, the presence of elevated transaminases, commonly the transaminases alanine transaminase (ALT) and aspartate transaminase (AST), may be an indicator of liver dysfunction. Other terms include transaminasemia, transaminitis, and elevatedliver enzymes. Normal ranges for both ALT and AST vary by gender, age, and geography and are roughly 8-40 U/L. Mild transaminesemia refers to levels up to 250 U/L. Drug-induced increases such as that found with the use of anti-tuberculosis agents such as isoniazid are limited typically to below 100 U/L for either ALT or AST. Muscle sources of the enzymes, such as intense exercise, are unrelated to liver function and can markedly increase AST and ALT. Cirrhosis of the liver or fulminant liver failure secondary to hepatitis commonly reach values for both ALT and AST in the >1000 U/L range; however, many people with liver disease have normal transaminases. Elevated transaminases that persist less than six months are termed "acute" in nature, and those values that persist for six months or more are termed "chronic" in nature.

<span class="mw-page-title-main">Fibrolamellar hepatocellular carcinoma</span> Medical condition

Fibrolamellar carcinoma (FLC) is a rare form of carcinoma that typically affects young adults and is characterized, under the microscope, by laminated fibrous layers interspersed between the tumor cells. It has been estimated that 200 new cases are diagnosed worldwide each year. However, in light of recent advances in our molecular understanding, this has recently been revised to suggest it may be at least ten times more common. FLC, also known as fibrolamellar hepatocellular carcinoma, is different from the more common hepatocellular carcinoma (HCC) in that it afflicts young people with normal liver function and no known risk factors.

<span class="mw-page-title-main">Bilirubin glucuronide</span> Chemical compound

Bilirubin glucuronide is a water-soluble reaction intermediate over the process of conjugation of indirect bilirubin. Bilirubin glucuronide itself belongs to the category of conjugated bilirubin along with bilirubin di-glucuronide. However, only the latter one is primarily excreted into the bile in the normal setting.

Hemolytic jaundice, also known as prehepatic jaundice, is a type of jaundice arising from hemolysis or excessive destruction of red blood cells, when the byproduct bilirubin is not excreted by the hepatic cells quickly enough. Unless the patient is concurrently affected by hepatic dysfunctions or is experiencing hepatocellular damage, the liver does not contribute to this type of jaundice.

Hyperbilirubinemia is a clinical condition describing an elevation of blood bilirubin level due to the inability to properly metabolise or excrete bilirubin, a product of erythrocytes breakdown. In severe cases, it is manifested as jaundice, the yellowing of tissues like skin and the sclera when excess bilirubin deposits in them. The US records 52,500 jaundice patients annually. By definition, bilirubin concentration of greater than 3 mg/ml is considered hyperbilirubinemia, following which jaundice progressively develops and becomes apparent when plasma levels reach 20 mg/ml. Rather than a disease itself, hyperbilirubinemia is indicative of multifactorial underlying disorders that trace back to deviations from regular bilirubin metabolism. Diagnosis of hyperbilirubinemia depends on physical examination, urinalysis, serum tests, medical history and imaging to identify the cause. Genetic diseases, alcohol, pregnancy and hepatitis viruses affect the likelihood of hyperbilirubinemia. Causes of hyperbilirubinemia mainly arise from the liver. These include haemolytic anaemias, enzymatic disorders, liver damage and gallstones. Hyperbilirubinemia itself is often benign. Only in extreme cases does kernicterus, a type of brain injury, occur. Therapy for adult hyperbilirubinemia targets the underlying diseases but patients with jaundice often have poor outcomes.

References

  1. 1 2 Reuben, Adrian (March 26, 2008). "Hy's Law Explained" (PDF). fda.gov. Retrieved December 7, 2016.
  2. 1 2 United States Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research (CDER) Center for Biologics Evaluation and Research (CBER): Guidance for Industry Drug-Induced Liver Injury: Premarketing Clinical Evaluation, Final, July 2009
  3. Robles-Diaz M, Lucena MI, Kaplowitz N, Stephens C, Medina-Cáliz I, González-Jimenez A, Ulzurrun E, Gonzalez AF, Fernandez MC, Romero-Gómez M, Jimenez-Perez M, Bruguera M, Prieto M, Bessone F, Hernandez N, Arrese M, Andrade RJ (July 2014), "Use of Hy's law and a new composite algorithm to predict acute liver failure in patients with drug-induced liver injury", Gastroenterology, 147 (1): 109–118, doi: 10.1053/j.gastro.2014.03.050 , hdl: 10668/1859 , PMID   24704526
  4. Tansel A, Kanwal F, Hollinger FB (Aug 2015), "Use of Hy's Law, R criteria, and nR criteria to predict acute liver failure or transplantation in patients with drug-induced liver injury.", Gastroenterology, 148 (2): 452, doi: 10.1053/j.gastro.2014.11.046 , PMID   25532807
  5. Senior, John R. (22 March 2006), "How can 'Hy's law' help the clinician?", Pharmacoepidemiology and Drug Safety, 15 (4): 235–239, doi:10.1002/pds.1210, PMID   16552792
  6. Zimmerman, Hyman (1999). Hepatotoxicity . ISBN   978-0781719520.
  7. Andrade, Raúl J.; Lucena, M. Isabel; Fernández, M. Carmen; Pelaez, Gloria; Pachkoria, Ketevan; García-Ruiz, Elena; García-Muñoz, Beatriz; González-Grande, Rocio; Pizarro, Angeles (2005-08-01). "Drug-induced liver injury: an analysis of 461 incidences submitted to the Spanish registry over a 10-year period". Gastroenterology. 129 (2): 512–521. doi: 10.1016/j.gastro.2005.05.006 . ISSN   0016-5085. PMID   16083708.
  8. Björnsson, Einar; Olsson, Rolf (2005-08-01). "Outcome and prognostic markers in severe drug-induced liver disease". Hepatology. 42 (2): 481–489. doi: 10.1002/hep.20800 . ISSN   0270-9139. PMID   16025496.