Methemoglobinemia is a rare cause of hypoxemia, characterized by abnormal levels of oxidized hemoglobin that cannot bind to and transport oxygen. Acutely developing methemoglobinemia is infrequently. Blood transfusions may also be of benefit in severe cases. Topical benzocaine associated with methemoglobinemia. In addition to a functional anemia, methhemoglobinemia causes the o2binding affinity of the remaining o2 sites in the hemoglobin tetramer to increase. Severe methemoglobinemia caused by continuous lidocaine infusion in a term neonate. Benzocaine is a common topical anesthetic that has the ability to induce methemoglobinemia methgb in large doses.
The following report describes a patient with benzocaine induced methemoglobinemia who was seen at our hospital. Topical benzocaine associated with methemoglobinemia medscape. A 47yearold female with medical history of vulvar cancer and hiv undergoing chemoradiation was sent by the oncology clinic to the emergency department for worsening dyspnea, fatigue, hypoxia to 78% on room air, and gradual onset of cyanosis over the past week. The fda has issued a public health advisory regarding inappropriate use of benzocaine topical sprays and risk factors for methemoglobinemia. It is the active ingredient in many overthecounter anesthetic ointments such as products for oral ulcers. Acquired methemoglobinemia is a known complication of topical anesthesia during endoscopic procedures. Most commonly it is reported after the use of oropharyngeal topical anesthetic sprays such as benzocaine, lidocaine, and prilocaine. Tetracaine is rapidly absorbed from the respiratory and gastrointestinal tract when used to anesthetize.
A single spray of benzocaine may induce methemoglobinemia. Methods from 818 439 adverse event reports received by the us food and drug administration from november 1997 through march 2002, we. Methemoglobinemia methba is a clinical syndrome caused by an increase in the blood levels of methemoglobin methb 1 secondary to both congenital chronic changes in hemoglobin hb synthesis or metabolism, or acute imbalances in reduction and oxidation reactions redox imbalance induced by the exposure to several chemical agents 2,3. Tacaine benzocaine 14%, tetracaine 2% and hurricaine benzocaine 20% have been implicated in cases of methemoglobinemia, a serious and sometimes fatal adverse drug reaction. The fda said it is continuing to monitor the safety of topical benzocaine products. In 2015, the food and drug administration fda approved 45 novel. Case report a 48yearold female patient was admitted with multiple fascial space infections that required incision and drainage. Treatments include administration of methylene blue, which is an agent that causes reduction of the abnormal hemoglobin. Fortunately, acquired methemoglobinemia can be treated. Methemoglobinemia occurs when iron in hemoglobin is changed from its ferrous to its ferric form. Methemoglobinemia, betaglobin type, is caused by a mutation in the hbb gene. Methemoglobinemia can cause lifethreatening hypoxia associated with cyanosis and dyspnea not responsive to oxygen. In a retrospective cohort study of 50 children aged 331 months undergoing infiltration anesthesia of the scalp before craniofacial surgery, lidocaine 1% with adrenaline caused this complication in 10 children 45 c. Diagnosis of methemoglobinemia in cats you should take your cat to a veterinarian as soon as possible after spotting these dangerous symptoms, as methemoglobinemia is a lifethreatening condition.
Methemoglobinemia as a complication of 20% benzocaine. Methemoglobinemia and benzocaine article nursingcenter. Some of these medications include benzocaine, lidocaine and prilocaine. Through march 16, 2011, a total of 21 cases of methemoglobinemia associated with the use of over. Esters include benzocaine cepacol, reckitt benckiser. With methemoglobinemia, the hemoglobin can carry oxygen, but is not able to release it effectively to. Methemoglobinemia definition when excessive hemoglobin in the blood is converted to another chemical that cannot deliver oxygen to tissues, called methemoglobin. Dec 09, 2018 methemoglobinemia congenital or acquired occurs when red blood cells rbcs contain methemoglobin at levels higher than 1%. Topical anestheticinduced methemoglobinemia advisory.
Methemoglobinemia should be considered in any patient who demonstrates cyanosis, respiratory distress, headache, lightheadedness, and a dark, chocolatecolored blood after receiving pharyngeal anesthesia. Benzocaine sprays, gels, and liquids may cause methemoglobinemia, a rare but serious and potentially fatal condition. Methods from 818 439 adverse event reports received by the us food and drug. Nov 29, 2016 benzocaine side effects cause methemoglobinemia. He developed central cyanosis and his oxygen saturation was 85% via pulse oximetry. It develops in some people after they have been exposed to certain foods, chemicals or drugs. Methemoglobinemia congenital or acquired occurs when red blood cells rbcs contain methemoglobin at levels higher than 1%. Benzocaine and lidocaine induced methemoglobinemia after. Benzocaine has been reported to cause methemoglobinemia when applied to infants as an ointment or a rectal suppository 2, 3 and when used topically to the perineal area. It is also combined with antipyrine to form ab otic drops to relieve ear pain and remove earwax.
A novel finding in our study was the identification of clinical. Risk of topical anestheticinduced methemoglobinemia. Although, as reported in the adult population, it happens most often due to prescribed medication or procedural anesthesia and not due to easily accessed overthecounter medications, the authors will describe an otherwise healthy male adult with no known. These medications can inhibit the bodys systems of reducing methemoglobin to hemoglobin resulting in methemoglobinemia.
A 27yearold woman was found to be in respiratory distress during postoperative recovery. This results in a decreased availability of oxygen to the tissues. Yet, the incidence of benzocaineinduced methemoglobinemia with tee. Methemoglobinemia as a complication of 20% benzocaine spray.
Methemoglobinemia definition of methemoglobinemia by. A patient is described who developed methemoglobinemia after topical administration of benzocaine during surgery for multiple fascial space infections. Benzocaine induced methemoglobinemia based on the mayo clinic experience from 28 478 transesophageal echocardiograms. Benzocaine lawsuit methemoglobinemia lawyer, attorney, law firm. Benzocaine is available as prescription only or over the counter in a wide variety of products, such as gels for toothache, solutions for otitis, and suppositories for relief of hemorrhoidal symptoms. Methemoglobinemia results from oxidation of ferrous to ferric iron in hemoglobin. Acute methemoglobinemia induced by topical benzocaine and.
Methemoglobinemia an overview sciencedirect topics. Twohundredseventeen episodes of local anestheticrelated methemoglobinemia were identified by pubmed of which 19 were rejected for the following reasons. The following report describes a patient with benzocaineinduced methemoglobinemia who was seen at our hospital. There may be serious symptoms such as cyanosis bluish discoloration of the skin. Methemoglobinemia from topical benzocaine cleveland.
H ealthcare professionals know that intravenous or inhaled anesthetics are not innocuous substances. Acquired methemoglobinemia can be caused by a host of substances. Inappropriate use of benzocaine sprays linked to risk for. We present a case of recurrent methemoglobinemia because of occult use of topical benzocaine to the vulva.
Few such reports of benzocaineinduced methemoglobinemia are available in the. Find all the books, read about the author, and more. When induced by benzocaine anesthetic spray and other chemicals, it can result in cyanosis and lifethreatening complications. Inherited methemoglobinemia is rarer and more complex that acquired methemoglobinemia. Background methemoglobinemia mhb is characterized by abnormal levels of oxidized hemoglobin that cannot bind and transport oxygen. Schug, hari krshnan, in side effects of drugs annual, 2010. Few such reports of benzocaineinduced methemoglobinemia are available in the englishlanguage cardiology literature. Prilocaineinduced methemoglobinemia wisconsin, 1993.
One such report15 details dapsone being the cause of 42% of methemoglobinemia cases, whereas another report16 implicated benzocaine in 82% of cases. A case is reported in which a patient developed methemoglobinemiainduced cyanosis while under general anesthesia during surgery for multiple fascial space infections. Methemoglobinemia is an uncommon disorder in which hemoglobin is not oxidized and not capable of binding oxygen. Currently, few systemic reports of methemoglobinemia in a hospital setting exist. Although it occurs infrequently, benzocaineinduced methemoglobinemia is a potentially fatal complication if not promptly diagnosed and treated. Acquired methemoglobinemia typically results from ingestion of specific drugs or agents that cause an increase in the production of methemoglobin.
A longknown side effect of benzocaine, methemoglobinemia happens when oxygen levels in the blood drop dangerously low. Symptoms can develop within two hours of using the products. Methemoglobinemia 1st edition by manfred kiese author visit amazons manfred kiese page. Local anesthetics are widely used and are known for eliciting this condition. This results in elevated methemoglobin by direct or indirect oxidation of the hemoglobin 3. We describe a patient with respiratory failure following trauma who had two episodes of acute methemoglobinemia, one after the topical application of benzocaine and the second following. Acquired methemoglobinemia is caused by an external source, usually a drug or medication. A diagnosis of acute toxic methemoglobinemia should be considered when cyanosis, with or without neurologic symptoms, occurs following the use of local anesthetics in the absence of cardiopulmonary disease. Benzocaineinduced methemoglobinemia is a rare complication associated with topical anesthesia and can be lifethreatening. This condition may be associated with exposure to nitratecontaminated drinking water, aniline dyes, and amidecontaining medications. Aug 31, 2015 methemoglobinemia is lifethreatening and bears pathognomonic signs difficult to diagnose in real time.
Jun 04, 2018 benzocaine overthecounter products can increase the risk of serious or lifethreatening methemoglobinemia jun 4, 2018 2. Benzocaine cetacaine spray has been shown previously to cause methemoglobinemia in two patients when applied topically to the mucous membranes. Benzocaine overthecounter products can increase the risk of serious or lifethreatening methemoglobinemia jun 4, 2018 2. Benzocaine induced methemoglobinemia pediatric research. We report a case of methemoglobinemia after topical use of benzocaine in. Methemoglobinemia methb is a blood disorder in which an abnormal amount of methemoglobin is produced. Abstractacute cyanosis and methemoglobinemia developed following topical application and partial ingestion of benzocaine for esophagogastroduodenoscopy. In a separate study14 of 242 cases of methemoglobinemia, 60. Benzocaine sprays, gels, and liquids, used as anesthesia during medical procedures and as a treatment for tooth and gum pain, have been associated with a serious and potentially fatal blood disorder called methemoglobinemia. In 123 of these cases 93%, the product was a spray. Methylene blue intravenously is the treatment of choice to reduce methemoglobinemia. Patients may remain asymptomatic with significant levels of methemoglobin. Hemoglobin is the protein in red blood cells rbcs that carries and distributes oxygen to the body.
The order also included instructions to repeat the spray every six hours for pain relief. Kedar ps, gupta v, warang p, chiddarwar a, madkaikar m. Yet, the widespread availability of anesthetics like benzocaine, dyclonine, and lidocaine in many topical overthecounter otc products, such as cepacol anesthetic troches and sucrets maximum strength lozenges may lead to the perception of. Pdf reported adverse event cases of methemoglobinemia. Benzocaine has been implicated in a majority of cases and has been removed from some hospital formularies. Benzocaine administration to facilitate upper endoscopic procedures can result in the relatively uncommon but potentially fatal complication known as methemoglobinemia. After removal of the ng tube, benzocaine 20% topical oral spray hurricaine was ordered, with nursing instructions to apply one spray to the back of the throat. Methemoglobinemia is a common adverse effect of prilocaine see also benzocaine above.
A 46yearold woman with a medical history of hypertension, anemia, depression, and morbid obesity which persisted after a gastric bypass in 2003 presented on april 3, 20, for laparoscopic fistula repair and revision of her 2003. We describe a 4yearold girl who received a standard dose of topical benzocaine to her gastrostomy mucosa that resulted in rapid, severe methgb. Unexplained acute severe methaemoglobinaemia in a young adult. The cause of methemoglobinemia was 20% benzocaine spray used for local anesthesia before intubation.
A 47yearold female with medical history of vulvar cancer and hiv undergoing chemoradiation was sent by the oncology. Clinical symptoms may be observed at relatively low methemoglobin values, including coma at 32. Benzocaineinduced methemoglobinemia in the pediatric. Methemoglobinemia in cats symptoms, causes, diagnosis. In a retrospective cohort study of 50 children aged 331 months undergoing infiltration anesthesia of the scalp before craniofacial surgery, lidocaine 1% with adrenaline caused this complication in. A healthy 14 month infant developed severe cyanosis 2030 minutes after topical application of a benzocaine containing gel administered for relief of teething discomfort. Benzocaine overthecounter products can increase the risk. Methemoglobinemia is lifethreatening and bears pathognomonic signs difficult to diagnose in real time. Jun, 2018 symptoms of this acquired form of methemoglobinemia typically begin after exposure to the offending toxin or new medication. A 47yearold female with medical history of vulvar cancer and hiv undergoing chemoradiation was sent by the oncology clinic to the emergency. Methemoglobinemia mhb is characterized by abnormal levels of oxidized hemoglobin that cannot bind and transport oxygen. Severity of symptoms depends upon the percentage of methemoglobin, and symptoms are related to the lack of oxygen delivery to tissues. Clinical symptoms may be observed at relatively low methemoglobin values, including coma at.
Reported adverse event cases of methemoglobinemia associated with benzocaine products. Acquired methemoglobinemia is an uncommon hemoglobinopathy that results from exposure to oxidizing agents, such as chemicals or medications. Learn more about methemoglobinemia, betaglobin type, causes, symptoms, and genes. Rebound methemoglobinemia may occur up to 18 hours after mb administration, due to prolonged absorption of lipophilic agents benzocaine from adipose tissue. For this reason, the veterans health administration va announced on february 8, 2006, that they would stop using benzocaine containing sprays for procedures involving the. Benzocaineinduced methemoglobinemia based on the mayo clinic experience from 28 478 transesophageal echocardiograms.
Description the molecule hemoglobin in the blood is responsible for binding oxygen to give to the body. We describe a patient with respiratory failure following trauma who had two episodes of acute methemoglobinemia, one after the topical application of benzocaine and the second following lidocaine. Increased levels of methemoglobin results in functional anemia. A 62yearold male underwent bronchoscopy where lidocaine oral solution and hurricaine spray 20% benzocaine were used. Physicians should consider treating methemoglobinemia if the patient is symptomatic or the methemoglobin concentration rises to 30%. Methemoglobinemia, betaglobin type, is a rare inherited disorder that disrupts the function of hemoglobin, the molecule in red blood cells that delivers oxygen throughout the body.
Benzocaineinduced methemoglobinemia based on the mayo clinic. For this reason, the veterans health administration va announced on february 8, 2006, that they would stop using benzocainecontaining sprays for procedures involving the. They include cyanosis bluish color of the skin and chocolate browncolored blood. Benzocaine, sold under the brand name orajel amongst others, is an ester local anesthetic commonly used as a topical pain reliever or in cough drops. She required intubation, mechanical ventilation, and multiple doses of methylene blue for treatment. Benzocaine lawsuit methemoglobinemia lawyer, attorney. Methemoglobinemia associated with use of topical benzocaine has mostly been reported in children aged 2 years or younger who received topical benzocaine gels for relief of teething pain. Tell the vet what symptoms you have observed, when they began, and if your cat has been exposed to any chemicals or been given any medications recently. Collins portland veterans administration medical center and oregon health sciences university department of medicine, division of gastroenterology, portland, oregon topical 20% benzocaine hurricaine, beutlich, inc. We report a case of methemoglobinemia secondary to selfadministered use of benzocaine spray. Jan 24, 2004 benzocaine has been reported to cause methemoglobinemia when applied to infants as an ointment or a rectal suppository 2, 3 and when used topically to the perineal area. Rebound methemoglobinemia may occur up to 18 hours after mb administration, due to prolonged absorption of lipophilic.
The signs and symptoms may occur within minutes or hours after a single application or after multiple applications, and the effect does not appear to be dose. Although, as reported in the adult population, it happens most often due to prescribed medication or procedural anesthesia and not due to easily accessed overthecounter medications, the authors will describe an otherwise healthy. Benzocaine side effects, methemoglobinemia parker waichman llp. For this reason, the veterans health administration va announced on february 8, 2006, that they would stop using benzocainecontaining sprays for procedures involving the mouth and throat. When hemoglobin is oxidized to methemoglobin its structure changes and it is no longer. When induced by benzocaine anesthetic spray and other chemicals, it can result in cyanosis. Methemoglobin results from the presence of iron in the ferric form instead of the usual ferrous form. Benzocaine overthecounter products can increase the risk of. Acquired methemoglobinemia is the more common form of this condition. Reported adverse event cases of methemoglobinemia associated. Benzocaine, a commonly used topical anesthetic employed in multiple products, has been associated with methemoglobinemia.