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Treatment varies depending on the specific type. A low protein diet may be required in the management of tyrosinemia. Recent experience with nitisinone has shown it to be effective. It is a 4-hydroxyphenylpyruvate dioxygenase inhibitor indicated for
the treatment of hereditary tyrosinemia type 1 (HT-1) in combination with
dietary restriction of tyrosine and phenylalanine. The most effective treatment in patients with tyrosinemia type I seems to be full or partial liver transplant.
The primary treatment for type 1 tyrosinemia is nitisinone (Orfadin) and restriction of tyrosine in the diet. Nitisinone inhibits the conversion of 4-OH phenylpyruvate to homogentisic acid by 4-Hydroxyphenylpyruvate dioxygenase, the second step in tyrosine degradation. By inhibiting this enzyme, the accumulation of the fumarylacetoacetate is prevented. Previously, liver transplantation was the primary treatment option and is still used in patients in whom nitisinone fails.
Treatment is depended on the type of glycogen storage disease. E.g. GSD I is typically treated with frequent small meals of carbohydrates and cornstarch to prevent low blood sugar, while other treatments may include allopurinol and human granulocyte colony stimulating factor.
No treatment modality has been unequivocally demonstrated to reduce the complications of alkaptonuria. Main treatment attempts have focused on preventing ochronosis through the reduction of accumulating homogentisic acid. Such commonly recommended treatments include large doses of ascorbic acid (vitamin C) or dietary restriction of amino acids phenylalanine and tyrosine. However, vitamin C treatment has not shown to be effective, and protein restriction (which can be difficult to adhere to) has not shown to be effective in clinical studies.
Several recent studies have suggested that the herbicide nitisinone may be effective in the treatment of alkaptonuria. Nitisinone inhibits the enzyme, 4-hydroxyphenylpyruvate dioxygenase, responsible for converting tyrosine to homogentisic acid, thereby blocking the production and accumulation of HGA. Nitisinone has been used for some time at much higher doses in the treatment of type I tyrosinemia. Nitisinone treatment has been shown to cause a larger than 95% reduction in plasma and urinary HGA. The main drawback is accumulation of tyrosine, the long-term risks of which are unknown; there is a particular concern about damage to the cornea of the eye. Long-term use would require frequent monitoring for complications.
Treatment consists of oral bicarbonate supplementation. However, this will increase urinary bicarbonate wasting and may well promote a bicarbonate . The amount of bicarbonate given may have to be very large to stay ahead of the urinary losses. Correction with oral bicarbonate may exacerbate urinary potassium losses and precipitate hypokalemia. As with dRTA, reversal of the chronic acidosis should reverse bone demineralization.
Thiazide diuretics can also be used as treatment by making use of contraction alkalosis caused by them.
Treatment of children with Fanconi syndrome mainly consists of replacement of substances lost in the urine (mainly fluid and bicarbonate).
Another approach would
Alkaptonuria does not appear to affect life expectancy, although the last study on the topic is from 1985. The main impact is on quality of life; many people with alkaptonuria have disabling symptoms such as pain, poor sleep and breathing symptoms. These generally start in the fourth decade. The average age at requiring joint replacement surgery is 50–55 years.
Type 1 tyrosinemia, also known as hepatorenal tyrosinemia or tyrosinosis, is the most severe form of tyrosinemia, a buildup of too much of the amino acid tyrosine in the blood and tissues due to an inability to metabolize it. It is caused by a deficiency of the enzyme fumarylacetoacetate hydrolase.
Tyrosinemia or tyrosinaemia is an error of metabolism, usually inborn, in which the body cannot effectively break down the amino acid tyrosine. Symptoms include liver and kidney disturbances and intellectual disability. Untreated, tyrosinemia can be fatal.Most inborn forms of tyrosinemia produce hypertyrosinemia (high levels of tyrosine).
Often, empirical treatment is required if the diagnostic suspicion of a porphyria is high since acute attacks can be fatal. A high-carbohydrate diet is typically recommended; in severe attacks, a dextrose 10% infusion is commenced, which may aid in recovery by suppressing heme synthesis, which in turn reduces the rate of porphyrin accumulation. However, this can worsen hyponatraemia and should be done with extreme caution as it can prove fatal.
Hematin (trade name Panhematin) and heme arginate (trade name NormoSang) are the drugs of choice in acute porphyria, in the United States and the United Kingdom, respectively. These drugs need to be given very early in an attack to be effective; effectiveness varies amongst individuals. They are not curative drugs but can shorten attacks and reduce the intensity of an attack. Side effects are rare but can be serious. These heme-like substances theoretically inhibit ALA synthase and hence the accumulation of toxic precursors. In the United Kingdom, supplies of NormoSang are kept at two national centers; emergency supply is available from St Thomas's Hospital, London. In the United States, Lundbeck manufactures and supplies Panhematin for infusion.
Heme arginate (NormoSang) is used during crises but also in preventive treatment to avoid crises, one treatment every 10 days.
Any sign of low blood sodium (hyponatremia) or weakness should be treated with the addition of hematin, heme arginate, or even tin mesoporphyrin, as these are signs of impending syndrome of inappropriate antidiuretic hormone (SIADH) or peripheral nervous system involvement that may be localized or severe, progressing to bulbar paresis and respiratory paralysis.
Cimetidine has also been reported to be effective for acute porphyric crisis and possibly effective for long-term prophylaxis.
Seizures often accompany this disease. Most seizure medications exacerbate this condition. Treatment can be problematic: barbiturates especially must be avoided. Some benzodiazepines are safe and, when used in conjunction with newer anti-seizure medications such as gabapentin, offer a possible regimen for seizure control. Gabapentin has the additional feature of aiding in the treatment of some kinds of neuropathic pain.
Magnesium sulfate and bromides have also been used in porphyria seizures; however, development of status epilepticus in porphyria may not respond to magnesium alone. The addition of hematin or heme arginate has been used during status epilepticus.
A Glycogen storage disease (GSD, also glycogenosis and dextrinosis) is a metabolic disorder caused by enzyme deficiencies affecting either glycogen synthesis, glycogen breakdown or glycolysis (glucose breakdown), typically within muscles and/or liver cells.
GSD has two classes of cause: genetic and acquired. Genetic GSD is caused by any inborn error of metabolism (genetically defective enzymes) involved in these processes. In livestock, acquired GSD is caused by intoxication with the alkaloid castanospermine.
People with hypermethioninemia often do not show any symptoms. Some individuals with hypermethioninemia exhibit learning disabilities, mental retardation, and other neurological problems; delays in motor skills such as standing or walking; sluggishness; muscle weakness; liver problems; unusual facial features; and their breath, sweat, or urine may have a smell resembling boiled cabbage.
Hypermethioninemia can occur with other metabolic disorders, such as homocystinuria, tyrosinemia and galactosemia, which also involve the faulty breakdown of particular molecules. It can also result from liver disease or excessive dietary intake of methionine from consuming large amounts of protein or a methionine-enriched infant formula.
Tyrosinemia type III is a rare disorder caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase (), encoded by the gene "HPD". This enzyme is abundant in the liver, and smaller amounts are found in the kidneys. It is one of a series of enzymes needed to break down tyrosine. Specifically, 4-hydroxyphenylpyruvate dioxygenase converts a tyrosine byproduct called 4-hydroxyphenylpyruvate to homogentisic acid. Characteristic features of type III tyrosinemia include mild mental retardation, seizures, and periodic loss of balance and coordination (intermittent ataxia). Type III tyrosinemia is very rare; only a few cases have been reported.
Hawkinsinuria, also called 4-Alpha-hydroxyphenylpyruvate hydroxylase deficiency, is an autosomal dominant metabolic disorder affecting the metabolism of tyrosine. Normally, the breakdown of the amino acid tyrosine involves the conversion of 4-hydroxyphenylpyruvate to homogentisate by 4-Hydroxyphenylpyruvate dioxygenase. Complete deficiency of this enzyme would lead to tyrosinemia III. In rare cases, however, the enzyme is still able to produce the reactive intermediate 1,2-epoxyphenyl acetic acid, but is unable to convert this intermediate to homogentisate. The intermediate then spontaneously reacts with glutathione to form 2-L-cystein-S-yl-1,4-dihydroxy-cyclohex-5-en-1-yl acetic acid (hawkinsin).
Patients present with metabolic acidosis during the first year of life, which should be treated by a phenylalanine- and tyrosine-restricted diet. The tolerance toward these amino acids normalizes as the patients get older. Then only a chlorine-like smell of the urine indicates the presence of the condition, patients have a normal life and do not require treatment or a special diet.
The production of hawkinsin is the result of a gain-of-function mutation, inheritance of hawkinsinuria is therefore autosomal dominant (presence of a single mutated copy of the gene causes the condition). Most other inborn errors of metabolism are caused by loss-of-function mutations, and hence have recessive inheritance (condition occurs only if both copies are mutated).
Hypermethioninemia is an excess of the amino acid methionine, in the blood. This condition can occur when methionine is not broken down properly in the body.
Many major studies showing improvement in kidney function in patients with hepatorenal syndrome have involved expansion of the volume of the plasma with albumin given intravenously. The quantity of albumin administered intravenously varies: one cited regimen is 1 gram of albumin per kilogram of body weight intravenously on the first day, followed by 20 to 40 grams daily. Notably, studies have shown that treatment with albumin alone is inferior to treatment with other medications in conjunction with albumin; most studies evaluating pre-transplant therapies for HRS involve the use of albumin in conjunction with other medical or procedural treatment.
Midodrine is an alpha-agonist and octreotide is an analogue of somatostatin, a hormone involved in regulation of blood vessel tone in the gastrointestinal tract. The medications are respectively systemic vasoconstrictors and inhibitors of splanchnic vasodilation, and were not found to be useful when used individually in treatment of hepatorenal syndrome. However, one study of 13 patients with hepatorenal syndrome showed significant improvement in kidney function when the two were used together (with midodrine given orally, octreotide given subcutaneously and both dosed according to blood pressure), with three patients surviving to discharge. Another nonrandomized, observational study of individuals with HRS treated with subcutaneous octreotide and oral midodrine showed that there was increased survival at 30 days.
The vasopressin analogue ornipressin was found in a number of studies to be useful in improvement of kidney function in patients with hepatorenal syndrome, but has been limited in its use, as it can cause severe ischemia to major organs. Terlipressin is a vasopressin analogue that has been found in one large study to be useful for improving kidney function in patients with hepatorenal syndrome with a lesser incidence of ischemia but is not available in the United States. A key criticism of all of these medical therapies has been heterogeneity in the populations investigated and the use of kidney function, instead of mortality, as an outcome measure.
Other agents that have been investigated for use in treatment of HRS include pentoxifylline, acetylcysteine, and misoprostol. The evidence for all of these therapies is based on either case series, or in the case of pentoxifylline, extrapolated from a subset of patients treated for alcoholic hepatitis.
Tyrosinemia type II (Oculocutaneous tyrosinemia, Richner-Hanhart syndrome) is an autosomal recessive condition with onset between ages 2 and 4 years, when painful circumscribed calluses develop on the pressure points of the palm of the hand and sole of the foot.
A 2006 Cochrane review did not find evidence sufficient for the use of androgenic anabolic steroids. Corticosteroids are sometimes used; however, this is recommended only when severe liver inflammation is present.
Sylimarin has been investigated as a possible treatment, with ambiguous results. One review claimed benefit for S-adenosyl methionine in disease models.
The effects of anti–tumor necrosis factor medications such as infliximab and etanercept are unclear and possibly harmful. Evidence is unclear for pentoxifylline. Propylthiouracil may result in harm.
Evidence does not support supplemental nutrition in liver disease.
The definitive treatment for hepatorenal syndrome is liver transplantation, and all other therapies can best be described as bridges to transplantation. While liver transplantation is by far the best available management option for HRS, the mortality of individuals with HRS has been shown to be as high as 25% within the first month after transplantation. Individuals with HRS and evidence of greater hepatic dysfunction (quantified as MELD scores above 36) have been found to be at greatest risk of early mortality after liver transplantation. A further deterioration of kidney function even after liver transplantation in individuals with HRS has been demonstrated in several studies; however, this is transient and thought to be due to the use of medications with toxicity to the kidneys, and specifically the introduction of immunosuppressants such as tacrolimus and cyclosporine that are known to worsen kidney function. Over the long-term, however, individuals with HRS who are the recipients of liver transplants almost universally recover kidney function, and studies show that their survival rates at three years are similar to those who have received liver transplants for reasons other than HRS.
In anticipation of liver transplantation (which may be associated with considerable in-hospital delay), several other strategies have been found to be beneficial in preserving kidney function. These include the use of intravenous albumin infusion, medications (for which the best evidence is for analogues of vasopressin, which causes splanchnic vasoconstriction), radiological shunts to decrease pressure in the portal vein, dialysis, and a specialized albumin-bound membrane dialysis system termed molecular adsorbents recirculation system (MARS) or liver dialysis.
Type II tyrosinemia is caused by a deficiency of the enzyme tyrosine aminotransferase (), encoded by the gene "TAT". Tyrosine aminotransferase is the first in a series of five enzymes that converts tyrosine to smaller molecules, which are excreted by the kidneys or used in reactions that produce energy. This form of the disorder can affect the eyes, skin, and mental development. Symptoms often begin in early childhood and include excessive tearing, abnormal sensitivity to light (photophobia), eye pain and redness, and painful skin lesions on the palms and soles. About half of individuals with type II tyrosinemia are also mentally challenged. Type II tyrosinemia occurs in fewer than 1 in 250,000 individuals.
Acetylcysteine, also called "N"-acetylcysteine or NAC, works to reduce paracetamol toxicity by replenishing body stores of the antioxidant glutathione. Glutathione reacts with the toxic NAPQI metabolite so that it does not damage cells and can be safely excreted. NAC was usually given following a treatment nomogram (one for patients with risk factors, and one for those without) but the use of the nomogram is no longer recommended as the evidence base to support the use of risk factors was poor and inconsistent and many of the risk factors are imprecise and difficult to determine with sufficient certainty in clinical practice. Cysteamine and methionine have also been used to prevent hepatotoxicity, although studies show that both are associated with more adverse effects than acetylcysteine. Additionally, acetylcysteine has been shown to be a more effective antidote, particularly in patients presenting greater than 8 hours post-ingestion.
If the patient presents less than eight hours after paracetamol overdose, then acetylcysteine significantly reduces the risk of serious hepatotoxicity and guarantees survival. If acetylcysteine is started more than 8 hours after ingestion, there is a sharp decline in its effectiveness because the cascade of toxic events in the liver has already begun, and the risk of acute liver necrosis and death increases dramatically. Although acetylcysteine is most effective if given early, it still has beneficial effects if given as late as 48 hours after ingestion. In clinical practice, if the patient presents more than eight hours after the paracetamol overdose, then activated charcoal is not useful, and acetylcysteine is started immediately. In earlier presentations, charcoal can be given when the patient arrives and acetylcysteine is initiated while waiting for the paracetamol level results to return from the laboratory.
In United States practice, intravenous (IV) and oral administration are considered to be equally effective and safe if given within 8 hours of ingestion. However, IV is the only recommended route in Australasian and British practice. Oral acetylcysteine is given as a 140 mg/kg loading dose followed by 70 mg/kg every four hours for 17 more doses, and if the patient vomits within 1 hour of dose, the dose must be repeated. Oral acetylcysteine may be poorly tolerated due to its unpleasant taste, odor, and its tendency to cause nausea and vomiting. If repeated doses of charcoal are indicated because of another ingested drug, then subsequent doses of charcoal and acetylcysteine should be staggered.
Intravenous acetylcysteine is given as a continuous infusion over 20 hours for a total dose 300 mg/kg. Recommended administration involves infusion of a 150 mg/kg loading dose over 15 to 60 minutes, followed by a 50 mg/kg infusion over four hours; the last 100 mg/kg are infused over the remaining 16 hours of the protocol. Intravenous acetylcysteine has the advantage of shortening hospital stay, increasing both doctor and patient convenience, and allowing administration of activated charcoal to reduce absorption of both the paracetamol and any co-ingested drugs without concerns about interference with oral acetylcysteine. Intravenous dosing varies with weight, specifically in children. For patients less than 20 kg, the loading dose is 150 mg/kg in 3 mL/kg diluent, administered over 60 minutes; the second dose is 50 mg/kg in 7 mL/kg diluent over 4 hours; and the third and final dose is 100 mg/kg in 14 mL/kg diluent over 16 hours.
The most common adverse effect to acetylcysteine treatment is an anaphylactoid reaction, usually manifested by rash, wheeze, or mild hypotension. Adverse reactions are more common in people treated with IV acetylcysteine, occurring in up to 20% of patients. Alaphylactoid reactions are more likely to occur with the first infusion (the loading dose). Rarely, severe life-threatening reactions may occur in predisposed individuals, such as patients with asthma or atopic dermatitis, and may be characterized by respiratory distress, facial swelling, and even death.
If an anaphylactoid reaction occurs the acetylcysteine is temporarily halted or slowed and antihistamines and other supportive care is administered. For example, a nebulised beta-agonist like salbutamol may be indicated in the event of significant bronchospasm (or prophylactically in patients with a history of bronchospasm secondary to acetylcysteine). It is also important to closely monitor fluids and electrolytes.
In adults, the initial treatment for paracetamol overdose is gastrointestinal decontamination. Paracetamol absorption from the gastrointestinal tract is complete within two hours under normal circumstances, so decontamination is most helpful if performed within this timeframe. Gastric lavage, better known as stomach pumping, may be considered if the amount ingested is potentially life-threatening and the procedure can be performed within 60 minutes of ingestion. Activated charcoal is the most common gastrointestinal decontamination procedure as it adsorbs paracetamol, reducing its gastrointestinal absorption. Administering activated charcoal also poses less risk of aspiration than gastric lavage.
It appears that the most benefit from activated charcoal is gained if it is given within 30 minutes to two hours of ingestion. Administering activated charcoal later than 2 hours can be considered in patients that may have delayed gastric emptying due to co-ingested drugs or following ingestion of sustained- or delayed-release paracetamol preparations. Activated charcoal should also be administered if co-ingested drugs warrant decontamination. There was reluctance to give activated charcoal in paracetamol overdose, because of the concern that it may also absorb the oral antidote acetylcysteine. Studies have shown that 39% less acetylcysteine is absorbed into the body when they are administered together. There are conflicting recommendations regarding whether to change the dosing of oral acetylcysteine after the administration of activated charcoal, and even whether the dosing of acetylcysteine needs to be altered at all. Intravenous acetylcystine has no interaction with activated charcoal.
Inducing vomiting with syrup of ipecac has no role in paracetamol overdose because the vomiting it induces delays the effective administration of activated charcoal and oral acetylcysteine. Liver injury is extremely rare after acute accidental ingestion in children under 6 years of age. Children with accidental exposures do not require gastrointestinal decontamination with either gastric lavage, activated charcoal, or syrup of ipecac.
Impaired liver synthesis of clotting factors, low-grade fibrinolysis, and intravascular coagulation are typical of ALF. Thrombocytopenia is common and may also be dysfunctional. Replacement therapy is recommended only in the setting of bleeding or prior to an invasive procedure. Vitamin K can be given to treat an abnormal prothrombin time, regardless of whether there is poor nutritional status. Administration of recombinant factor VIIa has shown promise; however, this treatment approach requires further study. The use of gastrointestinal hemorrhage prophylaxis with a histamine-2 (H2) blocker, proton pump inhibitor, or sucralfate is recommended.
In patients with grade I or II encephalopathy, enteral feeding should be initiated early. Parenteral nutrition should be used only if enteral feeding is contraindicated as it increases the risk of infection. Severe restriction of protein is not beneficial; 60 g/day of protein is generally reasonable. Fluid replacement with colloid (e.g. albumin) is preferred rather than crystalloid (e.g. saline); all solutions should contain dextrose to maintain euglycemia. Multiple electrolyte abnormalities are common in ALF. Correction of hypokalemia is essential as hypokalemia increases the kidneys' ammonia production, potentially exacerbating encephalopathy. Hypophosphatemia is especially common in patients with acetaminophen-induced ALF and in those with intact renal function. Hypoglycemia occurs in many patients with ALF and is often due to depletion of hepatic glycogen stores and impaired gluconeogenesis. Plasma glucose concentration should be monitored and hypertonic glucose administered as needed.