During an acute hyperammonemic episode, oral proteins must be avoided and intravenous (I.V.) lipids, glucose and insulin (if needed) should be given to promote anabolism. I.V. nitrogen scavenging therapy (with sodium benzoate and/or sodium phenylacetate) should normalize ammonia levels, but if unsuccessful, hemodialysis is recommended. Long-term management involves dietary protein restriction as well as arginine supplementation. In those with frequent episodes of metabolic decompensation or with hyperammonemia even when following a protein-restricted diet, daily oral nitrogen scavenging therapy may be successful. Orthotopic liver transplantation offers long-term relief of hyperammonemia but does not seem to sufficiently correct neurological complications. Arterial hypertension can be treated by restoring nitric oxide deficiency

Treatment for all forms of this condition primarily relies on a low-protein diet, and depending on what variant of the disorder the individual suffers from, various dietary supplements. All variants respond to the levo isomer of carnitine as the improper breakdown of the affected substances results in sufferers developing a carnitine deficiency. The carnitine also assists in the removal of acyl-CoA, buildup of which is common in low-protein diets by converting it into acyl-carnitine which can be excreted in urine. Though not all forms of methylmalonyl acidemia are responsive to cobalamin, cyanocobalamin supplements are often used in first line treatment for this disorder. If the individual proves responsive to both cobalamin and carnitine supplements, then it may be possible for them to ingest substances that include small amounts of the problematic amino acids isoleucine, threonine, methionine, and valine without causing an attack.

The treatment goal for individuals affected with OTC deficiency is the avoidance of hyperammonemia. This can be accomplished through a strictly controlled low-protein diet, as well as preventative treatment with nitrogen scavenging agents such as sodium benzoate. The goal is to minimize the nitrogen intake while allowing waste nitrogen to be excreted by alternate pathways. Arginine is typically supplemented as well, in an effort to improve the overall function of the urea cycle. If a hyperammonemic episode occurs, the aim of treatment is to reduce the individual's ammonia levels as soon as possible. In extreme cases, this can involve hemodialysis.

Gene therapy had been considered a possibility for curative treatment for OTC deficiency, and clinical trials were taking place at the University of Pennsylvania in the late 1990s. These were halted after the death of Jesse Gelsinger, a young man taking part in a phase I trial using an adenovirus vector. Currently, the only option for curing OTC deficiency is a liver transplant, which restores normal enzyme activity. A 2005 review of 51 patients with OTC deficiency who underwent liver transplant estimated 5-year survival rates of greater than 90%. Severe cases of OTC deficiency are typically evaluated for liver transplant by 6 months of age.

A more extreme treatment includes kidney or liver transplant from a donor without the condition. The foreign organs will produce a functional version of the defective enzymes and digest the methylmalonic acid, however all of the disadvantages of organ transplantation are of course applicable in this situation. There is evidence to suggest that the central nervous system may metabolize methylmalonic-CoA in a system isolated from the rest of the body. If this is the case, transplantation may not reverse the neurological effects of methylmalonic acid previous to the transplant or prevent further damage to the brain by continued build up.

Treatment consists of dietary protein restriction, particularly leucine. During acute episodes, glycine is sometimes given, which conjugates with isovalerate forming isovalerylglycine, or carnitine which has a similar effect.

Elevated 3-hydroxyisovaleric acid is a clinical biomarker of biotin deficiency. Without biotin, leucine and isoleucine cannot be metabolized normally and results in elevated synthesis of isovaleric acid and consequently 3-hydroxyisovaleric acid, isovalerylglycine, and other isovaleric acid metabolites as well. Elevated serum 3-hydroxyisovaleric acid concentrations can be caused by supplementation with 3-hydroxyisovaleric acid, genetic conditions, or dietary deficiency of biotin. Some patients with isovaleric acidemia may benefit from supplemental biotin. Biotin deficiency on its own can have severe physiological and cognitive consequences that closely resemble symptoms of organic acidemias.

Patients with propionic acidemia should be started as early as possible on a low protein diet. In addition to a protein mixture that is devoid of methionine, threonine, valine, and isoleucine, the patient should also receive -carnitine treatment and should be given antibiotics 10 days per month in order to remove the intestinal propiogenic flora. The patient should have diet protocols prepared for him with a “well day diet” with low protein content, a “half emergency diet” containing half of the protein requirements, and an “emergency diet” with no protein content. These patients are under the risk of severe hyperammonemia during infections that can lead to comatose states.

Liver transplant is gaining a role in the management of these patients, with small series showing improved quality of life.

Dietary control may help limit progression of the neurological damage.

The treatment of 2-Hydroxyglutaric aciduria is based on seizure control, the prognosis depends on how severe the condition is.

A diet with carefully controlled levels of the amino acids leucine, isoleucine, and valine must be maintained at all times in order to prevent neurological damage. Since these three amino acids occur in all natural protein, and most natural foods contain some protein, any food intake must be closely monitored, and day-to-day protein intake calculated on a cumulative basis, to ensure individual tolerance levels are not exceeded at any time. As the MSUD diet is so protein-restricted, and adequate protein is a requirement for all humans, tailored metabolic formula containing all the other essential amino acids, as well as any vitamins, minerals, omega-3 fatty acids and trace elements (which may be lacking due to the limited range of permissible foods), are an essential aspect of MSUD management. These complement the MSUD patient's natural food intake to meet normal nutritional requirements without causing harm. If adequate calories cannot be obtained from natural food without exceeding protein tolerance, specialised low protein products such as starch-based baking mixtures, imitation rice and pasta may be prescribed, often alongside a protein-free carbohydrate powder added to food and/or drink, and increased at times of metabolic stress. Some patients with MSUD may also improve with administration of high doses of thiamine, a cofactor of the enzyme that causes the condition.

Usually MSUD patients are monitored by a dietitian. Liver transplantation is another treatment option that can completely and permanently normalise metabolic function, enabling discontinuation of nutritional supplements and strict monitoring of biochemistry and caloric intake, relaxation of MSUD-related lifestyle precautions, and an unrestricted diet. This procedure is most successful when performed at a young age, and weaning from immunosuppressants may even be possible in the long run. However, the surgery is a major undertaking requiring extensive hospitalisation and rigorous adherence to a tapering regime of medications. Following transplant, the risk of periodic rejection will always exist, as will the need for some degree of lifelong monitoring in this respect. Despite normalising clinical presentation, liver transplantation is not considered a cure for MSUD. The patient will still carry two copies of the mutated BKAD gene in each of their own cells, which will consequently still be unable to produce the missing enzyme. They will also still pass one mutated copy of the gene on to each of their biological children. As a major surgery the transplant procedure itself also carries standard risks, although the odds of its success are greatly elevated when the only indication for it is an inborn error of metabolism. In absence of a liver transplant, the MSUD diet must be adhered to strictly and permanently. However, in both treatment scenarios, with proper management, those afflicted are able to live healthy, normal lives without suffering the severe neurological damage associated with the disease.

The conversion of tryptophan to serotonin and other metabolites depends on vitamin B. If tryptophan catabolism has any impact on brain glutaric acid and other catabolite levels, vitamin B levels should be routinely assayed and normalized in the course of the treatment of GA1.

Treatment centers on limiting intake of ammonia and increasing its excretion. Dietary protein, a metabolic source of ammonium, is restricted and caloric intake is provided by glucose and fat. Intravenous arginine (argininosuccinase deficiency) sodium phenylbutyrate and sodium benzoate (ornithine transcarbamoylase deficiency) are pharmacologic agents commonly used as adjunctive therapy to treat hyperammonemia in patients with urea cycle enzyme deficiencies. Sodium phenylbutyrate and sodium benzoate can serve as alternatives to urea for the excretion of waste nitrogen. Phenylbutyrate, which is the product of phenylacetate, conjugates with glutamine to form phenylacetylglutamine, which is excreted by the kidneys. Similarly, sodium benzoate reduces ammonia content in the blood by conjugating with glycine to form hippuric acid, which is rapidly excreted by the kidneys. A preparation containing sodium phenylacetate and sodium benzoate is available under the trade name Ammonul.

Acidification of the intestinal lumen using lactulose can decrease ammonia levels by protonating ammonia and trapping it in the stool. This is a treatment for hepatic encephalopathy.

Treatment of severe hyperammonemia (serum ammonia levels greater than 1000 μmol/L) should begin with hemodialysis if it is otherwise medically appropriate and tolerated.

Treatment or management of organic acidemias vary; eg see methylmalonic acidemia, propionic acidemia, isovaleric acidemia, and maple syrup urine disease.

As of 1984 there were no effective treatments for all of the conditions, though treatment for some included a limited protein/high carbohydrate diet, intravenous fluids, amino acid substitution, vitamin supplementation, carnitine, induced anabolism, and in some cases, tube-feeding.

As of 1993 ketothiolase deficiency and other OAs were managed by trying to restore biochemical and physiologic homeostasis; common therapies included restricting diet to avoid the precursor amino acids and use of compounds to either dispose of toxic metabolites or increase enzyme activity.

The goal for treatment of GSD type 0 is to avoid hypoglycemia. This is accomplished by avoiding fasting by eating every 3-4 hours during the day. At night, uncooked corn starch can be given because it is a complex glucose polymer. This will be acted on slowly by pancreatic amylase and glucose will be absorbed over a 6 hour period.

In adults, fibrates and statins have been prescribed to treat hyperglycerolemia by lowering blood glycerol levels. Fibrates are a class of drugs that are known as amphipathic carboxylic acids that are often used in combination with Statins. Fibrates work by lowering blood triglyceride concentrations. When combined with statins, the combination will lower LDL cholesterol, lower blood triglycerides and increase HDL cholesterol levels.

If hyperglycerolemia is found in a young child without any family history of this condition, then it may be difficult to know whether the young child has the symptomatic or benign form of the disorder. Common treatments include: a low-fat diet, IV glucose if necessary, monitor for insulin resistance and diabetes, evaluate for Duchenne muscular dystrophy, adrenal insufficiency & developmental delay.

The Genetic and Rare Diseases Information Center (GARD) does not list any treatments at this time.

Response to treatment is variable and the long-term and functional outcome is unknown. To provide a basis for improving the understanding of the epidemiology, genotype/phenotype correlation and outcome of these diseases their impact on the quality of life of patients, and for evaluating diagnostic and therapeutic strategies a patient registry was established by the noncommercial International Working Group on Neurotransmitter Related Disorders (iNTD).

Due to the rarity of the disease, it is hard to estimate mortality rates or life expectancy. One 2003 study which followed 88 cases receiving two different kinds of treatment found that very few persons lived beyond age 20 and none beyond age 30.

Succinic acid has been studied, and shown effective for both Leighs disease, and MELAS syndrome. If the mutation is in succinate dehydrogenase then there is a build up of succinate, in which case succinic acid won't work so the treatment is with fumaric acid to replace the fumarate than can not be made from succinate. A high-fat, low-carbohydrate diet may be followed if a gene on the X chromosome is implicated in an individual's Leigh syndrome. Thiamine (vitamin B) may be given if a deficiency of pyruvate dehydrogenase is known or suspected. The symptoms of lactic acidosis are treated by supplementing the diet with sodium bicarbonate (baking soda) or sodium citrate, but these substances do not treat the cause of Leigh syndrome. Dichloroacetate may also be effective in treating Leigh syndrome-associated lactic acidosis; research is ongoing on this substance. Coenzyme Q10 supplements have been seen to improve symptoms in some cases.

Clinical trials of the drug EPI-743 for Leigh disease are ongoing.

In 2016, John Zhang and his team at New Hope Fertility Center in New York, USA, performed a spindle transfer mitochondrial donation technique on a mother in Mexico who was at risk of producing a baby with Leigh disease. A healthy boy was born on 6 April 2016. However, it is not yet certain if the technique is completely reliable and safe.

On 9 May 2014, the UK National Screening Committee (UK NSC) announced its recommendation to screen every newborn baby in the UK for four further genetic disorders as part of its NHS Newborn Blood Spot Screening programme, including isovaleric acidemia.

A 1999 retrospective study of 74 cases of neonatal onset found that 32 (43%) patients died during their first hyperammonemic episode. Of those who survived, less than 20% survived to age 14. Few of these patients received liver transplants.

Infant mortality is high for patients diagnosed with early onset; mortality can occur within less than 2 months, while children diagnosed with late-onset syndrome seem to have higher rates of survival. Patients suffering from a complete lesion of mut0 have not only the poorest outcome of those suffering from methylaonyl-CoA mutase deficiency, but also of all individuals suffering from any form of methylmalonic acidemia.

Several tests can be done to discover the dysfunction of methylmalonyl-CoA mutase. Ammonia test, blood count, CT scan, MRI scan, electrolyte levels, genetic testing, methylmalonic acid blood test, and blood plasma amino acid tests all can be conducted to determine deficiency.

There is no treatment for complete lesion of the mut0 gene, though several treatments can help those with slight genetic dysfunction. Liver and kidney transplants, and a low-protein diet all help regulate the effects of the diseases.

2-hydroxyglutaric aciduria is a rare neurometabolic disorder characterized by the significantly elevated levels of hydroxyglutaric acid in ones urine. It is either autosomal recessive or autosomal dominant.

2-Methylbutyryl-CoA dehydrogenase deficiency, also called 2-Methylbutyryl glycinuria or short/branched-chain acyl-CoA dehydrogenase deficiency (SBCADD), is an autosomal recessive metabolic disorder. It causes the body to be unable to process the amino acid isoleucine properly. Initial case reports identified individuals with developmental delay and epilepsy, however most cases identified through newborn screening have been asymptomatic.

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.