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.

The antibiotic rifaximin may be recommended in addition to lactulose for those with recurrent disease. It is a nonabsorbable antibiotic from the rifamycin class. This is thought to work in a similar way to other antibiotics, but without the complications attached to neomycin or metronidazole. Due to the long history and lower cost of lactulose use, rifaximin is generally only used as a second-line treatment if lactulose is poorly tolerated or not effective. When rifaximin is added to lactulose, the combination of the two may be more effective than each component separately. Rifaximin is more expensive than lactulose, but the cost may be offset by reduced hospital admissions for encephalopathy.

The antibiotics neomycin and metronidazole are other antibiotics used to treat hepatic encephalopathy. The rationale of their use was the fact that ammonia and other waste products are generated and converted by intestinal bacteria, and killing these bacteria would reduce the generation of these waste products. Neomycin was chosen because of its low intestinal absorption, as neomycin and similar aminoglycoside antibiotics may cause hearing loss and kidney failure if used by injection. Later studies showed that neomycin was indeed absorbed when taken by mouth, with resultant complications. Metronidazole, similarly, is less commonly used because prolonged use can cause nerve damage, in addition to gastrointestinal side effects.

Lactulose and lactitol are disaccharides that are not absorbed from the digestive tract. They are thought to decrease the generation of ammonia by bacteria, render the ammonia inabsorbable by converting it to ammonium (NH) ions, and increase transit of bowel content through the gut. Doses of 15-30 ml are administered three times a day; the result is aimed to be 3–5 soft stools a day, or (in some settings) a stool pH of <6.0. Lactulose may also be given by enema, especially if encephalopathy is severe. More commonly, phosphate enemas are used. This may relieve constipation, one of the causes of encephalopathy, and increase bowel transit.

Lactulose and lactitol are beneficial for treating hepatic encephalopathy, and are the recommended first-line treatment. Lactulose does not appear to be more effective than lactitol for treating people with hepatic encephalopathy. Side effects of lactulose and lactitol include the possibility of diarrhea, bloating, flatulence, and nausea. In acute liver failure, it is unclear whether lactulose is beneficial. The possible side effect of bloating may interfere with a liver transplant procedure if required.

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.

Treatment is directed largely to removing the cause, or, where that is impossible, to modifying its effects. Thus, therapy aimed at improving right heart function will also improve congestive hepatopathy. True nutmeg liver is usually secondary to left-sided heart failure causing congestive right heart failure, so treatment options are limited.

Although in rare cases liver cirrhosis is reversible, the disease process remains mostly irreversible. Liver transplantation remains the only definitive therapy. Today, survival after liver transplantation is similar for people with ALD and non-ALD. The requirements for transplant listing are the same as those for other types of liver disease, except for a 6-month sobriety prerequisite along with psychiatric evaluation and rehabilitation assistance (i.e., Alcoholics Anonymous). Specific requirements vary among the transplant centers. Relapse to alcohol use after transplant listing results in delisting. Re-listing is possible in many institutions, but only after 3–6 months of sobriety. There are limited data on transplant survival in patients transplanted for acute alcoholic hepatitis, but it is believed to be similar to that in nonacute ALD, non-ALD, and alcoholic hepatitis with MDF less than 32.

The following therapeutic drugs were withdrawn from the market primarily because of hepatotoxicity: Troglitazone, bromfenac, trovafloxacin, ebrotidine, nimesulide, nefazodone, ximelagatran and pemoline.

Treatment generally includes supportive care including pain management and possibly diuretics. In the those severe disease due to a bone marrow transplant, defibrotide is a proposed treatment. It has been approved for use in severe cases in Europe and the United States. A placebo controlled trial, however, has not been done as of 2016.

"Acute on chronic liver failure" is said to exist when someone with chronic liver disease develops features of liver failure. A number of underlying causes may precipitate this, such as alcohol misuse or infection. People with ACLF can be critically ill and require intensive care treatment, and occasionally a liver transplant. Mortality with treatment is 50%.

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.

Clinical practice guidelines by the American College of Gastroenterology have recommended corticosteroid treatment. Patients should be risk stratified using a MELD Score or Child-Pugh score.

- Corticosteroids: These guidelines suggest that patients with a modified Maddrey's discriminant function score > 32 or hepatic encephalopathy should be considered for treatment with prednisolone 40 mg daily for four weeks followed by a taper. Models such as the Lille Model can be used to monitor for improvement or to consider alternative treatment.

- Pentoxifylline: A randomized controlled trial found that among patients with a discriminant function score > 32 and at least one of the following symptoms (a palpable, tender enlarged liver, fever, high white blood cell count, hepatic encephalopathy, or hepatic systolic bruit), 4.6 patients must be treated with pentoxifylline for 4 weeks to prevent one patient from dying. Subsequent trials have suggested that pentoxifylline may be superior to prednisolone in the management of acute alcoholic hepatitis with discriminant function score >32. Advantage of pentoxifylline over prednisolone was better tolerability, lesser side effects, with decreased occurrence of renal dysfunction in patients receiving pentoxifylline.

- Potential for combined therapy: A large prospective study of over 1000 patients investigated whether prednisolone and pentoxifylline produced benefits when used alone or in combination. Pentoxifylline did not improve survival alone or in combination. Prednisolone gave a small reduction in mortality at 28 days but this did not reach significance, and there were no improvements in outcomes at 90 days or 1 year.

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.

In most cases, liver function will return to normal if the offending drug is stopped early. Additionally, the patient may require supportive treatment. In acetaminophen toxicity, however, the initial insult can be fatal. Fulminant hepatic failure from drug-induced hepatotoxicity may require liver transplantation. In the past, glucocorticoids in allergic features and ursodeoxycholic acid in cholestatic cases had been used, but there is no good evidence to support their effectiveness.

An elevation in serum bilirubin level of more than 2 times ULN with associated transaminase rise is an ominous sign. This indicates severe hepatotoxicity and is likely to lead to mortality in 10% to 15% of patients, especially if the offending drug is not stopped (Hy's Law). This is because it requires significant damage to the liver to impair bilirubin excretion, hence minor impairment (in the absence of biliary obstruction or Gilbert syndrome) would not lead to jaundice. Other poor predictors of outcome are old age, female sex, high AST.

In those with severe (tense) ascites, therapeutic paracentesis may be needed in addition to medical treatments listed above. As this may deplete serum albumin levels in the blood, albumin is generally administered intravenously in proportion to the amount of ascites removed.

Anti-viral medications are available to treat infections such as hepatitis B. Other conditions may be managed by slowing down disease progression, for example:

- By using steroid-based drugs in autoimmune hepatitis.

- Regularly removing a quantity of blood from a vein (venesection) in the iron overload condition, hemochromatosis.

- Wilson’s disease, a condition where copper builds up in the body, can be managed with drugs which bind copper allowing it to be passed from your body in urine.

- In cholestatic liver disease, (where the flow of bile is affected due to cystic fibrosis) a medication called ursodeoxycholic acid (URSO, also referred to as UDCA) may be given.

Since salt restriction is the basic concept in treatment, and aldosterone is one of the hormones that acts to increase salt retention, a medication that counteracts aldosterone should be sought. Spironolactone (or other distal-tubule diuretics such as triamterene or amiloride) is the drug of choice since they block the aldosterone receptor in the collecting tubule. This choice has been confirmed in a randomized controlled trial. Diuretics for ascites should be dosed once per day. Generally, the starting dose is oral spironolactone 100 mg/day (max 400 mg/day).

40% of patients will respond to spironolactone. For nonresponders, a loop diuretic may also be added and generally, furosemide is added at a dose of 40 mg/day (max 160 mg/day), or alternatively (bumetanide or torasemide). The ratio of 100:40 reduces risks of potassium imbalance. Serum potassium level and renal function should be monitored closely while on these medications.

Monitoring diuresis: Diuresis can be monitored by weighing the patient daily. The goal is weight loss of no more than 1.0 kg/day for patients with both ascites and peripheral edema and no more than 0.5 kg/day for patients with ascites alone.

If daily weights cannot be obtained, diuretics can also be guided by the urinary sodium concentration. Dosage is increased until a negative sodium balance occurs. A random urine sodium-to-potassium ratio of > 1 is 90% sensitivity in predicting negative balance (> 78-mmol/day sodium excretion).

Diuretic resistance: Diuretic resistance can be predicted by giving 80 mg intravenous furosemide after 3 days without diuretics and on an 80 mEq sodium/day diet. The urinary sodium excretion over 8 hours < 50 mEq/8 hours predicts resistance.

If a patient exhibits a resistance to or poor response to diuretic therapy, ultrafiltration or aquapheresis may be needed to achieve adequate control of fluid retention and congestion. The use of such mechanical methods of fluid removal can produce meaningful clinical benefits in patients with diuretic resistance and may restore responsiveness to conventional doses of diuretics.

Acute fatty liver of pregnancy is best treated in a centre with expertise in hepatology, high-risk obstetrics, maternal-fetal medicine and neonatology. The physicians who treat this condition will often consult with experts in liver transplantation in severe cases. Admission to the intensive care unit is recommended.

Initial treatment involves supportive management with intravenous fluids, intravenous glucose and blood products, including fresh frozen plasma and cryoprecipitate to correct DIC. The foetus should be monitored with cardiotocography. After the mother is stabilized, arrangements are usually made for delivery. This may occur vaginally, but, in cases of severe bleeding or compromise of the mother's status, a caesarian section may be needed. Often AFLP is not diagnosed until the mother and baby are in trouble, so it is most likely that an emergency C-section is needed.

The complications of acute fatty liver of pregnancy may require treatment after delivery, especially if pancreatitis occurs. Liver transplantation is rarely required for treatment of the condition, but may be needed for mothers with severe DIC, those with rupture of the liver, or those with severe encephalopathy.

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.

There is currently no specific therapy. Intravenous fluids and treatment of the hepatic encephalopathy may help. Increasing dietary levels of branched chain amino acids and feeding low protein diets can help signs of hepatic encephalopathy, which is often accomplished by feeding small amounts of grain and/or beet pulp, and removing high-protein feedstuffs such as alfalfa hay. Grazing on non-legume grass may be acceptable if it is late summer or fall, although the horse should only be permitted to eat in the evening so as to avoid photosensitization. Due to the risk of gastric impaction, stomach size should be monitored.

Sedation is minimized and used only to control behavior that could lead to injury of the animal and to allow therapeutic procedures, and should preferably involve a sedative other than a benzodiazepine. Stressing the animal should be avoided if at all possible. Plasma transfusions may be needed if spontaneous bleeding occurs, to replace clotting factors. Antibiotics are sometimes prescribed to prevent bacterial translocation from the intestines. Antioxidants such as vitamin E, B-complex vitamins, and acetylcysteine may be given. High blood ammonia is often treated with oral neomycin, often in conjunction with lactulose, metronidazole and probiotics, to decrease production and absorption of ammonia from the gastrointestinal tract.

Initial treatment is supportive, with the use of agents to treat cholestasis and pruritus, including the following:

- Ursodeoxycholic acid

- Cholestyramine

- Rifampin

- Naloxone, in refractory cases

The partial external biliary diversion (PEBD) procedure is a surgical approach that diverts bile from the gallbladder externally into an ileostomy bag.

Patients should be supplemented with fat-soluble vitamins, and occasionally medium-chain triglycerides in order to improve growth.

When liver synthetic dysfunction is significant, patients should be listed for transplantation. Family members should be tested for PFIC mutations, in order to determine risk of transmission.

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.

Untreated, the disease has a mortality rate upwards of 90%. Cats treated in the early stages can have a recovery rate of 80–90%. Left untreated, the cats usually die from severe malnutrition or complications from liver failure. Treatment usually involves aggressive feeding through one of several methods.

Cats can have a feeding tube inserted by a veterinarian so that the owner can feed the cat a liquid diet several times a day. They can also be force-fed through the mouth with a syringe. If the cat stops vomiting and regains its appetite, it can be fed in a food dish normally. The key is aggressive feeding so the body stops converting fat in the liver. The cat liver has a high regeneration rate and the disease will eventually reverse assuming that irreparable damage has not been done to the liver.

The best method to combat feline hepatic lipidosis is prevention and early detection. Obesity increases the chances of onset. In addition, if a cat stops eating for 1–2 days, it should be taken to a vet immediately. The longer the disease goes untreated, the higher the mortality rate.

Extrahepatic cholestasis can usually be treated by surgery.

Pruritis in cholestatic jaundice is treated by Antihistamines, Ursodeoxycholic Acid, Phenobarbital

Treatment may involve the prescription of immunosuppressive glucocorticoids such as prednisone, with or without azathioprine, and remission can be achieved in up to 60–80% of cases, although many will eventually experience a relapse. Budesonide has been shown to be more effective in inducing remission than prednisone, and result in fewer adverse effects. Those with autoimmune hepatitis who do not respond to glucocorticoids and azathioprine may be given other immunosuppressives like mycophenolate, ciclosporin, tacrolimus, methotrexate, etc. Liver transplantation may be required if patients do not respond to drug therapy or when patients present with fulminant liver failure.