Medications used to treat diabetes do so by lowering blood sugar levels. There are a number of different classes of anti-diabetic medications. Some are available by mouth, such as metformin, while others are only available by injection such as GLP-1 agonists. Type 1 diabetes can only be treated with insulin, typically with a combination of regular and NPH insulin, or synthetic insulin analogs.

Metformin is generally recommended as a first line treatment for type 2 diabetes, as there is good evidence that it decreases mortality. It works by decreasing the liver's production of glucose. Several other groups of drugs, mostly given by mouth, may also decrease blood sugar in type II DM. These include agents that increase insulin release, agents that decrease absorption of sugar from the intestines, and agents that make the body more sensitive to insulin. When insulin is used in type 2 diabetes, a long-acting formulation is usually added initially, while continuing oral medications. Doses of insulin are then increased to effect.

Since cardiovascular disease is a serious complication associated with diabetes, some have recommended blood pressure levels below 130/80 mmHg. However, evidence supports less than or equal to somewhere between 140/90 mmHg to 160/100 mmHg; the only additional benefit found for blood pressure targets beneath this range was an isolated decrease in stroke risk, and this was accompanied by an increased risk of other serious adverse events. A 2016 review found potential harm to treating lower than 140 mmHg. Among medications that lower blood pressure, angiotensin converting enzyme inhibitors (ACEIs) improve outcomes in those with DM while the similar medications angiotensin receptor blockers (ARBs) do not. Aspirin is also recommended for people with cardiovascular problems, however routine use of aspirin has not been found to improve outcomes in uncomplicated diabetes.

There are several classes of anti-diabetic medications available. Metformin is generally recommended as a first line treatment as there is some evidence that it decreases mortality; however, this conclusion is questioned. Metformin should not be used in those with severe kidney or liver problems.

A second oral agent of another class or insulin may be added if metformin is not sufficient after three months. Other classes of medications include: sulfonylureas, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, SGLT2 inhibitors, and glucagon-like peptide-1 analogs. There is no significant difference between these agents. Rosiglitazone, a thiazolidinedione, has not been found to improve long-term outcomes even though it improves blood sugar levels. Additionally it is associated with increased rates of heart disease and death. Angiotensin-converting enzyme inhibitors (ACEIs) prevent kidney disease and improve outcomes in those with diabetes. The similar medications angiotensin receptor blockers (ARBs) do not. A 2016 review recommended treating to a systolic blood pressure of 140 to 150 mmHg.

Injections of insulin may either be added to oral medication or used alone. Most people do not initially need insulin. When it is used, a long-acting formulation is typically added at night, with oral medications being continued. Doses are then increased to effect (blood sugar levels being well controlled). When nightly insulin is insufficient, twice daily insulin may achieve better control. The long acting insulins glargine and detemir are equally safe and effective, and do not appear much better than neutral protamine Hagedorn (NPH) insulin, but as they are significantly more expensive, they are not cost effective as of 2010. In those who are pregnant insulin is generally the treatment of choice.

Vitamin D supplementation to people with type 2 diabetes can improve markers of insulin resistance and HbA1c.

People with diabetes can benefit from education about the disease and treatment, good nutrition to achieve a normal body weight, and exercise, with the goal of keeping both short-term and long-term blood glucose levels within acceptable bounds. In addition, given the associated higher risks of cardiovascular disease, lifestyle modifications are recommended to control blood pressure.

There is no single dietary pattern that is best for all people with diabetes. For overweight people with type 2 diabetes, any diet that the person will adhere to and achieve weight loss on is effective.

Injections of insulin—either via subcutaneous injection or insulin pump— are necessary for those living with type 1 diabetes because it cannot be treated by diet and exercise alone. Insulin dosage is adjusted taking into account food intake, blood glucose levels and physical activity.

Untreated type 1 diabetes can commonly lead to diabetic ketoacidosis which is a diabetic coma which can be fatal if untreated. Diabetic ketoacidosis can cause cerebral edema (accumulation of liquid in the brain). This is a life-threatening issue and children are at a higher risk for cerebral edema than adults, causing ketoacidosis to be the most common cause of death in pediatric diabetes.

Treatment of diabetes focuses on lowering blood sugar or glucose (BG) to the near normal range, approximately 80–140 mg/dl (4.4–7.8 mmol/L). The ultimate goal of normalizing BG is to avoid long-term complications that affect the nervous system (e.g. peripheral neuropathy leading to pain and/or loss of feeling in the extremities), and the cardiovascular system (e.g. heart attacks, vision loss). This level of control over a prolonged period of time can be varied by a target HbA level of less than 7.5%.

There are four main types of insulin: rapid acting insulin, short-acting insulin, intermediate-acting insulin, and long-acting insulin. The rapid acting insulin is used as a bolus dosage. The action onsets in 15 minutes with peak actions in 30 to 90 minutes. Short acting insulin action onsets within 30 minutes with the peak action around 2 to 4 hours. Intermediate acting insulin action onsets within one to two hours with peak action of four to 10 hours. Long-acting insulin is usually given once per day. The action onset is roughly 1 to 2 hours with a sustained action of up to 24 hours. Some insulins are biosynthetic products produced using genetic recombination techniques; formerly, cattle or pig insulins were used, and even sometimes insulin from fish.

People with type 1 diabetes always need to use insulin, but treatment can lead to low BG (hypoglycemia), i.e. BG less than 70 mg/dl (3.9 mmol/l). Hypoglycemia is a very common occurrence in people with diabetes, usually the result of a mismatch in the balance among insulin, food and physical activity. Symptoms include excess sweating, excessive hunger, fainting, fatigue, lightheadedness and shakiness. Mild cases are self-treated by eating or drinking something high in sugar. Severe cases can lead to unconsciousness and are treated with intravenous glucose or injections with glucagon. Continuous glucose monitors can alert patients to the presence of dangerously high or low blood sugar levels, but technical issues have limited the effect these devices have had on clinical practice.

As of 2016 an artificial pancreas looks promising with safety issues still being studied.

A proper diet and exercise are the foundations of diabetic care, with a greater amount of exercise yielding better results. Aerobic exercise leads to a decrease in HbA and improved insulin sensitivity. Resistance training is also useful and the combination of both types of exercise may be most effective. A diabetic diet that promotes weight loss is important. While the best diet type to achieve this is controversial, a low glycemic index diet or low carbohydrate diet has been found to improve blood sugar control. Culturally appropriate education may help people with type 2 diabetes control their blood sugar levels, for up to 24 months. If changes in lifestyle in those with mild diabetes has not resulted in improved blood sugars within six weeks, medications should then be considered. There is not enough evidence to determine if lifestyle interventions affect mortality in those who already have DM2. Vegetarian diets in general have been related to lower diabetes risk, but do not offer advantages compared with diets which allow moderate amounts of animal products. There is not enough evidence to suggest that cinnamon improves blood sugar levels in people with type 2 diabetes.

In some cases, a pancreas transplant can restore proper glucose regulation. However, the surgery and accompanying immunosuppression required may be more dangerous than continued insulin replacement therapy, so is generally only used with or some time after a kidney transplant. One reason for this is that introducing a new kidney requires taking immunosuppressive drugs such as cyclosporine, which allows the introduction of a new pancreas to a person with diabetes without any additional immunosuppressive therapy. However, pancreas transplants alone may be beneficial in people with extremely labile type 1 diabetes mellitus.

There is evidence that prediabetes is a curable disease state. Intensive weight loss and lifestyle intervention, if sustained, may improve glucose tolerance substantially and prevent progression from IGT to type 2 diabetes. The Diabetes Prevention Program (DPP) study found a 16% reduction in diabetes risk for every kilogram of weight loss. Reducing weight by 7% through a low-fat diet and performing 150 minutes of exercise a week is the goal. In observational studies, individuals following vegetarian diets are about half as likely to develop diabetes, compared with non-vegetarians. The ADA guidelines recommend modest weight loss (5–10% body weight), moderate-intensity exercise (30 minutes daily), and smoking cessation.

There are claims in the media that a high-fat, high-protein, low carbohydrates diet can reverse prediabetes, but scientific evidence is not conclusive as to whether this diet has any efficacy.

For patients with severe risk factors, prescription medication may be appropriate. This may be considered in patients for whom lifestyle therapy has failed, or is not sustainable, and who are at high-risk for developing type 2 diabetes. Metformin and acarbose help prevent the development of frank diabetes, and also have a good safety profile. Evidence also supports thiazolidinediones but there are safety concerns, and data on newer agents such as GLP-1 receptor agonists, DPP4 inhibitors or meglitinides are lacking.

If monitoring reveals failing control of glucose levels with these measures, or if there is evidence of complications like excessive fetal growth, treatment with insulin might be necessary. This is most commonly fast-acting insulin given just before eating to blunt glucose rises after meals. Care needs to be taken to avoid low blood sugar levels due to excessive insulin. Insulin therapy can be normal or very tight; more injections can result in better control but requires more effort, and there is no consensus that it has large benefits. A 2016 Cochrane review concluded that quality evidence is not yet available to determine the best blood sugar range for improving health for pregnant women with GDM and their babies.

There is some evidence that certain medications by mouth might be safe in pregnancy, or at least, are less dangerous to the developing fetus than poorly controlled diabetes. The medication metformin is better than glyburide. If blood glucose cannot be adequately controlled with a single agent, the combination of metformin and insulin may be better than insulin alone. Another review found good short term safety for both the mother and baby with metformin but unclear long term safety.

People may prefer metformin by mouth to insulin injections. Treatment of polycystic ovarian syndrome with metformin during pregnancy has been noted to decrease GDM levels.

Almost half of the women did not reach sufficient control with metformin alone and needed supplemental therapy with insulin; compared to those treated with insulin alone, they required less insulin, and they gained less weight. With no long-term studies into children of women treated with the drug, there remains a possibility of long-term complications from metformin therapy. Babies born to women treated with metformin have been found to develop less visceral fat, making them less prone to insulin resistance in later life.

About 80% of all LADA patients initially misdiagnosed with type 2 (and who have GAD antibodies) will become insulin-dependent within 3 to 15 years (according to differing LADA sources).

The treatment for Type 1 diabetes/LADA is exogenous insulin to control glucose levels, prevent further destruction of residual beta cells, reduce the possibility of diabetic complications, and prevent death from diabetic ketoacidosis (DKA). Although LADA may appear to initially respond to similar treatment (lifestyle and medications) as type 2 diabetes, it will not halt or slow the progression of beta cell destruction, and people with LADA will eventually become insulin-dependent. People with LADA have insulin resistance similar to long-term type 1 diabetes; some studies showed that people with LADA have less insulin resistance, compared with those with type 2 diabetes; however, others have not found a difference.

Counselling before pregnancy (for example, about preventive folic acid supplements) and multidisciplinary management are important for good pregnancy outcomes. Most women can manage their GDM with dietary changes and exercise. Self monitoring of blood glucose levels can guide therapy. Some women will need antidiabetic drugs, most commonly insulin therapy.

Any diet needs to provide sufficient calories for pregnancy, typically 2,000 – 2,500 kcal with the exclusion of simple carbohydrates. The main goal of dietary modifications is to avoid peaks in blood sugar levels. This can be done by spreading carbohydrate intake over meals and snacks throughout the day, and using slow-release carbohydrate sources—known as the G.I. Diet. Since insulin resistance is highest in mornings, breakfast carbohydrates need to be restricted more. Ingesting more fiber in foods with whole grains, or fruit and vegetables can also reduce the risk of gestational diabetes.

Regular moderately intense physical exercise is advised, although there is no consensus on the specific structure of exercise programs for GDM.

Self monitoring can be accomplished using a handheld capillary glucose dosage system. Compliance with these glucometer systems can be low. Target ranges advised by the Australasian Diabetes in Pregnancy Society are as follows:

- fasting capillary blood glucose levels <5.5 mmol/L

- 1 hour postprandial capillary blood glucose levels <8.0 mmol/L

- 2 hour postprandial blood glucose levels <6.7 mmol/L

Regular blood samples can be used to determine HbA1c levels, which give an idea of glucose control over a longer time period.

Research suggests a possible benefit of breastfeeding to reduce the risk of diabetes and related risks for both mother and child.

Oral medications like Glipizide that stimulate the pancreas, promoting insulin release (or in some cases, reduce glucose production), are less and less used in cats, and these drugs may be completely ineffective if the pancreas is not working. These drugs have also been shown in some studies to damage the pancreas further or to cause liver damage. Some owners are reluctant to switch from pills to insulin injections, but the fear is unjustified; the difference in cost and convenience is minor (most cats are easier to inject than to pill), and injections are more effective at treating the disease.

Early diagnosis and interventive treatment can mean reduced incidence of complications such as cataracts and neuropathy. Since dogs are insulin dependent, oral drugs are not effective for them. They must be placed on insulin replacement therapy. Approved oral diabetes drugs can be helpful to sufferers of Type 2 diabetes because they work in one of three ways: by inducing the pancreas to produce more insulin, by allowing the body to more effectively use the insulin it produces, or by slowing the glucose absorption rate from the GI tract. Unapproved so-called "natural" remedies make similar claims for their products. All of this is based on the premise of having an endocrine pancreas with beta cells capable of producing insulin. Those with Type 1, or insulin-dependent diabetes, have beta cells which are permanently damaged, thus unable to produce insulin. This is the reason nothing other than insulin replacement therapy can be considered real and effective treatment. Canine diabetes means insulin dependency; insulin therapy must be continued for life.

The goal is to regulate the pet's blood glucose using insulin and some probable diet and daily routine changes. The process may take a few weeks or many months. It is basically the same as in Type 1 diabetic humans. The aim is to keep the blood glucose values in an acceptable range. The commonly recommended dosing method is by "starting low and going slow" as indicated for people with diabetes.

During the initial process of regulation and periodically thereafter, the effectiveness of the insulin dose at controlling blood glucose needs to be evaluated. This is done by a series of blood glucose tests called a curve. Blood samples are taken and tested at intervals of one to two hours over a 12- or 24-hour period. The results are generally transferred into graph form for easier interpretation. They are compared against the feeding and insulin injection times for judgment. The curve provides information regarding the action of the insulin in the animal. It is used to determine insulin dose adjustments, determine lowest and highest blood glucose levels, discover insulin duration and, in the case of continued hyperglycemia, whether the cause is insufficient insulin dose or Somogyi rebound, where blood glucose levels initially reach hypoglycemic levels and are brought to hyperglycemic ones by the body's counterregulatory hormones. Curves also provide evidence of insulin resistance which may be caused by medications other than insulin or by disorders other than diabetes which further testing can help identify.

Other diagnostic tests to determine the level of diabetic control are fructosamine and glycosylated hemoglobin (GHb) blood tests which can be useful especially if stress may be a factor. While anxiety or stress may influence the results of blood or urine glucose tests, both of these tests measure glycated proteins, which are not affected by them. Fructosamine testing provides information about blood glucose control for an approximate 2- to 4-week period, while GHb tests measure a 2- to 4-month period. Each of these tests has its own limitations and drawbacks and neither are intended to be replacements for blood glucose testing and curves, but are to be used to supplement the information gained from them. While HbA1c tests are a common diagnostic for diabetes in humans, there are no standards of measurement for use of the test in animals. This means the information from them may not be reliable.

The diabetic pet is considered regulated when its blood glucose levels remain within an acceptable range on a regular basis. Acceptable levels for dogs are between 5 and 10 mmol/L or 90 to 180 mg/dL. The range is wider for diabetic animals than non-diabetics, because insulin injections cannot replicate the accuracy of a working pancreas.

An acute hypoglycemic episode (very low blood sugar) can happen to even careful pet owners, since cats' insulin requirements sometimes change without warning. The symptoms include depression/lethargy, confusion/dizziness, loss of excretory/bladder control, vomiting, and then loss of consciousness and/or seizures. Immediate treatment includes administering honey or corn syrup by rubbing on the gums of the cat (even if unconscious, but not if in seizures). Symptomatic hypoglycemia in cats is a medical emergency and the cat will require professional medical attention. The honey/corn syrup should continue to be administered on the way to the vet, as every minute without blood sugar causes brain damage.

A cat with hypoglycemia according to a blood glucose meter (<2.2 mmol/L or 40 mg/dL), but with no symptoms, should be fed as soon as possible. Hypoglycemic cats that refuse to eat can be force-fed honey or corn syrup until they stabilize.

Mild hypoglycemic episodes can go unnoticed, or leave evidence such as urine pools outside the litter box. In these cases the blood sugar will probably appear paradoxically "high" upon the next test hours later, since the cat's body will react to the low blood sugar by stimulating the liver to release stored glycogen.

The general form of this treatment is an intermediate-acting basal insulin with a regimen of food and insulin every 12 hours, with the insulin injection following the meal. The most commonly used intermediate-acting insulins are NPH, also referred to as isophane, or Caninsulin, also known as Vetsulin, a porcine Lente insulin. While the normal diabetes routine is timed feedings with insulin shots following the meals, dogs unwilling to adhere to this pattern can still attain satisfactory regulation. Most dogs do not require basal/bolus insulin injections; treatment protocol regarding consistency in the diet's calories and composition along with the established feeding and injection times is generally a suitable match for the chosen intermediate-acting insulin.

With Lantus and protamine zinc insulin (PZI) being unreliable in dogs, they are rarely used to treat canine diabetes. Bovine insulin has been used as treatment for some dogs, particularly in the UK. Pfizer Animal Health discontinued of all three types of its veterinary Insuvet bovine insulins in late 2010 and suggested patients be transitioned to Caninsulin. The original owner of the insulin brand, Schering-Plough Animal Health, contracted Wockhardt UK to produce them. Wockhardt UK has produced both bovine and porcine insulins for the human pharmaceutical market for some time.

Chronic hyperglycemia due to any cause can eventually cause blood vessel damage and the microvascular complications of diabetes. The principal treatment goals for people with MODY — keeping the blood sugars as close to normal as possible ("good glycemic control"), while minimizing other vascular risk factors — are the same for all known forms of diabetes.

The tools for management are similar for all forms of diabetes: blood testing, changes in diet, physical exercise, oral hypoglycemic agents, and insulin injections. In many cases these goals can be achieved more easily with MODY than with ordinary types 1 and 2 diabetes. Some people with MODY may require insulin injections to achieve the same glycemic control that another person may attain with careful eating or an oral medication.

When oral hypoglycemic agents are used in MODY, the sulfonylureas remain the oral medication of first resort. When compared to patients with type 2 diabetes, MODY patients are often more sensitive to sulphonylureas, such that a lower dose should be used to initiate treatment to avoid hypoglycaemia. Patients with MODY less often suffer from obesity and insulin resistance than those with ordinary type 2 diabetes (for whom insulin sensitizers like metformin or the thiazolidinediones are often preferred over the sulfonylureas).

The progression to type 2 diabetes mellitus is not inevitable for those with prediabetes. The progression into diabetes mellitus from prediabetes is approximately 25% over three to five years.

In many cases, neonatal diabetes may be treated with oral sulfonylureas such as glyburide. Physicians may order genetic tests to determine whether or not transitioning from insulin to sulfonylurea drugs is appropriate for a patient.

The transfer from insulin injections to oral glibenclamide therapy seems highly effective for most patients and safe. This illuminates how the molecular understanding of some monogenic form of diabetes may lead to an unexpected change of the treatment in children. This is a spectacular example of how the pharmacogenomic approach improves in a tremendous way the quality of life of the young diabetic patients.

Insulin Therapy

- Long Acting Insulin: (Insulin glargine)-is a hormone that works by lowering levels of blood glucose. It starts to work several hours after an injection and keeps working for 24 hours. It is used to manage blood glucose of diabetics. It is used to treat Type 1 and 2 diabetes in adults and Type 1 diabetes in kids as young as 6 years old.

- Short Acting Insulin (e.g. Novolin or Velosulin)-It works similarly to natural insulin and takes up to 30 minutes and lasts for about 8 hours depending on the dosage used.

- Intermediate Insulin: (e.g. NPH insulin)- Usually taken in combination with a short acting insulin. Intermediate acting insulin starts to activate within the first hour of injecting and enters a period of peak activity lasting for 7 hours.

Sulfonylureas

- Sulfonylureas: This medication signals the pancreas to release insulin and help the body's cells use insulin better. This medicaiton can lower A1C levels ( AIC is defined as a measurement of the blood glucose after previous 2–3 months) by 1-2%.

There are no known ways of preventing LADA type 1 diabetes, though some researchers believe it could be stopped at a very early stage if a diagnosis is made prior to the body's destruction of its beta cells.

Diabetes mellitus may be effectively managed by appropriate meal planning, increased physical activity and properly-instituted insulin treatment. Some tips for controlling diabetes in pregnancy include:

- Meals – Cut down sweets, eats three small meals and one to three snacks a day, maintain proper mealtimes, and include balanced fiber intake in the form of fruits, vegetables and whole-grains.

- Increased physical activity - walking, swimming/aquaerobics, etc.

- Monitor blood sugar level frequently, doctors may ask to check the blood glucose more often than usual.

- The blood sugar level should be below 95 mg/dl (5.3 mmol/l) on awakening, below 140 mg/dl (7.8 mmol/l) one hour after a meal and below 120 mg/dl (6.7 mmol/l) two hours after a meal.

- Each time when checking the blood sugar level, keep a proper record of the results and present to the health care team for evaluation and modification of the treatment. If blood sugar levels are above targets, a perinatal diabetes management team may suggest ways to achieve targets.

- Many may need extra insulin during pregnancy to reach their blood sugar target. Insulin is not harmful for the baby.

Modulating and ameliorating diabetic complications may improve the overall quality of life for diabetic patients. For example; when elevated blood pressure was tightly controlled, diabetic related deaths were reduced by 32% compared to those with less controlled blood pressure.

Treatment is typically achieved via diet and exercise, although metformin may be used to reduce insulin levels in some patients (typically where obesity is present). A referral to a dietician is beneficial. Another method used to lower excessively high insulin levels is cinnamon as was demonstrated when supplemented in clinical human trials.

A low carbohydrate diet is particularly effective in reducing hyperinsulinism.

A healthy diet that is low in simple sugars and processed carbohydrates, and high in fiber, and vegetable protein is often recommended. This includes replacing white bread with whole-grain bread, reducing intake of foods composed primarily of starch such as potatoes, and increasing intake of legumes and green vegetables, particularly soy.

Regular monitoring of weight, blood sugar, and insulin are advised, as hyperinsulinemia may develop into diabetes mellitus type 2.

It has been shown in many studies that physical exercise improves insulin sensitivity. The mechanism of exercise on improving insulin sensitivity is not well understood however it is thought that exercise causes the glucose receptor GLUT4 to translocate to the membrane. As more GLUT4 receptors are present on the membrane more glucose is taken up into cells decreasing blood glucose levels which then causes decreased insulin secretion and some alleviation of hyperinsulinemia. Another proposed mechanism of improved insulin sensitivity by exercise is through AMPK activity. The beneficial effect of exercise on hyperinsulinemia was shown in a study by Solomon et al. (2009), where they found that improving fitness through exercise significantly decreases blood insulin concentrations.

The primary treatment for insulin resistance is exercise and weight loss. Research shows that a low-carbohydrate diet may help. Both metformin and thiazolidinediones improve insulin resistance, but only are approved therapies for type 2 diabetes, not for insulin resistance. By contrast, growth hormone replacement therapy may be associated with increased insulin resistance.

Metformin has become one of the more commonly prescribed medications for insulin resistance. Unfortunately, Metformin also masks Vitamin B12 deficiency, so accompanying sub-lingual Vitamin B12 tablets are recommended.

Insulin resistance is often associated with abnormalities in lipids particularly high blood triglycerides and low high density lipoprotein.

The "Diabetes Prevention Program" (DPP) showed that exercise and diet were nearly twice as effective as metformin at reducing the risk of progressing to type 2 diabetes. However, the participants in the DPP trial regained about 40% of the weight that they had lost at the end of 2.8 years, resulting in a similar incidence of diabetes development in both the lifestyle intervention and the control arms of the trial. One 2009 study found that carbohydrate deficit after exercise, but not energy deficit, contributed to insulin sensitivity increase.

Resistant starch from high-amylose corn, amylomaize, has been shown to reduce insulin resistance in healthy individuals, in individuals with insulin resistance, and in individuals with type 2 diabetes. Animal studies demonstrate that it cannot reverse damage already done by high glucose levels, but that it reduces insulin resistance and reduces the development of further damage.

Some types of polyunsaturated fatty acids (omega-3) may moderate the progression of insulin resistance into type 2 diabetes, however, omega-3 fatty acids appear to have limited ability to reverse insulin resistance, and they cease to be efficacious once type 2 diabetes is established.

Caffeine intake limits insulin action, but not enough to increase blood-sugar levels in healthy persons. People who already have type 2 diabetes may see a small increase in levels if they take 2 or 2-1/2 cups of coffee per day.

Desmopressin will be ineffective in nephrogenic DI which is treated by reversing the underlying cause (if possible) and replacing the free water deficit. The diuretic hydrochlorothiazide (a thiazide diuretic) or indomethacin can be used to create mild hypovolemia which encourages salt and water uptake in proximal tubule and thus improve nephrogenic diabetes insipidus. Amiloride has additional benefit of blocking Na uptake. Thiazide diuretics are sometimes combined with amiloride to prevent hypokalemia. It seems paradoxical to treat an extreme diuresis with a diuretic, and the exact mechanism of action is unknown but the thiazide diuretics will decrease distal convoluted tubule reabsorption of sodium and water, thereby causing diuresis. This decreases plasma volume, thus lowering the glomerular filtration rate and enhancing the absorption of sodium and water in the proximal nephron. Less fluid reaches the distal nephron, so overall fluid conservation is obtained.

Lithium-induced nephrogenic DI may be effectively managed with the administration of amiloride, a potassium-sparing diuretic often used in conjunction with thiazide or loop diuretics. Clinicians have been aware of lithium toxicity for many years, and traditionally have administered thiazide diuretics for lithium-induced polyuria and nephrogenic diabetes insipidus. However, amiloride has recently been shown to be a successful treatment for this condition.

Cerebral edema, if associated with coma, often necessitates admission to intensive care, artificial ventilation, and close observation. The administration of fluids is slowed. The ideal treatment of cerebral edema in DKA is not established, but intravenous mannitol and hypertonic saline (3%) are used—as in some other forms of cerebral edema—in an attempt to reduce the swelling.

Resolution of DKA is defined as general improvement in the symptoms, such as the ability to tolerate oral nutrition and fluids, normalization of blood acidity (pH>7.3), and absence of ketones in blood (<1 mmol/l) or urine. Once this has been achieved, insulin may be switched to the usual subcutaneously administrered regimen, one hour after which the intravenous administration can be discontinued.

In people with suspected ketosis-prone type 2 diabetes, determination of antibodies against glutamic acid decarboxylase and islet cells may aid in the decision whether to continue insulin administration long-term (if antibodies are detected), or whether to withdraw insulin and attempt treatment with oral medication as in type 2 diabetes. Generally speaking, routine measurement of C-peptide as a measure of insulin production is not recommended unless there is genuine doubt as to whether someone has type 1 or type 2 diabetes.