Restrict

Uses

Restrict is used for an adjunct to diet and exercise to lower the blood glucose level in patients with type 2 diabetes mellitus (NIDDM) whose hyperglycaemia cannot be controlled satisfactorily by diet and exercise alone. It is also used for use in combination with Metformin to lower blood glucose in patients whose hyperglycaemia cannot be controlled by exercise, diet, and either Restrict or Metformin alone. Restrict binds to specific receptors in the cell membrane leading to the closure of ATP dependent K+ channels and the depolarisation of cell membrane. This in turn, leads to Ca++ influx, increased intracellular Ca++ and the stimulation of insulin secretion.

Restrict is also used to associated treatment for these conditions: Type 2 Diabetes Mellitus

How Restrict works

Restrict activity is dependent on the presence functioning β cells and glucose. In contrast to sulfonylurea insulin secretatogogues, repaglinide has no effect on insulin release in the absence of glucose. Rather, it potentiates the effect of extracellular glucose on ATP-sensitive potassium channel and has little effect on insulin levels between meals and overnight. As such, repaglinide is more effective at reducing postprandial blood glucose levels than fasting blood glucose levels and requires a longer duration of therapy (approximately one month) before decreases in fasting blood glucose are observed. The insulinotropic effects of repaglinide are highest at intermediate glucose levels (3 to 10 mmol/L) and it does not increase insulin release already stimulated by high glucose concentrations (greater than 15 mmol/L). Restrict appears to be selective for pancreatic β cells and does not appear to affect skeletal or cardiac muscle or thyroid tissue.

Dosage

Restrict dosage

Restrict has to be taken just before or up to 30 minutes before the meal. Restrict can be taken two, three or four times a day, depending on how many meals are taken. If a meal is missed, Restrict should also be avoided. If an extra meal is taken, an extra dose of Restrict should be taken with that meal. If a dose of Restrict is missed, it should not be taken between meals.

Rather the usual dose should be taken before the next meal. The dose ranges from 0.5 to 4 mg before each meal. The starting dose of Restrict in patients with HbA1c <8% is 0.5 mg before each meal. In patients with HbA1c >8% the starting dose is 1 or 2 mg before each meal. The dose may be increased gradually up to 4 mg before each meal.

Side Effects

Hypoglycaemia is possible with all blood glucose lowering drugs. If there are symptoms of low blood glucose (for example, headache, dizziness, tiredness, nervousness or shakiness, rapid heartbeat, or nausea), blood glucose should be tested right away. If it is low (less than 70 mg/dl on a home glucose meter), a simple carbohydrate food (for example, orange juice, quick dissolving sugar, candies, or glucose tablets) should be taken. If the symptoms do not go away, doctor should be informed. Some of the other common symptoms reported by patients taking Restrict include cold and flu-like symptoms, diarrhoea, joint ache, and back pain. There is some evidence that oral anti-diabetic drugs may increase the risk of heart problems. But experts are not sure what the real risk is, if any, from taking oral anti-diabetic drugs.

Toxicity

LD₅₀ >1 g/kg (rat) (W. Grell)

Precaution

Restrict should also be used with caution in renal and hepatic insufficiency.

Interaction

The dose of Restrict may need to be adjusted, if taken with other medications. The possible interactions of Restrict with other drugs are:

• Inhibitors of the cytochrome P450 enzyme system (azole antifungals and macrolides) may lead to lower Restrict clearance and longer half life.
• Inducers of the cytochrome P450 enzyme system (Rifampin, Phenobarbital, Carbamazepine, Troglitazone, etc.) may accelerate Restrict metabolism and shorten its effect.
• Cimetidine has no significant effect on Restrict absorption or clearance.
• Restrict has no significant effect on Digoxin, Theophyllin, or Warfarin.
• Highly protein bound drugs (e.g., NSAIDs) may increase the plasma level of unbound Restrict and potentiate its glucose lowering effect. Thus, co-administration of these drugs with Restrict may increase the risk of hypoglycaemia.
• The risk of hypoglycaemia may also be increased when hypoglycaemic agents are co-administered with certain drugs such as salicylates, sulphonamides, Chloramphenicol, coumarins, Probenecid, monoamine oxidase (MAO) inhibitors, and adrenergic blockers.

Food Interaction

• Take before a meal. Restrict should be taken before each meal of the day.

[Moderate] MONITOR: Grapefruit juice may increase the plasma concentrations of orally administered drugs that are substrates of the CYP450 3A4 isoenzyme.

The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.

Because grapefruit juice inhibits primarily intestinal rather than hepatic CYP450 3A4, the magnitude of interaction is greatest for those drugs that undergo significant presystemic metabolism by CYP450 3A4 (i.e., drugs with low oral bioavailability).

In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands.

Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition.

Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients who regularly consume grapefruit or grapefruit juice should be monitored for adverse effects and altered plasma concentrations of drugs that undergo significant presystemic metabolism by CYP450 3A4.

Grapefruit and grapefruit juice should be avoided if an interaction is suspected.

Orange juice is not expected to interact with these drugs.

Restrict Alcohol interaction

[Moderate] GENERALLY AVOID:

Alcohol may cause hypoglycemia or hyperglycemia in patients with diabetes.

Hypoglycemia most frequently occurs during acute consumption of alcohol.

Even modest amounts can lower blood sugar significantly, especially when the alcohol is ingested on an empty stomach or following exercise.

The mechanism involves inhibition of both gluconeogenesis as well as the counter-regulatory response to hypoglycemia.

Episodes of hypoglycemia may last for 8 to 12 hours after ethanol ingestion.

By contrast, chronic alcohol abuse can cause impaired glucose tolerance and hyperglycemia.

[Moderate alcohol consumption generally does not affect blood glucose levels in patients with well controlled diabetes.

A disulfiram-like reaction (e.g., flushing, headache, and nausea) to alcohol has been reported frequently with the use of chlorpropamide and very rarely with other sulfonylureas.

Patients with diabetes should avoid consuming alcohol if their blood glucose is not well controlled, or if they have hypertriglyceridemia, neuropathy, or pancreatitis.

Patients with well controlled diabetes should limit their alcohol intake to one drink daily for women and two drinks daily for men (1 drink = 5 oz wine, 12 oz beer, or 1.5 oz distilled spirits) in conjunction with their normal meal plan.

Alcohol should not be consumed on an empty stomach or following exercise.

Restrict Drug Interaction

Moderate: aspirin, aspirin, canagliflozin, sitagliptin, empagliflozin, furosemide, metoprolol, metoprolol, levothyroxine, dulaglutide, liraglutideUnknown: rosuvastatin, apixaban, insulin glargine, insulin glargine, atorvastatin, esomeprazole, cyanocobalamin, ascorbic acid, cholecalciferol

Restrict Disease Interaction

Major: type I diabetes, cardiovascular riskModerate: hypoglycemia, liver disease, renal impairment

Volume of Distribution

31 L following IV administration in healthy individuals

Elimination Route

Rapidly and completely absorbed following oral administration. Peak plasma concentrations are observed within 1 hour (range 0.5-1.4 hours). The absolute bioavailability is approximately 56%. Maximal biological effect is observed within 3-3.5 hours and plasma insulin levels remain elevated for 4-6 hours. When a single 2 mg dose of repaglinide is given to healthy subjects, the area under the curve (AUC) is 18.0 - 18.7 (ng/mL/h)^3.

Half Life

1 hour

Clearance

33-38 L/hour following IV administration

Elimination Route

90% eliminated in feces (<2% as unchanged drug), 8% in urine (0.1% as unchanged drug)

Pregnancy & Breastfeeding use

In pregnancy, safety of Restrict has not been established. Hence, Restrict should be used during pregnancy only if it is clearly needed. It is not known whether Restrict is excreted in human milk. Because many drugs are excreted in human milk and because of potential for serious adverse reactions in nursing infants from Restrict, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the mother.

Contraindication

Restrict is contraindicated in patients with diabetic ketoacidosis, with or without coma, in patients with type I diabetes and in patients with known hypersensitivity to any of the components of the product.

Acute Overdose

Patients receiving up to 80 mg of Restrict developed few adverse effects other than lowering of blood glucose. Hypoglycemia did not occur when meals were given with these high doses. Severe hypoglycemic reactions with coma, seizure or other neurological impairment occur infrequently.

Storage Condition

Store below 25° C. Protect from moisture.

Innovators Monograph

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