Istavel (Sitagliptin Phosphate 100mg) Tablets

Istavel general information

What is Istavel used for?

The pancreas, a small organ found in the abdomen behind your stomach, secretes digestive enzymes and hormones that play a vital role in digestion and maintain healthy blood sugar levels.  The Islets of Langerhans in the pancreas produce two hormones that work in opposite ways to regulate blood sugar (glucose) levels.  When blood glucose levels increase, such as after a meal, insulin is secreted by the pancreatic beta cells.  In between meals, when blood glucose levels fall, glucagon is released by the pancreatic alpha cells and prevents glucose levels from falling too low.  Diabetes is a chronic condition where blood glucose levels are difficult to control and become too high, resulting in hyperglycaemia.  This is known as poor glycaemic control.  Istavel tablets 100mg are used to treat diabetes to restore glycaemic control and reduce high blood glucose levels.

Type 2 Diabetes

Diabetes is caused by various factors, and there two forms of diabetes.  Type 1 diabetes is usually hereditary, develops early in life, and is caused by damage to the pancreas due to attack by the body’s immune system.  Type 2 diabetes usually begins later in life and is related to lifestyle factors, including obesity, poor diet, smoking, and lack of exercise.  Type 2 Diabetes is also called Type 2 Diabetes Mellitus (T2DM) after the Latin word for honey, as the blood and urine contain excess sugar.

Insulin ensures that there is enough glucose needed for energy throughout the body, particularly the brain.  However, insulin also prevents too much glucose circulating in the blood by promoting glucose uptake by fat and muscle cells.  Glucose is produced in the liver and absorbed from the diet.  Excess glucose is stored in the liver and muscles.  Hyperglycaemia is either the result of your body not making enough insulin or because your body has become resistant to the effects of insulin. 

What are incretins?

Incretins are small proteins that are involved in the regulation of glucose homeostasis (maintaining healthy glucose levels).  They are glucose-dependent Insulinotropic polypeptide (GIP) is and glucagon-like peptide-1 (GLP-1) and are released from the intestine in response to increased glucose levels after a meal.  The incretins stimulate insulin production from the pancreas, which lowers blood glucose levels and also suppress glucagon release, which reduces glucose production in the liver.  This is known as the incretin effect.  However, the incretins are short-lived proteins.  As soon as they have done their job, they are rapidly degraded by an enzyme called dipeptidyl peptidase 4 (DPP-4) to inactive metabolites.  In type 2 diabetes, the incretin effect does not work efficiently, and this adds to the problem of poor glycaemic control.

Diabetic complications

Diabetes increases the risk of serious health complications caused by damage to blood vessels.  Damage to large blood vessels like arteries (macrovascular) can cause cardiovascular disease resulting in heart attack and stroke.  Damage to small blood vessels like capillaries (microvascular) can cause kidney failure (diabetic nephropathy), and eye damage with loss of vision (diabetic retinopathy).  Damage to nerves (diabetic neuropathy) can result in amputation, particularly of the toes.

How does Istavel work?

Istavel tablets 100mg contain sitagliptin, a potent and selective DPP-4 inhibitor that is used to treat type 2 diabetes, to improve glycaemic control. 

Sitagliptin in Istavel tablets 100mg works by inhibiting the enzyme dipeptidyl peptidase 4 (DPP-4) that degrades the incretin hormones.  This action of sitagliptin prevents the destruction of incretins, so that insulin release from the pancreas is stimulated and glucagon is suppressed, resulting in lower blood glucose levels. 

Sitagliptin action is glucose-dependent and is only activated when blood glucose levels are high.  Therefore, unlike other diabetic medicines, sitagliptin does not lead to hypoglycaemia (low blood sugar), which is a potentially serious side effect.

Istavel tablets 100mg should be used alongside lifestyle changes such as improved diet and exercise.  Istavel can also be used in conjunction with other antihyperglycemic medications to help maintain steady blood glucose levels.

What does Istavel contain?

Istavel tablets 100mg contain the active ingredient sitagliptin phosphate, a DPP-4 inhibitor used to treat Type 2 Diabetes.  They also contain microcrystalline cellulose, anhydrous dibasic calcium phosphate, croscarmellose sodium, magnesium stearate, sodium stearyl fumarate, polyvinyl alcohol, polyethylene glycol (macrogol), talc, titanium dioxide, red iron oxide, and yellow iron oxide

What are the side effects of Istavel?

Most medications have some side effects, but they are not experienced by everyone.  Some side effects are commonly experienced when taking Istavel tablets 100mg, but others are not so common, and you should discuss any problems or concerns with your primary care physician. 

Common side effects when taking Istavel are generally due to the combination with other antihyperglycemic and include gastrointestinal upset (nausea, diarrhoea, indigestion, flatulence, vomiting) headache, upper respiratory infection, stuffy or runny nose and sore throat, cough, fungal skin infection, peripheral oedema (swelling of the hands or leg).  Hypoglycaemia (low blood sugar) can occur when Istavel is used in combination with a sulfonylurea medicine.

When should Istavel not be used?

Have a talk with your primary healthcare physician before taking Istavel tablets 100mg so that you have a full understanding of what this medicine is for and how to use it.  There are some reasons for not taking a medication; these are called contraindications, and for Istavel you should consider the following before taking Istavel:

• Have you ever had an unusual reaction or an allergy when taking Istavel?
• Are you pregnant or breastfeeding?
• Do you have type 1 diabetes or diabetic ketoacidosis?
• Do you have severe kidney disease?
• Do you have symptoms of pancreatitis while taking Istavel, including severe persistent stomach pain, with or without vomiting?

What medications interact with Istavel?

Some medicines interact with Istavel tablets 100mg and may affect the way it works, or are affected by Istavel or increase side effects; you should discuss possible interactions with your primary care physician.  These may include digoxin for heart failure. 

If other medications may interact with Istavel, your doctor will discuss these with you. 

How should Istavel be taken and for how long?

You should take your Istavel tablets 100mg, swallowed whole with a glass of water, once daily and with or without food.  You may be taking Istavel 100 in combination with other antidiabetic drugs, which you should take according to your doctor’s recommendations.  You will be given a diet and exercise programme to follow as well as your medication.  You should continue to take your Istavel tablets 100mg along with your other medication and a healthy diet and exercise programme for as long as recommend by your doctor, which may be for long-term to maintain your blood sugar levels.  

Missed dose of Istavel

If you miss a dose of Istavel tablets 100mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose.  Do not take a double dose.

How should Istavel be stored?

You should store your Istavel tablets 100mg below 25°C in a cool dry place.