Dr. Alvin G. Isaac

Know About Your Diabetes Medicines

Post 10b: Insulin – Administration, Storage, and Safety

Insulin doses are prescribed in units. The correct dose depends on the individual's blood glucose levels, type of diabetes, meals, physical activity, body weight, kidney function, and treatment goals. There is no single dose suitable for everyone.

The most common route is subcutaneous injection (SC), meaning injection into the fatty tissue beneath the skin.

Common injection sites include:
✅ Abdomen, avoiding the area immediately around the navel.
✅ Front or outer part of the thigh.
✅ Upper arm, in the appropriate subcutaneous area.

Injection sites should be rotated regularly to reduce the risk of lumps and changes in fatty tissue.

The frequency and timing depend on the prescribed insulin preparation and treatment regimen. Some products are used around meals, while others provide basal insulin coverage.

Preparing and administering insulin

Most insulin products are supplied as ready-to-use solutions or suspensions and do not require reconstitution with water or another diluent.
Before administration:
1. Wash your hands.
2. Confirm the insulin name, concentration, prescribed dose, and expiration date.
3. Inspect the insulin and prepare it according to the manufacturer's instructions.
4. Use the correct syringe or pen device.
5. Use a new needle for each injection

Storage of insulin

Proper storage helps maintain insulin potency.
✅ Unopened insulin is generally stored in a refrigerator at 2°C to 8°C, according to the product instructions.
✅ Do not freeze insulin or expose it to excessive heat or direct sunlight.
✅ Insulin in use may be stored at room temperature within the temperature limits and time period specified for that particular product.
✅ The time an insulin product can be used after opening varies by formulation and device. Check the manufacturer's instructions and do not assume every insulin lasts 28 days after opening

Side effects and safety
✔️The most important adverse effect of insulin is hypoglycemia (low blood glucose). Severe hypoglycemia can cause seizures or loss of consciousness and may be life-threatening.
✔️Other possible problems include injection-site reactions and changes in the fatty tissue at injection sites.

NB: Insulin treatment should be individualized and regularly reviewed by a qualified healthcare professional.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 10a: Insulin – Preparations, Forms, and Strength

Insulin is available in different preparations, concentrations, and delivery devices. Understanding how to identify insulin and its strength is essential for preventing medication errors and ensuring safe treatment.

Common forms of insulin

Insulin is commonly supplied in the following forms:
✅ Vials: Small glass containers with a rubber stopper. Insulin is usually withdrawn using a compatible insulin syringe.
✅ Insulin pens: Devices that contain insulin and allow the prescribed dose to be dialed and administered using a compatible pen needle. Some pens are prefilled and disposable, while others are reusable.
✅ Cartridges: Containers of insulin designed for use with compatible reusable insulin pens.

The available forms depend on the specific insulin product.

Insulin concentration and strength

Insulin concentration tells us how many units of insulin are contained in each milliliter (mL). Common concentrations include:
✔️ U-100: 100 units per mL.
✔️ U-200: 200 units per mL.
✔️ U-300: 300 units per mL.
✔️ U-500: 500 units per mL.

For example, U-100 contains 100 units per mL, while U-500 contains 500 units per mL. Not all insulin products are available in every concentration.

Always check the insulin name and concentration before use. Never withdraw insulin from a pen or cartridge using a syringe, as this can cause serious dosing errors. Never switch insulin products or concentrations without guidance from a qualified healthcare professional.

Appearance of insulin

The appearance of insulin depends on the preparation.
✔️ Many insulin solutions are clear and colorless.
✔️ Some insulin suspensions, including NPH and certain premixed preparations, are expected to appear uniformly cloudy or milky after proper mixing according to the manufacturer's instructions.

Never use insulin if its appearance is inconsistent with the product instructions or if it contains unexpected clumps, particles, or discoloration.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 10: Insulin

Insulin is a hormone naturally produced by the pancreas. It helps lower blood glucose by increasing glucose uptake into insulin-sensitive tissues such as muscle and fat, while also reducing glucose production by the liver. It promotes the storage of glucose for later use.

Insulin is also available as a medicine and is essential for people with type 1 diabetes, because their bodies produce little or no insulin. People with type 2 diabetes may also need insulin. It may be started when blood glucose is very high, when symptoms of significant high blood glucose are present, when there are signs of severe insulin deficiency such as unexpected weight loss or ketosis, or when adequate blood glucose control cannot be achieved with other treatments.

Insulin preparations are commonly classified according to how quickly they start working and how long their effects last.
✅ Rapid-acting insulin — starts working quickly and is commonly used around mealtimes. Examples include insulin lispro, insulin aspart, and insulin glulisine.
✅ Short-acting insulin — includes regular human insulin, which generally starts working more slowly than rapid-acting insulin.
✅ Intermediate-acting insulin — NPH insulin is the main example.
✅ Long-acting insulin — provides longer-lasting basal insulin coverage. Examples include insulin glargine and insulin degludec.
✅ Premixed insulin — contains combinations of different types of insulin in a single preparation.

Insulin lowers blood glucose by:
✅ Increasing glucose uptake into muscle and fat cells.
✅ Reducing glucose production by the liver.
✅ Promoting storage of glucose as glycogen for later use.

The most important adverse effect of insulin is hypoglycemia (low blood glucose). Symptoms may include:
✅ Shaking
✅ Sweating
✅ Hunger
✅ Dizziness
✅ Weakness
✅ Fast heartbeat
✅ Confusion

Severe hypoglycemia can cause seizures, loss of consciousness, and may be life-threatening. People using insulin should be educated about preventing, recognizing, and treating hypoglycemia.

Insulin may also cause weight gain in some people.

The type of insulin, dose, timing, and method of administration should be individualized by a qualified healthcare professional.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 9: Alpha-Glucosidase Inhibitors

Alpha-glucosidase inhibitors are a class of oral diabetes medicines used mainly to help control type 2 diabetes. They are particularly useful for reducing the rise in blood glucose that occurs after meals.

The main medicines in this class include:
✅ Acarbose
✅ Miglitol

These medicines work mainly in the small intestine. They inhibit enzymes called alpha-glucosidases, which help break down complex carbohydrates into smaller sugars that can be absorbed.

By slowing carbohydrate digestion and delaying glucose absorption, they reduce and delay the rise in blood glucose after eating.

Alpha-glucosidase inhibitors:
✅ Mainly help control after-meal blood glucose.
✅ Have a low risk of hypoglycemia when used alone.
✅ Are generally weight-neutral.

Because these medicines slow carbohydrate digestion, more undigested carbohydrates reach the large intestine, where bacteria ferment them. This can cause:
✅ Gas (flatulence)
✅ Abdominal bloating
✅ Abdominal discomfort
✅ Diarrhea

These gastrointestinal effects can often be reduced by starting with a low dose and increasing it gradually.

✔️If hypoglycemia occurs while an alpha-glucosidase inhibitor is being used together with insulin or a medicine such as a sulfonylurea, pure glucose (dextrose) should be used to treat the low blood glucose rather than ordinary table sugar (sucrose). This is because these medicines slow the breakdown of sucrose, which can delay the correction of hypoglycemia.

✔️These medicines are generally taken with meals, usually with the first bite of the meal.

✔️People with significant kidney or liver problems may not be suitable for these medicines, so their use should be determined by a qualified healthcare professional.

These medicines are not suitable for everyone, and the choice of diabetes medicine should be individualized based on the person's health conditions, treatment goals, other medicines, and risk of side effects.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 8: DPP-4 Inhibitors

DPP-4 inhibitors are a group of oral diabetes medicines mainly used to treat type 2 diabetes.

DPP-4 means dipeptidyl peptidase-4. It is an enzyme in the body that normally breaks down two natural hormones called GLP-1 and GIP. These hormones help the body control blood sugar after eating. By blocking the DPP-4 enzyme, these medicines allow GLP-1 and GIP to remain active for longer, helping the body control blood glucose.

Examples of DPP-4 inhibitors include:
✅ Sitagliptin
✅ Saxagliptin
✅ Linagliptin
✅ Alogliptin
✅ Vildagliptin

DPP-4 inhibitors block the DPP-4 enzyme, which normally breaks down GLP-1 and GIP. When these hormones remain active for longer, they help:
✅ Increase insulin release when blood glucose is high.
✅ Reduce the release of glucagon, a hormone that normally increases blood glucose.

DPP-4 inhibitors generally:
✅ Have a low risk of hypoglycemia (low blood sugar) when used alone.
✅ Are generally weight-neutral, meaning they usually do not cause significant weight gain or weight loss.
✅ Are available as oral medicines.
✅ Are generally well tolerated by most people.

Possible side effects include:
✅ Headache
✅ Nasopharyngitis (common cold-like symptoms)
✅ Mild stomach or digestive problems

Rare but important side effects have also been reported, including acute pancreatitis (inflammation of the pancreas), severe joint pain, and serious allergic reactions.

✔️ Severe or persistent abdominal pain should be medically evaluated.
✔️ Some DPP-4 inhibitors require dose adjustment in people with reduced kidney function.
✔️ Linagliptin is different because it generally does not require a dose adjustment for reduced kidney function.
✔️ Saxagliptin should be used cautiously in people with heart failure because an increased risk of hospitalization for heart failure was observed in a major clinical trial.

When DPP-4 inhibitors are combined with medicines such as sulfonylureas or insulin, the risk of hypoglycemia (low blood sugar) may increase.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 6: GLP-1 Receptor Agonists and Related Medicines

GLP-1 receptor agonists (GLP-1 RAs) are a class of medicines used mainly to treat type 2 diabetes. They can also help with weight management and, with certain medicines, provide cardiovascular and kidney benefits. GLP-1 stands for glucagon-like peptide-1, a hormone involved in blood glucose regulation, appetite, and digestion.

Examples include:
✅ Semaglutide
✅ Dulaglutide
✅ Liraglutide
✅ Exenatide
✅ Lixisenatide

Tirzepatide is a related medicine. It is a dual GIP and GLP-1 receptor agonist, meaning it acts on two hormone pathways involved in glucose regulation and appetite.

Most GLP-1 receptor agonists are given by subcutaneous injection. Oral semaglutide is an important exception.

GLP-1-based medicines work as follows:
✅ Increase insulin release when blood glucose is elevated.
✅ Reduce glucagon release.
✅ Slow gastric emptying, helping reduce rises in blood glucose after meals.
✅ Reduce appetite and food intake, which can lead to weight loss.

The most common side effects are:
✅ Nausea
✅ Vomiting
✅ Diarrhea
✅ Constipation
✅ Abdominal discomfort

These effects are often more noticeable when treatment is started or the dose is increased.

People with significant gastrointestinal problems, particularly severe gastroparesis, may not be suitable for some GLP-1-based medicines.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 5: SGLT2 Inhibitors

SGLT2 inhibitors are a class of medicines used mainly in the treatment of type 2 diabetes. Some members of this class are also used to treat heart failure and chronic kidney disease, even in some people who do not have diabetes.

SGLT2 stands for sodium-glucose cotransporter 2. These medicines work mainly in the kidneys. Common members include:
✅ Dapagliflozin
✅ Empagliflozin
✅ Canagliflozin
✅ Ertugliflozin

Normally, the kidneys filter glucose from the blood and then reabsorb most of it back into the bloodstream. SGLT2 inhibitors block much of this glucose reabsorption in the kidneys. As a result, more glucose is passed out of the body through urine, helping to lower blood glucose.

They also increase the amount of sodium and water passed out in the urine. This contributes to some of their effects on the heart and kidneys.

SGLT2 inhibitors can provide important heart and kidney benefits in appropriate people. They can:
✅ Reduce the risk of hospitalization for heart failure.
✅ Help slow the progression of chronic kidney disease in appropriate patients.
✅ Reduce the risk of certain cardiovascular and kidney complications in selected people.

These benefits may occur even when blood glucose is already close to the person's individual treatment goal.

Common side effects

Because these medicines increase glucose in the urine, they can increase the risk of:
✅ Ge***al fungal infections
✅ They may also cause:
-Increased urination
-Dehydration or low blood pressure, particularly in people who are already at risk of fluid loss.
✅ Urinary tract infections can occur, although the increase in risk is less consistent than it is for ge***al fungal infections.

✅ SGLT2 inhibitors can rarely cause a serious condition called diabetic ketoacidosis (DKA). Importantly, DKA can sometimes occur even when blood glucose is not extremely high. This is known as euglycemic diabetic ketoacidosis. The risk can increase during situations such as severe illness, prolonged fasting, dehydration, or significant insulin deficiency.

Healthcare professionals may advise temporarily stopping an SGLT2 inhibitor during certain illnesses or before some surgical procedures.

SGLT2, are not suitable for everyone. The choice of medicine should be individualized based on factors such as kidney function, other health conditions, treatment goals, and the risk of side effects.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 4: Meglitinides

Meglitinides are a group of diabetes medicines used mainly to help control blood glucose in people with type 2 diabetes. They are also called insulin secretagogues because they stimulate the pancreas to release more insulin.

Common examples include:
✅ Repaglinide
✅ Nateglinide

Meglitinides stimulate the beta cells of the pancreas to release insulin. They act relatively quickly and have a shorter duration of action than most sulfonylureas. Their action is therefore closely related to meals and helps control the rise in blood glucose after eating.

Because they require functioning pancreatic beta cells to work, meglitinides cannot replace insulin therapy in people with type 1 diabetes.

The main concern is hypoglycemia (low blood glucose), although the risk can vary depending on the medicine, dose, meals, and other factors. Symptoms may include:
✅ Shaking or trembling
✅ Sweating
✅ Hunger
✅ Dizziness
✅ Confusion
✅ Weakness or unusual tiredness

Like Sulfonylureas, meglitinides can also cause weight gain.

Because their action is closely related to meals, it is important to follow the prescribed instructions about when to take the medicine in relation to meals. If you are unable to eat or are experiencing repeated episodes of low blood glucose, seek advice from a qualified healthcare professional.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 3: Sulfonylureas

Sulfonylureas are a class of diabetes medicines used mainly to treat type 2 diabetes. They belong to a group of medicines called insulin secretagogues because they stimulate the pancreas to release more insulin.

Common sulfonylureas include:
✅ Glibenclamide (glyburide)
✅ Glipizide
✅ Gliclazide
✅ Glimepiride

Sulfonylureas stimulate the beta cells of the pancreas to release more insulin. The increased insulin helps lower the amount of glucose in the blood.

Because sulfonylureas depend on functioning pancreatic beta cells, they cannot replace insulin therapy in people with type 1 diabetes.

The most important side effect is hypoglycemia (low blood glucose). Symptoms may include:
✅ Shaking or trembling
✅ Sweating
✅ Hunger
✅ Dizziness
✅ Confusion
✅ Weakness or unusual tiredness

Severe hypoglycemia can cause seizures, loss of consciousness, and can be life-threatening.

Sulfonylureas can also cause weight gain. The risk of hypoglycemia may be greater in older adults and people with reduced kidney function.

Glibenclamide (glyburide) is generally not recommended in people with chronic kidney disease because of its higher risk of prolonged hypoglycemia.

Although sulfonylureas can effectively lower blood glucose, they are not the preferred choice for everyone because of their risk of hypoglycemia and weight gain.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.

Know About Your Diabetes Medicines

Post 2: Metformin

Metformin is one of the most commonly used medicines for managing type 2 diabetes.

It belongs to a group of diabetes medicines called biguanides. Metformin is the main biguanide currently used in routine medical practice.

MoA - Metformin works by:

✅ Reducing the amount of glucose (sugar) produced by the liver.
✅ Helping the body respond better to insulin, so the body can use insulin more effectively.

When used alone, metformin generally has a low risk of causing hypoglycemia (low blood sugar) and usually does not cause weight gain. Some people may experience modest weight loss.

Metformin can be used alone or combined with other diabetes medicines when additional blood sugar control or other treatment benefits are needed.

The most common side effects involve the digestive system and may include:
✅ Nausea
✅ Diarrhea
✅ Abdominal discomfort
✅ Bloating

Taking metformin with food and gradually increasing the dose can help reduce these effects. The extended-release (ER/XR) form may also cause fewer stomach-related problems in some people.

✅ Metformin is removed from the body mainly through the kidneys, so kidney function is important when using this medicine.

Metformin should not be used when kidney function is severely reduced, generally when eGFR is below 30 mL/min/1.73 m².

It generally should not be started when eGFR is below 45 mL/min/1.73 m², and the dose and continued use should be carefully reviewed if kidney function falls below 45.

eGFR is a blood-test measure used to estimate how well the kidneys are working.

Long-term use of metformin can be associated with vitamin B12 deficiency. A healthcare professional may recommend checking vitamin B12, especially in people with anemia (low blood count) or nerve problems such as numbness or tingling.

A serious complication called lactic acidosis is very rare, but the risk is higher in certain situations, particularly severe kidney impairment and some acute illnesses.

NB: Metformin is an important medicine for many people with type 2 diabetes, but it is not suitable for everyone. The choice and dose should be based on the person's health, kidney function, other medical conditions, treatment goals, and how well the medicine is tolerated.

Disclaimer: This post is for health education only and is not a substitute for medical advice. Do not start, stop, or change any diabetes medicine without consulting a qualified healthcare professional.