PTCB Guide to Antidiabetic Drugs.

Diabetes as a Topic of the PTCB Exam.

There are more than 40 million people with diabetes throughout the United States, and almost half a billion cases globally.

Diabetes is set to rocket further in the years and decades ahead. Almost 1 in 5 Americans are expected to be diabetic by 2060, if the current trend continues.

Diabetes type 2 is a condition that, in the long term, can affect multiple organ systems. For example, diabetes can lead to:

• Vision loss / blindness
• Increased risk of heart attacks and strokes
• Kidney damage / kidney failure
• Nerve damage, potentially leading to limb amputation

Though lifestyle changes, such as weight loss and regular exercise and an improved diet, are highly beneficial in patients with type 2 diabetes, many patients require drugs to help lower blood sugar levels and manage this chronic condition.

For the PTCB exam, pharmacy technicians are required to know all major antidiabetic drug classes:

• To be able to identify drugs from major drug classes
• To understand, on a basic level, how each drug class works
• To know which insulins are rapid-acting, intermediate-acting, and long-acting
• To identify significant side effects or adverse reactions
• To learn any significant drug interactions
• To be able to identify brand names of the most common antidiabetic drugs.

Pharmacy technicians are not required to master detailed mechanisms of action or make clinical decisions regarding diabetes treatment. To study efficiently, focus on the major adverse effects, key safety concerns, and notable drug interactions that are most likely to be tested.

Later in this guide, we will review sample PTCB exam-style questions to help you understand the standard, difficulty, and level of knowledge expected on this topic. For now, we’ll concentrate on the essential diabetes medications and the high-yield facts technicians need to know.

Antidiabetic Drug Classes.

There are six major antidiabetic drug classes that pharmacy technicians are required to study for the PTCB exam:

• Insulins
• Sensitizers
• Alpha-glucosidase inhibitors
• Peptide analogs
• Glycosurics
• Secretagogues

Insulins.

Insulin is used to help replace insulin in patients with type 1 diabetes and to control blood glucose levels in patients with type 2 diabetes.

There are four major insulin classes, depending on their duration of effect:

Insulin Class	Examples
Rapid acting	Regular insulin Lispro Aspart Glulisine
Intermediate-acting	Isophane insulin Insulin zinc
Long-acting	Insulin glargine Insulin detemir
Ultra long-acting insulin	Degludec Glargine U300

• Rapid-acting insulins (such as insulin lispro and insulin aspart) are used around mealtimes to control postprandial glucose, while short-acting insulin (Regular Insulin) has a slightly slower onset.
• Intermediate-acting insulin (NPH insulin) provides coverage for part of the day, whereas long-acting insulins (such as insulin glargine and insulin detemir) provide relatively steady basal insulin levels over an extended period.
• Insulin lowers blood glucose by facilitating cellular glucose uptake, particularly in muscle and adipose tissue, while also suppressing hepatic glucose production.
• The most significant adverse effect is hypoglycemia, characterized by symptoms such as sweating, tremor, palpitations, confusion, and, in severe cases, seizures or loss of consciousness.
• Some insulin formulations are clear solutions, while others, such as NPH insulin, are cloudy suspensions that require gentle mixing before administration.

Sensitizers.

As the name suggests, sensitizers are drugs that increase the body’s sensitivity to insulin – making it more effective at controlling blood sugar levels in affected patients.

There are two major sensitizer classes:

• Biguanides – which includes the drug metformin
• Thiazolidinediones – which includes drugs such as pioglitazone

Metformin is the most prescribed drug for patients with type 2 diabetes:

• Unlike many other antidiabetic drugs, it does not cause weight gain.
• In some patients, it can even cause weight loss. This makes the drug particularly effective for patients whose type 2 diabetes is linked to obesity.
• Common side effects include GI-related effects such as nausea and diarrhea. Many patients report experiencing a metallic taste (remember: metformin = metallic taste!).
• Lactic acidosis is a rare adverse effect of metformin, and this risk increases in cases of acute alcohol intoxication.
• Metformin must also be withheld for 48 hours before/after the use of IV contrast media to help prevent kidney damage and lactic acidosis.
• Long-term use of metformin is associated with vitamin B12 deficiency.

Glitazones – such as pioglitazone and rosiglitazone – work by activating PPAR-gamma. However, their use is associated with an increased risk of cardiovascular events, such as heart attack and stroke.

Alpha-glucosidase inhibitors.

Alpha-glucosidase are less likely to be used to manage type 2 diabetes, but they are typically used when first-line drugs have proven insufficient.

Examples:

• Acarbose
• Miglitol

Type 2 diabetes invariably centers around blood sugar levels. Carbohydrates are nutrients which when digested, metabolize into sugars. Alpha-glucosidase inhibitors are drugs that slow carbohydrate metabolism, thereby slowing the rate of sugar absorption into the body. This reduces the risk of elevated high blood sugar (hyperglycemia).

Side effects are gastrointestinal related and include bloating, flatulence, and diarrhea.

Peptide analogs.

Peptides are short chains of amino acids linked by chemical bonds called peptide bonds.

Analogs of peptides are effective in the treatment of type 2 diabetes. These include drugs such as:

• GLP-1 agonists – liraglutide, exenatide, semaglutide
• DPP-4 inhibitors – saxagliptin, linagliptin, sitagliptin

Both GLP-1 agonists and DPP-4 inhibitors promote the release of insulin from the pancreas; the pancreas being the organ responsible for the synthesis and release of the insulin hormone.

Glycosurics.

First, let’s break down the drug class name: – glycos, referring to sugar, and –uric, referring to elimination, such as through the urine.

And that’s exactly how glycosuric drugs work. They promote the elimination of sugar through urine from the body. This helps to lower blood sugar levels in patients with type 2 diabetes.

The major glycosuric drug class are SGLT-2 inhibitors.

Examples include:

• Dapagliflozin (Farxiga)
• Empagliflozin (Jardiance)
• Canagliflozin (Invokana)
• Ertugliflozin (Steglatro)

Note that SGLT-2 inhibitors can be readily identified because they all end with the suffix –flozin.

Possible adverse effects of SGLT-2 inhibitors include an increased risk of urinary tract infections, elevated cholesterol, thirst, hypoglycemia, and an increased risk of diabetic ketoacidosis.

In rare cases, SGLT-2 inhibitors can cause Fournier gangrene; a rare but life-threatening necrotizing soft tissue infection of the genital, perineal, or perianal region that rapidly destroys tissue and requires emergency surgical treatment and antibiotics.

Secretagogues.

As the name suggests, secretagogues help the body secrete – or release – insulin from the pancreas.

Examples of secretagogue drug classes include:

• Sulfonylureas – glipizide, glyburide, gliclazide
• Meglitinides – rapeglinide, nateglinide

Both sulfonylureas and meglitinides act at the same target in the pancreas – namely, pancreatic beta cells (just they act at different sites on these cells).

One of the drawbacks of both sulfonylureas and meglitinides is that they can cause weight gain, which may prove problematic in patients whose type 2 diabetes was caused by obesity.

Sample PTCB Exam Questions.

Below you can find five sample PTCB exam questions on the topic of antidiabetic drugs.

These five questions reflect the type of questions that get tested about antidiabetic drugs on the exam – both the style and difficulty. As always, have a go at the questions yourself before comparing your answers with the explanations (in the section below).

Question 1.

A patient taking an insulin product reports shakiness, sweating, and confusion. Which adverse effect is most likely occurring?

a. hyperglycemia

b. hypoglycemia

c. pancreatitis

d. ketoacidosis

Question 2.

What is the active ingredient of the medicine, Invokana?

a. liraglutide

b. pioglitazone

c. semaglutide

d. canagliflozin

Question 3.

All the following side effects are associated with metformin, except?

a. weight gain

b. vitamin B12 deficiency

c. lactic acidosis

d. metallic taste

Question 4.

Identify the rapid-acting insulin from the following list:

a. insulin detemir

b. isophane insulin

c. insulin lispro

d. insulin glargine

Question 5.

Which of the following antidiabetic drugs works by inhibiting the DPP-4 enzyme?

a. saxagliptin

b. exenatide

c. glipizide

d. nateglinide

Answer Explanations.

Answer to Question 1 – b. Hypoglycemia

Hypoglycemia is the most common and clinically significant adverse effect of insulin therapy because insulin lowers blood glucose levels. It can occur if too much insulin is administered, a meal is missed or delayed, or physical activity increases unexpectedly, leading to symptoms such as sweating, tremor, dizziness, confusion, and, in severe cases, seizures or loss of consciousness.

Answer to Question 2 – d. Canagliflozin

Canagliflozin is the active ingredient of the medicine, Invokana. Canagliflozin belongs to the SGLT-2 inhibitor class of antidiabetic drugs. It works by promoting the elimination of glucose in the urine.

Answer to Question 3 – a. Weight gain

Metformin is one of the few antidiabetic drugs associated with weight loss rather than weight gain. This makes the drug particularly effective in patients whose type 2 diabetes is linked to obesity. Long-term use of metformin at high doses can cause vitamin B12 deficiency and lactic acidosis. Patients often report a metallic taste with metformin.

Answer to Question 4 – c. Insulin lispro

There are three rapid-acting insulins: lispro, aspart, and glulisine.

Insulins glargine and detemir are long-acting insulins, whereas isophane insulin is an example of an intermediate-acting insulin.

Answer to Question 5 – a. Saxagliptin

DPP-4 inhibitors all end in the suffix -gliptin. These drugs include saxagliptin, linagliptin, and sitagliptin. DPP-4 inhibitors work by encouraging the release of insulin from the pancreas.

PTCB Diabetes Cheat Sheet.

Antidiabetic Drug Class	Examples
Insulins Fast acting Intermediate acting Slow acting Ultra long acting	lispro, aspart, glulisine isophane insulin; insulin zinc glulisine degludec; glulisine U300
Sensitizers Biguanides Thiazolidinediones	metformin pioglitazone
Alpha-glucosidase inhibitors	acarbose              miglitol
Peptide Analogs GLP-1 agonists DPP-4 inhibitors	liraglutide; exenatide saxagliptin; linagliptin; sitagliptin
Glycosurics SGLT-2 inhibitors	empagliflozin; dapagliflozin
Secretagogues Sulfonylureas Meglitinides	glipizide; glyburide; gliclazide rapeglinide; nateglinide