Chapter 32 Antidiabetic Drugs

Question 1

Insulin

Answer 1

• Primary treatment for Type 1 diabetes
• Functions as a substitute for the endogenous hormone therefore it has the same effects as normal endogenous insulin
• Metabolizes carbohydrates, fats, and proteins, stores glucose in the liver, and converts glycogen to fat stores.
• Some are derived from porcine sources, but most are now human derived by using recombination DNA technologies.
• Only drug recommend during pregnancy
• Special dosing guidelines for children

Question 2

Types of insulin

Answer 2

• Rapid acting (onset of 10-15 minutes): insulin aspart (NovoRapid) and insulin lispro (Humalog)
• Short acting (onset of 30-60 minutes): Humulin R, Novolin ge Toronoto
• Intermediate acting (slower onset and prolonged duration): insulin isophane/NPH (Humulin-N, Novolin ge NPH)
• Long acting: insulin glargine (Lantus) and insulin detemir (Levemir)

Question 3

Adverse effects and interactions of insulin

Answer 3

Adverse effects include: hypoglycemia, tachycardia, palpitations, headache, blurred vision, dry mouth, hunger, lethargy, and tremors

• Interactions include: B-blockers, corticosteroids, EPI, Lasix, thyroid hormones will reduce effects in insulin which results in an increased blood glucose levels.
• Interactions: sulfa drugs, alcohol, ACE inhibitors, MAIOs, propanolol, anabolic steroids will increase effects in insulin which results in an decreased blood glucose levels.

Question 4

Oral Antihyperglycemics

Answer 4

• Typically used for type 2 diabetes. Insulin resistance, ongoing reduction in β cells
• Target is to lower A1C (less than 7%)
• Patients are also recommended lifestyle modifications
• Combination therapy is recommended if A1C exceeds 9% (Two drugs from two different classes)

Question 5

Sulfonylureas

Answer 5

• gliclazide (second generation - typically used)
• Stimulate insulin secretion from beta cells so there needs to be functioning cells
• Enhance action of insulin in muscle, liver, adipose tissue and Prevent liver from breaking down insulin as fast

Question 6

Gliclazide (sulfonylureas)

Answer 6

• Interactions: Alcohol (Alcohol may cause a reaction similar to Antabuse - induced vomiting and hypertension), anabolic steroids, β blockers, chloramphenicol, MAOI’s, oral anticoagulants, sulfonamides, garlic, and ginseng will increse the effect leading to hypoglycemia
  Interactions: Adrenergics, corticosteroids, thiazides, and thyroid drugs will decrease the effect
• Contraindications: liver and kidney failure, Active hypoglycemia, Not used in pregnancy

Question 7

Biguanides

Answer 7

• Metformin
• Does not increase insulin secretion from pancreas and therefore does not cause hypoglycemia
• Reduces glucose production/gluconeogenesis
• Reduced triglycerides & cholesterol
• Decreases intestinal absorption of glucose
• Improves glucose uptake by skeletal muscle, adipose, liver

Question 8

Metformin

Answer 8

• May be used in combination with sulfonylureas or thiazolidinediones when monotherapy & lifestyle measure are not successful
• Adverse Effects: Mainly GI: bloating, nausea, cramping, diarrhea. Also a Metallic taste, and a reduction in vitamin B12
• Concentrations increased when given with furosemide and nifedipine, cimetidine and digoxin
• Discontinue metformin 48hrs before undergoing radiological study that requires radioactive iodine based dye. This may leads to kidney failure and lactic acidosis

Question 9

Glucose elevating

Answer 9

• Used in the event of hypoglycemia
• Concentrated Glucose: Rapidly dissolving buccal tablets given and semisolid gels for oral use; better than regular sugar
• Intravenous glucose solutions up to 50%
• Glucagon: a natural hormone given by injection
• Diazoxide: useful for long-term illness such as pancreatic cancer (oral)
• Monitor blood glucose levels