Lecture 1: Drugs for Diabetes Flashcards
List the 3 rapid-acting insulin agents
- Aspart
- Lispro
- Glusine
What is the drug that is an intermediate-acting insulin called?
Neutral Protamine Hagerdorn (NPH)
What are the 2 long-acting insulins?
- Detemir
- Glargine
Which mutations from the human sequence of insulin allow for fast absorption of the rapid-acting insulin drugs?
Block assembly of dimers and hexamers
What is the clinical use for the rapid-acting insulin drugs, aspart, lispro, and glulisine; how are they administered?
Post-prandial hyperglcemia - take before meal via SQ injections
What makes the absorption rate of short-acting, regular insulin, slower and less predictable?
Form hexamers, which are too bulky to be transported via endothelium into the blood stream
List 4 clinical uses for using short-acting, regular insulin?
- Basal insulin maintenance
- Overnight coverage
- Postprandial hyperglycemia - but must inject 45 min before meal
- Can be given IV in urgent situations
What is the composition of the intermediate-acting insulin, neutral protamine hagerdon, and how does this relate to its pharmacokinetics?
- Complex of protamine w/ zinc insulin
- Protamine has to be digested by tissue proteolytic enzymes before insulin can be absorbed
What is the clinical use of the intermediate-acting insulin, neutral protamine hagerdon (NPH)?
- Basal insulin maintenance and/or overnight coverage
- Use is declining due to being replaced by long-acting insulins
What is the molecular composition of the long-acting insulin, Detemir, and how is this related to its pharmacokinetics?
- Lys 29 in B chain is myristoylated (lipid)
- Rapid absorbed into blood but binds strongly to albumin
What is the molecular composition of the long-acting insulin, Glargine, and how is this related to its pharmacokinetics?
- AA substitution in both A and B chains enhance crystal stability, change pKA of insulin
- Soluble at low pH (4) but precipitates at pH 7
What is the clinical use of the long-acting insulins, Detemir and Glargine; how are they administered?
- Basal insulin maintenance
- 1-2 SQ injections daily
How does the peak of actions differ between the long-acting insulin Detmir and Glargine?
- Detemir peaks from 3-9 hours
- Glargine is peakless!
Which drugs are given for severe hyperkalemia and explain why each is given?
- Insulin (IV) + glucose (to prevent hypoglycemic shock) + furosemide
- Insulin (IV) rapidly activates Na/K-ATPase to shift K+ into cells
- K+ is eliminated from the body using the loop diuretic, furosemide
List some potential AE’s of using insulin drugs.
- Hypoglycemia = most common
- Lipodystrophy
- Resistance
- Allergic rxns —> immediate type hypersensitivity = rare
- Hypokalemia
How can resistance to exogenous insulin develop?
- Pt’s commonly develop insulin binding antibodies
- IgG antibodies can neutralize the action of insulin
What are 3 common causes of hypoglycemia as an AE in patient on insulin therapy?
- Delayed of meal or a missed meal
- Exercise —> ↑ consumption of glucose by muscle + hyperemic skin has ↑ rate of insulin absorption
- Overdose of insulin
What is used in the tx of hypoglycemia as a complication of insulin therapy?
- Glucose: juice or candy if conscious; IV glucose if unconscious
- Diazoxide: inhibits release of insulin by beta cells
- Glucagon (SQ)
What is the MOA of diazoxide and why is it used for hypoglycemia induced by insulin therapy?
- Strong hyperglycemic agent –> K+-ATPchannelopener
- Inhibits release of insulin by beta cells
Where is amylin secreted from and what is the amylin analog used for diabetics?
- Pancreatic β-cells
- Amylin analong drug = Pramlintide
List 4 actions of amylin secreted by pancreatic β-cells
- Inhibits glucagon secretion
- Enhances insulin sensitivity
- ↓ gastric emptying (slows rate of intestinal glucose absorption)
- Causes satiety
What are the clinical uses for the amylin analog, Pramlintide; how is it administered?
- T1DM
- T2DM pt’s who take mealtime insulin therapy
- Injected SQ before mals as an ajunct to insulin therapy
What are some of the AE’s associated w/ the amylin analog, Pramlintide?
- GI: nausea, vomiting, diarrhea, anorexia
- Severe hypoglycemia: especially if used together w/ insulin (↓ dose of insulin)
What is a drug interaction you must be aware of when using the amylin analog, Pramlintide?
Enhances effects of anticholinergic drugs in GI tract –> Constipation
What are 2 ligands for GPCR-Gs which enhance the secretion of insulin?
- β2-AR agonists
- GLP-1 receptor agonists (incretins)
What are 2 ligands for GPCR-Gi which inhibit the secretion of insulin?
- Somatostatin
- α2-AR agonists (remember α2 uses a Gi)
Which cells synthesize and secrete GLP-1?
Intestinal L-cells
What are 5 actions of the incretin, GLP-1?
- Promotes β-cell proliferation + insulin gene expression + glucose-dependent insulin secretion
- Inhibits glucagon secretion
- Causes satiety, by inhibiting gastric emptying
What are the 2 long-acting GLP-1 receptor agonists used for diabetes?
- Exenatide
- Liraglutide