Oral hypoglycemics 2 - slides 18 to 47 Flashcards

1
Q

What are biguanides?

A

AMP dependent protein kinase activators
They decrease hepatic glucose production, increase fatty acid oxidation, and increase peripheral glucose uptake and utilization by increasing tissue insulin sensitivity
They also decrease glucose absorption from the GI tract
(Metformin)

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2
Q

True or False: Biguanides increase insulin release

A

False, they decrease glucose production in the body and increase glucose uptake

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3
Q

True or False: Biguanides have a high incidence of hypoglycemia

A

False, they have limited hypoglycemia

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4
Q

Indications for biguanides?

A

Impaired glucose tolerance (to slow progression to diabetes)
Off label to improve cycling, ovulation, and decrease androgens in PCOS
Also used in T2 diabetes obvi as monotherapy

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5
Q

Pharmacokinetics of metformin?

A

Not metabolized in the liver
Not bound to proteins
Excreted unchanged by kidneys via renal tubular excretion

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6
Q

Cautions with metformin?

A

Contraindicated in hepatic disease due to lactic acid formation
Not used in renal impairment bc depends on kidneys for excretion

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7
Q

Side effects of metformin?

A

Weight loss possible
GI: unpleasant or metallic taste, anorexia, constipation, diarrhea, heartburn
Lactic acidosis: Increased incidence in renal impairment, aging, and after surgery
Rash
Megaloblastic anemia (decreased VB12 absorption)

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8
Q

Contraindications for Metformin?

A

Heart failure (MI)
Renal disease
Metabolic acidosis or hypoxia
Hepatic disease
Severe pulmonary disease
Cationic drugs compete for tubular excretion
Should be stopped before surgery and radiographic procedures using contrast dies (withhold drug for 48 hours after surgery due to increased lactic acid)

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9
Q

What are Thiazolidinediones?

A

Pioglitazone
Rosiglitazone (limited by CV toxicity)
Troglitazone (removed bc liver toxicity)

They are peroxisome proliferator activated receptor gamma (PPAR gamma receptor activators)

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10
Q

Mechanism of Thiazolidinediones?

A

Selective and potent agonists for peroxisome proliferated activated recepotr gamma

PPAR-Y regulates insulin responsive genes
Genes involved in lipid and glucose metabolism

They increase uptake of fatty acids into fat cells and muscle to decrease triglycerides. Also increase tissue sensitivity to insulin

Also increase peripheral glucose uptake and utlization, increasing tissue insulin sensitivity ~60% and decreasing hepatic glucose production

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11
Q

Pharmacokinetics of Thiazolidinediones?

A

Highly protein bound, metabolized by the liver (Pio CYP2C8 and 3A4, Ros CYP2C8 and 2C9)

Maximal effect requires 6-12 weeks bc you’re depending on gene transcription changes

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12
Q

Adverse effects of Thiazolidinediones?

A

Weight gain (2-4 kg first year)
Expanded blood volume, edema (10%) - macular edema, yearly retinal exams
Respiratory tract infections
Headache, fatigue, muscle pain
Increased HDL, LDL, decreased TG
Monitor liver enzymes every 2 months for first year, stop drug if ALT is over 3x normal
Increased bone fracture risk

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13
Q

Which thiazolidinediones had to undergo further study? For what? What was the result?

A

Rosiglitazone further studied for CV effects, end result was it could increase MI risk so it was put under a restricted access program to ensure patients knew the risk of taking the drug

However, further studies showed there was no difference in increased risk of CV event versus other oral diabetes drugs

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14
Q

Cautions with Pioglitazone?

A

Increased bladder cancer risk

Lots of law suits filed/settled over bladder cancer

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15
Q

What is the “Incretin” effect?

A

Taking oral glucose vs IV glucose, incretin effect increases glucose levels when taken PO route

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16
Q

What are incretins?

A

Glucagon-like-peptide-1
GLP is secreted from the L-cells of the intestine
This increases glucose dependent insulin release from the pancreas
Decreases gastric emptying and food intake

17
Q

What does GLP-1 do?

A

Stimulates release, biosynthesis, and gene transcription of insulin

In alpha cells: Decreases postprandial glucagon secretion
Liver: Decreased glucagon reduces hepatic glucose output
B cells: Enhances glucose-dependent insulin secretion
Stomach: Helps regulate gastric emptying
Brain: Promotes satiety and reduces appetite

18
Q

How is GLP-1 metabolized?

A

By dipeptidyl peptidase (DPP-IV)

19
Q

How is GLP-1 release affected in diabetes?

A

Release of GLP-1 is impaired in pts with T2DM

20
Q

What is Exenatide?

A

Isolated from the saliva of gila monster

53% homology with GLP-1

21
Q

Indications for Exenatide?

A

Type 2 diabetics taking metformin AND sulfonylureas or combination and not controlled

22
Q

Adverse effects of exenatide?

A
Can cause weight loss
Nausea and vomiting (decreases over time)
Hypoglycemia with sulfonylureas
Delays absorption of other oral meds
Concern for pancreatitis
23
Q

How is exenatide administered?

A
5-10 mcg twice daily 0-60 mins before meals
SubQ injection (prefilled pen injectors)
24
Q

How does exenatide affect insulin response?

A

It comes the closest to having a biphasic insulin response

25
Q

True or False: Exenatide is only available as a once daily injection

A

False, bydureon is a long acting once weekly formulation

26
Q

Cautions with Exenatide?

A

Black box warning for medullary thyroid carcinoma (MTC)

Company must do follow up studies

27
Q

What is Liraglutide?

A

Human GLP-1 analog linked to fatty acids, binds albumin to be released slowly

28
Q

How does the half life of Liraglutide compare to Exenatide?

A

Liraglutide is 12 hours, Exenatide is 10-12 hours

29
Q

Administration of Liraglutide?

A

Once daily SubQ injections

30
Q

Adverse effects of Liraglutide?

A
N/V
Hypoglycemia
Allergic rxn
Pancreatitis
Headache
Dizziness
Thyroid tumor**** FDA looked into this
31
Q

What is Albiglutide?

A

Once weekly SubQ GLP-1 receptor agonist

2 GLP-1 molecules fused to albumin

32
Q

What is Dulaglutide?

A

Once weekly SubQ GLP-1 receptor agonist

Modified GLP-1 molecule resistant to DPP4

33
Q

What is Lixinsenatide?

A

GLP-1 receptor agonist
FDA approval on hold for further studies
Resubmitted to FDA fall 2015

34
Q

What is Semaglutide?

A

Once weekly GLP-1 receptor agonist
Completing phase 3 clinical trials
Also undergoing phase 2 trials as an oral agent
Combined with absorption enhancing excipient Salcaprozate carrier agents to enhance oral absorption

35
Q

Adverse effects of GLP-1 agonists?

A
N/V
hypoglycemia
pancreatitis
Headache
Dizziness
Thyroid tumors