Oral Anti-diabetic Medications

Mario Skugor, MD FACEEndocrine and Metabolic InstituteCleveland Clinic

Insulin secretaguages

Insulin sensitizers

Incretin based therapies

Alpha-glucosidase inhibitors

CNS acting

Long acting

Sulphonylureas

Liver

Metformin

PPD-4 inhibitors

Acarbose Bromocriptine

Short acting

Meglitinides

Muscle and Fat

Thiazolidinediones

Miglitol

Other

Bile acid sequestrants

Orlistat

CLASSES OF ORAL ANTIDIABETIC MEDICATIONS

In development

Dual PPAR gamma agonists

SGLT-2 antagonists

Insulin secretaguages

Insulin sensitizers

Incretin based therapies

Alpha-glucosidase inhibitors

CNS acting

Long acting

Sulphonylureas

Liver

Metformin

PPD-4 inhibitors

Acarbose Bromocriptine

Short acting

Meglitinides

Muscle and Fat

Thiazolidinediones

Miglitol

Other

Bile acid sequestrants

Orlistat

CLASSES OF ORAL ANTIDIABETIC MEDICATIONS

In development

Dual PPAR gamma agonists

SGLT-2 antagonists

Canagliflozin just approved.

METFORMIN

French lilac – used in folk medicine for centuries.

Synthesized in 1920s

In 1950 Metformin was used to treat influenca and noted to lower blood glucose to physiologic levels.

METFORMIN

• In 1957 first clinical trial of diabetes treatment was published in France

• Approved in 1958 in UK, 1972 in Canada and in 1995 in US.

METFORMIN

• Suppression of hepatic gluconeogenesis through activation AMP-activated protein kinase (AMPK).

• Improves glucose uptake in muscle and fat.

• Causes weight loss in some individuals.

• Improves menstrual cycle and fertility in PCOS

• May improve NASH.

• May reduce risk of range of different carcinomas

METFORMIN

• Comes in 500, 850 and 1000 mg pills.

• Extended release pills are available (but more expensive)

• Usual dose is 1000 mg twice a day.

• Main side effects is abdominal cramping and diarrhea

• Metformin extended release is better tolerated by some patients

• Even mild renal failure (Cr>1.4 in males and >1.5 in females) is contraindication for use

Metformin – Bottom line

• Clearly the first line.

• Cheap

• Improves physiology

• Has other benefits.

• Unfortunately, significant proportion of patients has contraindications or cannot tolerate it.

SULPHONYLUREAS

• Marcel Janbon and co-workers discovered hypoglycemic effect of sulfonylurea in 1942.

• They were studying sulfonamide antibiotics and discovered that the compound sulfonylurea induced hypoglycemia in animals

Sulphonylureas

• First sulfonylurea for treatment of DM introduced in 1955.

– General structure:

Sulphonylurea

• First generation – Binds to the proteins in the blood.

–Tolbutamide

–Chlorpropamide

–Tolazamide

–Acetohexamide

–Carbutamide

Sulphonylurea

• Second generation – Not bound to serum proteins.

–Glipizide

–Glyburide (glibenclamide)

–Gliclazide

– Glibornuride

– Gliquidone

– Glisoxepide

– Glyclopyramide

Sulphonylurea

• Third generation

– Glimepiride

SUFONYLUREAS

Sulfonylurea

• Advantages

–Fast acting

–Once a day dosing

–Gliclazide may be particularly beneficial

• Disadvantages

–Risk of hypoglycemia

–Weight gain

–Possible problems with ischemic preconditioning

Glicilizide

• Inhibits platelet aggregation

• Associated with lower mortality from malignant neoplasms.

• Improves repair of DNA damage caused by oxidative stress in tissue cultures.

Sulfonylureas – Bottom line

• Fast acting

• Older ones are cheap

• Do not improve physiology

• Hypoglycemia is significant risk

• Require strict regime of diet

Meglitinides

• Nategelinde

• Repaglinide

• Act on same potassium channel as sulfonylurea but bind to different part of the molecule.

• Short acting – taken 0-30 min before meal.

• Risk of hypoglycemia is small

Meglitinides – Bottom line

• Useful in small number of patients for relatively short period of time.

• Allow for some flexibility in timing of the meals.

TZD-s – actually Pioglitazone

• The proliferator-activated receptor gamma (PPAR-γ) and to a lesser extent PPAR-α agonist in the muscle, adipose tissue, and the liver.

• Pioglitazone reduces insulin resistance in the liver and peripheral tissues.

• Pioglitazone decreases the level of triglycerides and increases HDL without changing LDL and total cholesterol.

• Pioglitazone - 15 - 30 - 45 mg pills

• Peripheral edema is main side effect.

• More hospitalizations for CHF in studies with all TZD-s

• Effect is maintained when combined with metformin and incretin based therapies.

Pioglitazone

Thiazolidinediones and bladder cancer.

Colmers IN, et al. CMAJ 2012I:10.1503

TZD-s and fracture risk

Toulis KA, et al. CMAJ, 2009, 180 (8) 841-842

TZD-s and fractures

TZD-s are associated with fractures in females over 50 years of age.In men risk is increased if TZD-s are used with loop diuretic

Bilik D, et al. JCEM. 2010 (10) 1210.

Bottom line on Pioglitazone

• Benefits are still higher than risks.

• There is some evidence that lower dose is not associated with risk of bladder cancer.

• However – at this time Metformin and PPD-4 inhibitors are clearly ahead of Pioglitazone as choices for treatment.

Incretins

• Gut-derived hormones, secreted in response to nutrient ingestion, that potentiate insulin secretion from islet cells in a glucose-dependent fashion, and lower glucagon secretion from islet cells

• Two predominant incretins:

– Glucagon-like peptide–1 (GLP-1)

– Glucose-dependent insulinotropic peptide (GIP) (also known as gastric inhibitory peptide)

• Incretin effect is impaired in type 2 diabetes

– Known as GLP-1 deficiency

Incretin system and DPP-4 physiologic action

Native GLP-1 is rapidly degraded by DPP-IV

Human ileum, GLP-1 producingL-cells

Capillaries,DPP-IV (Di-Peptidyl Peptidase-IV)

Adapted from: Hansen et al. Endocrinology 1999;140:5356–5363.

Double immunohistochemical staining for DPP-IV (red) and GLP-1 (green) in the human ileum

Slide Source:Lipids Online Slide Librarywww.lipidsonline.org

Glucagon-Like Peptide–1Glucagon-Like Peptide–1 Normalizes Normalizes Postprandial Hyperglycemia in Patients Postprandial Hyperglycemia in Patients with Type 2 Diabeteswith Type 2 Diabetes

Nauck MA et al. Acta Diabetol. 1998;35:117-129.

Time (h)

Pla

sma g

luco

se (

mg/d

l)

0

300

100

50

150

200

250

2 3 4 1 0 –1

Infusion

GLP-1 [7-36 amide] 1.2 pmol/kg/min

Placebo

Liquid meal

0

300

100

50

150

200

250

2 3 4 1 0 –1

Infusion

GLP-1 [7-36 amide] 1.2 pmol/kg/min

Placebo

Liquid meal

Pla

sma g

luco

se (

mg/d

l)

Healthy subjects T2DM patients

Time (h)

Slide Source:Lipids Online Slide Librarywww.lipidsonline.org

Continuous Continuous Glucagon-Like Peptide–1Glucagon-Like Peptide–1 Infusion Reduces Appetite over 6 WeeksInfusion Reduces Appetite over 6 Weeks

All data for patients treated with glucagon-like peptide–1 (n = 10).No changes in these parameters were observed in the saline group.

0

100

200

300

400

500

Mean (SE) AUC for Visual

Analogue Score (mm) vs Time (h)

Time (wk)

610

Zander M et al. Lancet. 2002;359:824–830.

Time (wk)

*Prospective food intake

*Hunger

*Satiety

*Fullness

*p<.05

Slide Source:Lipids Online Slide Librarywww.lipidsonline.org

Glycemic Control with GLP-1 Receptor Glycemic Control with GLP-1 Receptor Agonists in Head-to-Head Clinical TrialsAgonists in Head-to-Head Clinical Trials

*Significant difference vs comparator GLP-1 *Significant difference vs comparator GLP-1 receptor agonistreceptor agonist

1Buse JB et al. Lancet. 2009;374:39-47 | 2Drucker DJ et al. Lancet. 2008;372:1240-1250 | 3Blevins T, et al. J Clin Endocrinol Metab. 2011;96:1301-1310 | 4Buse JB et al. Presented at 47th EASD Annual Meeting, Lisbon, Portugal, 14 September 2011.

Trial:Size (N):

Study length (weeks):

LEAD-61

46426

DURATION-12

30330

DURATION-53

25424

DURATION-64

91226

-0.8

-1.5

-0.9

-1.3-1.1

-1.9

-1.6-1.5

-2.0

-1.5

-1.0

-0.5

0.0A1

C Ch

ange

(%)

**

**

**

EXN BID

LIRA

EXN QW

Slide Source:Lipids Online Slide Librarywww.lipidsonline.org

Comparison of Incretin ModulatorsComparison of Incretin Modulators

GLP-1 Analogues DPP-4 Inhibitors

Administration route Injection Oral

GLP-1 Sustained Meal-related

Effect on A1C

Effects on body weight

Side effectsNausea,

Rare: pancreatitis

(Well tolerated) Nasopharyngitis, skin rashes, Stevens-Johnson syndrome

-cell function

GLP-1=glucagon-like peptide–1; DDP-4=dipeptidyl peptidase–4

DPP – 4 inhibitors

• Sitagliptin

• Saxagliptin

• Linagliptoin

• Alogliptin

• Vildagliptin – marketed in EU

• More in development

–Gemigliptin

DPP4 inhibitors

• All taken once a day

–Sitaglipitin 100 mg daily

–50 mg if Cr 1.7-3.0 for men and 1.5-2.5 for women

–25 mg in ESRD

–Saxagliptin 5 mg per day

–2.5 mg in renal impairment

–2.5 if taken with cytochrome P450 inhibitors (ketoconazole)

–Linagliptin 5 mg daily

Sitagliptin - example

DPP-4 inhibitors

• Side effects are minimal

• Acute pancreatitis is seen

–Linagliptin 15.2/10.000 patients

–Placebo 3.7/10,000 patients

–Saxaglipin – No data but some postmarketing cases are reported

–Sitagliptin – There is 88 cases in 2.5 years in postmarketing reporting.

DDP-4 inhibitors – Bottom Line

• Very well tolerated

• Improve physiology

• Expensive

• So far, no serious adverse effects with long term use.

• No increased risk of pancreatic caner.

Alpha-Glucosidase inhibitors

• Acarbose - 25, 50 or 100 mg tablets

• Miglitol - 25, 50 and 100 mg tablets

–They block intestinal enzyme breaking sugars to monosaccharides.

–This slows down and blocks some of carbohydrate absorption.

–Postprandial peak is diminshed and Hba1c improves.

Alpha-Glucosidase inhibitors

Alpha-glucosidase inhibitors

• Taken with each meal.

• Side effects are flatulence and diarrhea

• This can be diminished with low carb, high fiber diet and slow titration of the dose form 25 mg to 100 mg per day.

• Very low risk of hypoglycemia

Alpha-glucosidase inhibitors – Bottom line

• Very useful if tolerated

• Relatively cheap.

Bromocriptine

• Bromocriptine mesylate given within 2 hours of waking up in the morning improves glycemic control by unknown mechanism.

• It is given in escalating dose starting with 0.8 mg and increasing by 0.8 mg every week to maximal tolerated dose.

• Therapeutic dose is between 1.6 to 4.8 mg per day.

• Very low risk of hypoglycemia.

• About 25% of patients experience some nausea.

Bromocriptine

Bromocriptine

Bromocriptine – Bottom line

• Useful if tolerated.

• Still expensive

• Many patients are discuoraged by need to use 2-6 pills at once (In US only 0.8 mg pill is available).

Bile acid sequestrants

• Colesevelam

• Cholestyramine

• Colestid

–Mechanism is unknown

– In db/db mice these drugs increase metabolic utilization of glucose in peripheral tissues which corelates with decrease in muscle long chain acylcarnitine content

Meissner M, et al. PLOS 2011 (6)11 e24564.

Coleselavam

Cholestyramine

Colesevalam

Colesevalam

Orlistat

Effect on weight

Effects on Hba1c

Chao EC, et al. Nat Rev Drug Discovery. 2010;9:551-559.

Targeting the Kidney

Chao, EC & Henry RR. Nature Reviews Drug Discovery. 2010;9:551-559.

Renal Glucose Transport

Rationale for SGLT2 Inhibitors

• SGLT2 is a low-affinity, high capacity glucose transporter located in the proximal tubule and is responsible for 90% of glucose reabsorption

• Mutation in SGLT2 transporter linked to hereditary renal glycosuria, a relatively benign condition in humans

• Selective SGLT2 inhibitors have a novel & unique mechanism of action reducing blood glucose levels by increasing renal excretion of glucose

• Decreased glycemia will decrease glucose toxicity leading to further improvements in glucose control

• Selective SGLT2 inhibition, would also cause urine loss of the calories from glucose, potentially leading to weight loss

Brooks AM, Thacker SM. Ann Pharmacother. 2009;42(7):1286-1293.

Canagliflozin

*P˂.001 vs. placebo calculated using LS meansRosenstock J, et al. Abstract 77-OR. ADA 2010.

Metformin + Canagliflozin Dose-Ranging Study

Mean Baseline A1C (%)

7.71 8.01 7.81 7.57 7.70 7.71 7.62

*

*

*

**

*

Changes from Baseline in Body Weight in Phase 3 Dapagliflozin Studies

Placebo Dapa 2.5mg Dapa 5mg Dapa 10mg

Wilding JPH, et al. Abstract 78-OR. ADA 2010; Strojek K, et al. Abstract 870. EASD 2010; Ferrannini E, et al. Diabetes Care. 2010;33(10):2217-2224; Bailey CJ, et al. Lancet. 2010;375(9733):2223-2233.

Canagliflozin Trials

• Symptomatic genital infections in 3-8% canagliflozin arms– 2% placebo

– 2% SITA

• Urinary tract infections in 3-9% canagliflozin arms– 6% placebo

– 2% SITA

• Hypoglycemia in 0-6% canagliflozin arms– 2% placebo

– 5% SITA

Rosenstock J, et al. Abstract 77-OR. ADA 2010.

Treatment and cancer risk

metformin

sulphonylurea

metformin + sulpha

insulin

No treatment

Treatment and colorectal cancer risk

metformin

sulphonylurea

metformin + sulpha

insulin

Treatment and pancreatic cancer risk

metformin

sulphonylurea

metformin + sulpha

insulin

ADOPT and RECORD Trials

ADOPT and RECORD Trials

METFORMIN

METFORMIN

Are all sulphonylureas the same?

Retrospective cohort study

Glibenclamide treated N-378

Gliclizide treated N-190

5 year follow up

Cancer mortality higher for glibenclamide after adjustments for age and sex, BMI, metformin and insulin treatment- HR 3.56 (1.1-11.9)

Are all sulphonylureas the same?

Matched case-control study

195 diabetic patients with incident malignancy

195 matched diabetic patients with no malignancy

Matched for sex, age, BMI, duration of diabetes, Hba1c, smoking and alcohol abuse

Exposure to antidiabetic drugs over last 10 years was analyzed.

Are all sulphonylureas the same?

Possible mechanism

New Classes Presently in Development

• Long-acting GLP-1 receptor agonists

• Ranolazine

• 11 Hydroxysteroid Dehydrogenase (HSD)- 1 inhibitors

• Fructose 1,6-bisphosphatase inhibitors

• Glucokinase activators

• G protein-coupled Receptor (GPR)- 40 & -119 agonists

• Protein Tyrosine Phosphatase (PTB)- 1b inhibitors

• Camitine- Palmitoyltransferase (CPT)- 1 inhibitors

• Acetyl COA Carboxylase (ACC)- 1 & -2 inhibitors

• Glucagon receptor antagonists

• Salicylate derivatives