Drugs for Diabetes Flashcards
What are the main actions of insulin?
Inc glucose uptake
Inc glycogen synthesis
Dec glycogenolysis
Dec gluconeogenesis
What are the main actions of glucagon?
inc glycogenolysis
Inc gluconeogenesis
Considering insulin phases, what is the difference between T1DM and T2DM?
T2DM = missing only phase 2 of insulin regulation
T1DM = missing both phases 1 and 2 of insulin regulation
Summarise the key points of T1DM
Juvenile-onset –> immune mediated
Insulin dependent = little or no insulin produced
Usually non-obese and symptoms appear suddenly
Summarise the key points of T2DM
Adult onset
Non-insulin dependent diabetes = begins w/ insulin resistance –> eventual beta cell failure
Genetic basis, sx appear slowly
Require oral hypoglycaemic agents
What are the main symptoms of diabetes?
Hyperglycaemia
Glycosuria
Polyuria
Polydipsia
Insulin def
Diabetic ketoacidosis
What symptoms are more common in T1DM?
Lethargy
stupor
Weight loss
Kussmaul breathing (hyperventilation)
Smell of acetone
N/V, abdominal pain
What are the complications of diabetes?
Macrovascular disease = accelerated atheroma
Microangiopathy = retinopathy, nephropathy, neuropathy
What is HbA1c?
Glycosylated haemoglobin = glucose that is haem/protein bound
Ideal is 7% (53 mmol/mol)
What amino acids determine the length of action of the insulins?
B-3
B-28-30
List the different types of insulin
Human insulin
Insulin aspart (asp at B-28_
Insulin lispro (lys B-28, proline B-29)
Insulin glulisine (lysine B-3)
Insulin glargine (glycine A-21)
Insulin detemir (nothing on B-30)
Insulin degludec (nothing on B-30, may have missing B-29 lysine)
List the ultra short acting insulins
Insulin aspart
Insulin lispro
Insulin glulisine
Faster acting insulin aspart
List the short acting insulin
neutral insulin (human insulin ?)
List the long acting insulin
Isophane insulin
List the long acting insulin analogues
Insulin detemir
Insulin glargine
Outline the mechanism behind insulin release
Phase 1:
Glucose transported in through the GLUT4 transporter –> inc in ATP –> inhibition of K+ATPase channel –> depolarisation of beta cell –> opening of voltage gated Ca2+ channel –> release of insulin granules
Describe the mechanism behind diabetic ketoacidosis
Hyperglycaemia –> insufficient glucose uptake –> cells use proteins and fat as energy –> FFA broken down in liver to ketone bodies (kidney - ketonuria) –> acetoacetate converted to acetone in liver (exhaled - fruity breath)
Cont lipolysis –> inc ketogenesis –> exceeds elimination –> ketonaemia –> inc FFA lvls –> worsening acidosis
Initial compensation through Kussmaul breathing and buffering in blood –> blood and breathing no longer able to compensate –> ketoacidosis
What are some adverse effects of insulin?
Hypoglycaemia
Rebound hyperglycaemia
Insulin resistance
local reactions (lipodystrophy)
What are the counter regulatory sympathetic stimulation responses seen in diabetes?
Sweating
Anxiety
Palpitations
Tremor
What are the main drug interactions associated with insulin?
B-adrenergic blockers = prolong hypoglycaemia due to inhibition of compensatory mechanisms
Diuretics, corticosteroids, oral contraceptives = inc blood glucose
Alcohol = precipitates hypoglycaemia due to depletion of hepatic glycogen
Salicylates, lithium, theophylline = precipitate hypoglycaemia –> enhance insulin sec and peripheral glucose utilisation
List the oral drug classes used in T2DM
Metformin
SGLT2 inhibitors
DPP-4 inhibitors
Sulfonylureas
thiazolidinedione
Acarbose
List the parenteral drugs used in diabetes
Insulin
GLP-1 analogue
List the relevant sulfonylureas used in DM
*all end in -ide
Glibenclamide (long acting)
Gliclazide
Glipizide (short acting)
Glimepiride (short acting)
What is the MOA of sulfonylureas?
Bind + inhibit K+ATPase channel —> inc insulin release from pancreatic beta cells in response to glucose
Act to inc insulin release
Which sulfonylureas have a lesser affinity for the K+ATPase channel?
glimepride, Gliclazide
Augment second phase of insulin, little effect on 1st phase
What are some ADRs of sulfonylureas?
GI dist = n/v/diarrhoea/constipation
Hypoglycaemia
Hypersensitivity reactions
blood disorders
cardiovascular mortality
What drugs inc the effect of sulfonylureas? (cause hypos)
CYP inducers = azole antifungals, salicylates, sulphonamides
Clarithromycin, alcohol, ACE-i
Disopyramide, BB, MAO-i
List the important biguanide used to treat diabetes and its MOA
Metformin
MOA = inc the activity of AMP-dependent kinase (AMPK) –> dec expression of G6P –> inhibits mitochondrial glycerol-3-phosphate
Dec cellular energy stores (ATP & phosphocreatine) –> activates AMPK
Facilitates glucose uptake by skeletal muscle and adipocytes, inhibits mitochondrial resp chain oxidation (promote peripheral glucose utilisation)
What does metformin mediated activation of AMPK do?
Inc fatty acid oxidation
Inc glucose uptake
dec lipogenesis
dec gluconeogenesis
What is the effect of metformin on the liver?
dec gluconeogenesis
Dec glycogenolysis
dec glucose production
What is the effect of metformin on the intestine?
Inc anaerobic glucose metabolism
What is the effect of metformin on the muscle?
Inc insulin-mediated glucose uptake
Inc glycogenesis
What are some benefits to metformin?
Suppress appetite = less weight gain than sulfonylureas
May be cardioprotective
Improves adverse plasma lipid profile
- inc FFA oxidation
- Inc HDL
- Dec plasma triglycerides
What are some notable ADRs of metformin?
Diarrhoea
- anorexia, abdominal discomfort, nausea, weight loss
Dec Vit B12 absorption
Metallic taste
Inhibition of pyruvate metabolism –> lactate accumulation –> lactic acidosis
List the relevant thiazolidinediones and their MOA
Pioglitazone = no effect on insulin secretion, “insulin sensitizer”
MOA = its a ligand for PPARY (peroxisome proliferation activating receptor gamma) –> involved in regulation of genes involved in glucose and lipid metabolism
What are some general effects of the PPAR-Y agonists used in diabetes?
Dec insulin resistance (both muscle and kidney) —> inc muscle glucose uptake and dec liver gluconeogenesis (inhibition of fructose-1,6-bisphosphate)
Inc glucose utilisation in peripheral tissues and ehances expression of cell glucose transporters (GLUT 1 and 4)
Name a glucosidase inhibitor used in T2DM treatment and its MOA
Acarbose
MOA = competes w/ dietary oligosaccharides for alpha-glucosidase enz —> irreversibly binds to the enzyme –> slow digestion/absorption of glucose –> preprandial peak of glucose is low, BGC is more stable
What are some ADRs for acarbose?
GI effects = flatulence, abdominal discomfort, diarrhoea
Abnormal liver function = hepatitis
What are the actions of incretins (generally)?
Enhance glucose-dependent insulin secretion
Inhibit glucagon secretion –> dec hepatic glucose production
Slow gastric emptying
Inc satiety –> less food intake
Both GLP-1 and GIP are rapidly cleaved and inactivated by dipeptidyl peptidase 4 (DPP4)
List the drugs that belong to the glucagon-like peptide-1 (GLP-1) analogue class and their overall MOA
- all end in “-glutide”
Exenatide
Liraglutide
Semaglutice
Dulaglutide
MOA = incretin mimics
How are GLP-1 analogues used in diabetes and what are some of their ADRs?
Good adjuvant w/ metformin and/or sulfonylurea
ADRs:
- n/v
- diarrhoea, constipation, dyspepsia, GORD, abdominal pain
- hypoglycaemia, headache, dizziness, injection site reactions
- pancreatitis, allergic reactions
What diabetic drugs belong in the Dipeptidyl peptidase-4 (DPP-4) inhibitor class?
- “-gliptin”
Aloglipin
Linagliptin
Saxagliptin
Sitagliptin
Vildagliptin
How are DPP-4 inhibitors used in diabetes and what are some of their ADRs?
Good adjuvant in dual therapy w/ metformin, a sulfonylurea, or a thiazolidinedione
ADRs:
- hypoglycaemia, n/c, acute pancreatitis
What diabetic drugs belong in the Na+/glucose co-transporter 2 (SGLT2) inhibitor class?
- “-gliflozin”
Canagliflozin
Dapagliflozin
Empagliflozin
ertugliflozin
What is the MOA of SGLT2 inhibitors and what are some of their ADRs?
MOA = inhibit SGLT2 co-transporters in the kidney –> reduce glucose reabsorption
ADRs:
- genital infections, polyuria, UTI, dyslipidaemia, hypoglycaemia
- renal impairment
- Hypovolaemia, hypotension, dehydration
- euglycemic ketoacidosis