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DRUGS FOR THE TREATMENT OF DIABETES MELLITUS. DIABETES MELLITUS. One of the leading cause of death by diseases (cardiovascular problems, stroke) One of the leading cause of blindness One of the leading cause of renal failure One of the leading cause of impotence (males) - PowerPoint PPT Presentation
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DRUGS FOR THE DRUGS FOR THE TREATMENT OF TREATMENT OF
DIABETES MELLITUSDIABETES MELLITUS
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• One of the leading cause of death by
diseases (cardiovascular
problems, stroke)
• One of the leading cause of blindness
• One of the leading cause of renal
failure
• One of the leading cause of impotence
(males)
• Risk of foot amputation
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N.B.
IDDM: insulin dependent diabetes mellitus.
NIDMM: non-insulin dependent diabetes mellitus.
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Characteristic Type 1 ( 10% ) Type 2 (90%)
Onset (Age) Usually < 30 Usually > 40
Type of onset Abrupt Gradual
Nutritional status Usually thin Usually obese
Diet Mandatory with insulin Mandatory with or without drug (can be controlled by diet & exercise)
Hypoglycemic drugs
Should not be used Clinically indicated
Clinical symptoms Polydipsia, polyphagia, polyurea, weight loss
Often asymptomatic due to insulin’s presence
Ketosis Frequent (acetone aroma)
Usually absent
Endogenous insulin Absent Present, but relatively ineffective
Related lipid abnormalities
Hypercholesterolemia frequent, all lipid fractions elevated in ketosis
Cholesterol & triglycerides often elevated; carbohydrate- induced hypertriglyceridemiaInsulin therapy Required Required in 20 - 30% of patients (for postprandial hyperglycemia)
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Glucose is reabsorbed in the kidney tubules in the form of glucose 6 phosphate.
In diabetic patients glucose filtration floods the renal tubules exceeding 180 g/dl, threshold for glucose’s reabsorption, leading to the appearance of glucose in the urine (glucosuria). This results in osmotic dragging of water into the tubules resulting in polyuria with subsequent polydypsia.
Hydrolysis of the disulfide linkage between
α & β chains.Metabolism of insulin:
Endogenous: 60% in liver & 40% in kidney (because it goes directly to the liver by the portal circulation).
Exogenous: 60% kidney & 40% liverHalf-Life 5-7min (endogenous insulin)
Delayed-release form( injected one)
• Pregnant women with type II or gestational DM should take insulin by injection and avoid taking oral hypoglycemics. 8
Insulin Degradation
cont’d
Category B (not teratogenic)The site of injection should be changed every once in
a while,(Injection in same place hypertrophy to subcutaneous
tissue ↓ absorption)Should be stored in refrigerator & warm up to room
temp before use.Must be used within 30 days.
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Fast action Fast action of insulin of insulin
in the in the abdomenabdomen
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TYPES OF INSULIN PREPARATIONS
A) Insulin used to control postprandial (after meals) hyperglycemia and emergency ketoacidosis
1. Ultra-short-acting ( e.g. insulin lispro, insulin aspart)( e.g. insulin lispro, insulin aspart)
2. Short-acting -Regular- (e.g. Novolin R, Humulin R)
B) Insulin used for maintenance treatment of type I DM
• Intermediate-acting (NPH, Lente insulin)
4. Long-acting (Glargine ,Ultralente )
Clear liquid
Turbid suspension عكر
N.B.
NPH = Neutral protamine Hagedorn
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Advantages of Insulin Lispro (ultra-short) vs Regular Insulin (short acting) :1) Rapid onset of action ( patients will not
wait long before they eat ).2) Its duration of action is no longer than 3-
4 hrs regardless of the dose.3) Decreased risk of postprandial
hypoglycemia4) Decreased risk of hyperinsulinemia
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قواعد جوهرية
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In emergency you can use either ultra-
short or regular insulin (no difference in the duration
of action because it is
given IV)
In postprandia
l hyperglycemia you can
use both but
Ultra-short has less duration of action
no hypoglycemia
Use ultra-short, wait for 5 minutes before
having a meal while in regular, wait for 30
minutes
Isophane (NPH) (Humulin N; Novolin N, etc.)
• Turbid suspension (shaken before use)
• Injected S.C. (Only)
• Onset of action 1 - 2 hr
• Peak serum level 5 - 7 hr
• Duration of action 13 - 18 hr
Insulin mixtures
75/25 70/30 50/50 ( mix isophane with ultra-short or
short acting insulin).
3. Intermediate - acting insulins
Isophane (NPH)Isophane (NPH)
Ultra-short or short actingUltra-short or short acting
Insulin mixture is given to patients with high postprandial
hyperglycemia
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(contd.) Lente insulin (Humulin L; Novolin L).
Turbid suspension
Mixture of 30% semilente insulin small crystals
rapidly acting 70% ultralente insulin large crystals
slow acting with prolonged duration
Injected S.C. (only)
Onset of action 1 - 3 hr
Peak serum level 4 - 8 hr
Duration of action 13 - 20 hr
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Cont’d
Lente and NPH insulins
• have the same effect.
• given once or twice a day.
N.B: They are not used during emergencies
(e.g. diabetic ketoacidosis).
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4. Long – acting insulins e.g. Glargine ( Lantus )
Insulin glargine
Onset of action: 2 hr
Absorbed less rapidly than NPH or Lente insulins
Duration of action up to 24 hr
Advantages• Constant circulating insulin over 24 hr with no pronounced peak (see next
slide)• Safer than NPH & Lente insulins ( less risk of nocturnal hypoglycemia)
• Clear solution (does not require resuspension before administration)
Designed to overcome the disadvantages of intermediately
acting insulins
Nocturnal = أثناء النوم
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Profile of Insulin Glargine vs NPH
Glargine NPH
glargine
(plateau )
In the previous figure NPH gives a peak risk of hypoglycemia
But glargine doesn’t give a peak risk of hypoglycemia
N.B: intermediate & long acting use for maintenance of blood sugar during 24 hr in type I DM
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GlargineGlargine
Methods of Adminisration
Insulin Syringes (most common)
Pre-filled insulin pens (expensive)
External insulin pump
Under Clinical Trials1. Oral tablets2. Inhaled aerosol (still undergoing trials)
3. Intranasal, Transdermal 4. Insulin Jet injectors (needle less)5. Ultrasound pulses
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COMPLICATIONS OF INSULIN THERAPY
1. Severe Hypoglycemia (< 50 mg/dl ) life-threatening
2. Weight gain
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3. Local or systemic allergic reactions (rare)
4. Insulin resistance (when the patient needs more than
200 units/day) (IgG anti-insulin antibodies, infection, expired insulin(rare)).
5. Lipohypertrophy at injection sites
6. Hypokalemia
Cont’d
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Severe insulin reaction
(Hypoglycemic Shock)
Diabetic coma
(Diabetic Ketoacidosis)Onset Rapid Slow- Over several days
Insulin Excess Too little
Acidosis & dehydration
No Ketoacidosis
Signs and symptoms
B.P. Normal or elevated Subnormal or in shock
Respiration Normal or shallow Deep & air hunger
Skin Pale & Sweating Hot & dry
CNS Tremors, mental confusion, sometimes convulsions
General depression
Blood sugar Lower than 70 mg/100cc Elevated above 200 mg/100cc
Ketones Normal Elevated
Oral Hypoglycemics All taken orally in the form of tablets.
Patients with type II diabetes have two physiological defects:
1. Abnormal insulin secretion (most important)
2. Resistance to insulin action in target tissues associated with decreased number of insulin receptors
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Oral Anti-Diabetic Agents1. Sulfonylureas e.g. Tolbutamide, Glyburide.
2. Meglitinides e.g. Repaglinide, Nateglinide.
3. Biguanides e.g. Metformin.
4. Alpha-glucosidase inhibitors e.g. Acarbose.
5. Thiazolidinediones e.g. Pioglitazone.
6. Dipeptidyl peptidase-4 inhibitors e.g. Sitagliptin, vildagliptin
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More selective an
smaller dose
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FIRST GENERATION SULPHONYLUREA COMPOUNDS
* Good for patients with renal impairment Good for patients with renal impairment
** Patients with renal impairment can expect long t1/2
*** Chlorpropamide isn’t well metabolized
N.B. All 1st
G Metabolized in liver.
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GlipizideShort- acting
Glibenclamide
(Glyburide)Long-acting
Glimepiride
Long-acting
Absorption Well Well Well
Metabolism
Yes Yes Yes
Metabolites
Inactive Inactive Inactive
Half-life 3 – 4 hrs Less than 3 hrs (hit and run)
5 - 9 hrs
Duration of action
10 – 16 hrs
12 – 24 hrs 12 – 24 hrs
Excretion Urine Urine Urine
SECOND GENERATION SULPHONYLUREA COMPOUNDS
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MECHANISM OF ACTION OF SULPHONYLUREAS (SU)
1) Release of insulin from β-cells* (hence, no use in type 1
DM).
2) Reduction of serum glucagon concentration.(in long
term use)
3) Potentiation of insulin action on target tissues.- SU’s binds to k+ channel no efflux depolarization Opening of voltage gated Calcium channel insulin release
Sulphonylureas ( Cont.)CLINICAL USE:Approved for monotherapy and in
combination with metformin or thiazolidinediones in type II DM
Taken before each meal, 1-2 times/day
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SIDE EFFECTS OF SULPHONYLUREAS
1) Nausea, vomiting, abdominal pain, diarrhea
2) Hypoglycaemia
3) Dilutional hyponatraemia & water intoxication (Chlorpropamide) because it ↑ADH
4) Disulfiram*-like reaction with alcohol (Chlorpropamide) “contain sulfur”
Disulfiram R: Ingestion of chlorpropamide with alcohol hyperemic flush
5) Weight gain alcoholism* Disulfiram is a drug used to support the treatment of chronic
alcoholism by producing an acute sensitivity to alcohol.
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CONTRAINDICATIONS OF SULPHONYLUREAS
1) Type 1 DM ( insulin dependent)
2) Parenchymal disease of the liver or kidney. metabolism excretion
3) Pregnancy, lactation (due to the physiologic stress, not teratogenicity)
4) Major stress.
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DRUGS THAT AUGMENT THE HYPOGLYCEMIC ACTION OF
SULPHONYLUREAS
Sulfonamides (increase insulin secretion)
Warfarin (displace the drugs ↑t1/2 )
Salicylates (displace the drugs ↑t1/2 )
Propranolol (mask the hypoglycemia)
Alcohol (acute)
Liver enzymes inhibitors ↑SU conc.
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DRUGS THAT ANTAGONIZE THE HYPOGLYCEMIC ACTION OF
SULPHONYLUREAS
Thiazide diuretics (a K+ opener hyperpolarization no release of insulin)
Corticosteroids
Epinephrine
Liver enzymes inducers e.g. alcohol (in chronic alcohlic patients )
↓sensitivity of insulin
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MEGLITINIDES
e.g. Repaglinide, Nateglinide (SU without sulfur)
PKs: Taken orally Rapidly absorbed ( Peak approximately 1hour ) Metabolized by liver t1/2 = 1 hr
Duration of action 4-5 hr
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MEGLITINIDES (Contd.)
MECHANISM OF ACTION
Bind to the same KATP Channel
as do Sulfonylureas,
to cause insulin release from β-cells.
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MEGLITINIDES (Contd.)
CLINICAL USE
Approved for monotherapy and in combination with metformin in type 2 diabetes
Taken before each meal, 3 times / day
Does not offer any advantage over sulfonylureas
SIDE EFFECTS:
Hypoglycemia
Weight gain( less than sulfonylureas )Caution in patients with renal & hepatic impairement.
We can use it if the patient is allergic to sulfonylurea
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BIGUANIDES
e.g. Metformin
PKs: Given orally
Do not bind to plasma proteins
Not metabolized
Excreted unchanged in urine
t 1/2 2 hr
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BIGUANIDES (Contd.)
MECHANISM OF ACTION
1. Increase peripheral glucose utilization (increase insulin
receptor sensitivity thus is insulin dependent)
2. Inhibits gluconeogenesis
3. Impaired absorption of glucose from the gut
Advantages of Metformin over SUlfonylurea
Does not cause hypoglycemia because they don’t stimulate the release of insulin from pancreas no hypoglycemia
Does not result in weight gain because they ↓appetite.
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BIGUANIDES (Contd.) SIDE EFFECTS
1. Metallic taste in the mouth
2. Gastrointestinal (anorexia, nausea, vomiting,
diarrhea, abdominal discomfort)
3. Vitamin B 12 deficiency (prolonged use)
4. Lactic acidosis ( rare – 01/ 30,000-exclusive in
renal failure) (they ↑anerobic glycolysis ↑lactic acid) this
phenomenon is treated with NaHCO3.
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1. Hepatic impairment
2. Heart failure
3. Renal impairment
4. Alcoholism
BIGUANIDES (Contd.)
CONTRAINDICATIONS
In these situations the body is more sensitive to
lactic acidosis
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1. Obese patients with type II diabetes
2. Alone or in combination with sulfonylureas or
meglitinides.
BIGUANIDES (Contd.)
INDICATIONS
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α-GLUCOSIDASE INHIBITORS
e.g. Acarbose
PKs:
• Given orally.
• Not absorbed from intestine except small
amount (hence, no systemic effect).
• t1/2 3 - 7 hr.
• Excreted with stool.
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MECHANISM OF ACTION
α-GLUCOSIDASE INHIBITORS(Contd.)
With the use of drugs,
there is no sharp rise in blood
sugar
مايشطح )السكر بعد
(األكل
They delay the
absorption but don’t inhibit it
α-GLUCOSIDASE INHIBITORS (Contd.)It is a competitive inhibitor of glucosidase
enzyme (has more affinity than sugar ).It used as supportive not as treatment .Also can be used in border line patients.It can be use with type I DM but not alone.
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SIDE EFFECTS
• Flatulence sugar fermentation
• Loose stool or diarrhea results in gas formation
• Abdominal pain
• Alone does not cause hypoglycemia
α-GLUCOSIDASE INHIBITORS(Contd.)
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INDICATIONS Patients with Type II inadequately controlled by diet with or without other agents( SU, Metformin)
Can be combined with insulin to reduce postprandial hyperglycemia
Maybe helpful in obese Type II patients (similar to metformin)
α-GLUCOSIDASE INHIBITORS can also be used with type I DM with meals.
α-GLUCOSIDASE INHIBITORS(Contd.)
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e.g.: Pioglitazone
PKs:
99% absorbed
Metabolized by liver
99% of drug binds to plasma proteins
T1/2 = 3 – 4 h
Eliminated via the urine 64% and feces 23%
THIAZOLIDINEDIONE DERIVATIVES
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MECHANISM OF ACTION
- Increase target tissue sensitivity to insulin by: reducing hepatic glucose output & increase
glucose uptake & oxidation in muscles & adipose tissues.
They do not cause hypoglycemia (similar to metformin and acarbose ) .
THIAZOLIDINEDIONE DERIVATIVES(Contd.)
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ADVERSE EFFECTS
- Mild to moderate edema
- Weight gain
- Headache
- Myalgia (muscle pain)
- Hepatotoxicity ? Thus a liver function test is done before giving
this drug.
- Congestive heart failure?
- Alone does not cause hypoglycemia.
THIAZOLIDINEDIONE DERIVATIVES(Contd.)
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INDICATIONS
Type II diabetes alone or in combination with
metformin , sulfonylurea or insulin in patients
resistant to insulin treatment.
THIAZOLIDINEDIONE DERIVATIVES(Contd.)
Dipeptidyl peptidase-4 inhibitors (DPP- 4 inhibitors)
e.g. Sitagliptin, vildagliptinMechanism of action
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Dipeptidyl pepidase (enzyme) incretininactivate
DPP-4 inhibitors
Clinical usesUsed in type II DM as an adjunct to diet & exercise as a monotherapy or in combination with other antidiabetic drugs. Is also used in
borderline patients.
Adverse effectsNausea, abdominal pain, diarrhea
Nasopharyngitis
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