3. DRUG INTERACTIONS
The effect of one drug on the effectiveness
or toxicity of another drug
or
It occurs when the effect of a particular drug
is altered when it is taken with another
drug or food
4. INSULIN
I.DRUG INTERACTIONS CAUSING
‘HYPOGLYCEMIA’
A. β-adrenergic blockers
Impair the sympathetic mediated release of glucose from the
liver in response to hypoglycemia
Decrease adrenergic mediated symptom of hypoglycemia
B. SALICYLATES, LITHIUM andTHEOPHYLLINE
Enhances insulin secretion and peripheral utilization of glucose
C. MAO INHIBITORS
Potentiates insulin secretion
eg. Selegiline,Moclobemide
D. ETHYL ALCOHOL
Alcohol exerts effect on pancreatic microcirculation by evoking a
massive redistribution of pancreatic blood flow
5. II. DRUGS CAUSING
‘HYPERGLYCEMIA’
A. THIAZIDES
Diuretics K+ depletion
-
Proinsulin Insulin
Hence it causes inhibition of insulin release and precipitates diabetes
mellitus
B. ADENOCORTICOSTEROIDS
C. ORAL CONTRACEPTIVE PILLS
Supression of basal level of Cholecystokinin and hence causes decrease in
insulin release
D.SALBUTAMOL
plasma glucagon level and plasma insulin level
E.NIFEDEPINE
6. ORAL HYPOGLYCEMIC DRUGS
I.SULFONYLUREAS
A . Drugs that cause ‘HYPOGLYCEMIA’: These drugs enhance sulfonylureas
action
1.Induce metabolism of glucose
Cimetidine
Acute alcohol intake
Warfarin
2.Prolong pharmacological action
Salicylates
Lithium
Propanolol
B. DRUGS THAT CAUSE ‘HYPERGLYCEMIA’:These drugs decreases
sulfonylureas action
1.Inhibits metabolism of glucose
Phenobarbitone
Phenytoin
Chronic alcoholism
2. Suppress insulin release
Corticosteroids
OC Pills
Thiazides
7. II. BIGUANIDES
A. Drugs causing ‘HYPOGLYCEMIA’
1. Biguanides along with oral sulfonylureas causes
hypoglycemic effect
2. Phenylbutazone and Sulfaphenazole causes severe
hypoglycemic collapse
3. Biguanides interact with endogenous metals
Zn2+,Cu2+,Fe3+
Zn2+ causes inhibition of insulin degradation
4. Cimetidine increases metformin plasma concentration by
inhibiting drug metabolising enzyme
8. III.MEGLITINIDE/PHENYLALA
NINE ANALOGUES
A.Drugs that cause ‘HYPOGLYCEMIA’
1.Meglitiniide with metformin causes additive glucose lowering
effect
2.It interacts with α-glucosidase inhibitors decreases
HbA1c,fasting glucose,post prandial glucose levels
3.Some anti hypertensives like ACE inhibitors favour
hypoglycemic action.
B. Drugs that cause ‘HYPERGLYCEMIA’
CYT P4503A4 inhibitors like fluronazole decreases metabolism of
meglitinide
9. IV.α-GLUCOSIDASE
INHIBITORS
1.Increases the levels of sulfonylureas and induce
hypoglycemia
2.Reduce serum digoxin concentration
3. Digestive enzymes and intestinal adsorbents such
as charcoal should not be taken as it decreases
efficiency of α-glucosidase inhibitors
10. DRUG INDUCED
HYPOGLYCEMIA AND
HYPERGLYCEMIA
Drug which causes ‘HYPERGLYCEMIA’
HORMONES
GLUCAGON
Secreted by α-cells of islets of langerhans
Promotes glycogenolysis in liver by stimulating adenyl cyclase enzyme
ESTROGEN
These are group of steroid compounds that diffuses cell membrane and
activate estrogen receptor
THYROID HORMONES
They are required for proper development and differentiation of all cells of
the body regulating metabolism of protein and carbohydrate
11. contd……
OTHER DRUGS
NICOTINIC ACID
Acts on G-protein coupled receptors and at
high doses elevates blood sugar level and
thus worsen diabetes mellitus
PHENYTOIN
Inhibits insulin release
THIAZIDES
12. DRUG WHICH CAUSES
‘HYPOGLYCEMIA’
ACE inhibitors
•Prevents nephropathy in diabetes mellitus
•eg. Captopril,Enalapril,Ramipril
Alcohol
•Interferes with the positive effects of oral diabetes medicines
or insulin.
MAO Inhibitors
Lithium
Quinine
Large doses of salicylates
13. HYPOGLYCEMIC EFFECT OF
DRUGS ON VARIOUS ORGANS
DRUGS with
hypoglycemic
effect
PANCREAS LIVER PERIPHERY
Β-adrenergic
antagonist
+ +
Salicylates +
Endomethacin
Ethanol +
Li2+ + +
Ca2+ +
Theophylline +
Sulfonamides
Tetracyclines
Pyridoxine +
MAO inhibitors