pharmacology of drugs used in the management of diabetes: drugs affecting absorption and reabsorption of glucose

what are the 2 classes of anti diabetic drugs that act at targets involved in the absorption of glucose in the GIT and reabsorption of glucose in the kidney, thus affecting glucose homeostasis

• sodium glucose co-transport 2 (SGLT-2) inhibitors e.g. dapagliflozin

• alpha-glucosidase inhibitors e.g. acarbose

what does dapagliflozin affect

the reabsorption of glucose

what does acarbose reduce

absorption in the gut

what do neither mechanisms of SGLT-2 inhibitors and alpha-glucosidase inhibitors directly involve

insulin

what is the pharmacological target of SGLT-2 inhibitors

SGLT-2

what is SGLT-2

• a major transporter that mediates the reabsorption of glucose in the kidney 

what will inhibitors of SGLT-2 do

• reduce reabsorption and therefore increase excretion of glucose in the urin 

• hence plasma conc. of glucose is reduced

where is SGLT-2 found and what can you say about its affinity and capacity

• proximal convoluted tubule

• low affinity, high capacity 

• means majority of glucose reabsorbed

where is SGLT-1 found and what can you say about its affinity and capacity 

• proximal straight tubule 

• high affinity, low capacity 

what is the main isoform in the gut between SGLT-2 and SGLT-1 

SGLT-1

why do we still absorb some glucose even with an SGLT-2 inhibitor 

SGLT-1 can still reabsorb glucose

what is the pharmacological target of alpha-glucosidase inhibitors

alpha-glucosidase (maltase)

what is alpha-glucosidase and what does it do

• an enzyme

• breaks down short-chain oligosaccharides including maltose to glucose in the GIT 

what is required before glucose can be absorbed from the gut into the blood stream 

alpha-glucosidase

what would inhibition of alpha-glucosidase do

decrease glucose absorption after a mela

what does acarbose inhibit

• alpha-glucosidase

• therefore reducing glucose absorption and therefore decreasing post-prandial blood glucose concentration.