Metformin

Question 1

what class of drug is metformin

Answer 1

Biguanide

Question 2

what does metformin inhibit?

Answer 2

complex 1 of the mitochondrial respiratory chain

Question 3

what does inhibition of complex one of the mitochondrial resp chain lead to?

Answer 3

Fall in cellular ATP (rise in ADP/ATP ratio)

Question 4

a fall in cellular ATP in relation to metformin leads to

Answer 4

a reduction in gluconeogenesis

Question 5

is metformin hydrophilic or hydrophobic?

Answer 5

hydrophilic

Question 6

does metformin require active transport?

Answer 6

yes, by organic cation transporters (OCT)

Question 7

where are organic cation transporters found?

Answer 7

intestines, liver and kidney

Question 8

metformin is excreted unchanged in urine-true or false?

Answer 8

true (means its not metabolised)

Question 9

what is the main impact of metformin?

Answer 9

lowers hepatic glucose production (in patients with poorly controlled diabetes)
increases gut glucose utilisation and metabolism
decreases lipogenesis

Question 10

does metformin increase tissue sensitivity to insulin?

Answer 10

No

Question 11

does metformin cause weight loss?

Answer 11

yes

Question 12

what is a normal metformin dose?

Answer 12

500mg bd

Question 13

what is the max dose of metformin?

Answer 13

1g bd

Question 14

how many patients have a GI side affect?

Answer 14

20% have GI intolerance
5% have to stop because of these symptoms (Diarrhoea, Bloating, Abdominal Pain, Dyspepsia, Metallic taste in mouth)

Question 15

how are metformin side effects reduced?

Answer 15

initiate medication slowly

Question 16

does metformin increase lactate production?

Answer 16

yes

Question 17

in what is metformin associated with a greater risk of lactic acidosis?

Answer 17

acute kidney injury

Question 18

what are other benefits of metformin?

Answer 18

has a largely sustained benefit on CV mortality