Antidiabetic drugs Flashcards
(39 cards)
1) Name the P drug which is a Biguanide.
2) Give the P drug examples of Sulfonylureas.
3) Name the P drug which is a Meglitinide.
1) Metformin
2) Gliclazide and Glimepiride.
3) Repaglinide
1) Name the 2 P drugs which are DPP-4 inhibitors.
2) Name the P drug which is a thiazolidinedione.
3) Name the P drug which is a glucosidase inhibitor.
1) Sitagliptin and Linagliptin
2) Pioglitazone
3) Acarbose
1) Name 3 P drugs which are SGLT-2 inhibitors.
2) Name 2 P drugs which are GLP-1 agonists.
1) Empagliflozin, Canagliflozin and Dapagliflozin
2) Liraglutide and Semaglutide
Give the main common clinical indication for the use of Metformin.
T2DM as a first choice medication for control of blood glucose, used alone or in combination with other oral hypoglycaemic drugs (sulphonylureas or insulin).
1) How does Metformin lower blood glucose?
2) What does Metformin suppress?
3) What does Metformin increase?
4) What does Metformin suppress?
1) By increasing the response (sensitivity) to insulin.
2) It suppresses hepatic glucose production (glycogenolysis and gluconeogenesis).
3) Increases glucose uptake and utilisation by skeletal muscle.
4) It suppresses intestinal glucose absorption.
1) Why is hypoglycaemia not a risk factor of Metformin?
2) How can Metformin prevent the worsening of insulin resistance and slow deterioration of DM?
1) Because it does not stimulate pancreatic insulin secretion.
2) By reducing weight gain and inducing weight loss.
1) What adverse effect does Metformin commonly cause which can also result in weight loss?
2) What is a rare adverse effect associated with Metformin use?
1) GI upset (nausea, vomiting, taste disturbance, anorexia and diarrhoea).
2) Lactic acidosis which can be fatal if untreated (does not occur in stable patients).
Name 3 things which can precipitate lactic acidosis with Metformin use?
1) Intercurrent illness which causes Metformin accumulation (for example, worsening renal impairment).
2) Increased lactate production (sepsis, hypoxia, cardiac failure).
3) Reduced lactate metabolism (liver failure).
1) How is Metformin excreted?
2) When is Metformin contraindicated and when is a dose reduction required?
3) When should Metformin be withheld?
1) Unchanged by the kidney.
2) Contraindicated in severe renal impairment and a dose reduction is required for patients with moderate renal impairment.
3) When there is AKI (sepsis/ shock/ dehydration) or severe tissue hypoxia (cardiac or respiratory failure/ MI).
1) Why is caution with the use of Metformin required in hepatic impairment?
2) Why should Metformin be withheld during acute alcohol intoxication?
3) Why should Metformin be used with caution in chronic alcohol overuse?
1) Because clearance of excess lactate may be impaired.
2) Because in acute alcohol intoxication it can precipitate lactic acidosis.
3) Because there is a risk of hypoglycaemia.
1) Why must Metformin be withheld before and for 48 hours after injection of IV contrast media?
2) What other drugs need to be used with caution in combination with Metformin and why?
3) Name 3 drugs which elevate blood glucose and therefore reduce the efficacy of Metformin.
1) Because there is an increased risk of renal impairment, metformin accumulation and lactic acidosis.
2) Drugs such as ACEi’s, NSAIDs and diuretics which have potential to impair renal function, especially when used in combination with Metformin (ensure to monitor renal function).
3) Prednisolone, thiazides and loop diuretics as they oppose the actions and reduce efficacy of Metformin.
1) How is Metformin available for administration?
2) Why should Metformin be started at a low dose and increased gradually?
3) Describe the common regimen for the commencement of Metformin.
1) Available for oral administration.
2) Because this way, GI adverse effects of Metformin are better tolerated.
3) Common regimen = start Metformin 500mg OD with breakfast, then increase dose by 500mg weekly to 500-850mg TDS with meals.
1) Give 2 reasons as to why Metformin would be stopped.
2) If patients find GI side effects difficult to tolerate, what could be done to help?
3) For safety, what must you do before starting Metformin?
1) If adverse effects are intolerable or if new contraindications develop.
2) Changing from a standard to a modified-release preparation may help.
3) Measure renal function before starting treatment, and then measure at least annually.
1) When might renal function need to be measured more frequently?
2) How long should conservative treatment be tried for for T2DM before introducing drug therapy?
3) Why is Metformin usually the first choice of drug treatment in T2DM unless contraindicated?
1) In people with deteriorating renal function or an increased risk of renal impairment (needs to be measured at least twice annually).
2) For 3 months.
3) Because it does not cause weight gain where as insulin and drugs which increase insulin secretion cause weight gain which can worsen DM over the long term.
Give the main common clinical indication for the use of Sulphonylureas.
Used in T2DM as a single agent to control blood glucose and reduce complications where metformin is contraindicated or not tolerated.
Can also be used in combination with Metformin (and/ or other hypoglycaemic agents) where blood glucose is not adequately controlled on a single agent.
1) How do sulphonylureas lower blood glucose?
2) What do sulphonylureas block and what does this cause?
3) What causes the stimulation of insulin secretion with sulphonyl ureas?
1) By stimulating pancreatic insulin secretion.
2) They block ATP-dependent K+ channels in pancreatic beta-cell membranes, causing depolarisation of the cell membrane and opening voltage-gated Ca2+ channels.
3) Increases in intracellular Ca2+ concentrations stimulate insulin secretion.
1) Sulphonylureas are only effective in which types of patients?
2) Why is stimulation of insulin by sulphonylureas associated with weight gain?
3) What is a negative effect of weight gain caused by sulphonylureas?
1) They are only effective in patients with residual pancreatic function.
2) Because insulin is an anabolic hormone.
3) Weight gain increases insulin resistance and can worsen DM in the long-term.
Describe the dose related side effects of Sulphonylureas.
GI upset: nausea, vomiting, diarrhoea, constipation - these are usually mild and infrequent.
1) Name a potentially serious adverse effect of sulphonylureas.
2) When might this potentially serious side effect be more likely?
3) How long might sulphonylurea-induced hypoglycaemia last for?
1) Hypoglycaemia.
2) More likely with high treatment doses, in cases where drug metabolism is reduced or where other hypoglycaemic medications are prescribed.
3) Can last for hours, and if severe, should be managed in hospital.
Name 3 rare hypersensitivity reactions which can occur with use of sulphonylureas.
1) Hepatic toxicity (e.g. cholestatic jaundice)
2) Drug hypersensitivity syndrome (rash, fever and internal organ involvement).
3) Haematological abnormalities (e.g. agranulocytosis)
1) Where is gliclazide metabolised?
2) How is gliclazide excreted?
3) When might a dose reduction of sulphonylureas be required?
4) When might you need to monitor blood glucose levels carefully in a patient taking sulphonylureas?
1) Metabolised in the liver (half-life of 10-12 hours)
2) Unchanged drug and metabolites are excreted in the urine.
3) In those with hepatic impairment.
4) In those with renal impairment as this might cause a slower level of excretion (risk of hypoglycaemia).
When should sulphonylureas be prescribed with caution?
In those at an increased risk of hypoglycaemia:
1) hepatic impairment (reduced gluconeogenesis)
2) malnutrition
3) adrenal or pituitary insufficiency (lack of counter-regulatory hormones)
4) in the elderly.
1) When is the risk of hypoglycaemia increased in patients taking Sulphonylureas?
2) When is efficacy of Sulponylureas reduced?
1) When there is co-prescription of other anti diabetic drugs (Metformin, Thiazolidinediones - Pioglitazone and insulin).
2) Efficacy is reduced by drugs that elevate blood glucose (e.g. Prednisolone, thiazide and loop diuretics).
1) Which types of sulphonylureas are easiest to use?
2) How are sulphonylureas administered?
3) At what times of day should sulphonylureas be taken?
1) Those with a shorter duration of action and hepatic metabolism (e.g. gliclazide) - particularly in the elderly with impaired renal function.
2) Oral administration only.
3) With meals.
