FOAM4GP Map – Type 2 Diabetes tablets – How many are there now!?!

Sweet…

Let’s start this one with a question…

What do thiazolidinediones, DPP4 inhibitors, acarbose, SGLT2 inhibitors, sulphonylureas, GLP1-agonists, metformin, gliptins, and glitazones all have in common? Yep, they all have stupid names.

I remember an old saying – “If there are many ways to treat something it is likely none of them are the best”.

The amount of Type 2 diabetic oral or injectable hypoglycaemic agents (even that is a mouthful) on the market has now become amazingly broad.

As we all know, diabetes is one of the greatest challenges to modern healthcare, and yes, we do need to lower people’s sugars to help prevent the macro and micro vascular complications of prolonged hyperglycaemia – (though even the macro benefits are still under debate!).

So here it is. I have put together a basic summary of each agent and its current recommendations from Diabetes Australia and a large pool of other references.

My tip is to use it as a reference. If you are studying, just focus on the summary “Key points to remember” column.

The table is my own research. If there are details that I have left out then please let me know. I hope to have this as an evolving table which will change and improve over time as new data becomes available.

Screen Shot 2014-06-29 at 10.18.43 am

Summary Table of T2DM hypoglycaemic agents 29/06/14 – Click for link

 

Conflicts of Interest – None! – Let me make it clear I get no money from anyone (other than my patients when I treat them). My only interest in this topic is getting the best outcome for my patients (and hopefully help clarify some of the information for other doctors in Australia!)

 


A few other useful diabetic items


 

Brilliant websites for resources and information

RACGP Handbook (getting bit big for the hand though…) – LinkScreen Shot 2014-06-29 at 11.25.38 am

 

Diabetes Australia – LinkScreen Shot 2014-06-29 at 11.25.43 am

 

Australian Diabetes Council – LinkScreen Shot 2014-06-29 at 11.28.56 am

 

National Diabetes Services Scheme (NDSS) – LinkScreen Shot 2014-06-29 at 11.25.57 am

 


Abbreviated stepwise approach to T2DM in Australia – Flow diagram for diagnosis Link (based on T2DM handbook RACGP)

  1. Screen patients who come in (some are obvious, others you can use the AusDRISK scoring survey – (Link))
    Turbine
  2. Send them for fasting BSL. If > 7 then repeat again. If >7 again then T2DM! If fasting BSL between 5.5-6.9 then off for a fasting Glucose Tolerance Test (GTT).         (Can we use HbA1c? Currently not funded – but info on the flow diagram above…)
  3. If fasting GTT > 11 at 2 hrs (or >7 fasting) then T2DM!
  4. Then you do a lot of counselling and education etc (info sheets here – Link). Organise your GP Management Plan and Team Care Arrangement (Link) and Diabetes cycle of care (Link)
  5. Then you do your Hba1c and tests (An example from Tassie – Link). Can do lifestyle management for 3 mths if borderline. Consider medication in very high Hba1c (>7 or depends on patient).
  6. Aim target of Hba1c (controversial) – approx <7% but depends on patient. (link)
  7. Start medication – Metformin is FIRST LINE. Therapeutic guidelines suggests starting at 500mg BD with food. Can titrate up to 3g/day (1g TDS).
  8. Second line?? Have a look at this flow chart (link) and the table below. Usually start the medication and then review 3mthly including follow up testing and examinations (as per above cycle of care)

Mode of Action – Physiology Refresher

Metformin:

Contingency Plan

XKCD

  • Decreases gluconeogenesis of the liver
  • Increases glucose uptake at muscle.
  • Increases insulin sensitivity in the liver

Sulfonylurea:

  • Causes an increased release of insulin from the pancreas

Glitazones:

  • Increases insulin sensitivity

SGLT-2 inhibitors:

  • These BLOCK reuptake of glucose by the nephron and therefore you urinate out the extra glucose

Acarbose:

  • Inhibits enzymes required to digest carbohydrates

DPP4 Inhibitors: (Remember this is ONE STEP BEFORE GLP1 agonists – Byetta – so remember them together!)

  • Glucagon increases blood glucose –> DPP4 inhibitors increase incretin. Incretin BLOCKS glucagon release and increases insulin release. This DECREASES blood glucose.

 

Combination drugs available that I could find:

  • Avandamet = Rosiglitazone + Metformin
  • Galvumet = Vildagliptin + Metformin
  • Glucovance = Glibenclamide + Metformin
  • Janumet XR = Sitagliptin + Metformin
  • Kombiglyze XR = Saxagliptin + Metformin
  • Nesina Met = Alogliptin + Metformin
  • Trajentamet = Linagliptin + Metformin

 

https://i1.wp.com/www.sangrea.net/free-cartoons/medical_brain-surgery.jpg

Thanks to Sangrea.net

Finally, PBS prescribing restrictions.

I have summarised it because the proper ones are very detailed. The original PBS restrictions are here – Link

 

SUMMARY of PBS restrictions for second line medications (other than sulfonylureas) (they are all SLIGHTLY different so see full details on PBS website – Link).

Generally, you will need these to use a second line agent funded by PBS (other than a sulfonylurea)

  1. Must be used either with Metformin OR Sulfonylurea,
  2. Must have a contraindication or intolerance to combination of Meformin and Sulfonylurea
  3. Must have HbA1c measurement >7%, within the last 4mths, PRIOR to intiation despite treatment with metformin or sulfonylurea AND you must write this in the notes

Rob’s Diabetes Type Two cents worth…
So the options available are broad; but lets narrow things down. Metformin is first line. I will titrate this up to control Hba1c USUALLY below 7% (If they are elderly, or have other medical comorbidities I may have a target a little higher than this – I will discuss it with my patient). If I cannot get control of their Hba1c then I will consider starting Sulfonylurea as per the PBS guidelines. If my patient in intolerant of sulfonylureas or there are contraindications (eg. the patient is elderly and hypoglycaemia could be dangerous, or the patient is significantly worried about the possibility of gaining weight) then I will look at other second line agents.

I cannot tell you which one to use. My basic suggestion, however, would be to look at your usual demographic of patients and get experience and learn about one or two agents. For example, if most of your patients are postmenopausal women at high risk of vaginal infections then don’t spend alot of time learning about SGLT2 inhibitors.

If your demographic has alot of GI issues (a large proportion of IBS patients) then perhaps learning all about acarbose would not be so useful.

Either way, I would get used to one or two agents and know the ins and outs of these. Have your own framework in your head about how you will titrate up therapy (RACGP loves this sort of stuff in fellowship exams).

Remember, if you are on two maximal agents and Hba1c is still > 7% you might want to start discussions about basal insulin.

Good luck. Use the above resources wisely and never forget to consider if your medication plan is not working – check to see how, and if, the patient is taking the medication you have prescribed!

* Top picture from: Link

 

 

 

 

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4 thoughts on “FOAM4GP Map – Type 2 Diabetes tablets – How many are there now!?!

  1. Practically:
    metformin –> +sulfonylurea –> +insulin (& -sulfonylurea)

    You might use a sulfonylurea or insulin as first line if someone is particularly hyperglycaemic at diagnosis, but it would be a good idea to get guidance from an endocrinologist in such a setting in any case.

    My 2c: there is very little practical benefit of the newer oral agents over sulfonylureas (especially, the slow release ones). After the fallout of the glitazones, I’d wait for better safety data before making too much out of the apparent theoretical benefits of the newer drugs. I’m also of the view that we (as prescribers) need to resist the onward creep towards prescribing increasingly expensive diabetes drugs (e.g., the gliptins) that have no patient-meaningful benefits over the vastly cheaper older drugs.

    • Hi Michael,

      I agree. My practice has been metformin –> sulfonylurea –> prepare for insulin and basal bolus. I understand the desire for another oral agent so patients can avoid insulin and the social difficulties and high ‘health workload’ associated with it. It can have weight issues for some patients.

      All of that aside however, I don’t see any of these ‘intermediate’ agents has filled the void between medications and insulin. I remain, underwhelmed but hopeful.

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