Oral Hypoglycaemics to give or not to give

core0 · Nov 11, 2007

Hello everyone,
I'm new to the group. I have been on maternity leave for the past 2 years with my 4th child. I am currently doing clinical updates to re-enter the hospital system. I've been out of acute care for 3 years.
My question is when to withhold oral hypoglycaemics. ie do you give them when BSL is within low normal range, asuming they will eat their meal. I would also be looking at previous BSL's. If for example the patient has just been admitted. (I would ask whats normal for him), or BSL's have been higher but still within normal limits.
Thanks

Oral hypoglycemics work differently than insulin. You generally should not hold oral hypoglycemics except in the face of profoundly low blood sugars.

Remember that even if the patient does not eat there is still glucose released from the liver. The treatment goal is completely different than with insulin. With insulin you are treating the lack of insulin production or insulin resistance in the case of insulin dependent type II diabetics. With oral hypoglycemics the body still produces insulin but has become resistant. The body can still regulate insulin production in the case of not eating.

There are six types of drugs generally used here. Metaglitinides like Prandin and Sulfonoureas like Glucotrol work by increasing insulin production. Biguanides like Metformin work by decreasing hepatic glucose production and increasing insulin sensitivity in peripheral tissues. Thiazolinediones like Avandia work in a similar manner. Incretins like Byetta are newer drugs that work by enhancing glucose inhibition. Finally alpha-glucosidase inhibitors like Precose work by inhibiting carbohydrate absorption.

So if you look at the six types of medications only two (metaglitinides and Sulfonoureas have the potential to cause hypoglycemia in patients. This really only happens if they have been NPO for a while. If a patient taking alpha-glucosidase inhibitors don't eat there will be no effect. Biguanides and Thiazolinediones have no real adverse effects if people don't eat. They tend to be true BID drugs and the bodies natural insulin regulation will take care of things. Incretins allow normal glucagon response to hypoglycemia. I tend to hold them the morning of any procedures if the patient is NPO the night before (I have been told by endocrine that I don't need to do this).

So realistically only Sulfonoureas are associated with hypoglycemia. It is rarely reported in Metaglitinides. It is really not reported in other druges.

The other issue is what do the orders say. If you are holding meds without parameters then this is a problem. Of course as usual if you are uncomfortable with an order then call and get it clarified.

Here is an article that is somewhat dated but a pretty good coverage of oral anti hypoglycemics.

http://www.aafp.org/afp/20010501/1747.html

David Carpenter, PA-C

anne65 · Nov 11, 2007

Hello David,

Thankyou for your reply, it was very helpful.

Just one further question, to yourself or the group, Combination therapy with sulfonylureas and metformin. Is this combination something to be concerned about, or phone the doctor about if bsl is low normal, reading that metformin potentiates the hypoglycaemic effect when taken with the sulfonylureas or insulin? I get that you generally should not hold oral hypoglycaemics except in profound low bsl's.

Thanks again

core0 · Nov 11, 2007

Hello David,
Thankyou for your reply, it was very helpful.
Just one further question, to yourself or the group, Combination therapy with sulfonylureas and metformin. Is this combination something to be concerned about, or phone the doctor about if bsl is low normal, reading that metformin potentiates the hypoglycaemic effect when taken with the sulfonylureas or insulin? I get that you generally should not hold oral hypoglycaemics except in profound low bsl's.
Thanks again

Hopefully there aren't a whole lot of people on that particular combination for that reason (although with the new data on Avandia they may be making a comeback). When it was used, I still didn't see a lot of hypoglycemia even with low normal blood sugars. Generally if you are seeing a pattern of low normal blood sugars then it may be worthwhile to ask the prescriber about adjusting doseages. If you have to give D50 or OJ then it would definitely be worth having that discussion. Generally I don't worry about oral hypoglycemics in the hospital. They don't produce the death defying episodes that insulin overdoses do and you are giving them in a place where the blood sugar is regularly checked by people who actually know how to do it. That being said, in surgery we usually take them off oral meds and put them on an insulin sliding scale since its hard to know what their PO status is day to day. Not sure if I answered your question. Hope this helps.

David Carpenter, PA-C