In geriatrics, I see a lot of patches being used. There is definitely some convenience associated with the use of patches as we can avoid the GI tract. I have seen my fair share of mistakes as well. Here’s a breakdown:
- Fentanyl patches get into systemic circulation and are meant to do so. You do NOT place the patch at the site of the pain!
- I’ve seen a few cases of providers and patients not understanding that Lidoderm patches should be removed for a period of time (recommended dosing is 12 hours on/12 hours off). The risk of leaving the patches on for 24 hours is accumulation of lidocaine in the systemic circulation.
- Patches are advantageous in the fact that you may not have to change them very often. However, you need to know the recommended timing of patch change! Here’s 5 common medications with patch formulations that I see in my practice.
- Clonidine – change weekly
- Fentanyl – change every 3 days (rare cases may require 2 days)
- Lidoderm – daily with 12 hours on/12 hours off
- Oxybutynin – twice weekly
- Exelon – daily
- Lidoderm patches are intended to benefit the patient locally. Lidoderm (lidocaine) patches you SHOULD place at the site of pain.
- Of the 5 patches listed above, they all get into systemic circulation to exert their activity (except Lidoderm).
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You should add that it is ok to cut the Lidoderm (before removing the backing) and use in different smaller areas but DEFINITELY not Duragesic.
Thanks for the comment Bonnie!
Interesting topic.
Some generic fentanyl patches may actually be cut without a risk of overdose, due to their design. They are matrix, not reservoir, patches. Consult the manufacturer package insert.
I often recommend my patients cut their lidocaine patches to approximately fit the target spot: in half for each knee; in strips for hands, feet, fingers; etc. Most of the utility in this is a longer days supply for the cost, but it can provide better skin contact and drug transfer as well.
In general, older patients like to use heating pads. Remind them to never apply a heating pad over a patch. It could result in overdose or burns. Never freeze patches, or microwave them, either… seems obvious, but then so does unwrapping a suppository before insertion.
How significant is the risk of toxicity really with longer patch durations (e.g. 16, 18, or 24 hour use) though? I have had pharmacists tell me that this risk is quite small.
It probably depends upon the drug and if an alternative (inappropriate) route of administration is used. Fentanyl in my opinion is going to be the most dangerous in the majority of circumstances.
Let’s say Lidoderm patches. I agree that I would definitely be more concerned with fentanyl.