Methahemoglobinemia & Dental Work

A few years ago I had to go into the hospital for emergency surgery. After the surgery, I was given a substance called Hurricane Spray to help deal with a sore throat caused by a tube running down my nose.

After an hour or so of using the Hurricane Spray my lips and fingernails started turning blue. My oxygen stats were also plummeting fast. To make a long story short, I ended up spending the night in the ICU where I was eventually diagnosed with Methahemoglobinemia (where there is not enough hemoglobin to carry oxygen to the body). My ER doctors said that this reaction was likely caused by the benzocaine found in the Hurricane Spray. They handed us a list of other things that could cause Methahemoglobinemia and "caine" medications were present on that list.

The problem is, I'm now looking at having dental work done for possible cavities and eventual extraction of all four of my wisdom teeth. Obviously, dentists use things such as novocaine, benzocaine, prilocaine, ect. as a local anestetic during procedures. What can I do? Is there any safe "caine" I can have?

I really don't want to go under general anestesia for something as simple as a cavity filling.

Hi and ,

that must have been really scary .
The good news is that dentists don't use ester anaesthetics like novocaine or benzocaine for local anaesthesia (novocaine hasn't been used for many decades, and I think one of the reasons for the change may have been the incidence of allergic reactions to it).

The local anaesthetics used for dentistry nowadays are amides, which virtually nobody is allergic to. Esters can be found in topical anaesthetic (numbing gel used before an injection) though, and it's very important that you make your dentist aware of your medical history (this doesn't sound like something you'd forget to mention anyway ).

I'm not sure what the recommendations for allergy testing are in a case like yours. As far as I'm aware, there is no cross-allergenicity between esters and amides (though a person who is allergic to one ester is likely to be allergic to other esters as well). But I'm not a health professional and it would be best to ask your doctor and/or dentist if they recommend a test.

You can find more info here: Bad reactions to local anaesthetic

Thank you,

It is a matter I will definitely be discussing with my dentist and hopefully he'll know what I can do. I'd already read the page you linked in your post which started me on a search for safe "caines" or other people that have had a similar problem and needed dental work. No luck unfortunately. I'd love to undergo allergy testing if it is effective at detecting Methahemoglinemic reactions, but haven't really read about testing done on such a condition as they're usually looking for reactions like swelling or hives.

I did find something on the scary side online in a dental dictionary referring to Methahemoglobinemia. It said: "An abnormality of hemoglobin in which the iron is in the ferric state as a result of exposure to industrial substances or the ingestion of toxic agents such as phenacetin, sulfonamides, aniline nitrates, or nitrates."

I'm no doctor and don't know what all this means, but are sulfonamides the same thing as amide caines?

I have read on Wikipedia that Benzocaine as well as Prilocaine are prime triggers for Methahemoglobinemia, both of which, as you probably know, are very common in dentistry.

Benzocaine is only used in numbing gel in dentistry (so it's easily avoided). Prilocaine, unlike benzocaine, is an amide.

The most commonly used local anaesthetic used in dentistry is lidocaine/lignocaine (same thing, but different names in US/UK). At a guess, the second most common one is articaine.
I think prilocaine is sometimes used when a person doesn't want epinephrine in their anaesthetic. In that case, it's called "citanest plain" - but it wouldn't be the first drug of choice. Are you actually allergic to prilocaine? Although prilocaine can be used as a topical anaesthetic (numbing spray), the chemical composition is quite different from benzocaine.

Sulfonamides are something different again - they are used for some antibiotics, diuretics, anticonvulsants etc, but not for local anaesthetics.

Thanks, I just saw the "aminde" in the dictionary and thought sulfonamides might have some sort of link to amide caines.

I've never had allergy testing, and therefore have do not know if I would have a reaction to Prilocaine or not. I was just looking up caines on Wikipedia and according to that site both Benzocaine and Prilocaine were common triggers of Methahemoglobinemia.

From the Wikipedia site: "In some patients, a metabolite of prilocaine may cause the unusual side-effect of methaemoglobinaemia. And may be treated with methylene blue."

The Methaemolobinaemia entry in Wikipedia has an Acquired Methaemoglobinaemia section. It lists some common causes including Benzocaine, Prilocaine and Articaine.

Lidocaine is the only one not mentioned, however it is still a local anestetic and therefore, I guess it triggering the same reaction is always a possibility. :/

Lignocaine is probably totally safe, TBH I would bring you into my hospital clinic and try "challenging" your system with a small amount of lignocaine, then see if there was any problem. Not all dentists may have this facility, so you may need to go to a larger institution someplace.