injectable benadryl as local anesthetic?

[stoic]

so an attending at my school mentioned a while ago that you can use injectable benadryl as an effective local anesthetic (and claims to have done so). i've wondered - somewhat skeptically - about this for a while and thought i'd post the question here for some resolution.

has anyone else heard of this? anyone ever actually used it? the attending who mentioned this is pretty good... but i think i'd like some independent verification before i suggest this for a pt w/lido allergy and risk getting laughed out of the room.

?????

thanks,
dave

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[bulgethetwine]

so an attending at my school mentioned a while ago that you can use injectable benadryl as an effective local anesthetic (and claims to have done so). i've wondered - somewhat skeptically - about this for a while and thought i'd post the question here for some resolution.

has anyone else heard of this? anyone ever actually used it? the attending who mentioned this is pretty good... but i think i'd like some independent verification before i suggest this for a pt w/lido allergy and risk getting laughed out of the room.

?????

thanks,
dave

True story. Particularly useful for those allergic to lidocaine.

 

[FoughtFyr]

so an attending at my school mentioned a while ago that you can use injectable benadryl as an effective local anesthetic (and claims to have done so). i've wondered - somewhat skeptically - about this for a while and thought i'd post the question here for some resolution.

has anyone else heard of this? anyone ever actually used it? the attending who mentioned this is pretty good... but i think i'd like some independent verification before i suggest this for a pt w/lido allergy and risk getting laughed out of the room.

?????

thanks,
dave

On point: http://www.ncbi.nlm.nih.gov/entrez/...=Retrieve&dopt=abstractplus&list_uids=8198302 but if you look at the related articles, you will note that the head to head comparisons find diphenhydramine far inferior to lidocaine. so it's main utility is in those who are allergic to lido...

That said, I've never used it, I'm just looking at the research.

- H

 

[polygonal]

I've seen it used once (pt was allergic to "all caine drugs"). She said it burned but it did work. It took a little while though.

 

[EctopicFetus]

One of the attendings here mentioned it to me. Interesting but makes sense we should know this since it is good to have lots of options at your disposal!

 

[southerndoc]

I've never used it before as I've never had a patient allergic to lidocaine that needed suturing.

How much Benadryl do you use? Do you infiltrate just like standard lidocaine? If so, must the Benadryl be diluted to keep from injecting too much?

 

[mikecwru]

so an attending at my school mentioned a while ago that you can use injectable benadryl as an effective local anesthetic (and claims to have done so). i've wondered - somewhat skeptically - about this for a while and thought i'd post the question here for some resolution.

has anyone else heard of this? anyone ever actually used it? the attending who mentioned this is pretty good... but i think i'd like some independent verification before i suggest this for a pt w/lido allergy and risk getting laughed out of the room.

?????

thanks,
dave

You can use benadryl; some people say that infiltrating saline can be somewhat beneficial.

People who are allergic to lidocaine are usually allergic to the preservative methylparaben in it. You can use the cardiac lidocaine in a code box which does not have this preservative.

mike

 

[littlefield]

I used Benadryl as local once, and that was a hematoma block for a distal radius reduction. It worked nicely.

 

[docB]

You can use benadryl; some people say that infiltrating saline can be somewhat beneficial.

People who are allergic to lidocaine are usually allergic to the preservative methylparaben in it. You can use the cardiac lidocaine in a code box which does not have this preservative.

mike

Mike is right that it's the preservative that the majority of people are allergic to (just like with the old, pre Cerebyx, IV dilantin). But be careful. Some people are lido allergic. If you ignore their stated allergy and procede with cardiac lido and they have a problem you are hosed.

As always ask what the "allergic reaction" was. I've foud several times that the allergy was the the lido stings.

 

[GeneralVeers]

Mike is right that it's the preservative that the majority of people are allergic to (just like with the old, pre Cerebyx, IV dilantin). But be careful. Some people are lido allergic. If you ignore their stated allergy and procede with cardiac lido and they have a problem you are hosed.

As always ask what the "allergic reaction" was. I've foud several times that the allergy was the the lido stings.

My favourite allergy is: "I just didn't feel good after taking the medicine"

 

[bulgethetwine]

Mike is right that it's the preservative that the majority of people are allergic to (just like with the old, pre Cerebyx, IV dilantin). But be careful. Some people are lido allergic. If you ignore their stated allergy and procede with cardiac lido and they have a problem you are hosed.

As always ask what the "allergic reaction" was. I've foud several times that the allergy was the the lido stings.

I don't get it -- I mean, after they describe their "allergic reaction", regardless of whether it is pruritis, headache, swelling, or airway constriction, how does this help differentiate true lido allergy from preservative?

Agree with the sentiment, though... if someone says their allergy is pruritis and a hive or two, I have gone ahead and used cardiac lido. If someone says they had breathing difficulty, I wouldn't risk them or my license. Maybe that's what you meant, I'm a little tired!

 

[southerndoc]

My favourite allergy is: "I just didn't feel good after taking the medicine"

One patient I had claimed to be allergic to epi. "What's your reaction?" "It causes my heart to race." Duh!

Of course I did have one patient who claimed to be allergic to epi. I asked her what her reaction is. "Worsens my anaphylaxis. My allergist did tests. I'm allergic to one of the protein contaminants in commercial epi." OK, I'll buy that one.

 

[docB]

I don't get it -- I mean, after they describe their "allergic reaction", regardless of whether it is pruritis, headache, swelling, or airway constriction, how does this help differentiate true lido allergy from preservative?

Agree with the sentiment, though... if someone says their allergy is pruritis and a hive or two, I have gone ahead and used cardiac lido. If someone says they had breathing difficulty, I wouldn't risk them or my license. Maybe that's what you meant, I'm a little tired!

You're right. I didn't explain that well. I meant that if the "allergy" is bogus like in stings, I get nauseated, headache, and so on I'd be willing to try the cardiac lido. If the allergy was "my throat closed up and I was on a vent for a month." I'd go with benadryl.

 

[docB]

Speaking of patients and their allergies I had this one girl who I was doing the meningitis rule out with CT/LP. I wanted to get some antibiotics in as quickly as possible. Unfortunately she had the typical childhood PCN allergy. I asked what the reaction was. "I don't know. My mom knows." Very helpful as mom's in some other state. So I explain that we'll be giving her a second line drug that's not as good. I go back to the desk and am writing the order for chloramphenicol when the boyfriend walks up to the desk with his cell phone. He's talking to the mom in wherever. "She says the reaction was a guy's name. Steve something."
"Stevens-Johnson?" I asked.
"Yeah! That's it!"
So needless to say I didn't give her the pen based stuff.

 

[Jeff698]

One patient I had claimed to be allergic to epi. "What's your reaction?" "It causes my heart to race." Duh!

Sort of like that dreaded allergic reaction to succs.... respiratory arrest.

I just hate that one.

Take care,
Jeff

 

[nimbus]

I once injected a 0.1 ml of undiluted benadryl 50mg/ml skin wheal into a bug bite on my hand that was driving me nuts. It was very effective and definitely numbed up the spot. The only problem was the spot remained numb for a good 3 months.

 

[lattimer13]

Speaking of patients and their allergies I had this one girl who I was doing the meningitis rule out with CT/LP. I wanted to get some antibiotics in as quickly as possible. Unfortunately she had the typical childhood PCN allergy. I asked what the reaction was. "I don't know. My mom knows." Very helpful as mom's in some other state. So I explain that we'll be giving her a second line drug that's not as good. I go back to the desk and am writing the order for chloramphenicol when the boyfriend walks up to the desk with his cell phone. He's talking to the mom in wherever. "She says the reaction was a guy's name. Steve something."
"Stevens-Johnson?" I asked.
"Yeah! That's it!"
So needless to say I didn't give her the pen based stuff.

chloramphenicol huh? i remember last year on ms3 internal medicine rotation we had a lady at the VA that had urosepsis and was allergic to just about every antibiotic possible, then the attending decided on chloramphenicol...pharmacy called 5 minutes after the order was put into the computer and despite it being on formulary refused to release the order because of the risk of aplastic anemia. can't remember what she finally got.

 

[docB]

chloramphenicol huh? i remember last year on ms3 internal medicine rotation we had a lady at the VA that had urosepsis and was allergic to just about every antibiotic possible, then the attending decided on chloramphenicol...pharmacy called 5 minutes after the order was put into the computer and despite it being on formulary refused to release the order because of the risk of aplastic anemia. can't remember what she finally got.

Yup. It sucks. But check out Sanford for meningitis and documented PCN allergy. Chloramphenicol+Bactrim+Vanco and a partridge in a pear tree.

 

[BKN]

chloramphenicol huh? i remember last year on ms3 internal medicine rotation we had a lady at the VA that had urosepsis and was allergic to just about every antibiotic possible, then the attending decided on chloramphenicol...pharmacy called 5 minutes after the order was put into the computer and despite it being on formulary refused to release the order because of the risk of aplastic anemia. can't remember what she finally got.

When I first got to El Paso (mid-80s), the docs in Mexico were using it far more than in the US and for lesser infectious diseases. I talked to a couple of them about it. Their rationale was "Well, the incidence is 1 in 250,000. That's about the same as anaphylaxsis with injectable penicillin. Most other drugs have serious side effects at least that often. Why does the FDA give some much attention to this one drug?"

Well, they didn't quite convince me, but it is an argument.

 

[sdn1977]

Yes - the antihistamines work as local anesthetics because of their effect on the Na channel. Diphenhydramine works, but promethazine works better. You don't need that much for a small area & a bit of epi will keep it locally for longer while you get your suturing done.

For the local anesthetics, there are two types: esters (procaine, chloroprocaine & tetracaine) and amides (lidocaine, prilocaine, mepivicaine, bupivacaine, etidocaine). There are a few other types which have been newly introduced, primarily for dental use.

Most inherent allergies are to the ester type because of its structure. There are fewer allergies to the amides, altho as someone pointed out - it is usually to the additives - the paraben preservatives you are familiar with, but there are more reactions to the sulfite which is added to some as an antioxidant when the anesthetic is mixed with a vasoconstrictor (dental anesthesia). If your pt said they had a reaction at the dentist, its probably due to this. They just switch out the epi, change the choice of amide & rarely use ester types anymore at all.

You can switch to an amide without a preservative - Carbocaine or Marcaine, switch to an ester type (Novocain, Nesacaine or Pontocaine) or get the lidocaine from the code cart as someone else pointed out......or try the antihistamine.

 

[waterski232002]

Nobody ever answered the question about how to infuse benadryl as local anesthetic. Do you need to dilute it???

 

[docB]

That's so unlike EPs to get off topic on something like... oh look, something shiny!

(apologies to socute)