Sulfa allergy -Meloxicam

[jmail]

Hey guys, had a patient with sulfa/sulfonamides allergy who I dispensed Meloxicam.
Pt states that sulfa is in meloxicam structure so she is having anaphylactic reaction due to taking Meloxicam 8 hours earlier
I checked Lexicom/Clinical pharmacology, and I just cant find it being as contraindication...
Of course, pt is threatening to go to a hospital/sue/etc...
Am I overlooking it as a contraindication? Can you guys double check me?

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[WVUPharm2007]

Use your brain. Just because a molecule has a sulfer molecule in it doesn't mean they are all cross sensitive to each other. The O=S=O moiety is at the base of the molecule in celecoxib and in the middle of the molecule in sulfamethoxazole. Cross sensitivity is always possible, but is it really that likely in this case?

 

[lord999]

Please read that sentence again to yourself:

"Pt states .... she is having anaphylactic reaction"

Are the tenses correct? Because if they are, that can't be possible. If you are having an anaphylatic reaction presently, the power of speech is not within you. If not, clean it up. Now, if she did, and she used epinephrine, and then she is calling you, then the below applies.

But yes, meloxicam does have a carboxamide (which is not the same as a sulfonamide) and yes, it could. The question is whether or not she really has a true sulfa moiety allergy.

 

[WVUPharm2007]

But yes, meloxicam does have a carboxamide (which is not the same as a sulfonamide) and yes, it could. The question is whether or not she really has a true sulfa moiety allergy.

That seems dubious to me. In celecoxib, the R-CO-N-RR moiety is in the interior of the molecule and flanked by an array of fluorine molecules, whereas in sulfamethoxazole, it is, again, at the base of the molecule.

Just hold on to this, OP.

Sulfonamide cross-reactivity: Is there evidence to support broad cross-allergenicity?

AbstractPurpose. Published and manufacturer-provided data regarding potential cross-reactivity between antibacterial and nonantibacterial sulfonamide agent

academic.oup.com

To quote, "A review of the professional literature and manufacturer-provided data did not find convincing evidence of broad cross-reactivity between antibacterial and nonantibacterial sulfonamide agents. "

 

[lord999]

That seems dubious to me. In celecoxib, the R-CO-N-RR moiety is in the interior of the molecule and flanked by an array of fluorine molecules, whereas in sulfamethoxazole, it is, again, at the base of the molecule.

Just hold on to this, OP.

Sulfonamide cross-reactivity: Is there evidence to support broad cross-allergenicity?

AbstractPurpose. Published and manufacturer-provided data regarding potential cross-reactivity between antibacterial and nonantibacterial sulfonamide agent

academic.oup.com

To quote, "A review of the professional literature and manufacturer-provided data did not find convincing evidence of broad cross-reactivity between antibacterial and nonantibacterial sulfonamide agents. "

I agree, it is dubious, that's why I wrote that. It could in theory, but it's only been case reports. Meloxicam was formulated like ethocrynic acid to get rid of the full sulfa, but it still has the chance of cross. That said, I agree completely with your assessment as a true sulfa allergy or sulfone allergy is someone that everyone is ultra careful around when it does happen. The patient isn't going to call you about this, the hospital will!

 

[RxPreceptor]

lone pair of electrons usually only in sulfa antibiotics; a substituted sulfonamide (no lone pair of electrons) is very unlikely for cross reactivity.

A reading from Lexicomp:
"Sulfonamide ("sulfa") allergy

The FDA-approved product labeling for many medications containing a sulfonamide chemical group includes a broad contraindication in patients with a prior allergic reaction to sulfonamides. There is a potential for cross-reactivity between members of a specific class (eg, 2 antibiotic sulfonamides).Ref However, concerns for cross-reactivity have previously extended to all compounds containing the sulfonamide structure (SO2NH2). An expanded understanding of allergic mechanisms indicates cross-reactivity between antibiotic sulfonamides and nonantibiotic sulfonamides may not occur or at the very least this potential is extremely low.Ref In particular, mechanisms of cross-reaction due to antibody production (anaphylaxis) are unlikely to occur with nonantibiotic sulfonamides. T-cell-mediated (type IV) reactions (eg, maculopapular rash) are less well understood and it is not possible to completely exclude this potential based on current insights. In cases where prior reactions were severe (SJS/TEN), some clinicians choose to avoid exposure to these classes.Ref"

 

[Old Timer]

Did your software flag the interaction? Did you override it? The wise thing to do in a case like this is to question the patient about the nature of their allergic reaction to Sulfa antibiotics and to inform them there is very small chance they might be allergic to this and they should review it with their MD before proceeding with this therapy.

The evidence for a cross allergenicity is sketchy at best and is most likely to be a hyper active immune response. In the one study where there was a correlation between Sulfa antibiotics and non antibiotic Sulfa drugs has the problem of having a bigger correlation the beta lactams leading the authors to the hyper active immune response and not a true allergy

 

[beautifulrobot]

Really great discussion. The only other thing I would add is that even if there is no evidence of cross-reactivity, there is always the theoretical risk of hypersensitivity to almost any drug. I realize this isn't directly related to the OPs question, but just wanted to throw that out there. It's possible the patient is both allergic to meloxicam and sulfa antibiotics without it necessarily being a cross-reaction situation. If you counseled the patient on the potential risk for hypersensitivity, including anaphylactic reactions, or supplied them with the medication guide that you're required by law to give to them, AND documented that you've done so, then you've covered your butt and likely have nothing to worry about from a legal liability perspective (disclaimer: not a lawyer, take everything I say with a grain of salt). In addition to all the great articles folks have referenced above, the FDA-approved label/package insert for meloxicam does not mention anything about sulfa cross-reactions, which is further reassuring from a legal perspective.

 

[JustFillIt]

This is absolute rubbish... that is all I have to say about it.

I loathe the fact that we work in a profession where the decisions we make can be used as a lottery for the general public.

 

[owlegrad]

I am inclined to agree with giga. My thoughts run similar to cephalosporins and PCN allergies in that you can be allergic to both but it probably isn't really a cross-reaction.

I am sorry you have a patient coming after you but I doubt you need to worry about legal action. Do you have professional liability insurance? If so, I suggest you contact them ASAP.

 

[rxkrafted]

This story sounds so sketch. You have a patient who is experiencing anaphylaxis and this patient decides to make a call to the pharmacy before medical emergency to complain? Then, patient has the knowledge or time to find out the molecular structure and sulfa being in it?

 

[Xarelto-10]

That seems dubious to me. In celecoxib, the R-CO-N-RR moiety is in the interior of the molecule and flanked by an array of fluorine molecules, whereas in sulfamethoxazole, it is, again, at the base of the molecule.

Just hold on to this, OP.

Sulfonamide cross-reactivity: Is there evidence to support broad cross-allergenicity?

AbstractPurpose. Published and manufacturer-provided data regarding potential cross-reactivity between antibacterial and nonantibacterial sulfonamide agent

academic.oup.com

To quote, "A review of the professional literature and manufacturer-provided data did not find convincing evidence of broad cross-reactivity between antibacterial and nonantibacterial sulfonamide agents. "

I’m gonna admit Medchem is not my cup of tea, so, how does one determine wether there will be possible cross reactivity if two drugs have the same or similar molecular entities?

is it based on where the location of certain molecular entity like mentioned above (located at the base or in the center) ?

thanks !

 

[RxPreceptor]

Hey guys, had a patient with sulfa/sulfonamides allergy who I dispensed Meloxicam.
Pt states that sulfa is in meloxicam structure so she is having anaphylactic reaction due to taking Meloxicam 8 hours earlier
I checked Lexicom/Clinical pharmacology, and I just cant find it being as contraindication...
Of course, pt is threatening to go to a hospital/sue/etc...
Am I overlooking it as a contraindication? Can you guys double check me?

Like others have mentioned...does this sound like anaphylaxis to you knowing what anaphylaxis is?

 

[MilknCheerios]

I've never heard of a delayed anaphylactic reaction.

The consensus here is that the patient doesn't have a case and, if anything, is looking for a quick payout or just trying to make your life difficult.
You can't stop the patient from making these ridiculous claims but at least have the above evidence ready should you need it.

 

[jmail]

Thank you guys so much!
I work at Walgreens and we do 400 rxs per day, 600 on a busy day. We type our own scripts, and there is usually one pharmacist on duty who has to verify all the scripts ( we do have two hours overlap 2 days per week). That day we had corporate visiting us, and they push us to improve verified by promised time (how quick we make rxs ready), they threatened to fire my rxm if she does not improve it and she said they may fire me too if I am too slow... I think that day I was just too stressed out with the presence of people from corporate...I know its not an excuse, but its getting harder and harder to work at retail...
The interaction did come up in the computer but I overrode it. Then I wanted to go back and cap it (cap means to make a note in the computer so it would force me or another Rph to talk to the patient) but I either got distracted and forgot, either something else, anyway, somehow it slipped...

Few of my friends were looking for other jobs for few months and they cant find anything... I honestly, just need to survive somehow till next year, because my son is graduating high school. Then I can sell my house and move somewhere else...

 

[Xarelto-10]

Thank you guys so much!
I work at Walgreens and we do 400 rxs per day, 600 on a busy day. We type our own scripts, and there is usually one pharmacist on duty who has to verify all the scripts ( we do have two hours overlap 2 days per week). That day we had corporate visiting us, and they push us to improve verified by promised time (how quick we make rxs ready), they threatened to fire my rxm if she does not improve it and she said they may fire me too if I am too slow... I think that day I was just too stressed out with the presence of people from corporate...I know its not an excuse, but its getting harder and harder to work at retail...
The interaction did come up in the computer but I overrode it. Then I wanted to go back and cap it (cap means to make a note in the computer so it would force me or another Rph to talk to the patient) but I either got distracted and forgot, either something else, anyway, somehow it slipped...

Few of my friends were looking for other jobs for few months and they cant find anything... I honestly, just need to survive somehow till next year, because my son is graduating high school. Then I can sell my house and move somewhere else...

Hang in there for as long as you can while looking for a new opportunity.
Your friends are correct, the job market is beyond ugly.

 

[jmail]

Xarelto, you very sweet! Thank you so much for your kind words!
I do appreciate it!

 

[Sine Cura]

How often do you have to explain what "sulfate" in ferrous sulfate is?

 

[jmail]

How often do I explain what sulfate is in Ferrous sulfate? To patients?
Ive never explained that to any patient