Drug Allergies

[ultracet]

Why do people pretend that people with a sufla allergy will have no problems with Celebrex?

We even have one doctor who will argue literature and drug structure because their sales rep told them that was crap.

My questions is why?
As a person with allergies.... pen, ceph, and sulfa i hope someone out there is looking out for me...

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[Caverject]

Because my Pfizer rep told me so!

 

[Caverject]

and he also told me that if it doesn't work, I should use Bextra

 

[TotalKayOs]

for some reason people with sulfa allergies do not always react to cox2's. i'm trying to find literature to back it but so far it's a no go.

 

[Glycerin]

Why do people pretend that people with a sufla allergy will have no problems with Celebrex?

We even have one doctor who will argue literature and drug structure because their sales rep told them that was crap.

My questions is why?
As a person with allergies.... pen, ceph, and sulfa i hope someone out there is looking out for me...

I have a sulfa allergy, and I cannot take Celebrex. A few years back, I had a problem with my back, and my doctor prescribed Celebrex. At the time, I was not aware of the potential for an allergic reaction, but I knew that I was highly allergic to sulfa drugs (Septra does baaaaad things to me ). Luckily, the pharmacist who was filling my prescription knew of it, and the rx was changed to Vioxx...heh.

 

[jdpharmd?]

I have a few good cites on that one. It's true that a "sulfa antibiotic" allergy does not equal a "sulfa cox2" allergy. The sulfa antibiotics have an arylamine group para to the sulfa moeity. Cox2's just have the sulfa tossed in there.

Author Affiliation:
Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.

Authors:
Slatore CG; Tilles SA

Number of References:
60

Abstract:
Sulfonamide antibiotics can result in a wide variety of hypersensitivity reactions. No validated diagnostic tests are available for sulfonamide reactions; therefore, clinicians must rely on the combination of a careful patient history, review of medical records, and a sound knowledge base regarding the common clinical manifestations of sulfonamide hypersensitivity reactions. Although HIV-infected individuals have a high risk for hypersensitivity reactions to sulfamethoxazole, readministering the drug can usually be performed safely by using a desensitization protocol. Sulfonamide-containing medications that are not antibiotics also have the capacity for causing hypersensitivity reactions. Whether the sulfa moiety confers a risk of cross-reaction is controversial. The preponderance of available evidence suggests that sulfonamide antibiotics probably do not cross-react with sulfonamide nonantibiotics

Sulfonamide hypersensitivity.
Slatore CG - Immunol Allergy Clin North Am - 01-AUG-2004; 24(3): 477-90, vii
From NIH/NLM MEDLINE

NLM Citation ID:
15242722 (PubMed)
Cross-reactivity
Many medications other than SMX have a sulfonamide moiety (see Fig. 2 ), including some of the most widely prescribed drugs, such as diuretics, sulfonylureas, and the recently introduced cyclooxygenase-2 (COX-2) inhibitor celecoxib. A fundamental difference between sulfonamide-containing antibiotics and nonantibiotics is the presence or absence of an arylamine group at the N4 position. This group is present only in the sulfa antibiotics, and, given the evidence implicating the arylamine group in the SMX hypersensitivity reaction, the absence of this group should reduce the likelihood of cross-reactivity with sulfonamide nonantibiotics. This question has become controversial, because some patients report histories of reactions to sulfa antibiotics and sulfa nonantibiotics. Table 4 [49] summarizes several case reports and small experimental studies addressing sulfonamide cross-reactivity. In addition, a recently published epidemiologic study [50] addressed the question of sulfonamide cross-reactivity by evaluating the medical records of more than 20,000 patients. The investigators found that, for patients who previously reacted adversely to a sulfonamide antibiotic, the odds ratio for a reaction to another sulfonamide was 6.6; however, this same group of sulfonamide-allergic patients was more likely to report an adverse reaction to penicillin (odds ratio of 7.8). Patients with a history of a penicillin reaction were more likely to react to sulfonamide nonantibiotics than were patients with prior sulfonamide antibiotic reactions. It was concluded that sulfonamide cross-reactivity is unlikely, but that certain individuals have a general predisposition to adverse reactions to multiple drugs.

 

[ultracet]

thanks for the info JD...
I have also seen studies that the cross-sensitivites between penicillins and cephs is not related to actually their structure but perhaps the reaction occurs in "highly allergic" people.
Perhaps this is the same thing.

 

[MNnaloxone]

I run into this question about 4x/day here in clinic. Thanks for the source, JD.

 

[jdpharmd?]

thanks for the info JD...
I have also seen studies that the cross-sensitivites between penicillins and cephs is not related to actually their structure but perhaps the reaction occurs in "highly allergic" people.
Perhaps this is the same thing.

The article is a pretty interesting read. I suggest reading the full-text version, since there are a few more topics discussed (cross reactivity with furan rings of sulfa-diuretics, oral hypoglycemics, etc).

I recently overheard that the cross-sensitivites between penicillins and cephs was due to 1: "certain individuals' general predisposition to adverse reactions to drugs and 2: penicillin contamination/impure drugs during studies. I haven't looked into this one... yet.

 

[TotalKayOs]

futurerxgirl,
vioxx and celebrex are both in the same class. if you had a reaction to celebrex then there is a pretty good chance you would react to vioxx.

 

[Glycerin]

futurerxgirl,
vioxx and celebrex are both in the same class. if you had a reaction to celebrex then there is a pretty good chance you would react to vioxx.

It was several years ago when this occurred. At any rate, I didn't react to Vioxx and never took the Celebrex because it was changed to Vioxx.

However, from what little I know of structures and sulfa allergies, people with sulfa allergies (such as myself) are allergic to sulfanilamide and the sulfoamido group on the end of the aromatic ring. Rofecoxib lacks the NH2 that celecoxib has. In other words, celecoxib has a true sulfanilamide group on its structure. Therefore, there theoretically shouldn't be a problem with rofecoxib and most likely one with celecoxib. But, being that rofecoxib is no longer on the market, this is a moot point.

 

[ultracet]

It was several years ago when this occurred. At any rate, I didn't react to Vioxx and never took the Celebrex because it was changed to Vioxx.

However, from what little I know of structures and sulfa allergies, people with sulfa allergies (such as myself) are allergic to sulfanilamide and the sulfoamido group on the end of the aromatic ring. Rofecoxib lacks the NH2 that celecoxib has. In other words, celecoxib has a true sulfanilamide group on its structure. Therefore, there theoretically shouldn't be a problem with rofecoxib and most likely one with celecoxib. But, being that rofecoxib is no longer on the market, this is a moot point.

well said! exactly what i was thinking

cheers for those of us with sulfa allergies!!!! (and penicillins and cephs... and there was that thing once with decadron.........)