Gadolinium Allergy

[Winged Scapula]

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Any truth to the surgical rumor that Gad allergies in the form of rashes can be dependent on the brand of contrast used?

A couple of my books said I should advise patients to check on what brand was used so that they may avoid that but perhaps safely have another brand of Gad later.

I can't imagine there are a lot of people making Gadolinium and even if there were, does it really make a difference?

 

[colbgw02]

When you say "rash", do you mean the exceedingly rare gad-induced anaphylactoid reaction or do you mean the skin findings of NSF?

If it's the latter, then yes, I have heard that it's brand specific. I don't think there is hard enough evidence to start doing gad studies on the high risk pts. Come to think of it, I'm not sure they would let you do a double-blinded placebo-controlled trial on this.

 

[f_w]

The majority of NSF cases has occured with Omniscan (GE healthcare). This proportion is way larger than the proportion of Omniscan in the Gad market. A couple of cases have occured with Magnevist and all of the other agents. For the longest time, ProHance didn't have any NSF cases but finally there are one or two (what I do see with ProHance are patients puking, this was something the techs had warned me about but vehemently denied to be a problem by the manufacturer 😉 )

Initial evidence points to free Gd ions being the culprit in NSF. The weaker chelation in Omniscan vs the other agents in the setting of a uremic acidotic patient is hypothesized to be the reason for the seemingly hither incidence.

You can have skin reactions with any type of medications, I am not aware that any of the Gad agents is better or worse in that respect.

Personally, I am quite partial to Magnevist, the stuff is on the market for a long time and except for cost I don't see a reason to use anything else (disclosure: former grant recipient from Schering diagnostics 😉 )

 

[Winged Scapula]

When you say "rash", do you mean the exceedingly rare gad-induced anaphylactoid reaction or do you mean the skin findings of NSF?

The latter. She has quite a history of allergic reactions to meds, topical agents, etc.

If it's the latter, then yes, I have heard that it's brand specific. I don't think there is hard enough evidence to start doing gad studies on the high risk pts. Come to think of it, I'm not sure they would let you do a double-blinded placebo-controlled trial on this.

And I wouldn't be interested in doing an RCT...just wanted to be able to inform my patient.

 

[Winged Scapula]

The majority of NSF cases has occured with Omniscan (GE healthcare). This proportion is way larger than the proportion of Omniscan in the Gad market. A couple of cases have occured with Magnevist and all of the other agents. For the longest time, ProHance didn't have any NSF cases but finally there are one or two (what I do see with ProHance are patients puking, this was something the techs had warned me about but vehemently denied to be a problem by the manufacturer 😉 )

Initial evidence points to free Gd ions being the culprit in NSF. The weaker chelation in Omniscan vs the other agents in the setting of a uremic acidotic patient is hypothesized to be the reason for the seemingly hither incidence.

Ok...but in the normal patient without uremia or acidosis?

You can have skin reactions with any type of medications, I am not aware that any of the Gad agents is better or worse in that respect.

That's my sense as well...which is the reason I was asking. That and I'm too lazy to do the research myself!

Thanks guys...

 

[f_w]

Ok...but in the normal patient without uremia or acidosis?

In a patient with a GFR>60cc/min the occurence of NSF is exceedingly unlikely. Most cases have been in patients with stage 4 and 5 renal insufficiency, a few in stage 3.

 

[Docxter]

And I wouldn't be interested in doing an RCT...just wanted to be able to inform my patient.

NSF in essence does not occur in patients with normal renal function. It is rare to begin with and as f_w mentioned, even then almost exclusively in severe or end stage renal failure stages 4 and 5. Extremely rare cases reported in stage 3 renal failure. Also, it doesn't have a cross-association with having allergy to other medications. It is generally considered (exact mechanism unknown and maybe multifactorial) a toxic effect related to gadolinium-chelate disassociation and hence a toxic effect starting the chain of events in NSF.

 

[Winged Scapula]

Thanks...as far as I know, she has normal renal function, and only had the rash, no other symptoms leading to full blown NSF.

 

[bigfrank]

Thanks...as far as I know, she has normal renal function, and only had the rash, no other symptoms leading to full blown NSF.

I imagine she'll be OK in terms of NSF.

 

[Winged Scapula]

I imagine she'll be OK in terms of NSF.

Yeah. I was never worried about her. I just wanted to know if the rumor about brand of agent was really true and if we should spend any time figuring it out.

 

[f_w]

Yeah. I was never worried about her. I just wanted to know if the rumor about brand of agent was really true and if we should spend any time figuring it out.

Aside from NSF and nausea, I am not aware of differences in the side-effect profile between the different gad agents. (may well be another surgical rumor, similar to the one that using anything but 'gastrograffin' will lead to immediate disassembly of a fresh anastomosis).