Propacetamol


Propacetamol (N,N-diethyl glycidyl ester of acetaminophen) is a soluble bioprecursor of acetaminophen. It is composed of an acetaminophen molecule coupled to a vector: diethylglycine. A very effective and well tolerated analgesic, it is a prodrug widely used for its analgesic and antipyretic properties. Following intravenous injection, propacetamol is readily hydrolized into acetaminophen 2 and N,N-diethylglycine 3).
 
Incidence
Several cases of occupational contact dermatitis have been reported in nurses handling propacetamol.
 
Risk factors
Nurses frequently handling propacetamol (surgery, intensive care units, oncology).
 
Clinical manifestations
Chronic eczema with vesiculous flares on the back of the hands sometimes extending to wrists, forearms, and occasionally on the face.
 
Diagnostic methods
Cutaneous testing
 
Patch-tests with propacetamol are positive ; but negative with solvent, acetaminophen and diethylglycine.
 
Mechanisms
Patch-tests with N,N-diethylglycine phenyl ester (activated form of N,N- diethylglycine) in 10% pet. are positive in patients with contact dermatitis to propacetamol. This strongly suggests that propacetamol acts as an activated form of N,N-diethylglycine, transferring this part of the molecule to nucleophilic residues of proteins. So acetaminophen allergy has never been observed in propacetamol-allergic patients.
 
Management
The wearing of gloves for preparing propacetamol is mandatory, especially in cases where allergic history enhances the risk of occupational sensitization.
 

References

  1. Berl V, Barbaud A, Lepoitevin J.P, "Mechanism of allergic contact dermatitis from propacetamol: sensitization to activated N,N-diethylglycine", Contact Dermatitis, 1998 ; 38: 185-8
  2. Barbaud A, Trechot P, Bertrand O, Schmutz J.L, "Occupational allergy to propacetamol", Lancet; 1995 ; 346: 902

As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.