Tetrazepam


Tetrazepam is a benzodiazepine with the general properties of diazepam, used as muscle relaxants (50 to 200 mg daily).
 
Incidence
2/4767 recipients of benzodiazepine drugs.
 
Clinical manifestations
Cutaneous: pruritus, urticaria, angioedema, general papular, maculopapular or purpuric rash, hand and face contact dermatitis (handling of the drug), erythema multiforme.
 
Respiratory: tightness of the chest.
 
Diagnostic methods
Cutaneous testing.
 
Patch-tests with tetrazepam 1% aq or 1% and 5% pet.: positive in all cases.
 
Oral drug challenge.
 
Mechanisms
Type IV hypersensitivity.
 
Management
Avoidance of all benzodiazepines is not mandatory, since cross-reactivity is not always found in oral challenge tests.

References

  1. Blanco R, Diez-Gomez M.L, Gala G, Quirce S, "Delayed hypersensitivity to tetrazepam", Allergy, 1997; 52 (11): 1146-7
  2. Ortega N.R, Barranco P, Lopez-Serrano C, Romualdo L, Mora C, "Delayed cell-mediated hypersensitivity to tetrazepam", Contact. Dermatitis, 1996; 34 (2): 139
  3. Kämpgen E, Burger T, Brocker E.B, Klein E, "Cross-reactive type IV hypersensitivity reactions to benzodiazepines revealed by patch testing", Contact. Dermatitis, 1995; 33 (5): 356-7
  4. Camarasa J.G, Serra-Baldrich E, "Tetrazepam allergy detected by patch-test", Contact. Dermatitis, 1990; 22 (4): 246

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