Rifampicin


Rifampicin is a semi-synthetic broad-spectrum antibiotic very effective against mycobacteria, Brucella, and Staphylococci.
 
Incidence
Anaphylactic shock is rare (6/30 000 reports of possible allergic reactions to rifampicin).
 
Flu-like syndrome: rare when administered in daily regimens (0.1 to 4%) ; frequent in intermittent or discontinuous regimens (20%).
 
Risk factors
AIDS.
 
Intermittent treatment (flu-like syndrome, acute haemolytic anemia, renal failure, thrombocytopenic purpura).
 
Clinical manifestations
General: anaphylactic shock, serum sickness.
 
Cutaneous: pruritus, erythema, facial swelling, maculopapular rash, urticaria, vasculitis, Stevens-Johnson’s syndrome, red man syndrome.
 
Respiratory: shortness of breath, bronchospasm.
 
Haematological: thrombocytopenia, haemolytic anemia.
 
Renal: renal failure.
 
Diagnostic methods
Cutaneous testing
 
Intradermal skin-tests: 1/1000 to 1/10 (intravenous rifampicin 60 mg/ ml): positive in a few cases of anaphylactic shock.
 
Specific IgE (RAST)
 
Circulating rifampicin dependent antibodies, especially when intermittent therapy is used (Coombs test, complement binding test, antiglobulin test)
 
Circulating immune complexes.
 
Haemolytic complement titers
 
Mechanisms
Possible IgE-mediated hypersensitivity: anaphylactic shock with immediate positive skin-tests.
 
Type II hypersensitivity: blood dyscrasias.
 
Type III hypersensitivity: serum sickness.
 
Management
Desensitization (contra-indicated if severe manifestations: renal failure, thrombocytopenia).
 
2 protocols:
  • 0.1 mg ; 0.5 mg ; 1 mg ; 2 mg ; 4 mg ; 8 mg ; 16 mg ; 32 mg ; 50 mg: 100 mg ; 150 mg at 45 minutes intervals, then 300 mg 3H30 later, then 300 mg x 2 next day.
     
  • 0.1 mg to 300 mg within 17 hours.

References

  1. Matz J, Borish .C, Routes J.M, Rosenwasser L.J, "Oral desensitization to rifampin and ethambutol in mycobacterial disease", Am. J. Respir. Crit. Care. Med, 1994 ; 149 (3.1): 815-7
  2. Parra F.M, Perez-Elias M.J, Cuevas M, Ferreira A, "Serum sickness-like illness associated with rifampicin", Ann. Allergy., 1994 ; 73 (2): 123-5
  3. Cnudde F, Leynadier F, "The diagnosis of allergy to rifampicin confirmed by skin-test: letter ; comment", Am. J. Med., 1994 ; 97 (4): 403-4
  4. Holland C.L, Malasky C, Ogunkoya A, Bielory L, "Rapid oral desensitization to isoniazid and rifampin", Chest, 1990 ; 98: 1518-9.
  5. Nessi R, Domenichini E, Fowst G, "Allergic reactions during rifampicin treatment: a review of published cases", Scand. J. Respir. Dis. Suppl., 1973 ; 84: 15-19

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