Sullivan used a protocol for oral desensitization to a beta-lactam antibiotic in a patient with a history of penicillin drug allergy. This method is recommended for the patient with good intestinal absorption.
Patient selection:
(1) Desensitization to a beta-lactam antibiotic is not a good idea in a patient with a previous history of serious allergic reaction (anaphylactic) to that antibiotic.
(2) Desensitization may be considered in a patient with a serious allergic reaction to an alternate penicillin or other cephalosporin if the need is great. However, skin testing should probably per performed before attempting.
(3) A patient with a history of Stevens-Johnson Syndrome, erythroderma or toxic epidermal necrolysis to the beta-lactam antibiotic or related antibiotics should not undergo desensitization.
(4) Desensitization can usually be done safely in a patient with a minor allergic or nonallergic drug reaction to a beta-lactam antibiotic.
(5) A patient with fulminant infection who requires immediate therapy may need to be stabilized before attempting the desensitization.
Location for desensitization: This should be done in a health care setting under observation, preferably an intensive care unit.
Equipment required:
(1) resuscitation supplies readily available
(2) a very accurate infusion pump
(3) physiologic monitoring
All beta-adrenergic antagonists should be discontinued in advance.
|
Oral Solution |
beta-lactam antibiotic in mg |
Diluent in mL |
Final Concentration |
|
steps 1 to 7 |
50 mg |
100 mL |
0.5 mg/mL |
|
steps 8 to 10 |
500 mg |
100 mL |
5.0 mg/mL |
|
steps 11 to 14 |
5,000 mg |
100 mL |
50. mg/mL |
where:
• Small volumes of the drug solutions can be prepared, but accuracy is usually better with a larger volume
• Mendelson reported using dilutions of pediatric syrup with 250 mg/mL of the antibiotic.
|
Day 1 |
Solution |
Amount in mL |
Dose in mg |
Cumulative Dose in mg |
|
step 1 |
0.5 mg/mL |
0.1 mL |
0.05 |
0.05 |
|
step 2 |
0.5 mg/mL |
0.2 mL |
0.10 |
0.15 |
|
step 3 |
0.5 mg/mL |
0.4 mL |
0.20 |
0.35 |
|
step 4 |
0.5 mg/mL |
0.8 mL |
0.40 |
0.75 |
|
step 5 |
0.5 mg/mL |
1.6 mL |
0.80 |
1.55 |
|
step 6 |
0.5 mg/mL |
3.2 mL |
1.60 |
3.15 |
|
step 7 |
0.5 mg/mL |
6.4 mL |
3.20 |
6.35 |
|
step 8 |
5.1 mg/mL |
1.2 mL |
6 |
12.35 |
|
step 9 |
5.0 mg/mL |
2.4 mL |
12 |
24.35 |
|
step 10 |
5.0 mg/mL |
4.8 mL |
24 |
48.35 |
|
step 11 |
50.0 mg/mL |
1.0 mL |
50 |
98.35 |
|
step 12 |
50.0 mg/mL |
2.0 mL |
100 |
198.35 |
|
step 13 |
50.0 mg/mL |
4.0 mL |
200 |
398.35 |
|
step 14 |
50.0 mg/mL |
8.0 mL |
400 |
798.35 |
Administration:
(1) Each solution is diluted in 30 mL of water for ingestion.
(2) The patient is observed for 15 minutes after each dose.
(3) If no reaction is seen, then the next dose is given.
If the patient completes all of the steps without reaction, then
(1) observe the patient for 30 minutes
(2) administer 1 gram of the same antibiotic intravenously
Once a patient has been desensitized, therapy must not lapse or else there may be an increased risk of reaction.
Specialty: Infectious Diseases, Pharmacology, clinical
