Intravenous Desensitization Protocol of Ghosal and Taylor for Ceftazidime

Description

Intravenous cephalosporin therapy may be required for a patient with a previous history of allergy to penicillin or cephalosporin. Ghosal and Taylor used a protocol for intravenous desensitization to ceftazidime in patients with cystic fibrosis. The authors are from Sheffield Children's Hospital in England.

Patient selection:

(1) Desensitization to ceftazidime is not a good idea in a patient with a previous history of serious allergic reaction (anaphylactic) to ceftazidime.

(2) Desensitization may be considered in a patient with a serious allergic reaction to penicillin or other cephalosporin if the need is great.

(3) A patient with a history of Stevens-Johnson Syndrome, erythroderma or toxic epidermal necrolysis to ceftazidime 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.

Equipment required:

(1) resuscitation supplies readily available

(2) a very accurate infusion pump

Time required for protocol: 2 days, with infusions over a minimum of 4 hours (actual time may vary depending on interval between drug exposures)

Infusion Solutions	Ceftazidime in mg	Normal Saline (0.9%)	Final Concentration
day 1 steps 1 to 8	50	500	0.1 mg/mL
day 1 steps 9 to 14	500	500	1.0 mg/mL
day 2	1,000	500	2.0 mg/mL

Infusions at each step are performed over 15 minutes. The final step each day may take longer than 15 minutes to infuse.

Day 1	Solution	Amount in mL over 15 minutes	Dose in mg	Cumulative Dose in mg
step 1	0.1 mg/mL	0.25 mL	0.025	0.025
step 2	0.1 mg/mL	0.50 mL	0.05	0.075
step 3	0.1 mg/mL	1.0 mL	0.1	0.175
step 4	0.1 mg/mL	2.0 mL	0.2	0.375
step 5	0.1 mg/mL	4.0 mL	0.4	0.775
step 6	0.1 mg/mL	8.3 mL	0.83	1.63
step 7	0.1 mg/mL	16.6 mL	1.66	3.3
step 8	0.1 mg/mL	25 mL	2.5	5.8
step 9	1.0 mg/mL	6 mL	6	11.8
step 10	1.0 mg/mL	12 mL	12	23.8
step 11	1.0 mg/mL	25 mL	25	48.8
step 12	1.0 mg/mL	50 mL	50	98.8
step 13	1.0 mg/mL	100 mL	100	198.8
step 14	1.0 mg/mL	307 mL	307	505.8

Day 2	Amount of 2 mg/mL Solution over 15 minutes	Dose in mg	Cumulative Dose in mg
step 1	0.25 mL	0.5	0.5
step 2	0.5 mL	1.0	1.5
step 3	1.0 mL	2.0	3.5
step 4	2.0 mL	4.0	7.5
step 5	4.0 mL	8.0	15.5
step 6	8.3 mL	16.5	32
step 7	16.66 mL	32.3	64
step 8	25 mL	50	114
step 9	50 mL	100	214
step 10	100 mL	200	414
step 11	293 mL	586	1,000

where:

• The volumes for day 1 steps 9-14 and day 2 steps 1-11 is each about 500mL, so the prepared infusion solutions will be emptied if the protocol is completed.

If the patient tolerated the 2 day course, then the patient was administered a standard therapeutic dose as an infusion over 1 hour.

If the patient tolerated the standard therapeutic dose, then the person was started on the regular therapeutic regimen at full dose.

If signs of minor reactions appear then EITHER:

(1) switch to an alternative antibiotic, OR

(2) attempt to suppress reaction with diphenhydramine and antipyretics

If signs of serious reaction appear, then:

(1) discontinue antibiotic infusion and abort desensitization

(2) treat hypotension and anaphylactic reaction

(3) switch to an alternative antibiotic

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Description

Specialty

ICD-10