Madison Clinic
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Bactrim Desensitization Protocol

    1. ORAL Desensitization over 15 days
    2. Rapid ORAL Desensitization
    3. Intravenous Desensitization
    4. Harborview Medical Center (UW) Desensitization Protocol

I. Protocol: Oral TMP/SMX Desensitization over 15 days

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  • Day 1 – 3 TMP 20mg /SMX 100mg = 2.5ml of TMP/SMX suspension 8mg/40mg per ml.
  • Day 4 – 6 TMP 40mg /SMX 200mg = 5ml of TMP/SMX suspension 8/40mg per ml.
  • Day 7 – 9 TMP 60mg /SMX 300mg = 7.5ml of TMP/SMX suspension 8/40mg per ml.
  • Day 10 – 12 TMP 80mg/SMX 400mg = 1 single strength tablet
  • Day 13 – 15 TMP 120mg/SMX 600mg = 1.5 single strength tablets
  • Day 16 – 22 TMP 160mg/SMX 800mg = 1 double strength tablet

*Protocol is for patients with normal renal function.

II. Rapid ORAL TMP/SMX Desensitization over 5 hours

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Hour TMP/SMX Dose (mg) Dose #
0 0.004/0.02 per ml 1
1 0.04/0.2 per ml 2
2 0.4/2 per ml 3
3 4/20 per ml 4
4 40/200 per 5ml Stock Solution
5 160/800 Double Strength Tablet

* Take 6oz of water with each dose

Instruction for dilution:
1) Use stock solution TMP 40mg / SMX 200mg per 5ml, label this “Solution A”

2) Take 0.5ml from “Solution A” (amount = TMP 4mg / SMX 20mg), add 0.5ml of sterile water, final concentration = TMP 4mg / SMX 20mg / ml, label this Dose #4.

3) Take 1ml from “Solution A” (amount = TMP 8mg / SMX 40mg), add 9ml of sterile water, final concentration = TMP 0.8mg / SMX 4mg /ml, label this “Solution B”. Take 0.5ml from “Solution B”, and add 0.5ml of sterile water, final concentration = TMP 0.4mg/ SMX 2mg / ml, label this Dose #3.

4) Take 1ml from “Solution B” (amount = TMP 0.8mg / SMX 4mg), add 9ml of sterile water, final concentration = TMP 0.08mg / SMX 0.4 mg /ml, label this “Solution C”. Take 0.5ml from “Solution C”, and add 0.5ml of sterile water, final concentration = TMP 0.04mg / SMX 0.2mg /ml, label this Dose #2.

5) Take 1ml from “Solution C” (amount = TMP 0.08mg / SMX 0.4mg), add 9ml of sterile water, final concentration = TMP 0.008mg / SMX 0.04mg, label this “Solution D”. Take 0.5ml from “Solution D”, and add 0.5ml of sterile water, final concentration = TMP 0.004mg/ SMX 0.02mg / ml, label this Dose #1.

III. Intravenous TMP/SMX Desensitization over One Day

[Print PDF 19kb]

Standing orders:

epinephrine 1:1000 SQ prn for allergic reaction
diphenhydramine 50mg IV/PO before starting Bag #1 then Q6h thereafter

Use incremental doses every 20 minutes of the following concentrations:

  • Bag #1 TMP 0.16mg/SMX 0.8mg in 50ml D5W - infuse over 20 minutes
  • Bag #2 TMP 1.44mg/SMX 7.2mg in 50ml D5W - infuse over 20 minutes
  • Bag #3 TMP 8mg/SMX 40mg in 50ml D5W - infuse over 20 minutes
  • Bag #4 TMP 16mg/SMX 80mg in 50ml D5W - infuse over 20 minutes
  • Bag #5 TMP 80mg/SMX 400mg in 100ml D5W - infuse over 20 minutes
  • Bag #6 TMP 120mg/SMX 600mg in 150ml D5W - infuse over 30 minutes
  • Bag #7 TMP 240mg/SMX 1200mg in 250ml D5W - infuse over 60 minutes

Follow in 8 hours by 5mg/kg (TMP) dosing every 8 hours for treatment of PCP
*(for dosing in renal dysfunction please contact pharmacy)

IV. Harborview Medical Center (UW) Desensitization Protocol

These are the standard orders for Bactrim PO/IV desensitization. Note - It differs from the above referenced protocols. It includes systemic reaction chart and medications for reaction treatment.

[pdf 119kb]

References:

  1. Gluckstein D, Ruskin J. Rapid oral desensitization to trimethoprim-sulfamethoxazole (TMP-SMZ): use in prophylaxis for Pneumocystis carinii pneumonia in patients with AIDS who were previously intolerant to TMP-SMZ.
    Clin Infect Dis. 1995 Apr;20(4):849-53
  2. Rapid Oral TMP/SMX Desensitization over Five Hours. Sanford Guide 2004. Page 56, Table 6B
  3. CID 1995;20:849

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