Alternative PJP prophylaxis

For PJP prophylaxis in patients with nonsevere hypersensitivity to trimethoprim+sulfamethoxazole, or those unable to take trimethoprim+sulfamethoxazole, use:

1 dapsone 100 mg orally, daily123. For dosage adjustment in adults with kidney impairment, see dapsone dosage adjustment. For duration of prophylaxis, see Assessing the need for antimicrobial prophylaxis in immunocompromised adults without HIV infection pneumonia, PJP: primary prophylaxis (immunocompromised adult without HIV) dapsone    

OR

2 pentamidine 300 mg via nebuliser, every 4 weeks; for duration of prophylaxis, see Assessing the need for antimicrobial prophylaxis in immunocompromised adults without HIV infection45 pneumonia, PJP: primary prophylaxis (immunocompromised adult without HIV) pentamidine    

OR

3 atovaquone 1500 mg orally with fatty food or full-fat milk, daily; for duration of prophylaxis, see Assessing the need for antimicrobial prophylaxis in immunocompromised adults without HIV infection. pneumonia, PJP: primary prophylaxis (immunocompromised adult without HIV) atovaquone    

For patients with severe hypersensitivity to trimethoprim+sulfamethoxazole (eg anaphylaxis, DRESS, SJS/TEN), use pentamidine or atovaquone (see dosages above). Do not give dapsone because there is a possibility of cross-reactivity between dapsone and sulfamethoxazole (see Cross-reactivity between sulfonamides).

1 Test for glucose-6-phosphate dehydrogenase (G6PD) deficiency before starting treatment with dapsone—seek expert advice if the patient is G6PD deficient.Return
2 The cross-reactivity rate between dapsone and sulfamethoxazole is approximately 9 to 12%; do not use dapsone in patients with severe hypersensitivity (eg drug rash with eosinophilia and systemic symptoms [DRESS], Stevens–Johnson syndrome / toxic epidermal necrolysis [SJS/TEN]; see Types of antimicrobial hypersensitivity).Return
3 Reduce dapsone dosage to 50 mg daily in patients who develop toxicity (methaemoglobinaemia, chemical haemolysis).Return
4 Administer pentamidine via a jet nebuliser producing a droplet size of 1 to 2 microns.Return
5 Use with caution in patients with lung disease (eg asthma, COPD) because nebulised pentamidine may cause cough and bronchospasm.Return