Page 36 - Heart Transplant Protocol

Heart Function Service: Heart Transplant Protocols

Trimethoprim/sulfamethoxazole (TMP/SMZ, Sulfatrim, Septra®, and Bactrim®) is the agent of choice for
Pneumocystis carinii pneumonia (PCP) prophylaxis. Trimethoprim/Sulfamethoxazole is given orally once
daily for 3 months after transplantation.
Dosing
> 20 kg 1 Single-Strength tablet or 10 ml of suspension (400 mg/80 mg)
11 - 20 kg ½ Single-Strength tablet or 5 ml of suspension (200 mg/40 mg)
< 10 kg 2.5 ml of suspension (100 mg/20 mg)

Dosing adjustment in renal impairment:
Clcr 15-30 mL/minute: Reduce dose by 50%
Clcr <15 mL/minute: Not recommended

Drug interactions:
Warfarin decreases the clearance
Methotrexate (displaced from protein binding sites)
Sulfonylureas, Phenytoin, Digoxin, and Thiopental increases the effect
Cyclosporine concentrations decreases serum

Dapsone is indicated for use as prophylaxis against Pneumocystis carinii pneumonia (PCP) in patients
who cannot tolerate sulfamethoxazole and trimethoprim or aerosolized pentamidine. It is the drug of
choice for patients allergic to Bactrim or sulfa medications or has experienced an adverse reaction to
Trimethoprim/Sulfamethoxazole such as thrombocytopenia, rash, etc. A normal G6PD level is required
prior to starting therapy with Dapsone. Dapsone is given orally once daily for 3 months after
transplantation.
Dosing
> 70 kg 100 mg PO daily
< 70 kg 2 mg/kg PO daily; maximum dose 100 mg/day
Or
4 mg/kg/dose once weekly (maximum dose: 200 mg)

Drug interactions:
Rifampin (decreases Dapsone concentrations)
Trimethoprim (increases Dapsone concentration)
Pyrimethamine, Nitrofurantoin, Primaquine (increased risk of hematologic side effects)
Rifampin, Carbamazepine, Fosphenytoin, Oxcarbamazepine, Phenobarbital, Phenytoin, Primidone, and
St. John's wort may increase formation of Dapsone metabolite, Dapsone hydroxylamine, which is
associated with hemolysis
Antacids decrease Dapsone absorption

Food interactions:
Dairy products decrease Dapsone absorption
Bananas
Potatoes

Atovaquone is indicated for patients intolerant of TMP/SMZ are defined as having a significant rash (ie,
Stevens-Johnson-like syndrome), neutropenia, or hemolysis; prevention of PCP in patients who are
intolerant to TMP/SMZ may be used when the patient is allergic to Trimethoprim/Sulfamethoxazole or
Dapsone medications. It is not indicated in neonates.

Updated November 9, 2017 36