So CD4 counts appear to be a useful tool in assessing risk, but other factors also contribute such as lung architecture. In a retrospective study of 74 patients with interstitial lung disease on corticosteroids, 7 patients developed PCP. The mean dose at time of diagnosis was prednisone 37mg with mean duration of 10 weeks. CD4 counts ranged from 59 to 836, with a mean of 370 . The authors argued that due to their underlying lung disease, the patients were at higher risk for PCP and became infected at higher CD4 counts than patients with other underlying diseases.
Information for all healthcare professionals administering this drug: Administer this drug only as an IV infusion. Do not administer as an IV push or bolus. Premedicate before each infusion with acetaminophen and an antihistamine. Pneumocystis jiroveci pneumonia (PCP) is recommended for patients with GPA and MPA during treatment and for at least 6 months following treatment as appropriate.
-FIRST INFUSION: Initiate infusion at a rate of 50 mg/hr; in the absence of infusion toxicity, increase infusion rate by 50 mg/hr increments every 30 minutes, to a maximum of 400 mg/hr
-SUBSEQUENT INFUSIONS: Initiate infusion at a rate of 100 mg/hr; in the absence of infusion toxicity, increase rate by 100 mg/hr increments at 30 minute intervals, to a maximum of 400 mg/hr
-Interrupt the infusion or slow the infusion rate for infusion reactions. Continue the infusion at one-half the previous rate upon improvement of symptoms.
RECOMMENDED DOSE FOR GRANULOMATOSIS WITH POLYANGIITIS (GPA) (WEGENER'S GRANULOMATOSIS) AND MICROSCOPIC POLYANGIITIS (MPA):
-Administer rituximab as a 375 mg/m2 intravenous infusion once weekly for 4 weeks
-Glucocorticoids administered as methylprednisolone 1000 mg IV per day for 1 to 3 days followed by oral prednisone 1 mg/kg/day (not to exceed 80 mg/day and tapered per clinical need) are recommended to treat severe vasculitis symptoms. This regimen should begin within 14 days prior to or with the initiation of rituximab and may continue during and after the 4 week course of rituximab treatment.
-Safety and efficacy of treatment with subsequent courses of this drug have not been established
Use: This drug, in combination with glucocorticoids, is indicated for the treatment of adult patients with Granulomatosis with Polyangiitis (GPA) (Wegener's Granulomatosis) and Microscopic Polyangiitis (MPA)