Continuous infusion of porcine factor VIII in the management of patients with factor VIII inhibitors.

The effectiveness of continuous infusion porcine factor VIII (PFVIII) has been evaluated in the treatment of 7 consecutive patients with factor VIII(FVIII) inhibitors. Two patients had hemophilia A and five were nonhemophiliacs with acquired FVIII inhibitors. The median pretreatment anti-porcine FVIII titre was 0.2 (range: 0-15.0) Bethesda units (BU), and the anti-human FVIII titer was 12.0 BU (range: 2.4-50.0). All patients presented with major bleeding. Patients were given a bolus dose of PFVIII followed by continuous infusion. Six patients also received immunosuppressive therapy. Therapeutic FVIII levels (>0.5 U/ml) were achieved in 6 of 7 patients at a median time of 12.5 hr, and then maintained with continuous infusion PFVIII. Six patients were treated for more than 7 days, and in four of these there was a decline in FVIII recovery between days 7 to 11, presumably related to a rising antibody response to PFVIII. These four patients were plasmapheresed and the three patients with autoantibodies recovered therapeutic FVIII levels but this did not occur in the patient with hemophilia. Thrombocytopenia developed in 4 patients at days 18 to 24, with the platelet count falling to 11 to 87 x 10(9)/L, and the PFVIII was discontinued in 3 patients. All patients recovered from the acute bleeding events. With prolonged immunosuppressive therapy, the FVIII inhibitor disappeared in all patients with autoantibodies and there have been no relapses after a median follow-up period of 581 days. This study demonstrates that continuous infusion PFVIII is an effective therapy for patients with FVIII inhibitors, but that prolonged treatment is associated with the development of inhibitors to porcine FVIII and severe thrombocytopenia, which readily corrects with discontinuation of PFVIII.

In-vitro stability of porcine factor VIII (Hyate:C(®) ).

The stability of porcine factor VIII (Hyate:C(®) ) 30 units mL(-1) , 15 units mL(-1) and 5 units mL(-1) prepared aseptically in 0.9% sodium chloride injection was studied. Solutions were stored in plastic syringes at room temperature and ambient light, and at body temperature protected from light. Samples obtained immediately after mixing and at 4, 24, 48 and 72 h were assayed for FVIII activity using a one-stage FVIII assay. Samples were considered stable if FVIII activity did not decline more than 10% compared with baseline values. Hyate:C(®) 5 units mL(-1) stored at room temperature retained FVIII activity within 90% of baseline values for at least 24 h. When stored at body temperature, FVIII activity of Hyate:C(®) 5 units mL(-1) declined to less than 90% of baseline values within 4 h. Stability of Hyate:C(®) 15 units mL(-1) and 30 units mL(-1) stored at room temperature was retained for at least 72 h. When Hyate:C(®) 15 units mL(-1) and 30 units mL(-1) were stored at body temperature, stability was retained for 24 h. Results of this study will permit further evaluation of Hyate:C(®) stability when administered by ambulatory infusion pumps.

Establishment of a bone marrow transplant satellite pharmacy.

The planning, establishment and operation of a bone marrow transplant (B.M.T.) satellite pharmacy in a 1100-bed teaching hospital are described. The B.M.T. satellite pharmacy was established because of the specialized pharmaceutical care needs of this patient population with a high risk for drug-related problems. The satellite pharmacy, which is located within a 19-bed Oncology Unit, provides integrated clinical-distributive services (unit-dose, IV-admixture system) to all B.M.T. patients. The satellite is open 10.5 hours per day, seven days per week. Staff consists of three full-time equivalent (F.T.E.) staff pharmacists, a 0.5 F.T.E. technician, and one F.T.E. clinical pharmacist. Staff pharmacists rotate between provision of B.M.T. pharmacy services, and provision of pharmacy services for the provincial Home Parenteral Nutrition program. The pharmacists are responsible for all aspects of drug distribution and clinical services for B.M.T. patients. Additional drug distribution and clinical services are provided to other Oncology Unit patients. The establishment of a satellite pharmacy has provided unique opportunities for pharmaceutical care of the B.M.T. patient.

Stability and compatibility of fluorouracil and mannitol during simulated Y-site administration.

The stability and compatibility of fluorouracil admixtures with mannitol during simulated Y-site administration was studied. Fluorouracil injection 50 mg/mL was diluted with 5% dextrose injection, 0.9% sodium chloride injection, and 5% dextrose and 0.45% sodium chloride injection to final concentrations of 1 and 2 mg/mL. Combinations of fluorouracil admixtures with 20% mannitol injection were made using equal volumes in glass test tubes; immediately after mixing and at one, two, and four hours, the samples were examined for visual incompatibilities. Duplicate combinations of fluorouracil admixtures with 20% mannitol injection were made using equal volumes in plastic syringes; immediately after mixing with internal standard in glass test tubes and at 2, 4, 8, and 24 hours, samples were removed for chemical analysis. A high-performance liquid chromatographic assay was used to determine fluorouracil concentrations. No evidence of precipitation, color change, or haze was observed. During the 24-hour study, fluorouracil concentrations remained within 6% of initial concentrations for all combinations with mannitol. Fluorouracil 1 and 2 mg/mL in 5% dextrose injection, 0.9% sodium chloride injection, and 5% dextrose and 0.45% sodium chloride injection was chemically stable and visually compatible when combined with 20% mannitol injection during simulated Y-site administration.

Carboplatin: a new cisplatin analog.

Carboplatin, a new antineoplastic agent with a spectrum of antitumor activity similar to cisplatin, has shown appreciable activity in patients with ovarian carcinoma, head and neck cancer, and small-cell lung cancer. This platinum complex is less nephrotoxic, ototoxic, and neurotoxic than cisplatin. Myelosuppression may be severe and dose-limiting. Carboplatin distributes into a volume approximating total body water, and is slowly bound to plasma proteins; its elimination is a biphasic process. Renal clearance of free platinum from carboplatin correlates highly with creatinine clearance in patients with normal or impaired renal function. The recommended iv dose of carboplatin as a single agent in previously untreated patients is 400-500 mg/m2; dosage must be reduced in patients with decreased renal function, low initial platelet count, or extensive prior chemotherapy or radiation therapy. Carboplatin will be most useful in patients with decreased renal function and those who cannot tolerate high-volume hydration regimens. Patients at higher risk for development of cisplatin-related ototoxicity or neurotoxicity (e.g., patients expected to receive cumulative cisplatin doses exceeding 600-800 mg/m2) may be ideal candidates for carboplatin as initial therapy. Large-scale comparative trials are needed before carboplatin can be recommended as a replacement for cisplatin.