Comparing different routes and doses of phytonadione for reversing excessive anticoagulation.

BACKGROUND: Significant controversy exists concerning how best to reverse excessive anticoagulation (due to warfarin sodium therapy) with phytonadione (vitamin K1) while avoiding overcorrection in patients who need to have anticoagulation therapy maintained. METHODS: A retrospective review of phytonadione use in reversing excessive anticoagulation was performed in 3 institutions. The effectiveness of low-dose (< or =0.5 mg) intravenous (LDIV), high-dose (1-10 mg) intravenous (HDIV), subcutaneous (1-10 mg) (SC), and oral (2.5 or 5 mg) (PO) phytonadione was evaluated within 48 hours of administration. Anticoagulation correction (international normalized ratio [INR], > or =2.0 and < or =5.0) occurred in 5 of 8 patients in the LDIV, 5 of 9 in the HDIV, 7 of 10 in the SC, and 5 of 6 in the PO groups. Correction was inadequate (INR >5.0) in 2 of 8 patients in the LDIV, 0 of 9 in the HDIV, 3 of 10 in the SC, and 1 of 6 in the PO groups. Overcorrection (INR <2.0) occurred in 1 patient in the LDIV, 4 patients in the HDIV, 0 in the SC, and 0 in the PO groups. CONCLUSIONS: Anticoagulation correction was achieved in most patients in all 4 groups. The HDIV method was most effective in lowering the INR to less than 5.0, but overcorrection occurred more frequently (4 patients in the HDIV vs 1 patient in the LDIV and 0 patients in the SC and PO groups). Failure to achieve an INR of less than 5.0 was a greater problem in the SC group (3 patients in the SC vs 2 patients in the LDIV and 1 patient in the PO groups). The LDIV and PO methods appear to be acceptable alternatives to the HDIV and SC methods currently recommended.

Spironolactone-induced agranulocytosis.

OBJECTIVE: To report a case of agranulocytosis secondary to spironolactone in a patient with cryptogenic liver disease. CASE SUMMARY: A 58-year-old Hispanic woman with cryptogenic cirrhosis was admitted to University Hospital on October 31, 1995. Laboratory data revealed a leukocyte count of 1.0 x 10(3)/mm3 and an absolute neutrophil count (ANC) of 10 cells/mm3. Prior to treatment with spironolactone, the leukocyte count was 10.2 x 10(3)/mm3 and ANC 8400 cells/mm3. Agranulocytosis resolved 5 days following the discontinuation of spironolactone. Results from the bone marrow biopsies before and after treatment with spironolactone suggested that agranulocytosis was caused by the drug's toxic effect on the bone marrow. DISCUSSION: Drug-induced agranulocytosis is a serious adverse effect, occurring at a rate of approximately 6.2 cases per million persons each year. In addition to the case reported here, three other reports of agranulocytosis secondary to spironolactone have been published in the literature. Several factors have been identified that may increase a patient's risk for developing agranulocytosis, including increased age, hepatic or renal impairment, drug dosage and duration, and concurrent medications. CONCLUSIONS: Agranulocytosis secondary to spironolactone is a serious potential adverse effect. Patients with risk factors for developing this adverse effect should be closely monitored since early detection and discontinuation of spironolactone can improve prognosis.