ABSTRACT
The comparative effects of continuous versus intermittent cimetidine infusion on theophylline pharmacokinetics were evaluated in 12 nonsmoking healthy male volunteers. Each subject received aminophylline 0.9 mg/kg/hr over 6 hours alone (control) and in random order at 1 week intervals, in combination with intermittent cimetidine (300 mg IV over 15 minutes every 6 hours) and continuous cimetidine (50 mg/hr IV) infusions. Both cimetidine regimens were administered for a total of 50 hours. Serial plasma samples were obtained and assayed for theophylline by HPLC. No significant differences existed in mean theophylline clearance and mean volume of distribution among control, intermittent or continuous cimetidine regimens; the power was greater than 80% to detect a 30% change in clearance. Only a minor difference in theophylline half-life between control and continuous cimetidine infusion (7.59 +/- 2.52 vs. 9.05 +/- 3.17 hr; P less than .05) was observed. These findings do not support a clinically significant interaction between IV aminophylline and cimetidine administered IV either as a low dose continuous infusion or as an intermittent infusion.
Subject(s)
Cimetidine/administration & dosage , Theophylline/pharmacokinetics , Adult , Cimetidine/pharmacology , Drug Interactions , Half-Life , Humans , Infusions, Intravenous , Male , Metabolic Clearance Rate , Theophylline/administration & dosageSubject(s)
Peptic Ulcer/drug therapy , Adult , Drug Interactions , Female , Humans , Male , Peptic Ulcer/diagnosis , Peptic Ulcer/diet therapyABSTRACT
A 32-year-old Haitian male with acquired immunodeficiency syndrome presented with complications of Isospora belli enteritis. Therapy with the investigational drug difluoromethylornithine was initiated. Severe thrombocytopenia, nausea, and vomiting developed during intravenous drug therapy and recurred upon rechallenge with low-dose oral difluoromethylornithine. Therapy was discontinued because of these severe adverse effects.
Subject(s)
Eflornithine/adverse effects , Thrombocytopenia/chemically induced , Vomiting/chemically induced , Acquired Immunodeficiency Syndrome/complications , Adult , Coccidiosis/drug therapy , Coccidiosis/etiology , Eflornithine/therapeutic use , Enteritis/drug therapy , Enteritis/etiology , Humans , MaleABSTRACT
Two patients with autoimmune thrombocytopenic purpura (ATP) who received high-dose intravenous immune globulin before undergoing splenectomy are described, and the pathogenesis, clinical presentation, diagnosis, and treatment of chronic ATP are reviewed. One patient was a 62-year-old white man who was admitted to the hospital with a history of thrombocytopenia and probable steroid-induced diabetes mellitus. The second patient was a 24-year-old black woman who was admitted for recurrent bleeding episodes and splenectomy. In both patients, immune globulin 1.5 g/kg administered over four to six days resulted in marked elevations of platelet counts. ATP is a platelet disorder of unknown etiology. Platelets with surface-bound antiplatelet antibody are destroyed by the reticuloendothelial system. As the platelet count falls below 30,000-50,000/cu mm, the patient may manifest signs of bleeding such as petechiae, purpura, ecchymosis, menorrhagia, epistaxis, and bleeding from other mucosal surfaces. Corticosteroids are the initial treatment of choice. Splenectomy is considered for children with the life-threatening hemorrhage and for patients who do not respond to corticosteroids. Patients who are refractory to steroid therapy and splenectomy may respond to immunosuppressant agents. Approximately, 80% of patients treated with immune globulin have responded with an increase in platelet count, although this increase is sometimes transient. Immune globulin therapy is recommended for emergency treatment of ATP, as preoperative medication before splenectomy, and for young children in order to postpone splenectomy. Despite a good response to treatment, immune globulin therapy should not be considered a cure for ATP.
