Intravenous bolus administration intermittent infusions

All four Hj receptor antagonists are available as prescription and over-the-connter formnlations for oral administration. Intravenous and intramuscular preparations of cimetidine, ranitidine, and famotidine also are available. When the oral or nasogastric routes are not an option, these dmgs can be given in intermittent intravenous boluses or by continuous intravenous infusion. 

Continuous versus intermittent administration A study randomised 20 patients who underwent a transjugular intrahepatic portosystemic shunt procedure to be treated with either TV bolus infusion of terlipressin (1 mg) followed by continuous infusion (4 mg/24 h) or intravenous bolus injection of ferlipressin (2 mg) followed by intermittent injections (1 mg/6 h) [92 ]. The continuous administration route more stably reduced portal venous pressure and did so with a lower initial IV dose, which could minimise tiie risk of adverse drug reactions. Larger studies are required to assess that possibility. 

In early trials, aldesleukin was given with lymphokine-activated killer (LAK) cells or tumor-infiltrating lymphocytes. However, later data showed that the addition of LAK cells does not improve the therapeutic response in renal cell carcinoma and can produce more pulmonary toxicity and hypotension (1). Compared with aldesleukin or interferon alfa alone, the combination of aldesleukin plus interferon alfa produces a significantly longer event-free survival without effect on the overall survival, but induces substantial toxicity with severe and resistant hypotension (3). The optimal safe and effective dose and schedule of administration of aldesleukin is not yet well defined, and a variety of regimens have been tested, with doses of 600 000 units/kg by intermittent bolus intravenous infusion or 18 106 units/m by continuous subcutaneous or intravenous infusion. 

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