Octreotide plasma concentration

OCTREOTIDE ANTICANCER AND IMMUNOMODULATING DRUGS - CICLOSPORIN l plasma concentrations of cidosporin and risk of transplant rejection Octreotide is a strong inducer of CYP3A4-mediated metabolism of cidosporin Avoid co-administration if possible if not, monitor cidosporin levels closely... 

Fig. 2 The influence of Sandostatin LAR biodegradable depot formulation on the mean plasma growth hormone concentrations in humans. Plasma concentrations are shown over a 24 hour period 28 days after administration of a second monthly 20mg dose of Sandostatin LAR, . For comparison, plasma concentrations are provided for untreated controls, , and for patients receiving multiple daily subcutaneous octreotide injections, A. (From Refs. ° ° l)...

Of 12 patients with ascites due to cirrhosis of the liver, who received subcutaneous octreotide 300 micrograms bd for 11 days, 11 had increased renal plasma flow and 10 had a reduced GFR (44). Creatinine concentrations did not change. The effects of octreotide on the kidneys have been variably reported in previous studies. In patients with cirrhosis the effects are likely to be affected by the activated renin-angiotensin-aldosterone system. 

Sinus bradycardia is common, particularly in patients with acromegaly, and first- and second-degree atrioventricular blocks have been associated with octreotide use, but a mechanism has not been identified. The half-life of octreotide is about 90 minutes in healthy individuals and is doubled in cirrhosis. The time course of the bradycardia was inconsistent with the octreotide concentration in plasma but that does not exclude causality. 

In vivo imaging and therapy of SST receptors overexpressing tumors are usually performed with SST analogs such as octreotide and other small cyclic peptides with high receptor affinity, improved plasma stability, and fast clearance. These small peptides have excellent tissue permeability and lack of undesired side effects when administered at tracer concentrations (116). 

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