Grapefruit juice effect

Buspirone (BuSpar) [Anxiolytic] WARNING Closely monitor for worsening depression or emergence of suicidality Uses Short-term relief of anxiety Action Antianxiety antagonizes CNS serotonin receptors Dose Initial 7.5 mg PO bid T by 5 mg q2-3d to effect usual 20-30 mg/d max 60 mg/d Contra w/ MAOI Caution [B, /-] Avoid w/ severe hepatic/renal insuff Disp Tabs SE Drowsiness, dizziness, HA, N, EPS, serotonin synd, hostility, depression Notes No abuse potential or physical/psychologic d endence Interactions T Effects W/ erythromycin, clarithromycin, itraconazole, ketoconazole, diltiazem, verapamil, grapefruit juice effects W/ carbamazepine, rifampin, phenytoin, dexamethasone, phenobarbital, fluoxetine EMS T Sedation w/ concurrent EtOH use grapefruit juice may T risk of adverse effects OD May cause dizziness, miosis, N/V symptomatic and supportive... 

Kakar SM, Paine MF, Stewart PW, Watkins PB. 6 7 -Dihydroxybergamottin contributes to the grapefruit juice effect. Clin Pharmacol Ther 2004 75(6) 569-579. 

FIGURE 3.6 Drugs subject to the grapefruit juice effect... 

Dresser GK, Kim RB, Bailey DG. Duration of grapefruit juice effect on fexofenadine interaction. Clin Pharmacol Ther (2003) 73, P48. 

Lin H-L, Kenaan C, Hollenbeig PF (2012) Identification of the residue in human CYP3A4 that is covalently modified by bergamottin and the reactive intermediate that contributes to the grapefruit juice effect. Drug Metab Dispos 40 998-1006... 

Lin HL, Kent UM, Hollenberg PF (2005) The grapefruit juice effect is not limited to cytochrome P450... 

In addition to the problem of immediate potential toxicity of plant chemicals, there is a growing body of evidence that points to adverse interactions between foods and pharmaceuticals. For example, bergamottin in grapefruit juice is responsible for the grapefruit juice effect on the bioavailability of several prescription drugs. The compound inhibits cytochrome P-450 enzymes responsible for drug metabolism... 

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