4- Grapefruit juice

Grape color extract Grapefruit Grapefruit juice... 

At pH 7, [H ] = [OH ] that is, there is no excess acidity or basicity. The point of neutrality is at pH 7, and solutions having a pH of 7 are said to be at neutral pH. The pH values of various fluids of biological origin or relevance are given in Table 2.3. Because the pH scale is a logarithmic scale, two solutions whose pH values differ by one pH unit have a 10-fold difference in [H ]. For example, grapefruit juice at pH 3.2 contains more than 12 times as much H as orange juice at pH 4.3. 

Ounces fresh grapefruit juice (save a slice of grapefruit as garnish)... 

Fill a pitcher (at least 32 ounces) with ice cubes. Crush the raspberries in a bowl mix with vodka and creme de framboise. Separately, mix grapefruit juice with Champagne. Add both mixtures to the pitcher and garnish with the grapefruit slice. 

La Paloma, which translates as the dove, and also, similarly, as a meek or a mild person, is an aptly named cocktail. It acts like it s never held a gun before, and then it blows the tin can into the air. Perversely, it tastes better with grapefruit soda than grapefruit juice. 

The two examples given here will be the determination of flavones in grapefruit juice and the measurement of histamine in rat brain. 

The GIT supplements the kidney in the elimination of wastes and toxins. The P-glycoprotein of enterocytes, which is implicated in multi-drug resistance, plays a critical role. This export carrier exhibits varying responses to the different polyphenols present in green tea (Wang et al, 2002), and is inhibited by one or more components of grapefruit juice (Wagner et al, 2001). It is... 

EDWARDS D J, FITZSIMMONS M E, SCHUETZ E G, YASUDA K, DUCHARME M P, WARBASSE L H, WOSTER p M, SCHUETZ J D, WATKINS p (1999) 6, 7 -Dihydroxybergamottm in grapefruit juice and Seville orange juice effects on cyclosporine disposition, enterocyte CYP3A4, and P-glycoprotein. Clin Pharmacol Ther. 65 237-44. 

LOWN K S, BAILEY D G, FONTANA R J, JANARDAN S K, ADAIR C H, FORTLAGE L A, BROWN M B, GUO w, WATKINS p B (1997) Grapefruit juice increases felodipine oral availability in humans by decreasing intestinal CYP3A protein expression. J Clin Invest. 99 2545-53. 

There were also problems with interferences using HPLC/fluorescence with carrots and grapefruit juice for most of the carbamates at the 1 ngg level. For example,... 

Figure 6 HPLC/fluorescence of grapefruit juice control...

Figure HPLC/ESI-MSofgrapefruitjuice fortified with l.OngmL ofS-hydroxycarbofiiran (top) and grapefruit juice control (bottom). Ion monitored [M + NH4] ion at m z 238...

The authors thank Charles Stafford, Elizabeth Kolbe, Paul Golden (US EPA OPP, Analytical Chemistry Branch) and Elizabeth Flynt (US EPA OPP, Environmental Chemistry Branch) for gathering information on the validation work performed by both branches Lynda V. Podhorniak, US EPA, for providing the grapefmit juice extracts and the HPLC/fiuorescence chromatogram of the grapefruit juice control ... 

Specific concomitant medications or consumptions (check specific statin package insert for warnings) fibrates (especially gemfibrozil, but other fibrates too), nicotinic acid (rarely), cyclosporine, azole antifungals such as itraconazole and ketoconazole, macrolide antibiotics such as erythromycin and clarithromycin, protease inhibitors used to treat Acquired Immune Deficiency Syndrome, nefazodone (antidepressant), verapamil, amiodarone, large quantities of grapefruit juice (usually more than 1 quart per day), and alcohol abuse (independently predisposes to myopathy)... 

Theoretically buprenorphine metabolism could be inhibited by itraconazole, ketoconazole, grapefruit juice, and erythromycin or any other CYP3A4 inhibitor the effects may be greater than expected for the dose of buprenorphine being given may need to decrease buprenorphine dose. 

CYP3A4 is highly inducible by a large variety of commonly prescribed and utilized synthetic drugs (e.g., carbamazepine) and plant products (e.g., St. John s wort) (Roby, Anderson et al, 2000), and at the same time also is potently inhibited by various other medications (e.g., terfenadine and ketoconazole) (Jurima-Romet, Crawford etal, 1994) as well as common foodstuffs (e.g., grapefruit juice) (Oesterheld 8c Kallepalli, 1997). Since individual and ethnic/cultural groups vary dramatically in their exposure to these inducers and inhibitors, it stands to reason that... 

Fuhr, U., Klittich, K. et al. (1993). Inhibitory effect of grapefruit juice and its bitter principal, naringenin, on CYP1A2 dependent metabolism of caffeine in man. Br. J. Clin. Pharmacol., 35(4), 431-6. 

Oesterheld, J. Kallepalli, B. R. (1997). Grapefruit juice and clomipramine shifting metabolitic ratios./. Clin. Psychopharmacol, 17(1), 62-3. 

Risperidone Aripiprazole 2D6 > 3A4 2D6, 3A4 Carbamazepine and phenytoin topiramate hypericum (St. John s Wort). Paroxetine, fluoxetine, sertraline (high dose) grapefruit juice 2D6 or 3A4 substrates acting as competitive inhibitors. 

Quetiapine 3A4 2D6, 2C9 Carbamazepine and phenytoin topiramate prednisolone. Fluvoxamine fluoxetine sertraline (high dose) CYP3A4 substrates grapefruit juice. 

Fuhr, U. (1998). Drug interactions with grapefruit juice. Extent, probable mechanism and clinical relevance. DrugSaf., 18, 251-72. 

Table 8 Drugs Known to Interact with Grapefruit Juice... 

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