Then I went to look at the scientific literature, to see if it said anything about what sorts of foods I really should be avoiding taking with it. I found the article Pharmacokinetics of Rifampin Under Fasting Conditions, With Food, and With Antacids by Peloquin et al. The authors found that:
The article also summarizes the results of four other studies:
Siegler et al ... showed a 25% reduction in Cmax, 100% increase in Tmax, and 23% reduction in AUC when RIF[AMPIN] was administered with a high-fat meal. Zent and Smith administered RIF to 27 patients with active tuberculosis, and blood was collected at baseline and 12 time points over 8 h, plus a 24-h postdose. When RIF was given with a carbohydrate meal, a 15% reduction in Cmax, 19% increase in Tmax, and 4% reduction in AUC were shown. In contrast, when RIF was administered with a high-fat meal, these authors showed no significant effect of RIF's Cmax, Tmax, and AUC.On the basis of all this, the authors recommend that rifampin be taken without food. This rather surprised me. Even a 25% reduction in area under the curve -- the worst number they cite -- isn't that much. As for the decrease in maximum concentration, that might be good or bad, depending on whether it is better to deliver a sudden shock to the pathogen, or to keep up the pressure on it steadily. In any case, I'll no longer be treating the instruction to take rifampin without food as an absolute rule, but rather as a rule I can bend according to the dictates of convenience.Polasa and Krishnaswamy studied six healthy men, dosing them with 10 mg/kg of RIF. Blood was collected at seven time points over 8 h postdose. A wheat-based breakfast consisting of 565 calories, including 9 g protein, 109 g carbohydrate, and 11 g fat was administered on one of two occasions. Com- pared with the fasting treatment, food reduced the mean Cmax by 30%, doubled the Tmax to 4 h, and reduced the AUC by 26%. Finally, Hagelund et al studied six patients with tuberculosis, in addition to six gastrectomized patients, collecting blood at 1, 3, 5, and 7 h postdose. They compared fasting conditions with a breakfast of bread with butter and marmalade, meat, cheese, one egg, and coffee or tea with milk. This meal delayed absorption, but showed only minor effects on Cmax and AUC in the nongastrectomized patients.
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Thanks for the detail and
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CAPi for Cpni 11/04. Dx: 25yrs CFSi & FMSi. Currently: 150mg BID Roxithromycin, Doxycycline 100mg BID, Tinii 1000mg/day pulses; Vit D2000 units, T4 & T3
Norman, Thanks! I'm about
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The difference between what we do and what we are capable of doing would suffice to solve most of the world’s problems. Mohandas Gandhi
The 25% reduction in AUC
Thanks Norman the antacid
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Michèle (UK) GFAi: Wheldon CAPi 1st May 2006. Daily Doxyi, Azi MWF, metroi pulse. Zoo keeper for Ella, RRMSi, At worse EDSSi 9, 3 months later 7 now 5.5 Wheldon CAP 16th March 2006