Rifampicin St John’s wort

NA /D, abd pain, bleeding, fevCT, T QT Interactions t Effects W7 atazanavir, clarithromycin, CT5rthromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfi-navir, ritonavir, saquinavir, telithromycin X effects W7 antacids, carbamazqjine, dexamethasone, phenobarbital, phenytoin, rifampicin, St. John s wort EMS Drug contains lactose, may cause D/abd discomfort in pts w/ lactose intolerance OD Sxs unknown symptomatic and supportive... 

PXR NR1I2 603065 8856 Liver, small intestine, and colon Rifampicin, St. John s wort... 

Interactions. Involvement of protease inhibitors with the cytochrome P450 system provides scope for interaction with numerous substances. Agents that induce P450 enzymes (e.g. rifampicin, St John s wort) accelerate their metabolism, and reduce plasma concentration enzyme inhibitors (e.g. ketoconazole, cimetidine) raise their plasma concentration competition with other drugs for the cytochrome enzymes can lead to variable results. Ritonavir is itself a powerful inhibitor of CYP 3A4 and CYP 2D6. This effect is utilised when ritonavir in small quantity is combined (in capsules) with lopinavir to inhibit its metabolism and increase its therapeutic efficacy. The present account should be sufficient to warn the physician, and thereby the patient, to take particular heed when seeking to co-administer any drug a with protease inhibitor. 

CYP3A4 alprazolam, calcium channel blockers, cisapride, clarithromycin, cyclosporin A, erythromycin, HIV protease inhibitors, lidocaine, midazolam, simvastatin, terfenadine carbamazepine, dexamethsone, phenobarbital, phenytoin, rifampicin, St John s wort cimetidine, erythromycin, grapefruit juice, HIV protease inhibitors, itraconazole, ketoconazole... 

Potassium Competitive Acid Blockers The pregnane X receptor (PXR) is a promiscuous nuclear receptor, that has evolved to protect the body from toxic chemicals. It is activated by a wide variety of xenobiotics including several diugs like rifampicin, hyperforin ( the active ingredient of St. John s wort), clotrimazole and others. PXR heterodimerizes with the... 

Induction of P-gp by rifampicin has also been reported in vivo in humans. In a clinical study, duodenal biopsies were obtained and the duodenal P-gp contents in healthy volunteers were determined before and after oral administration of rifampicin at 600 mg/day for nine days (28). Treatment with rifampicin resulted in a significantly increased expression of duodenal P-gp content by 4.2-fold. In another clinical study, treatment with rifampicin at 600 mg/day for 10 days resulted in a 3.5-fold increase in intestinal P-gp in health volunteers (29). Similarly, induction of intestinal MRP2 by rifampicin (600 mg/day for 9 days) has been reported in humans. In a clinical study with 16 healthy volunteers, rifampicin induced duodenal MRP2 mRNA in 14 out of 16 individuals, while MRP2 protein was significantly induced by rifampicin in 10 out of 16 subjects (30). Interestingly, St. John s wort, a known PXR activator, also induces the expression of P-gp and MRP2 in animals and humans (31,32). 

Rifampicin, carba-mazepine, dexa-methasone, pheny-toin, St.John s wort... 

ST JOHN S WORT IMATINIB 1 imatinib levels Due to induction of CYP3A4-mediated metabolism of imatinib Monitor for clinical efficacy and adjust dose as required. Avoid co-administration of imatinib and rifampicin... 

IFOSFAMIDE 1. ANTIBIOTICS-rifampicin 2. ANTICANCER AND IMMUNOMODULATING DRUGS - dexamethasone 3. ANTIDEPRESSANTS-St John s wort 4. ANTI EPILEPTICS -carbamazepine, phenytoin, phenobarbital t rate of biotransformation to 4-hydroxyifbsfamide, the active metabolite, but there is no change in AUC of 4-hydroxyifosfamide Due to t rate of metabolism and of clearance owing to induction of CYP3A4 and CYP2D6 Be aware - clinical significance may be minimal or none... 

PACLITAXEL 1. ANTIBIOTICS-rifampicin 2. ANTIDEPRESSANTS-St John s wort 3. ANTIEPILEPTICS -carbamazepine, phenobarbital, phenytoin 1 plasma concentration of paclitaxel and 1 efficacy of paclitaxel Due to induction of hepatic metabolism of paclitaxel by the CYP isoenzymes Monitor for clinical efficacy and need to T dose if inadequate response is due to interaction... 

Etoposide and teniposide are substrates of CYP3A4, and their clearance rate is increased by inducers such as car-bamazepine, phenobarbital, phenytoin, rifampicin, and St. John s wort (49,51-54,156). 

Clinically important, potentially hazardous interactions with amantadine, anticholinergics, antidepressants, antimuscarinics, atazanavir, carbamazepine, clarithromycin, CYP2D6 inhibitors, CYP3A4 inducers, CYP3AF inhibitors, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, phenobarbital, phenytoin, rifampicin, ritonavir, saquinivir, St John s wort, telithromycin... 

Levonorgestrel is metabolised in the liver and drugs, including primidone, phenytoin, carbamazepine, St John s wort, griseofulvin, rifampicin, rifabutin and ritonavir, that induce liver enzymes will increase its metabolism and may... 

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