Drug interactions between Flomax and nefazodone
| Results for the following 2 drugs: |
|---|
| Flomax (tamsulosin) |
| nefazodone |
Interactions between your selected drugs
nefazodone ↔ tamsulosin
Applies to:nefazodone and Flomax (tamsulosin)
GENERALLY AVOID: Coadministration with potent inhibitors of CYP450 3A4 may increase the plasma concentrations and pharmacologic effects of tamsulosin, which is primarily metabolized by the hepatic microsomal isoenzymes CYP450 3A4 and 2D6. In 24 healthy volunteers, administration of a single 0.4 mg dose of tamsulosin with the potent CYP450 3A4 inhibitor ketoconazole (400 mg once daily for 5 days) resulted in a 2.2-fold increase in tamsulosin peak plasma concentration (Cmax) and a 2.8-fold increase in systemic exposure (AUC) compared to administration alone. The interaction may be more significant in individuals who have genetic polymorphisms of CYP450 2D6 resulting in reduced or absent enzyme activity, or so-called CYP450 2D6 poor metabolizers (approximately 7% of Caucasians and less than 2% of Asians and individuals of African descent), because of the isoenzyme's role in tamsulosin metabolism. In 24 healthy volunteers, concomitant treatment with the potent CYP450 2D6 inhibitor paroxetine (20 mg once daily for 9 days) resulted in an increase in the Cmax and AUC of a single 0.4 mg dose of tamsulosin by a factor of 1.3 and 1.6, respectively. A similar increase in exposure is expected in CYP450 2D6 poor metabolizers as compared to extensive metabolizers, and the increase should be even greater when tamsulosin is coadministered with a potent CYP450 3A4 inhibitor.
MANAGEMENT: Since CYP450 2D6 poor metabolizers cannot be readily identified, concomitant use of tamsulosin with potent CYP450 3A4 inhibitors such as itraconazole, ketoconazole, voriconazole, nefazodone, delavirdine, protease inhibitors, and ketolide and certain macrolide antibiotics should generally be avoided due to the potential for significant increase in tamsulosin systemic exposure. If tamsulosin administration is discontinued for several days or more at either the 0.4 or 0.8 mg dose, therapy should be reinitiated with the 0.4 mg once-daily dose and titrated gradually as needed.
See also...
Drug Interaction Classification
The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
| Major | Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. |
| Moderate | Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. |
| Minor | Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. |
Do not stop taking any medications without consulting your healthcare provider.
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