Tamulsin Drug Interactions

Interaction studies have only been performed in adults.
No interactions have been seen when Tamsulosin was given concomitantly with atenolol, enalapril or theophylline.
Concomitant cimetidine increases and concomitant furosemide lowers plasma levels of Tamsulosin, however, as levels remain within the normal range, posology need not be changed.
In vitro, neither diazepam nor propranolol, trichlormethiazide, chlormadinon, amitryptyline, diclofenac, glibenclamide, simvastatin and warfarin change the free fraction of Tamsulosin in human plasma. Neither does Tamsulosin change the free fractions of diazepam, propranolol, trichlormethiazide, and chlormadinon. Diclofenac and warfarin, however, may increase the elimination rate of Tamsulosin. Concomitant administration of Tamsulosin with strong inhibitors of CYP3A4 may lead to increased exposure to Tamsulosin.
Concomitant administration with ketoconazole (a known strong CYP3A4 inhibitor) resulted in an increase in AUC and Cmax of Tamsulosin by a factor of 2.8 and 2.2, respectively.
Tamsulosin should not be given in combination with strong inhibitors of CYP3A4 in patients that are poor metaboliser CYP2D6 phenotype.
Tamsulosin should be used with caution in combination with strong and moderate inhibitors of CYP3A4.
Concomitant administration of Tamsulosin with paroxetine, a strong inhibitor of CYP2D6, resulted in a Cmax and AUC of Tamsulosin that had increased by a factor of 1.3 and 1.6, respectively, but these increases are not considered clinically relevant.
There is a theoretical risk of enhanced hypotensive effect when given concomitantly with drugs which may reduce blood pressure, including anaesthetic agents and other alpha1-adrenoreceptors antagonists.