Viagra cialis for sale

Both therapeutic and supratherapeutic doses of vardenafil produce an increase in QTc interval. Tadalafil: (Major) The safety

and

Tamoxifen: (Moderate) Caution is advised with the concomitant use of tamoxifen and vardenafil due to an increased risk of QT prolongation. Tamoxifen has been reported to prolong the QT interval, usually in overdose or when used in high doses.

Rare case reports of QT prolongation have been described when tamoxifen is used at lower doses. Vardenafil is also associated with QT prolongation.

Both therapeutic and supratherapeutic doses of vardenafil produce an increase in QTc interval.

Tamsulosin: (Moderate) Due to the potential for symptomatic hypotension, patients should be stable on tamsulosin therapy before initiating therapy with the lowest dose of vardenafil.

Conversely, patients already receiving an optimized dose of vardenafil should be started on the lowest dose of tamsulosin; increases in the alpha-blocker dose should be done in a stepwise fashion.

Other variables, such as intravascular volume depletion, concurrent antihypertensive therapy, or evidence of hemodynamic instability with alpha-blocker monotherapy, may affect the safety of concomitant use of vardenafil and tamsulosin.

Telaprevir: (Major) Close clinical monitoring is viagra without prescription us advised when administering vardenafil with telaprevir due to an increased potential for vardenafil-related adverse events, such as QT interval prolongation. During coadministration, do not exceed a maximum vardenafil dosage of 2.5 mg in 72 hours.

If vardenafil dose adjustments are made, re-adjust the dose upon completion of telaprevir treatment. Predictions about the interaction can be made based on the metabolic pathways of vardenafil.

Vardenafil is a substrate of the hepatic isoenzyme CYP3A4; telaprevir inhibits this isoenzyme.

When used in combination, the plasma concentrations of vardenafil may be elevated.

Telavancin: (Moderate) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering telavancin with vardenafil. Telavancin has been associated with QT prolongation. Therapeutic (10 mg) and supratherapeutic (80 mg) doses of vardenafil also produces an increase in QTc interval (e.g., 4 to 6 msec calculated by individual QT correction). Telithromycin: (Major) Do not use vardenafil orally disintegrating tablets with telithromycin.

Decrease the dose of vardenafil oral tablets if administered with telithromycin. Coadministration may increase vardenafil exposure and the risk of QT prolongation. Vardenafil is a sensitive CYP3A4 substrate that can produce an increase in QTc interval at both therapeutic and supratherapeutic doses.

Telithromycin is a strong CYP3A4 inhibitor that is associated with QT prolongation and torsade de pointes (TdP). Coadministration with another strong CYP3A4 inhibitor increased the AUC and Cmax of vardenafil in healthy volunteers by 10-fold and 4-fold, respectively. Telotristat Ethyl: (Moderate) Use caution if coadministration of telotristat ethyl and vardenafil is necessary, as the systemic exposure of vardenafil may be decreased resulting in reduced efficacy. If these drugs are used together, monitor patients for suboptimal efficacy of vardenafil; consider increasing the dose of vardenafil if necessary. The mean Cmax and AUC of another sensitive CYP3A4 substrate was decreased by 25% and 48%, respectively, when coadministered with telotristat ethyl; the mechanism of this interaction appears to be that telotristat ethyl increases the glucuronidation of the CYP3A4 substrate.

Terazosin: (Moderate) Due to the potential for symptomatic hypotension, patients should be stable on alpha-blocker therapy before initiating therapy with the lowest dose of vardenafil. Conversely, patients already receiving an optimized dose of vardenafil should be started on the lowest dose of the alpha-blocker; increases in the alpha-blocker dose should be done in a stepwise fashion. Other variables, such as intravascular volume depletion, concurrent antihypertensive therapy, or evidence of hemodynamic instability with alpha-blocker monotherapy, may affect the safety of concomitant use of vardenafil and an alpha-blocker.

Tetrabenazine: (Major) Tetrabenazine causes a small increase in the corrected QT interval.

Caution is advisable during concurrent use of other agents associated with a possible risk for QT prolongation and TdP including vardenafil.

Therapeutic (10 mg) and supratherapeutic (80 mg) doses of vardenafil produces an increase in QTc interval (e.g., 4 to 6 msec calculated by individual QT correction). When vardenafil (10 mg) was given with gatifloxacin (400 mg), an additive effect on the QT interval was observed. The effect of vardenafil on the QT interval should be considered when prescribing the drug.