Persistent phototransformation products of vardenafil (Levitra®) and sildenafil (Viagra®)

Levitra > liquid levitra


suzetriginesuzetrigine decreases levels of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Monitor patients for loss of therapeutic effect of sensitive CYP3A substrates with narrow therapeutic indexes when coadministered with suzetrigine. Consider modifying dose of sensitive substrate according to prescribing recommendations. suzetrigine decreases levels of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Concomitant use may increase the risk of QTc interval prolongation. If concomitant use is unavoidable, adjust the frequency of ECG and electrolyte monitoring. tecovirimattecovirimat will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

tecovirimat will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. tetracyclinetetracycline will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors tetracycline will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors tobramycin inhaledtobramycin inhaled and vardenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity tobramycin inhaled and vardenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity topiramatetopiramate will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

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Important points

topiramate will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. valbenazinevalbenazine and vardenafil both increase QTc interval.

Product Dosage Quantity + Bonus Price
Levitra Soft Tabs20mg90 + 6 Pills241.31€ 229.82€
Levitra Generic40mg360 + 10 Pills704.99€ 671.42€
Levitra Generic40mg180 + 10 Pills405.06€ 385.77€
Levitra Professional20mg90 + 2 Pills304.49€ 289.99€
Levitra Soft Tabs20mg180 + 10 Pills398.14€ 379.18€
Levitra Original20mg12 Pills81.99€ 78.09€
Levitra Original20mg120 + 8 Pills528.19€ 503.04€
Levitra Generic20mg10 Pills31.49€ 29.99€
Levitra Soft Tabs20mg120 + 8 Pills288.52€ 274.78€
Levitra Generic60mg120 + 8 Pills372.33€ 354.60€
Levitra Professional20mg20 Pills101.00€ 96.19€
Levitra Generic40mg270 + 10 Pills561.89€ 535.13€

valbenazine and vardenafil both increase QTc interval.

verapamilverapamil will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Ingredient Concentration Purpose Notes
Vardenafil Hydrochloride 20 mg/mL Active component for erectile dysfunction relief Prescribed dose varies
Glycerin 10% Solvent and base Enhances absorption
Purified Water Q.S. to 100% Diluent Ensures stability
Flavoring Agents - Improves taste Commonly mint or berry

Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors verapamil will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors Either increases effects of the other by QTc interval.

Therapeutic indication

What are the most common side effects of vardenafil?

voriconazolevoriconazole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors voriconazole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors vorinostatvorinostat and vardenafil both increase QTc interval. vorinostat and vardenafil both increase QTc interval. zafirlukastzafirlukast will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. zafirlukast will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. acetazolamideacetazolamide will increase the level or levitra now online effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

5.6 Alpha-Blockers

azithromycinazithromycin increases toxicity of vardenafil by QTc interval. azithromycin increases toxicity of vardenafil by QTc interval. carvedilolvardenafil increases effects of carvedilol by pharmacodynamic synergism. vardenafil increases effects of carvedilol by pharmacodynamic synergism. chloroquinechloroquine increases toxicity of vardenafil by QTc interval.

How do the side effects compare for vardenafil and tadalafil?

chloroquine increases toxicity of vardenafil by QTc interval. cyclophosphamidecyclophosphamide will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. cyclophosphamide will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenonedrospirenone will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenone will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. acetazolamide will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozoleanastrozole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. azithromycinazithromycin increases toxicity of vardenafil by QTc interval. azithromycin increases toxicity of vardenafil by QTc interval. carvedilolvardenafil increases effects of carvedilol by pharmacodynamic synergism. vardenafil increases effects of carvedilol by pharmacodynamic synergism. chloroquinechloroquine increases toxicity of vardenafil by QTc interval. chloroquine increases toxicity of vardenafil by QTc interval.

7.3 Effects of Vardenafil on Other Drugs

suzetriginesuzetrigine decreases levels of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Monitor patients for loss of therapeutic effect of sensitive CYP3A substrates with narrow therapeutic indexes when coadministered with suzetrigine. Consider modifying dose of sensitive substrate according to prescribing recommendations. suzetrigine decreases levels of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Concomitant use may increase the risk of QTc interval prolongation.

What should I know about vardenafil before taking it?

If concomitant use is unavoidable, adjust the frequency of ECG and electrolyte monitoring. tecovirimattecovirimat will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered. tecovirimat will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. tetracyclinetetracycline will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. cyclophosphamidecyclophosphamide will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

References (16)

labetalolvardenafil increases effects of labetalol by pharmacodynamic synergism. vardenafil increases effects of labetalol by pharmacodynamic synergism. Possible additive vasorelaxation, leading to low blood pressure. Soluble guanylate cyclase (sGC) stimulators (eg, riociguat); concomitant use can cause hypotension Coadministration with nitrates (either regularly and/or intermittently) and nitric oxide donors Consistent with the effects of PDE5 inhibition on the nitric oxide/cyclic guanosine monophosphate pathway, PDE5 inhibitors may potentiate the hypotensive effects of nitrates A suitable time interval following PDE5 dosing for the safe administration of nitrates or nitric oxide donors has not been determined Use with caution in anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie’s disease), cardiovascular disease, left ventricular outflow obstruction, bleeding disorders, active peptic ulcer disease, liver disease, renal impairment, multidrug antihypertensive regimens, retinitis pigmentosa, concomitant use of CYP3A4 inhibitors, patients who have conditions that may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia) There have been rare reports of prolonged erections >4 hr and priapism (painful erections greater than 6 hours in duration) for this class of compounds, including vardenafil; in the event that an erection persists >4 hours, the patient should seek immediate medical assistance; if priapism is not treated immediately, penile tissue damage and permanent loss of potency may result Physicians should consider the cardiovascular status of their patients; there is a degree of cardiac risk associated with sexual activity; treatment for erectile dysfunction, should not be used in men for whom sexual activity is not recommended because of their underlying cardiovascular status Patients with left ventricular outflow obstruction, (for example, aortic stenosis and idiopathic hypertrophic subaortic stenosis) can be sensitive to the action of vasodilators including PDE5 inhibitors Until further information available, use is not recommended in unstable angina; hypotension (resting systolic blood pressure of <90 mmHg); uncontrolled hypertension (>170/110 mmHg); recent history of stroke, life-threatening arrhythmia, or myocardial infarction (within last 6 months); severe cardiac failure Consider counseling patients about protective measures necessary to guard against sexually transmitted diseases, including Human Immunodeficiency Virus (HIV); drug offers no protection against sexually transmitted diseases Patients taking Class 1A (eg, quinidine, procainamide) or Class III (eg, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using drug Safety and efficacy of drug used in combination with other treatments for erectile dysfunction not studied; use of such combinations not recommended Vision loss may occur rarely and may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION); patient should seek medical assistance for sudden loss in one or both eyes; patients who have already experienced NAION are at increased risk of recurrence; use is not recommended in patients with known degenerative retinal disorders May increase risk of rare sudden vision loss attributed to nonarteritic ischemic optic neuropathy; if vision problems arise, discontinue, and contact physician The drug has systemic vasodilatory properties that resulted in transient decreases in supine blood pressure in healthy volunteers (mean maximum decrease of 7 mmHg systolic and 8 mmHg diastolic); while this normally would be expected to be of little consequence in most patients, physicians should carefully consider whether their patients with underlying cardiovascular disease could be affected adversely by such vasodilatory effects Physicians should advise patients to stop taking all PDE5 inhibitors, and seek prompt medical attention in event of sudden decrease or loss of hearing; these events, which may be accompanied by tinnitus and dizziness, have been reported in temporal association to intake of PDE5 inhibitors, including vardenafil; it is not possible to determine whether these events are related directly to use of PDE5 inhibitors or to other factors CYP3A4 inhibitorsConcomitant administration with potent CYP3A4 inhibitors (eg, ritonavir, indinavir, cobicistat, ketoconazole) or moderate CYP3A4 inhibitors (eg, erythromycin) increases plasma concentrations of drug; dosage adjustment is necessary when drug is administered with certain CYP3A4 inhibitorsLong-term safety information is not available on concomitant administration of drug with HIV protease inhibitors Concomitant administration with potent CYP3A4 inhibitors (eg, ritonavir, indinavir, cobicistat, ketoconazole) or moderate CYP3A4 inhibitors (eg, erythromycin) increases plasma concentrations of drug; dosage adjustment is necessary when drug is administered with certain CYP3A4 inhibitors Long-term safety information is not available on concomitant administration of drug with HIV protease inhibitors Alpha blockersCaution advised when PDE5 inhibitors co-administered with alpha-blockers; PDE5 inhibitors, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure lowering effects; when vasodilators are used in combination, an additive effect on blood pressure may be anticipated; in some patients, concomitant use of these two drug classes can lower blood pressure significantly leading to symptomatic hypotension (eg, fainting)Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor; patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitorsIn patients who are stable on alpha-blocker therapy, initiate PDE5 inhibitors at lowest recommended starting doseIn patients already taking optimized dose of PDE5 inhibitor, initiate alpha-blocker therapy at lowest dose; stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure in patients taking a PDE5 inhibitorSafety of combined use of other PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs Caution advised when PDE5 inhibitors co-administered with alpha-blockers; PDE5 inhibitors, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure lowering effects; when vasodilators are used in combination, an additive effect on blood pressure may be anticipated; in some patients, concomitant use of these two drug classes can lower blood pressure significantly leading to symptomatic hypotension (eg, fainting) Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor; patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitors In patients who are stable on alpha-blocker therapy, initiate PDE5 inhibitors at lowest recommended starting dose In patients already taking optimized dose of PDE5 inhibitor, initiate alpha-blocker therapy at lowest dose; stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure in patients taking a PDE5 inhibitor Safety of combined use of other PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs QT prolonging drugsAvoid coadministration with drugs that have a high risk for QT prolonationPatients taking Class 1A (eg, quinidine, procainamide) or Class III (eg, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using drug Avoid coadministration with drugs that have a high risk for QT prolonation Patients taking Class 1A (eg, quinidine, procainamide) or Class III (eg, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using drug Controlled studies in pregnant women

Accuracy and precision

cyclophosphamide will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenonedrospirenone will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

How RedBox Rx can help

voriconazolevoriconazole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors voriconazole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors vorinostatvorinostat and vardenafil both increase QTc interval. vorinostat and vardenafil both increase QTc interval. zafirlukastzafirlukast will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Water Res.

zafirlukast will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. acetazolamideacetazolamide will increase the level or levitra now online effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. acetazolamide will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozoleanastrozole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozole will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenone will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. labetalolvardenafil increases effects of labetalol by pharmacodynamic synergism. vardenafil increases effects of labetalol by pharmacodynamic synergism.

Urethral Medications

Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors tetracycline will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors tobramycin inhaledtobramycin inhaled and vardenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity tobramycin inhaled and vardenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity topiramatetopiramate will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. topiramate will decrease the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Some side effects can be serious. If you experience any of the following symptoms , call your doctor immediately:

valbenazinevalbenazine and vardenafil both increase QTc interval. valbenazine and vardenafil both increase QTc interval. verapamilverapamil will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors verapamil will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Vardenafil dose may need to be reduced if coadministered with moderate or strong CYP3A4 inhibitors Either increases effects of the other by QTc interval. Possible additive vasorelaxation, leading to low blood pressure. Soluble guanylate cyclase (sGC) stimulators (eg, riociguat); concomitant use can cause hypotension Coadministration with nitrates (either regularly and/or intermittently) and nitric oxide donors Consistent with the effects of PDE5 inhibition on the nitric oxide/cyclic guanosine monophosphate pathway, PDE5 inhibitors may potentiate the hypotensive effects of nitrates A suitable time interval following PDE5 dosing for the safe administration of nitrates or nitric oxide donors has not been determined Use with caution in anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie’s disease), cardiovascular disease, left ventricular outflow obstruction, bleeding disorders, active peptic ulcer disease, liver disease, renal impairment, multidrug antihypertensive regimens, retinitis pigmentosa, concomitant use of CYP3A4 inhibitors, patients who have conditions that may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia) There have been rare reports of prolonged erections >4 hr and priapism (painful erections greater than 6 hours in duration) for this class of compounds, including vardenafil; in the event that an erection persists >4 hours, the patient should seek immediate medical assistance; if priapism is not treated immediately, penile tissue damage and permanent loss of potency may result Physicians should consider the cardiovascular status of their patients; there is a degree of cardiac risk associated with sexual activity; treatment for erectile dysfunction, should not be used in men for whom sexual activity is not recommended because of their underlying cardiovascular status Patients with left ventricular outflow obstruction, (for example, aortic stenosis and idiopathic hypertrophic subaortic stenosis) can be sensitive to the action of vasodilators including PDE5 inhibitors Until further information available, use is not recommended in unstable angina; hypotension (resting systolic blood pressure of <90 mmHg); uncontrolled hypertension (>170/110 mmHg); recent history of stroke, life-threatening arrhythmia, or myocardial infarction (within last 6 months); severe cardiac failure Consider counseling patients about protective measures necessary to guard against sexually transmitted diseases, including Human Immunodeficiency Virus (HIV); drug offers no protection against sexually transmitted diseases Patients taking Class 1A (eg, quinidine, procainamide) or Class III (eg, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using drug Safety and efficacy of drug used in combination with other treatments for erectile dysfunction not studied; use of such combinations not recommended Vision loss may occur rarely and may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION); patient should seek medical assistance for sudden loss in one or both eyes; patients who have already experienced NAION are at increased risk of recurrence; use is not recommended in patients with known degenerative retinal disorders May increase risk of rare sudden vision loss attributed to nonarteritic ischemic optic neuropathy; if vision problems arise, discontinue, and contact physician The drug has systemic vasodilatory properties that resulted in transient decreases in supine blood pressure in healthy volunteers (mean maximum decrease of 7 mmHg systolic and 8 mmHg diastolic); while this normally would be expected to be of little consequence in most patients, physicians should carefully consider whether their patients with underlying cardiovascular disease could be affected adversely by such vasodilatory effects Physicians should advise patients to stop taking all PDE5 inhibitors, and seek prompt medical attention in event of sudden decrease or loss of hearing; these events, which may be accompanied by tinnitus and dizziness, have been reported in temporal association to intake of PDE5 inhibitors, including vardenafil; it is not possible to determine whether these events are related directly to use of PDE5 inhibitors or to other factors CYP3A4 inhibitorsConcomitant administration with potent CYP3A4 inhibitors (eg, ritonavir, indinavir, cobicistat, ketoconazole) or moderate CYP3A4 inhibitors (eg, erythromycin) increases plasma concentrations of drug; dosage adjustment is necessary when drug is administered with certain CYP3A4 inhibitorsLong-term safety information is not available on concomitant administration of drug with HIV protease inhibitors Concomitant administration with potent CYP3A4 inhibitors (eg, ritonavir, indinavir, cobicistat, ketoconazole) or moderate CYP3A4 inhibitors (eg, erythromycin) increases plasma concentrations of drug; dosage adjustment is necessary when drug is administered with certain CYP3A4 inhibitors Long-term safety information is not available on concomitant administration of drug with HIV protease inhibitors Alpha blockersCaution advised when PDE5 inhibitors co-administered with alpha-blockers; PDE5 inhibitors, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure lowering effects; when vasodilators are used in combination, an additive effect on blood pressure may be anticipated; in some patients, concomitant use of these two drug classes can lower blood pressure significantly leading to symptomatic hypotension (eg, fainting)Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor; patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitorsIn patients who are stable on alpha-blocker therapy, initiate PDE5 inhibitors at lowest recommended starting doseIn patients already taking optimized dose of PDE5 inhibitor, initiate alpha-blocker therapy at lowest dose; stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure in patients taking a PDE5 inhibitorSafety of combined use of other PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs Caution advised when PDE5 inhibitors co-administered with alpha-blockers; PDE5 inhibitors, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure lowering effects; when vasodilators are used in combination, an additive effect on blood pressure may be anticipated; in some patients, concomitant use of these two drug classes can lower blood pressure significantly leading to symptomatic hypotension (eg, fainting) Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor; patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitors In patients who are stable on alpha-blocker therapy, initiate PDE5 inhibitors at lowest recommended starting dose In patients already taking optimized dose of PDE5 inhibitor, initiate alpha-blocker therapy at lowest dose; stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure in patients taking a PDE5 inhibitor Safety of combined use of other PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs QT prolonging drugsAvoid coadministration with drugs that have a high risk for QT prolonationPatients taking Class 1A (eg, quinidine, procainamide) or Class III (eg, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using drug Avoid coadministration with drugs that have a high risk for QT prolonation Patients taking Class 1A (eg, quinidine, procainamide) or Class III (eg, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using drug Controlled studies in pregnant women