Weak inhibitory effects toward other isoforms (CYP2C8, 2C9, 2C19, 2D6, 3A4) were found, but Ki values were in excess of plasma concentrations achieved following dosing.
| Advice | Explanation | Notes |
|---|---|---|
| Take on an empty stomach | Food, especially fatty meals, can delay onset | Take 30 minutes before activity |
| Do not exceed 1 dose/day | To avoid side effects and interactions | Follow prescribed dose |
| Notify doctor of side effects | Includes vision changes, chest pain, or prolonged erections | Medical consultation required |
| Avoid alcohol consumption | Alcohol can impair efficacy and increase side effects | Limit intake |
| Report adverse reactions | Such as severe headache, dizziness, or allergic responses | Seek medical help immediately |
The most potent inhibitory activity was observed for vardenafil metabolite M1, which had a Ki of 1.4 µM toward CYP3A4, which is about 20 times higher than the M1 Cmax values after an 80 mg LEVITRA dose.
Since higher doses of ketoconazole (400 mg daily) may result in higher increases in Cmax and AUC, a single 2.5 mg dose of LEVITRA should not be exceeded in a 24-hour period when used in combination with ketoconazole 400 mg daily (see WARNINGS and DOSAGE AND ADMINISTRATION). Indinavir (800 mg t.i.d.) co-administered with LEVITRA 10 mg resulted in a 16-fold increase in vardenafil AUC, a 7-fold increase in vardenafil Cmax and a 2-fold increase in vardenafil half-life. It is recommended not to exceed a single 2.5 mg LEVITRA dose in a 24-hour period when used in combination with indinavir (see WARNINGS and DOSAGE AND ADMINISTRATION). Ritonavir (600 mg b.i.d.) co-administered with LEVITRA 5 mg resulted in a 49-fold increase in vardenafil AUC and a 13-fold increase in vardenafil Cmax. The interaction is a consequence of blocking hepatic metabolism of vardenafil by ritonavir, a highly potent CYP3A4 inhibitor, which also inhibits CYP2C9.
Ritonavir significantly prolonged the half-life of vardenafil to 26 hours. Consequently, it is recommended not to exceed a single 2.5 mg LEVITRA dose in a 72-hour period when used in combination with ritonavir (see WARNINGS and DOSAGE AND ADMINISTRATION). Other CYP3A4 inhibitors: Although specific interactions have not been studied, other CYP3A4 inhibitors, including grapefruit juice would likely increase vardenafil exposure. Other Drug Interactions: No pharmacokinetic interactions were observed between vardenafil and the following drugs: glyburide, warfarin, digoxin, Maalox, and ranitidine. In the warfarin study, vardenafil had no effect on the prothrombin time or other pharmacodynamic parameters. Nitrates: The blood pressure lowering effects of sublingual nitrates (0.4 mg) taken 1 and 4 hours after vardenafil and increases in heart
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Levitra Original | 20mg | 8 Pills | 65.05€ 61.95€ | |
| Levitra Professional | 20mg | 180 + 4 Pills | 502.31€ 478.39€ | |
| Levitra Generic | 20mg | 270 + 10 Pills | 376.33€ 358.41€ | |
| Levitra Soft Tabs | 20mg | 90 + 6 Pills | 241.31€ 229.82€ | |
| Levitra Professional | 20mg | 20 Pills | 101.00€ 96.19€ | |
| Levitra Soft Tabs | 20mg | 180 + 10 Pills | 398.14€ 379.18€ | |
| Levitra Original | 20mg | 4 Pills | 45.87€ 43.69€ | |
| Levitra Generic | 20mg | 10 Pills | 31.49€ 29.99€ | |
| Levitra Original | 20mg | 76 + 4 Pills | 344.39€ 327.99€ | |
| Levitra Generic | 40mg | 30 + 2 Pills | 93.58€ 89.12€ | |
| Levitra Professional | 20mg | 60 + 2 Pills | 223.11€ 212.49€ | |
| Levitra Original | 20mg | 48 + 4 Pills | 235.14€ 223.94€ | |
| Levitra Generic | 40mg | 20 Pills | 67.56€ 64.34€ | |
| Levitra Generic | 40mg | 90 + 6 Pills | 234.73€ 223.55€ | |
| Levitra Generic | 60mg | 90 + 6 Pills | 291.82€ 277.92€ | |
| Levitra Original | 20mg | 14 + 2 Pills | 102.27€ 97.40€ | |
| Levitra Generic | 40mg | 60 + 4 Pills | 162.37€ 154.64€ |
rate when taken at 1, 4 and 8 hours were potentiated by a 20 mg dose of LEVITRA in healthy middle-aged subjects.
Physicians should discuss with patients the potential cardiac risk of sexual activity for patients with preexisting cardiovascular risk factors. The use of LEVITRA offers no protection against sexually transmitted diseases. Counseling of patients about protective measures necessary to guard against sexually transmitted diseases, including the Human Immunodeficiency Virus (HIV), should be considered. Physicians should inform patients that there have been rare reports of prolonged erections greater than 4 hours and priapism (painful erections greater than 6 hours in duration) for LEVITRA and this class of compounds. In vitro studies: Studies in human liver microsomes showed that vardenafil is metabolized primarily by cytochrome P450 (CYP) isoforms 3A4/5, and to a lesser degree by CYP2C9.
Therefore, inhibitors of these enzymes are expected to reduce vardenafil clearance (see WARNINGS and DOSAGE AND ADMINISTRATION). Erythromycin (500 mg t.i.d.) produced a 4-fold increase in vardenafil AUC and a 3-fold increase in Cmax when co-administered with LEVITRA 5 mg in healthy volunteers (see DOSAGE AND ADMINISTRATION). It is recommended not to exceed a single 5 mg dose of LEVITRA in a 24-hour period when used in combination with erythromycin. Ketoconazole (200 mg once daily) produced a 10-fold increase in vardenafil AUC and a 4-fold increase in Cmax when co-administered with LEVITRA (5 mg) in healthy volunteers. A 5-mg LEVITRA dose should not be exceeded when used in combination with 200 mg once daily ketoconazole. These effects were not observed when LEVITRA 20 mg was taken 24 hours before the NTG.
Potentiation of the hypotensive effects of nitrates for patients with ischemic heart disease has not been evaluated, and concomitant use of
These observations should be considered in clinical decisions when prescribing LEVITRA to patients with known history of QT prolongation or patients who are taking medications known to prolong the QT interval. amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using LEVITRA. In patients with moderate (CLcr = 30-50 ml/min) to severe (CLcr<30 ml/min) renal impairment, the AUC of vardenafil was 20 – 30% higher compared to that observed in a control group with normal renal function (CLcr>80 ml/min) (see CLINICAL PHARMACOLOGY, Pharmacokinetics in Special Populations). Vardenafil pharmacokinetics have not been evaluated in patients requiring renal dialysis. General: In humans, vardenafil alone in doses up to 20 mg does not prolong the bleeding time.
There is no clinical evidence of any additive prolongation of the bleeding time when vardenafil is administered with aspirin. Vardenafil has not been administered to patients with bleeding disorders or significant active peptic ulceration. Therefore LEVITRA should be administered to these patients after careful benefit-risk assessment. Treatment for erectile dysfunction should generally be used with caution by patients with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie’s disease) or by patients who have conditions that may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia). The safety and efficacy of LEVITRA used in combination with other treatments for erectile dysfunction have not been studied. LEVITRA and nitrates is contraindicated (see CLINICAL PHARMACOLOGY, Pharmacodynamics,Effects on Blood Pressure and Heart Rate when LEVITRA is Combined with Nitrates;CONTRAINDICATIONS). Nifedipine: Vardenafil 20 mg, when co-administered with slow-release nifedipine 30 mg or 60 mg once daily, did not
| Dose | Timing | Food Interaction | Notes |
|---|---|---|---|
| 20 mg tablet | 1 hour before activity | Can be taken with or without food | Max once per day |
| Take with water | Avoid high-fat meals | Slows absorption | Do not exceed prescribed dose |
| Onset of Effect | 30-60 minutes | Take 15-30 minutes in advance | |
| Missed Dose | Not applicable | Take as needed before activity | |
| Duration of Effect | Up to 4-5 hours | Effects vary by individual |
affect the relative bioavailability (AUC) or maximum concentration (Cmax) of nifedipine, a drug that is metabolized via CYP3A4.
Nifedipine did not alter the plasma levels of LEVITRA when taken in combination.
| Study | Number of Participants | Improvement Rate | Onset Time | Duration of Effect |
|---|---|---|---|---|
| Phase 3 Trial A | 500 | 80% | 30 min | Up to 4 hours |
| Phase 3 Trial B | 300 | 75% | 45 min | 4-5 hours |
| Comparative Study C | 450 | Slightly higher than placebo | 30 min | 4 hours |
| Real-world Study D | 1000 | 78% | 40 min | 4-5 hours |
| Post-marketing Data | N/A | 82% | 30-60 min | Up to 4 hours |
In these patients whose hypertension was controlled with nifedipine, LEVITRA 20 mg produced mean additional supine systolic/diastolic blood pressure reductions of 6/5 mmHg compared to placebo.
Blood pressure effects in patients on stable alpha-blocker treatment: Two clinical pharmacology studies were conducted in patients with benign prostatic hyperplasia (BPH) on stable-dose alpha-blocker treatment for at least four weeks.
Patients should be counseled regarding the dosing of LEVITRA. Patients should be advised to contact their healthcare provider for dose modification if they are not satisfied with the quality of their sexual performance with LEVITRA or in the case of an unwanted effect. Patients should be advised to contact the prescribing physician if new medications that may interact with LEVITRA are prescribed by another healthcare provider. Physicians should advise patients to stop use of all PDE5 inhibitors, including LEVITRA, and seek medical attention in the event of sudden loss of vision in one or both eyes. Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision, including permanent loss of vision, that has been reported rarely post-marketing in temporal association with the use of all PDE5 inhibitors.
It mail order levitra online is not possible to determine whether these events were related directly to the use of PDE5 inhibitors or to other factors. Physicians should also discuss with patients the increased risk of NAION in individuals who have already experienced NAION in one eye, including whether such individuals could be adversely affected by use of vasodilators such as PDE5 inhibitors (see POST-MARKETING EXPERIENCE, Ophthalmologic). Physicians should advise patients to stop taking PDE5 inhibitors, including LEVITRA, and seek prompt medical attention in the 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 the intake of PDE5 inhibitors, including LEVITRA. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors or to other factors (see ADVERSE REACTIONS). Study 1: This study was designed to evaluate the effect of 5 mg vardenafil compared to placebo when administered to BPH patients on
chronic alpha-blocker therapy in two separate cohorts: tamsulosin 0.4 mg daily (cohort 1, n=21) and terazosin 5 or 10 mg daily (cohort 2, n=21).
Therefore, the use of such combinations is not recommended. Physicians should discuss with patients the contraindication of LEVITRA with regular and/or intermittent use of organic nitrates. Patients should be counseled that concomitant use of LEVITRA with nitrates could cause blood pressure to suddenly drop to an unsafe level, resulting in dizziness, syncope, or even heart attack or stroke. Physicians should inform their patients that in some patients concomitant use of PDE5 inhibitors, including LEVITRA, with alpha-blockers can lower blood pressure significantly leading to symptomatic hypotension (e.g., fainting). Patients prescribed LEVITRA who are taking alpha-blockers should be started on the lowest recommended starting dose of LEVITRA (see Drug Interactions and DOSAGE AND ADMINISTRATION).
Patients should be advised of the possible occurrence of symptoms related to postural hypotension and appropriate countermeasures. Patients should be advised to contact the prescribing physician if other anti-hypertensive drugs or new medications that may interact with LEVITRA are prescribed by another healthcare provider. Physicians should discuss with patients the appropriate use of LEVITRA and its anticipated benefits. It should be explained that sexual stimulation is required for an erection to occur after taking LEVITRA. LEVITRA should be taken approximately 60 minutes before sexual activity.