When evaluating the cause of erectile dysfunction, one should consider entire medical assessment, all the potential underlying causes, and the identification of right kind of treatment. Before recommending LEVITRA, the following should be carefully noted:
Alpha-blockers: Caution is recommended when PDE5 inhibitors are co- governed with alpha-blockers. PDE5 inhibitors which even include LEVITRA and alpha-adrenergic blocking agents are considered as vasodilators which can lower the levels of blood pressure. In cases of some patients, concomitant use of this combination of drugs has caused symptoms such as fainting and hypotension. Careful consideration should be given to the following:
- Patients should show stability on alpha-blocker therapy before initiating PDE5. In case if a patient demonstrates instability, then he/she has an increased risk of symptomatic hypotension with concomitant usage of PDE5 inhibitors.
- In case of patients who are already taking an optimized dose of PDE5, alpha-blocker therapy must be started at the lowest possible dose.
- In case of those patients who are quite stable on alpha-blocker therapy, PDE5 inhibitors should be instigated at the lowest recommended starting dose.
- Safety of combined usage of alpha-blockers and PDE5 inhibitors might be affected by many other variables which include intravascular volume depletion and many other such anti-hypertensive drugs.
Renal Insufficiency: In cases of patients with severe (CLcr < 30 ml/min) to moderate (CLcr = 30-50 ml/min) renal impairment, the AUC of the vardenafil was calculated to be 20-30% higher as compared to the values observed in a group with normal (CLcr > 80 ml/min) renal function. The Vardenafil pharmacokinetics has not been evaluated in case of patients requiring renal dialysis.
Hepatic Insufficiency: In patients with moderate amounts of impairment (Child-Pugh B), the AUC and Cmax following a dose of 10mg vardenafil were increased up to 160% and 130% respective, as compared to healthy control subjects. Consequently, it is recommended to have a starting dose of 5mg for patients coming under the category of moderate hepatic impairment. The maximum dose, however, should never exceed 10mg.
Acquired or Congenital QT Prolongation: According to a study of the effect of LEVITRA on QT interval in about 59 healthy males, supratherapeutic (80mg) and therapeutic (10mg) doses of LEVITRA and the active control moxifloxacin (400mg) generated similar rises in QTc interval. As per a post marketing study evaluation, the effect of combining LEVITRA along with another drug of analogous QT showed an additive QT effect as compared with either drug alone. These are some of the observations which should be considered in clinical decisions when recommending LEVITRA to any patient with a known history of QT prolongation, or to patient consuming medications which are known to prolong QT interval.
