Levitra, with its active ingredient vardenafil, is a medication used to treat erectile dysfunction (ED) in adult males. This condition prevents individuals from achieving or maintaining a penile erection firm enough for satisfactory sexual activity. This article provides an overview of Levitra, covering its mechanism of action, typical usage, and important safety considerations.
How Levitra Works
Levitra targets phosphodiesterase type 5 (PDE5), an enzyme in the body. Sexual stimulation initiates penile erection by releasing nitric oxide in the corpus cavernosum, spongy tissue in the penis. Nitric oxide activates guanylate cyclase, increasing cyclic guanosine monophosphate (cGMP) production.
Increased cGMP levels relax smooth muscles in the penis, allowing increased blood flow into erectile tissues, resulting in an erection. PDE5 breaks down cGMP, ending the erection. As a PDE5 inhibitor, vardenafil blocks this breakdown, sustaining cGMP levels and improving blood flow for an erection when sexual stimulation is present.
Vardenafil is a selective inhibitor of PDE5. Sexual stimulation remains a prerequisite for Levitra to work, as it does not directly cause an erection without arousal.
Effectiveness and Administration
Levitra is effective for individuals experiencing erectile dysfunction. The recommended starting dose is 10 mg, taken orally about 60 minutes before anticipated sexual activity. While effects can begin as soon as 15 minutes, full effects usually appear within 30 minutes to 2 hours, with a median onset around 60 minutes.
Levitra’s effects can last approximately 4 to 5 hours, and up to 8 hours for some. It can be taken with or without food, but a high-fat meal might delay absorption and reduce effectiveness. The maximum recommended dosing frequency is once per day.
A healthcare provider might adjust the dose based on individual efficacy and tolerability. The dose can be increased to a maximum of 20 mg or decreased to 5 mg. For individuals aged 65 or older, or those with moderate hepatic impairment (Child-Pugh B), a lower starting dose of 5 mg is often considered.
Side Effects and Important Warnings
Levitra can cause side effects. Common side effects include headaches, facial flushing, nasal congestion, indigestion, and dizziness. Some individuals may also experience back pain or flu-like symptoms.
Serious, less common side effects include sudden vision loss in one or both eyes, or sudden decrease or loss in hearing, sometimes with ringing in the ears and dizziness. If an erection lasts longer than four hours and is painful (priapism), immediate medical assistance is necessary to prevent potential damage.
Levitra is contraindicated for patients with known hypersensitivity to any component. It should not be used by individuals taking nitrate drugs for chest pain or heart problems (e.g., nitroglycerin, isosorbide dinitrate), as this combination can cause a dangerous drop in blood pressure. Concomitant use with guanylate cyclase stimulators like riociguat is also contraindicated.
Caution is advised when Levitra is co-administered with alpha-blockers, used to treat enlarged prostate or high blood pressure, as both can lower blood pressure. Patients should be stable on alpha-blocker therapy before initiating Levitra, typically at a lower dose. Certain medications, including some antifungal drugs (ketoconazole, itraconazole), antibiotics (erythromycin, clarithromycin), and HIV protease inhibitors (ritonavir, indinavir), can increase vardenafil concentration, requiring dose adjustments.
Levitra Compared to Other ED Medications
Levitra (vardenafil) belongs to the same class of medications, PDE5 inhibitors, as sildenafil (Viagra) and tadalafil (Cialis).
Levitra generally has an onset of action within 25 to 60 minutes, similar to sildenafil (30 to 60 minutes). Both Levitra and sildenafil usually provide effects lasting about 4 to 5 hours. Tadalafil has a longer duration, lasting up to 36 hours, earning it the nickname “The Weekend Pill.”
The effectiveness of both Levitra and sildenafil can be reduced by high-fat meals. Tadalafil is largely unaffected by food. While all three share common side effects, tadalafil is more commonly associated with back pain and muscle aches due to its effect on PDE11.