PDE5 Inhibitors: Types and Differences

What are PDE5 Inhibitors?

PDE5 inhibitors are a class of medications used to treat erectile dysfunction. They work by blocking the enzyme phosphodiesterase type 5, which helps increase blood flow to the penis.

Types Available in the UK

Four main PDE5 inhibitors are available on prescription in the UK:

Sildenafil (Viagra)

Sildenafil was the first PDE5 inhibitor to be approved. It typically takes 30-60 minutes to work and its effects last for about 4-6 hours. It should be taken on an as-needed basis, approximately one hour before sexual activity.

Tadalafil (Cialis)

Tadalafil has a longer duration of action, with effects lasting up to 36 hours. It can be taken as needed or as a lower daily dose. It typically starts working within 30 minutes.

Vardenafil (Levitra)

Vardenafil works similarly to sildenafil but may work slightly faster. Its effects typically last 4-5 hours. It should be taken approximately 25-60 minutes before sexual activity.

Avanafil (Spedra)

Avanafil is a newer PDE5 inhibitor that may work faster than other options, sometimes in as little as 15 minutes. Its effects last for about 4-6 hours.

Which One is Right?

Different PDE5 inhibitors suit different people. Your doctor will consider factors such as your general health, other medications you’re taking, and your lifestyle when recommending a treatment. Some men may need to try different options to find the one that works best for them.

Note: All PDE5 inhibitors are prescription-only medicines in the UK. Never purchase these medications from unregulated sources, as they may be counterfeit, unsafe, or ineffective.

Frequently Asked Questions

Q: How do PDE5 inhibitors work? A: They block an enzyme that normally breaks down a substance important for relaxing blood vessels in the penis. By blocking this enzyme, more blood can flow to the penis, helping to achieve and maintain an erection in response to sexual stimulation.

Q: Do PDE5 inhibitors work immediately? A: No. They require sexual stimulation to work and typically take 15-60 minutes to become effective, depending on the specific medication. They do not cause automatic erections.

Q: Can PDE5 inhibitors be taken with food? A: This varies by medication. Some are better taken on an empty stomach, while others are less affected by food. Your pharmacist will advise on the best way to take your specific medication.

Q: What happens if a PDE5 inhibitor doesn’t work? A: If one PDE5 inhibitor doesn’t work well for you, your GP may suggest trying a different one. Individual responses vary, and what works for one person may not work for another.

Q: Are PDE5 inhibitors safe? A: When prescribed by a healthcare professional and taken as directed, PDE5 inhibitors are generally safe. However, they are not suitable for everyone and can interact with certain other medications, particularly nitrates. Your doctor will assess whether they are appropriate for you.