Viagra

Question 1

What is the primary use of sildenafil citrate (Viagra)?

Answer 1

To treat erectile dysfunction

Marketed in 1998 by Pfizer.

Question 2

What was the initial target for Pfizer’s drug development before sildenafil was identified?

Answer 2

Angina

Angina is severe pain in the heart and chest wall due to insufficient blood supply.

Question 3

What is the mechanism of action for sildenafil in relation to blood flow?

Answer 3

It inhibits an enzyme that ends natural vasodilation

This prolongs the dilation of arteries.

Question 4

What was the serendipitous outcome of the Phase I trials of UK-92480?

Answer 4

Increased frequency and duration of penile erection reported by male volunteers

This led Pfizer to investigate it for erectile dysfunction.

Question 5

What is erectile dysfunction?

Answer 5

Inability to obtain or sustain an erection

Often indicates underlying health issues.

Question 6

What was the sales figure for Viagra shortly after its launch?

Answer 6

Around £1 billion per year

Contributed to Pfizer becoming the largest pharmaceutical company.

Question 7

What phase of clinical trials did UK-92480 enter after pre-clinical trials showed safety?

Answer 7

Phase I trials

Conducted in healthy volunteers.

Question 8

What were common side effects of Viagra found in follow-up surveillance?

Answer 8

• Headache
• Hot flushes
• Indigestion

Certain heart conditions may contraindicate its use.

Question 9

What was the outcome of Phase III clinical trials for UK-92480?

Answer 9

Significant improvement compared to placebo

21 separate studies confirmed this.

Question 10

What did the licensing application for Viagra achieve in terms of response time?

Answer 10

Returned successfully in only 6 months

Due to the success of clinical trials.

Question 11

What role did Viagra play in public health beyond treating erectile dysfunction?

Answer 11

Encouraged men to seek help for ED, leading to earlier detection of underlying diseases

Indirectly saved lives and improved relationships.

Question 12

Fill in the blank: The initial drug that Pfizer developed was called _______.

Answer 12

UK-92480

Later marketed as Viagra.

Question 13

True or False: UK-92480 was found to be equally effective in treating angina as it was for erectile dysfunction.

Answer 13

False

It was less specific and potent for treating angina.

Question 14

What did Pfizer scientists clone to develop the drug?

Answer 14

The target enzyme

This was crucial for designing an effective assay.

Question 15

What was the key finding regarding the target enzyme in penile arteries?

Answer 15

UK-92480 is especially potent at inhibiting this enzyme subtype

This promotes penile vasodilation and erection.

Question 16

What was the cost incurred by Pfizer for the development of Viagra over 13 years?

Answer 16

£600 million

This cost was quickly recouped after launch.

Question 17

What did Pfizer’s work with UK-92480 and angina ultimately conclude?

Answer 17

It lacked sufficient potency to treat angina

This failure led to a pivot to erectile dysfunction.

Question 18

What was the purpose of conducting randomised, blind trials in Phase III?

Answer 18

To ensure no bias

This is a standard practice in clinical trials.