Second time's the charm? Pfizer tries again with OTC Viagra in the U.K.

Pfizer is looking to reclassify Viagra (sildenafil) as a pharmacy medicine in the U.K., almost a decade after its first OTC request.

The new application, filed by Pfizer Consumer Healthcare with the Medicine and Healthcare products Regulatory Agency (MHRA), seeks to have sildenafil 50 mg made available as a non-prescription drug administered under the supervision of a pharmacist. MHRA began a public consultation effort regarding the reclassification on Tuesday and will collect comments until April 18. Pfizer withdrew its application to switch Viagra from prescription to OTC in the European Union in 2008 after the European Medicines Agency noted some concerns.

A Pfizer spokesman said via email that it is working with MHRA and expects the regulatory review to continue through the coming months.

"Pfizer is committed to patient safety, and to ensuring that non-prescription sildenafil is supplied in a way that supports patient safety and improves patient health. Pharmacists are well placed to provide men with helpful and appropriate guidance to manage their erectile dysfunction, and should refer men to a doctor if they believe further investigation is required," he said.

If the reclassification is approved, Pfizer will offer pharmacists access to experience healthcare professionals who have been dispensing prescription sildenafil for more than 15 years and "access to specific training to support them in dispensing sildenafil, to appropriate patients only."

While the reclassified pharmacy medicine would be called by its generic name, sildenafil, the pills keep their familiar small blue diamond shapes with the company name “Pfizer” etched on the side. Viagra the branded drug, which comes in 25 mg, 50 mg and 100 mg versions, would continue to be marketed separately as a prescription-only erectile dysfunction treatment, according to the MHRA filing.

The MHRA will accept public comments on the change through April 18.

Viagra is already off patent in the U.K. and will see its patents expire in the U.S. in April 2020, according to Pfizer. As the result of a settlement with Pfizer, Teva Pharmaceuticals will be allowed to launch a generic version of Viagra in December, or possibly earlier. Pfizer will continue to sell branded Viagra while its wholly owned subsidiary Greenstone, will be able to launch a generic sildenafil citrate when Teva does. Viagra had global sales of $1.18 billion in 2016, down from $1.3 billion in 2015 but even with its 2014 haul. When asked about the potential for OTC Viagra in the U.S. the Pfizer spokesman said only that it "is evaluating a number of prescription drugs for a potential switch to non-prescription status."

Competitor Cialis from Eli Lilly, which is also facing patent expiration in the U.S., struck a deal with Sanofi in 2014 to begin work on an OTC Cialis to be marketed by Sanofi in the U.S., Europe, Canada, and Australia.

Editor's Note: The story was updated to include comments from Pfizer.