Reports show 19 deaths occurred due to sildenafil in the UK last year. What does this mean for the medicine, which is being considered for S3 status in Australia?
Data from the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) reveals sildenafil has been implicated in the deaths of seven people so far this year.
In the analysis of all UK spontaneous suspected Adverse Drug Reactions (ADRs) reported through the Yellow Card Scheme, a total of 1273 suspected Adverse Drug Reactions including 166 fatal cases have been linked to sildenafil since 1998.
The highest of these was 44 fatalities in 1999, dropping down to below 10 fatalities for most years before spiking up in 2017 with 19 deaths.
Referring to Viagra, which became available over the counter in the UK this March, the Daily Mail publication has covered the MHRA data by reporting that “the impotence drug is currently linked to seven fatalities this year”.
“The active drug in Viagra has been linked to 19 deaths in the UK last year, the highest on record since 1999.
“The findings come after it was reported nearly a million Viagra pills had been bought since it became legal to sell them without prescription in March,” says the publication.
The article has received nearly 1000 shares and 600 comments.
However as some commenters pointed out, the 19 deaths were from 2017 before the drug went OTC.
And 29 of the total 166 deaths in 20 years were actually women.
Sildenafil can also be used to treat pulmonary arterial hypertension, in addition to erectile dysfunction.
A spokesperson for Pfizer, the manufacturer of Viagra, has pointed out that the data is related to all sildenafil and is not limited to Viagra.
“It is important to note that the MHRA Yellow Card data relates to sildenafil, the active ingredient in Viagra. The dataset includes data for all spontaneous suspected Adverse Drug Reactions (ADRs) reports related to sildenafil and is not limited to Viagra. It is therefore misleading and inaccurate to report the MHRA Yellow Card data as being specific to Viagra, rather than all generic and branded sildenafil,” they told AJP.
“Pfizer takes the safety of our medicines very seriously. We regularly review safety data and post-marketing adverse events and report this to the independent regulator the Therapeutic Goods Administration.
“The effectiveness of Viagra for treating erectile dysfunction (ED) has been established in over 120 manufacturer-sponsored clinical trials and it’s estimated that more than 43 million patients have taken the prescription version of Viagra worldwide since 2003.”
Sildanafil causes of death
Looking at the UK data, of the total 166 fatal cases over 20 years, most (n = 45) were linked to coronary artery disorders.
A smaller number (n = 14) were due to central nervous system haemorrhages and cerebrovascular accidents.
Thirteen fatal outcomes were related to the respiratory system, nine to cardiac arrhythmias, six related to heart failure, three to vascular disorders, four to injury and poisoning, and four related to suicidal and self-injurious behaviour.
Thirty-five cases were just listed as ‘death’, while 26 were listed as ‘sudden death’.
In Australia there have been just 39 cases of death as an outcome related to the use of sildenafil in the last 20 years, of a total 1,075 adverse event reports.
In Australia, the TGA’s Advisory Committee on Medicines Scheduling (ACMS) is in the process reviewing the possibility of creating an S3 category for sildenafil (Viagra) in oral preparations containing 50 mg of sildenafil per dosage unit, in packs containing not more than 8 dosage units.
The new Australian proposal claims the move will increase access to sildenafil for men suffering from erectile dysfunction and will help de-stigmatise the condition.
It also argues the move will direct men away from the unregulated supply of purported erectile dysfunction medications.
However ACMS has previously ruled against making sildenafil OTC in Australia, reasoning that: “Adverse events and drug interactions of sildenafil can be potentially severe. The adverse event profile requires medical monitoring. Drug interactions may potentiate sildenafil toxicity.”
In 2017 it also found that: “There is increasing evidence of a direct link between erectile dysfunction and cardiovascular disease. Erectile dysfunction is a marker of early atherosclerosis and as an independent predictor of cardiovascular events and all-cause mortality.”
The UK’s move to launch OTC Viagra has been lauded by health professionals as “a great public health opportunity”.
This is because erectile dysfunction conversations are “picking up”, say pharmacists.
The AMCS is expected to publish its interim decision on the latest sildenafil application in September.