Spironolactone safe and effective for treating acne in women, research confirms

22nd May 2023

Spironolactone is a cheap, safe and effective for treating women with acne that can also be used in the longer term, a large UK study has shown.

The randomised controlled trial of 410 women over the age of 18 years with mild, moderate and severe acne found a significant difference in both in quality of life and self-reported acne improvement compared with placebo.

Reporting the results in the BMJ, researchers from the University of Southampton said the NIHR-funded trial was the first to provide clinical evidence that spironolactone was effective for the skin condition.

Differences were seen by 12 weeks but were more marked and statistically significant by 24 weeks, they said.

By this time, the number needed to treat for participants to report improvement in the condition of their skin was five.

There did not seem to be a difference in effectiveness between women who had PCOS and those who did not, the researchers noted.

It could mean a change in the way the condition is treated including a reduction in the number of antibiotics prescribed, as currently recommended in UK guidelines when topical treatments have not worked, they concluded.

More frequent headaches was the only difference in adverse effects between the two groups who were started on 50 mg spironolactone or matched placebo, increasing to two tablets daily at six weeks if tolerated, which was the case for more than 95% of participants.

Two other trials underway are looking at higher starting doses of the treatment.

Questions relative effectiveness in comparison with other treatments, use in younger age groups and which subgroups benefit would be answered in other studies, the team added.

Spironolactone is ‘fantastic alternative’

A linked editorial said the women in the study had already heard about spironolactone as a possible treatment on social media and were keen to try it.

Study author Professor Miriam Santer, a GP and professor of primary care research at the University of Southampton, said spironolactone could provide a ‘fantastic alternative’ to oral antibiotics in women where topical treatments had not worked.

‘We hope the publication of these results will mean more GPs and dermatologists feel confident to prescribe spironolactone as a treatment for acne,’ she said. ‘The drug is already included in treatment guidelines for persistent acne in the US and Europe, and we hope this trial will lead to a change in the UK guidelines.’

Professor Alison Layton from Harrogate and District NHS Foundation Trust and the Skin Research Centre at the University of York, who also worked on the study, said dermatologists had been prescribing the drug for severe acne for some time.

‘This is a cheap medication which has been used for decades in the treatment of high blood pressure. The drug also reduces the main hormone that leads to the development of acne.

‘However, previous studies of spironolactone for acne have been very small and there was no definitive proof that it actually worked.’

Professor Andrew Farmer, director of NIHR’s Health Technology Assessment programme, said: ‘The findings from this important trial provide compelling evidence which could help thousands of women affected by persistent acne.

‘The treatment provides a valuable alternative to antibiotics and ensures clinicians can also better avoid the harms that can arise from antimicrobial resistance.’

A version of this story was originally published by our sister publication Pulse.

Spironolactone use not associated with increased risk of cancer

15th February 2022

Spironolactone use is not associated with an increased risk of any type of cancer but may actually reduce the risk of prostate cancer

Use of spironolactone does not appear to be linked with a higher incidence of any form of cancer and may even be protective against prostate cancer. This was the conclusion from a systematic review and meta-analysis by researchers from the University of Miami Miller School of Medicine, Florida, US.

Spironolactone is a potassium-sparing diuretic with a number of licensed indications including oedema, ascites, nephrotic syndrome and resistant hypertension. In addition, the drug is often prescribed ‘off-license’ for the treatment of acne in women, female pattern hair loss and hirsutism.

In fact, a recent and retrospective analysis of 403 women concluded that spironolactone improves clinical outcomes and is well tolerated for many adult women with acne using it for an extended duration.

Despite being used for a wide range of indications, the US Food and Drug Administration carries a warning that spironolactone has been shown to be a tumourigen in chronic toxicity studies in rats and that it should be used only for licensed indications, adding that unnecessary use of this drug should be avoided.

Similarly, the summary of product characteristics (SPC) for the drug states that spironolactone has been shown to produce tumours in rats when administered at high doses over a long period of time.

While the SPC adds that the ‘significance of these findings with respect to clinical use is not certain‘, it does advise that the ‘long-term use of spironolactone in young patients requires careful consideration of the benefits and the potential hazard involved‘.

With some uncertainty over possible associations between the use of spironolactone and cancer, the US team undertook a systematic review and meta-analysis to synthesize the available evidence on the topic.

They searched for studies that reported on the risk of cancer development in adults in both sexes who were exposed to spironolactone, irrespective of its primary use. The main outcome of interest was cancer occurrence.

Spironolactone use and incidence of cancer

A total of 7 observational studies including a total population of 4,528,332 individuals with a mean age of 62.6 to 72 years and between 17.2 and 54.4% women, were included in the analysis. These studies examined the incidence of breast, ovarian, bladder, kidney, gastric and oesophageal cancers. Furthermore, all of the studies were deemed to be at a low risk of bias.

There was a non-significant association between spironolactone use and breast cancer (risk ratio, RR = 1.04, 95% CI 0.86 – 1.22), bladder cancer (RR = 0.89, 95% CI 0.71 – 1.07) and kidney cancer (RR = 0.96, 95% CI 0.85 – 1.07). In addition, similar non-significant associations were calculated for the other cancer examined.

However and in contrast, in relation to prostate cancer and based on a total of 4 studies, there was a significantly reduced risk in those using spironolactone (RR = 0.79, 95% CI 0.68 – 0.90), although the certainty of evidence for this estimate was considered to be low.

Commenting on these findings, the authors considered their results to be reassuring and that treatment with spironolactone appeared unlikely to be associated with a meaningful increased risk of cancer when prescribed at typical clinical doses.

Nevertheless, they concluded that the certainty of evidence was low and that future studies are needed to examine this relationship in more detail.

Citation
Bommareddy K et al. Association of Spironolactone Use With Risk of Cancer: A Systematic Review and Meta-analysis JAMA Dermatol 2022