Why are dermatologists prescribing women a blood pressure drug for acne?

ACNE didn’t take hold of JJ Boparai’s skin until she was in her late 20s. “I’d never had acne like this, my face was just covered,” said the 31-year-old from Metuchen, New Jersey, adding that experiencing acne as an adult was “horrible psychologically.”

Boparai’s breakouts - which she described as “very cystic, like a lot of under the skin, big, painful, ones, a lot on my chin and cheeks” - were stubborn. After about a year of trying various washes, chemical peels and creams, she went to a dermatologist, who started her on oral antibiotics and a topical medication. Her acne persisted.

It wasn’t until the doctor prescribed spironolactone - a blood pressure drug approved in 1960 - that Boparai saw a difference in her skin.

She’s far from alone: According to a study in JAMA Dermatology, the prescribing rates of spironolactone for acne in women rose by nearly 300% from 2017 to 2020. By 2020, dermatologists were prescribing the blood pressure medication at similar rates to antibiotics.

What is spironolactone and why does it treat acne?

Spironolactone works by blocking a hormone in the body called aldosterone. This hormone holds onto sodium; by blocking it, it helps the kidneys flush salt and water out of the body to lower blood pressure.

The drug, doctors later learned, also disrupts similar hormones in the body, including the ones that cause acne, said Dr John Barbieri, a dermatologist and epidemiologist at Brigham and Women’s Hospital in Boston, and the author of the JAMA Dermatology study.

These hormones are called androgens, and include testosterone.

“Testosterone increases the oil production in the skin, and when you have a lot of oil in your skin, it clogs the pores and causes acne,” said Dr Ayman Grada, a dermatologist and adjunct professor at Case Western Reserve University School of Medicine in Cleveland. Spironolactone blocks those effects on the skin.

After a few small studies in the 1980s showed the drug was effective for acne, some dermatologists began prescribing it to women. Men can also get acne as adults, but as an acne treatment, the drug is prescribed only to women.

“Its use has just grown and grown and grown over time” as word of the medication has spread, Barbieri said. Spironolactone is one of the acne treatments included in the American Academy of Dermatology treatment guidelines.

The drug isn’t generally used as a so-called firstline treatment for acne. It’s considered an option for women if other medications, including creams or oral antibiotics, don’t work.

“I do offer it more often than I used to, and I have become more comfortable with it,” said Dr Jessica Krant, a dermatologist at the Laser and Skin Surgery Centre of New York, who noted that she only typically prescribes it when other treatments don’t work. Oral antibiotics are the most common treatment for women with adult acne, but Barbieri expects spironolactone to soon surpass it. “There’s been growing high-quality data to support spironolactone use for acne, which I think has made more people become aware of it and be comfortable prescribing,” he said.

The American Academy of Dermatology, which issues prescribing guidelines for treating acne, has asked dermatologists to limit the use of antibiotics when possible.

“If we could use more spironolactone, that might help us use less antibiotics,” said Barbieri, who also co-chairs the group’s acne guidelines work group. “That’s going to create less antibiotic resistance in the community, and less antibiotic-associated complications for patients, like disrupting the microbiome.”

Is spironolactone safe for acne treatment?

Spironolactone isn’t approved by the Food and Drug Administration for acne and is prescribed off-label.

Barbieri noted that because the drug is generic — and has been for many years — it’s unlikely that a drugmaker would ever spend the money on the clinical trials that would be needed to apply for approval for its use for acne. “It’s unclear who would want to expend that effort,” he said.

As a blood pressure medication, spironolactone is usually prescribed at a dose of 25 milligrams a day.

For acne, the dosage is higher: it’s often started at 50 mg and then titrated up to 100 mg, and in some cases, 200 mg.

Those dosages haven’t been studied in large, long-term clinical trials. What’s more, the original studies on the drug were primarily carried out in older white men, not young women.

It shouldn’t be prescribed to men for acne, because at these high doses, can cause gynecomastia, or enlargement of breast tissue in men, Barbieri said.

As use of spironolactone for acne has increased, there have been a handful of small studies looking at the short-term safety and efficacy of the medication.

“It has been used for a long time, but there are limited clinical trials,” Grada said. He’s comfortable prescribing the drug, but would like to see long-term studies.

“The side-effects are very mild, you know, comparable to other drugs, but there’s no long-term safety data,” he added.

One phase 3 clinical trial, published in The BMJ last year, followed 400 women taking either spironolactone or a placebo for 24 weeks. Side-effects were slightly more common in women who got the drug compared to the placebo but, overall, they were mild.

Like other blood pressure drugs, it can cause side-effects including dizziness, lightheadedness and headaches. In older women taking it, or those with certain medical conditions, potassium levels should be monitored.

Krant said she has had a few women go off the medication because of breast tenderness or decreased sex drive. She also said it can disrupt the menstrual cycle, and cause irregular bleeding.

The drug shouldn’t be used during pregnancy, according to the American Academy of Dermatology, because it can cross the placenta and potentially affect the fetus.

Spironolactone does carry a FDA warning, based on a study showing that at extremely high levels — up to 150 times greater than human doses — it caused cancer in rats. A recent meta-analysis didn’t find an increased risk of cancer in humans, though the researchers noted “the certainty of the evidence was low and future studies are needed.”

“As a whole, spironolactone is a safe medicine with the data we know,” said Dr Christopher Bunick, a dermatologist and an associate professor at Yale University School of Medicine.

However, “there needs to be more highquality studies to truly understand the correlation between spironolactone use and cancer,” he said. “It’d be foolish to sweep it under the rug.