Hot on the heels of its $573 million women’s health funding pledge, three more medications  are now PBS-listed — including progestogen-only contraceptive drospirenone (Slinda) and relugolix with estradiol and with norethisterone (Ryeqo). Here’s what you need to know.

Ryeqo

Ryeqo is now on the PBS as a second line option for people who have had previous medical or surgical treatment for endometriosis.

It must initially be prescribed by a specialist, but can then be managed by GPs.

“It is a daily oral tablet that some people with endometriosis find really helpful to manage pain,” says gynaecologist and CREI accredited fertility specialist, Professor Louise Hull from the Robinson Research Institute, University of Adelaide, who has a PhD in endometriosis from Cambridge University.

It contains GnRH receptor antagonist relugolix, which blocks GnRH receptors in the pituitary gland, inhibiting the release of follicle-stimulating hormone and oocyte maturation, inducing a low oestrogen, menopause-like state.

It also contains low doses of oestradiol and norethisterone acetate to help prevent or reduce bone mineral density loss (called ‘add-back’ therapy).

While the GnRH analogues goserelin (Zoladex) and nafarelin acetate (Synarel) are also PBS-listed and are as effective as Ryeqo, “they’re more likely to lead to bone mineral density loss and therefore they are limited to six months,” Endometriosis Australia director Associate Professor Anusch Yazdani told Healthed.

Ryeqo can be used for up to two years.

Professor Hull says that while Ryeqo already contains oestradiol, you need to test bone density before commencing it, and check again every year.

If there are mild bone density changes, it may be possible to continue Ryeqo, she explains, but you may need to implement other bone-preserving strategies—such as additional oestrogen or weight training.

Ryeqo can’t be used concurrently with hormonal contraceptives – however it suppresses ovulation and provides adequate contraception in those who have been taking it for at least one month (a non-hormonal contraceptive should be used for the first month).

Possible side effects are similar to oral contraceptives, and it can interact with a number of drugs. See the PI for more information about possible adverse events and interactions.

Slinda

While we’ve had progestogen-only pills a long time, older pills “were hampered by the fact there was a very short window—only three hours—in which you had to remember to take the tablet before you lost contraceptive cover,” says sexual health physician Dr Terri Foran, Conjoint Senior Lecturer in the School of Women’s and Children’s Health, UNSW.

In contrast, Slinda has a 24-hour window, she says. “And that makes it a lot easier for women because we all try and take those on time, but we can get caught up with life sometimes. So it’s much more forgiving.”

Dr Sara Whitburn, Medical Director of Sexual Health Victoria and Chair of the RACGP Sexual Health Specific Interest Group, agrees that this longer window with Slinda is important.

“It’s closer to the combined pill, so it really helps with adherence,” she explains.

More reliable ovulatory suppression

Older progestogen-only pills didn’t reliably suppress ovulation in some women, Dr Foran adds, so their efficacy was lower than that of combined oral contraceptive pills.

“And we know from studies that Slinda does reliably suppress ovulation. So you can rely on it to the extent that you can rely on a combined oral contraceptive pill. Obviously, you still have to take it correctly and it’s not 100% effective—no method of contraception is—but it’s substantially more effective.”

Useful in women with certain risk factors and conditions

Slinda can be a suitable option for women who cannot use oestrogen, including women who get migraines with aura and those with risk factors such as high blood pressure, smoking, overweight, or a family history of heart disease, Dr Foran says.

It can be particularly useful for older women who need reliable contraception, she adds. “Unlike the combined oral contraceptive pill, which is suggested you should stop at 50, you can go on with a progestogen-only pill until around the age of 55—which is going to get most people through the menopause—and even longer with medical advice.”

Dr Whitburn agrees Slinda can be a good option for “people who can’t take estrogen and want something that’s really effective for contraception.”

“So people with migraine with aura, or people that don’t want to have an implant or an IUD because that’s not their choice,” she says.

“It really broadens the option of progestogen-only contraception.”

More consistent bleeding pattern

While older progestogen-only pills were taken continuously, resulting in a bleeding pattern that was “somewhat erratic”, Slinda has a regular bleed scheduled at the end of every packet, Dr Foran explains.

“But even then, what tends to happen is that the longer you take it, the less bleeding you get. So often by the end of 12 months, even if you’re taking the sugar pills, most women in fact aren’t bleeding. And that makes it a more acceptable option for some women because they don’t have to worry that they’ll get a bleed when they’re not expecting it.”

Any specific precautions?

There are few precautions for using progestogen-only pills—including Slinda, Dr Foran says.

If Slinda is appropriate, you can “encourage women to give it a two-to-three-month trial and make a judgment at the end of that whether it’s the right thing for them.”

As with all pills, you “might find a group of women who it just doesn’t suit, in which case you try something different,” she says.

She advises looking out for the usual issues such as an adverse effect on mood, which, if it occurs, typically “kicks in pretty quickly and probably won’t get better. So you might think about changing it early.”

Risks and side effects

Like other progestogen only pills, Slinda can cause irregular bleeding, spotting or breast tenderness, and is contraindicated in people with breast cancer, unexplained vaginal bleeding or severe liver disease. Its effectiveness can be compromised if it is not taken correctly every day, or if the woman is experiencing severe diarrhoea or vomiting, or if it’s taken with certain other drugs, such as ritonavir or phenytoin.