During our Your PKD Care in Canada: What the New ADPKD Commentary Means for You roundtable, registrants and participants submitted more questions than we could answer during the live event.

Below are answers to some of the questions that weren’t fully addressed during the discussion. These responses build on the 2025 KDIGO ADPKD guideline and the Canadian Society of Nephrology commentary, with additional review and input from Dr. Matt Lanktree, nephrologist, co-chair and co-author of the Canadian commentary.

We already have trusted resources for some of the touched-on topics, including nutrition and supplements, pain management, and family planning and reproductive care. We’ll continue to point people toward those expert resources.

Interested in learning more about the Canadian commentary? Read our blog about it, here.

1. What if my eGFR suddenly drops much faster than usual?

A sudden drop in eGFR is not always caused by PKD itself getting worse quickly. ADPKD usually progresses gradually, so if kidney function changes sharply over days, weeks or a few months, a nephrologist will usually look for another explanation as well.

The first step is often to repeat the blood test and look at the person’s recent health and medications.

Possible causes can include:

• dehydration
• vomiting or diarrhea
• an infection or other illness
• very low blood pressure
• some medications
• NSAID pain relievers
• diuretics or changes in blood pressure medications
• a urinary blockage, such as a kidney stone
• another kidney problem occurring in addition to ADPKD

Depending on the situation, a healthcare provider may review medications, repeat bloodwork, check urine tests and blood pressure, or order kidney imaging.

It is also important to remember that eGFR is an estimate based largely on creatinine. A single result can vary because of hydration, illness, recent exercise, muscle mass or normal laboratory variation.

That is why the trend over several measurements is usually more informative than one result.

Some causes of a sudden eGFR drop may be temporary or treatable. A sudden change should not automatically be assumed to represent permanent progression of ADPKD.

2. What if one of my kidneys appears to have shrunk on a recent scan?

If a kidney appears substantially smaller than it has on previous imaging reports, the first question is whether the measurements are truly comparable.

Kidneys affected by ADPKD can have an irregular shape. Measurements can vary depending on whether the scan was an ultrasound, CT or MRI, who measured the kidney, and exactly where the measurement was taken.

For example, a kidney reported as 18 cm long on one scan and 15 cm on another does not necessarily mean that the kidney itself has truly shrunk by that amount.

For ADPKD, total kidney volume (TKV) is generally more useful for assessing disease burden and progression than kidney length alone. TKV can also be adjusted for a person’s height and age as part of tools such as the Mayo Imaging Classification.

However, TKV is not normally measured over and over again in the same way that eGFR is. The amount of variation that can occur when kidney volume is measured may be similar to the amount of change expected over a relatively short period. Repeated MRI or CT imaging is also costly and impractical.

Reasons a nephrologist might consider new imaging include:

• new or worsening pain
• bleeding
• an unexpected change in kidney function
• an eGFR decline that does not seem to match earlier imaging or risk assessment

Individual cysts can also change size, rupture or bleed, which can affect the apparent size or shape of a kidney.

Tolvaptan is expected to slow the rate at which kidney volume increases over time. It is not generally used with the expectation that enlarged polycystic kidneys will substantially shrink.

If imaging appears to show a large decrease in kidney size, it may be useful for the healthcare team to compare the original images and measurements before assuming that the change represents a true biological change or an effect of treatment.

3. What if my blood pressure is low or changes a lot from day to day?

High blood pressure is common in ADPKD, but not everyone with PKD will have high blood pressure all the time.

It is also normal for everyone’s blood pressure to change throughout the day. Activity, anxiety, pain, medications, hydration and many other factors can affect a reading.

For this reason, it is helpful to measure blood pressure in a consistent way. Ideally, take measurements when you are relaxed and have been sitting quietly, rather than immediately after activity or during a stressful moment.

If someone is having unusually low blood pressure or large changes in readings, a healthcare provider may look at:

• whether the person has symptoms such as dizziness, fainting, weakness or light-headedness
• dehydration or changes in fluid intake
• recent illness
• blood pressure medications
• diuretics
• tolvaptan or other medications
• other health conditions that could affect blood pressure

A clinician may review home blood-pressure readings, medications, recent illnesses and bloodwork depending on the situation.

If blood pressure is changing significantly, it is important to discuss this with the healthcare provider prescribing the medication. People generally should not make major or frequent medication changes on their own unless they have a specific plan developed with their healthcare team.

The goal is not simply to make blood pressure as low as possible. It is to find a target that protects kidney and cardiovascular health while remaining safe and well tolerated.

4. What new treatments for ADPKD are being studied?

There is active research into treatments for ADPKD beyond tolvaptan. At present, however, tolvaptan remains the only approved treatment specifically shown to slow ADPKD progression.

One investigational treatment receiving attention is farabursen, previously known as RGLS8429. Farabursen is designed to affect a small regulatory molecule called microRNA-17, which is involved in biological pathways related to cyst growth.

Early clinical studies have examined safety, biological markers and changes in kidney volume. Farabursen remains investigational and is not currently an approved treatment for ADPKD.

Novartis is currently looking for sites to enrol patients in a Phase III clinical trial of farabursen.

Vertex is also planning a Phase III clinical trial of another investigational treatment for ADPKD.

Metformin has also been studied because laboratory and early clinical research suggested it might affect pathways involved in cyst growth. At this point, however, there is not enough evidence to recommend metformin specifically as a treatment for ADPKD.

People have also asked whether future treatments could be combined with tolvaptan. If people taking tolvaptan were excluded from an early clinical trial, we cannot automatically assume the two treatments can safely or effectively be used together. Combination treatment would need to be appropriately studied.

Ultimately, a new treatment will need to show not only that it affects kidney volume or biological markers, but that it can safely preserve kidney function and improve outcomes that matter to people living with ADPKD.

5. What treatments are available for polycystic liver disease?

Many people with ADPKD develop liver cysts, but not everyone develops symptoms that require treatment.

When polycystic liver disease becomes significant, symptoms can include:

• abdominal fullness or swelling
• pain or discomfort
• feeling full quickly when eating
• shortness of breath related to very large liver volume

Treatment depends on the pattern and severity of the disease.

Options can include procedures directed at individual large cysts, surgery in selected situations, and care at a centre with experience treating severe polycystic liver disease.

A group of medications called somatostatin analogues, including lanreotide and octreotide, can modestly reduce liver volume in some people and may improve symptoms. They are not appropriate for everyone, can have side effects, and access and drug coverage may be difficult in Canada.

The Canadian commentary suggests that people with severe polycystic liver disease may benefit from assessment at a centre with hepatology and ADPKD expertise.

For people with very severe polycystic liver disease, assessment for liver transplantation may provide a definitive treatment option. Referral to an appropriate specialist or transplant centre would be required for assessment.

If someone is concerned that a medication being used for one aspect of their health could affect their kidneys or liver, this is a good reason for the nephrologist, hepatologist, pharmacist and other members of the healthcare team to review the treatment together.

6. Is hypermobility a feature of ADPKD?

Hypermobility is not currently recognized as a typical feature of ADPKD.

ADPKD can affect structures outside the kidneys, and there is an association between ADPKD and some connective-tissue-related problems, including an increased occurrence of hernias.

However, if someone with ADPKD also has significant joint hypermobility or symptoms suggesting another connective-tissue disorder, those symptoms should not automatically be assumed to be caused by PKD.

Some people can have ADPKD and another inherited connective-tissue condition at the same time.

If hypermobility is causing pain, injuries or limiting someone’s ability to function, assessment by a physiatrist or rheumatologist may be appropriate.

Depending on the person’s symptoms and family history, other specialists such as medical genetics may sometimes also be involved.

7. Who with ADPKD should consider brain aneurysm screening?

People with ADPKD have a higher risk of intracranial, or brain, aneurysms than the general population, but most people with ADPKD will not develop an aneurysm that causes a problem.

The KDIGO guideline recommends screening particularly for people who:

• have previously had a subarachnoid hemorrhage
• have a family history of intracranial aneurysm or subarachnoid hemorrhage
• have a family history of unexplained sudden death that may have been caused by an aneurysm

Screening is most relevant when the person would be a candidate for treatment if an aneurysm were found.

The Canadian commentary considers these recommendations a minimum. Other people with ADPKD may also reasonably want to discuss screening with their healthcare provider after considering their own risks, preferences and circumstances.

Screening is usually done using vascular imaging such as an MR angiogram. Access to MRI varies across Canada, and CT angiography may sometimes be considered instead.

There are also potential downsides to screening that are important to consider.

For example, screening may find a small aneurysm that would never have caused a problem. Knowing that an aneurysm is present can cause ongoing anxiety. Preventive treatment of an aneurysm also has its own potential risks.

Some clinicians are therefore more aggressive about aneurysm screening than others, and shared decision-making is important.

If an initial scan does not find an aneurysm, repeat screening, when appropriate, is generally considered over a period longer than just a few years. The timing should be individualized according to risk and circumstances.

A useful question to bring to your healthcare provider is: “Based on my personal and family history, should I consider aneurysm screening?”

8. What should people with ADPKD know about cyst infections and kidney stones?

Both kidney cyst infections and kidney stones can occur in ADPKD, and their symptoms can sometimes overlap with other causes of pain or urinary infection.

Cyst infections

A cyst infection may cause symptoms such as:

• fever
• persistent pain in the side or abdomen
• feeling generally unwell
• symptoms that resemble a kidney or urinary infection

One challenge in ADPKD is that an ordinary kidney infection and an infected cyst can sometimes be difficult to tell apart.

When a cyst infection is suspected, clinicians may use blood and urine cultures along with imaging.

The Canadian commentary notes that cyst infections often require a longer course of antibiotics, commonly four to six weeks. The antibiotic also needs to be able to reach the infection inside the cyst.

Complex or persistent infections may require nephrology input, specialized imaging, or occasionally drainage of an infected cyst.

Kidney stones

Kidney stones can cause symptoms such as:

• significant side or back pain
• blood in the urine
• nausea
• blockage of urine flow

Many straightforward kidney stones can be treated locally. However, the anatomy of polycystic kidneys can sometimes make treatment more complicated.

Urologists may be more cautious about treatments such as laser procedures or shock-wave lithotripsy in someone with ADPKD. Some people may therefore need referral to a centre with more experience treating kidney stones in polycystic kidneys.

People experiencing severe pain, fever, difficulty keeping fluids down, difficulty passing urine, or other concerning symptoms should seek medical assessment rather than assuming the symptoms are simply part of living with PKD.

9. How can people find specialized ADPKD care in Canada?

This is one of the gaps discussed in the Canadian commentary.

Canada has clinicians and centres with significant expertise in ADPKD, but healthcare services have developed differently across provinces and regions. There is no single national healthcare system organizing referrals, medical records and specialist services across the entire country.

This can make it harder to build one national system for cross-consultation in areas such as:

• polycystic liver disease
• pain
• pregnancy and reproductive care
• kidney genetics
• brain aneurysms and vascular care
• complex kidney stones or cyst infections

The Canadian commentary recommends stronger multidisciplinary networks and greater use of virtual consultation so that local nephrologists do not necessarily need every type of specialist within their own clinic.

Importantly, the Canadian commentary also includes a supplemental table listing ADPKD centres across Canada.

Referral to one of the ADPKD specialists or centres listed in the commentary can provide a starting point. Those specialists can then help connect patients and local healthcare providers with other subspecialists when more specialized care is required.

The longer-term goal is not for every person with ADPKD to travel to a major centre for routine care. Ideally, most care can happen close to home, with local healthcare providers able to consult ADPKD centres and other specialists when more complex issues arise.

Learn more about ADPKD care in Canada

These questions came from registrants of our roundtable discussion, Your PKD Care in Canada: What the New ADPKD Commentary Means for You.

Watch the full roundtable discussion with Dr. Ahsan Alam, Dr. Matt Lanktree and ADPKD patient partner Nick Ashawasega.

What is the Canadian commentary on the 2025 KDIGO ADPKD guideline? Learn more here.

You can also read the full Canadian Society of Nephrology commentary here:

Lanktree MB, Ashawasega N, Bevilacqua M, et al. Canadian Society of Nephrology commentary on the 2025 Kidney Disease Improving Global Outcomes clinical practice guidelines for autosomal dominant polycystic kidney disease. Canadian Journal of Kidney Health and Disease. 2026;13. doi:10.1177/20543581261455635.

Here is the original 2025 KDIGO ADPKD Guideline, as well as a roundtable conversation with Dr. Lanktree that we presented in 2025.