What Are Intravesical Medications?

Intravesical medications are treatments placed directly into the bladder through a thin catheter. The word “intravesical” simply means “inside the bladder” (from Latin vesica, meaning bladder). Rather than taking a pill that travels through your entire body, these treatments deliver medication exactly where it is needed—the bladder lining itself.

This approach makes sense when you think about it. If the problem is damage to the bladder wall, why send medication on a roundabout journey through your digestive system and bloodstream when you can apply it directly to the affected tissue? It is a bit like putting ointment on a skin wound rather than taking a tablet and hoping some of the drug reaches your skin.

Intravesical therapy is used primarily for interstitial cystitis (IC), painful bladder syndrome (PBS), radiation cystitis, and recurrent urinary tract infections. These conditions share a common feature: damage or dysfunction of the bladder’s protective lining.

I should say upfront that intravesical treatments are not cures. They are symptom management strategies that can provide real relief for many patients, but they typically require ongoing treatment rather than being a one-time fix.

Understanding Why These Treatments Exist

To appreciate why intravesical medications matter, you need some background on bladder physiology.

The GAG Layer: Your Bladder’s Protective Coating

The inner surface of a healthy bladder is not directly exposed to urine. Instead, it is covered by a protective layer of glycosaminoglycans (GAGs)—a family of large, water-holding molecules that includes hyaluronic acid, chondroitin sulphate, and heparan sulphate 1.

This GAG layer acts as a barrier between the bladder wall and the contents of urine. Urine contains potassium, ammonia, and various waste products that would irritate the underlying bladder tissue if they made direct contact. The GAG layer prevents this contact, functioning as a biological shield.

What Goes Wrong in IC and Chronic Cystitis

In many patients with IC, PBS, or chronic cystitis, researchers believe this protective layer becomes damaged or deficient. When the GAG layer fails, irritating substances in urine can penetrate the bladder wall, triggering inflammation, pain, and the characteristic symptoms of these conditions: urgency, frequency, burning, and pelvic discomfort 2.

This “leaky bladder” theory explains why patients with IC often find that certain foods and drinks—particularly acidic or caffeinated ones—make their symptoms worse. Without adequate protection, these substances directly irritate sensitive bladder tissue.

The Logic of GAG Replacement

If the problem is a damaged protective layer, the obvious solution is to replace it. This is the principle behind most intravesical medications: instil GAG components directly into the bladder to temporarily restore the protective coating.

I say “temporarily” because these treatments do not permanently repair the underlying defect. Instead, they create a buffer that may allow inflamed tissue to heal while reducing symptom severity. This explains why repeated treatments are usually necessary—the coating gradually wears away and needs replenishing.

Types of Intravesical Medications

Several different intravesical treatments are available, each with different mechanisms and characteristics. Here is an overview of the main categories.

GAG-Replacement Therapies

These medications aim to replenish the protective GAG layer on the bladder wall. They contain one or more glycosaminoglycan components.

Sodium Hyaluronate (Hyaluronic Acid)

Sodium hyaluronate is the most widely used GAG-replacement therapy. Products include:

Cystistat – A sodium hyaluronate solution that temporarily coats the bladder lining
Hyacyst – Available in 40mg and 120mg formulations

Hyaluronic acid occurs naturally throughout the body, including in joint fluid and the bladder lining itself. Clinical studies suggest that roughly 50-85% of IC/PBS patients experience some improvement with sodium hyaluronate instillations, though response varies considerably between individuals 3.

Chondroitin Sulphate

Chondroitin sulphate is another GAG component found in the natural bladder lining. The main product is:

Gepan instill – A 0.2% chondroitin sulphate solution

Studies show response rates of 60-75% in IC/PBS patients 4. Like hyaluronic acid, it works by temporarily replacing the damaged protective layer.

Combination Products

Some products combine multiple GAG components:

iAluRil – Contains both hyaluronic acid and chondroitin sulphate

The theory is that since the natural GAG layer contains multiple glycosaminoglycan types, replacing more than one might provide better coverage. A study of 126 patients with refractory IC/PBS found 87% experienced symptom improvement with combination therapy at 12 weeks 5.

DMSO (Dimethyl Sulfoxide)

DMSO works differently from GAG-replacement therapies. It is an anti-inflammatory and muscle relaxant that also penetrates tissues readily. The medical-grade formulation (RIMSO-50) is the only intravesical treatment specifically approved by the US FDA for IC.

DMSO has been around since the 1970s and helps roughly 50-70% of patients. The main drawback is a distinctive garlic-like odour on the breath and skin that persists for one to three days after treatment. For some patients, this is a dealbreaker. It can also temporarily worsen bladder symptoms immediately after instillation.

Anaesthetic Mixtures

Some intravesical treatments work by numbing the bladder rather than replacing the GAG layer:

Cystilieve – Contains lidocaine and sodium bicarbonate to provide direct pain relief

These treatments address symptoms differently and may work more quickly than GAG-replacement therapies. Some clinicians use them for acute flares or combine them with other approaches.

Parsons Solution

Parsons Solution is a combination of high-dose heparin and lidocaine designed for immediate pain relief. Heparin is another GAG component, while lidocaine provides anaesthetic effect. This combination approach aims to both replenish the protective layer and reduce pain simultaneously.

How Intravesical Treatment Works in Practice

If your urologist recommends intravesical therapy, understanding what to expect can help you prepare.

The Instillation Procedure

Treatment is administered in a clinic or hospital outpatient setting by a urologist or specialist nurse. The process is straightforward:

You empty your bladder before the appointment
A thin catheter is inserted through the urethra into the bladder
The sterile medication is slowly instilled (typically 40-50ml)
The catheter is removed
You retain the solution for as long as comfortable—minimum 30 minutes, ideally longer
You urinate to empty the bladder when you can no longer hold it

The procedure itself takes only a few minutes, though you should allow time for the retention period. Catheter insertion can be uncomfortable, particularly for people with sensitive bladders, but the instillation of medication itself rarely causes problems.

Treatment Schedules

Most protocols follow a two-phase approach:

Initial intensive phase: Weekly instillations for four to six weeks. This regular schedule allows the protective coating to build up consistently.

Maintenance phase: After the initial course, treatments are spaced further apart based on your response. Many patients move to monthly instillations, then gradually extend to every six, eight, or twelve weeks if symptoms remain controlled.

Do not be discouraged if improvement is not immediate. Many patients need four to six treatments before noticing real benefit. The protective layer needs time to establish, and the underlying tissue needs time to settle down.

Self-Catheterisation

Some patients learn to perform instillations at home after receiving training. This requires good dexterity, reasonable comfort with the procedure, and proper technique to avoid infection. Home treatment can be more convenient, particularly during the intensive initial phase when weekly clinic visits become burdensome.

Your specialist can advise whether self-catheterisation is appropriate for your situation.

Choosing Between Different Treatments

With several options available, how do you and your urologist decide which to try?

Head-to-Head Comparisons

Honestly, we do not have enough rigorous comparative data to say definitively that one treatment is better than another. Response rates across studies overlap considerably—roughly 50-85% for various GAG therapies and 50-70% for DMSO.

The main differences relate to side effects and practical considerations rather than dramatically different effectiveness.

Factors That Might Influence the Choice

DMSO has the longest track record and FDA approval, but the garlic odour is a genuine issue. If you work in close contact with others or have social commitments, the one-to-three day odour window matters.

Sodium hyaluronate and chondroitin sulphate products have cleaner side effect profiles—no odour, no systemic effects. They are well tolerated but may be less widely available depending on your healthcare system.

Combination products offer theoretical advantages by replacing multiple GAG components, though whether this translates to meaningfully better outcomes is uncertain.

Anaesthetic mixtures work faster for pain relief but address symptoms differently. They may be useful for acute flares alongside longer-term GAG therapy.

Trial and Error

IC and PBS treatment often involves experimentation. What helps one patient may do nothing for another. Many people try multiple approaches before finding their optimal combination. Being open to trying different treatments—while giving each a proper trial of at least five or six sessions—is often necessary.

Side Effects and Safety

Intravesical medications generally have good safety profiles because the treatment stays local rather than circulating throughout the body.

Common Experiences

Most side effects relate to the catheterisation procedure rather than the medications themselves:

Mild burning or stinging during catheter insertion
Temporary urgency immediately after instillation
Occasional spotting of blood in urine

These effects typically resolve within a day or two.

DMSO-Specific Issues

DMSO has additional considerations:

The garlic-like odour (unavoidable)
Temporary symptom flare in some patients
Theoretical concerns about eye lens changes with very long-term use, though documented cases in humans at standard doses are essentially non-existent

Who Should Not Use Intravesical Therapy

Contraindications include:

Active urinary tract infection (treat the infection first)
Known allergy to any component of the specific product
Pregnancy (for DMSO specifically)
Recent bladder surgery or significant bladder injury

Questions to Ask Your Urologist

If intravesical therapy is being considered, here are questions worth discussing:

Which specific product do you recommend for my situation, and why?
How many treatments should I have before we decide if it is working?
What happens if the first option does not help?
Would I be a suitable candidate for self-catheterisation at home?
How will we determine the right maintenance schedule for me?

Realistic Expectations

Intravesical medications help many people with IC and related conditions, but they are not magic. Here is what I would want you to understand:

These are symptom management treatments, not cures. You may need ongoing treatment for years—possibly indefinitely—to maintain symptom control.

Response rates are good but not universal. Roughly 60-80% of patients benefit to some degree, which also means 20-40% do not respond adequately to any given treatment.

It takes time. Do not judge a treatment by how you feel after one or two sessions. Give each approach at least five or six instillations before deciding whether it is helping.

Trial and error is normal. If one medication does not work, another might. IC treatment is notoriously individual.

The procedure is not pleasant but is tolerable. Catheterisation is uncomfortable for most people. It becomes more routine with experience, but it is not something anyone enjoys.

For patients who have bounced off oral medications or lifestyle modifications without adequate relief, intravesical therapy represents a reasonable next step. The direct delivery of medication to the bladder lining makes intuitive sense, and the evidence supports its use. Discuss the options with your urologist to find the approach that best fits your situation.

References

Parsons CL. The role of the urinary epithelium in the pathogenesis of interstitial cystitis/prostatitis/urethritis. Urology. 2007;69(4 Suppl):9-16. PubMed
Madersbacher H, van Ophoven A, van Kerrebroeck PE. GAG layer replenishment therapy for chronic forms of cystitis with intravesical glycosaminoglycans—a review. Neurourol Urodyn. 2013;32(1):9-18. PubMed
Morales A, Emerson L, Nickel JC, Lundie M. Intravesical hyaluronic acid in the treatment of refractory interstitial cystitis. J Urol. 1996;156(1):45-48. PubMed
Nickel JC, Egerdie B, Downey J, et al. A real-life multicentre clinical practice study to evaluate the efficacy and safety of intravesical chondroitin sulphate for the treatment of interstitial cystitis. BJU Int. 2009;103(1):56-60. PubMed
Cervigni M, Natale F, Nasta L, et al. A combined intravesical therapy with hyaluronic acid and chondroitin for refractory painful bladder syndrome/interstitial cystitis. Int Urogynecol J. 2012;23(9):1193-1199. PubMed