What is Patisiran: Uses, Dosage, Side Effects and More

Patisiran is a specialized medication designed to treat a rare genetic condition called hereditary transthyretin-mediated amyloidosis (hATTR). This condition affects your nervous system when faulty proteins build up in your body and damage your nerves.

If you or someone you know has been diagnosed with hATTR, you're likely feeling overwhelmed by medical terminology and treatment options. This guide will help you understand patisiran in simple terms, so you can feel more confident about your healthcare decisions.

What is Patisiran?

Patisiran is a prescription medication that belongs to a class of drugs called RNA interference (RNAi) therapeutics. It works by stopping your liver from making the faulty protein that causes hATTR amyloidosis.

Think of patisiran as a molecular messenger that tells specific cells in your liver to stop producing the problematic protein. This helps prevent further nerve damage and may slow the progression of your symptoms.

The medication comes as a liquid solution that's given directly into your bloodstream through an IV infusion. You'll receive this treatment at a healthcare facility, typically every three weeks.

What is Patisiran Used For?

Patisiran is specifically approved to treat hereditary transthyretin-mediated amyloidosis (hATTR) in adults. This is a rare genetic condition where your body produces abnormal transthyretin proteins that clump together and damage your nerves.

People with hATTR often experience progressive nerve damage that affects their ability to walk, feel sensations in their hands and feet, and perform daily activities. The condition can also affect your heart, digestive system, and other organs over time.

Your doctor will only prescribe patisiran if you've been diagnosed with hATTR through genetic testing and other specialized examinations. It's not used for other types of amyloidosis or nerve conditions.

How Does Patisiran Work?

Patisiran works by using a sophisticated biological process called RNA interference to reduce the production of faulty transthyretin proteins in your liver. It's considered a highly targeted and effective treatment for hATTR.

Your liver normally makes transthyretin proteins, but in people with hATTR, these proteins are misshapen and tend to stick together. These protein clumps then travel through your bloodstream and deposit in your nerves, heart, and other tissues, causing damage.

Patisiran contains small pieces of genetic material that specifically target the instructions your liver cells use to make transthyretin. When patisiran reaches your liver, it essentially tells the cells to stop following these faulty instructions.

This medication is quite powerful in reducing transthyretin levels. Studies show it can decrease these harmful proteins by about 80% or more in most people who receive treatment.

How Should I Take Patisiran?

Patisiran is given as an intravenous (IV) infusion every three weeks at a healthcare facility. You cannot take this medication at home, as it requires careful monitoring and specialized preparation.

Before each infusion, you'll receive premedications to help prevent allergic reactions. These typically include an antihistamine, a corticosteroid, and a pain reliever. Your healthcare team will give you these medications about 60 minutes before your patisiran infusion.

The actual patisiran infusion takes about 80 minutes to complete. During this time, you'll be monitored for any signs of infusion reactions, which can include flushing, shortness of breath, or chest discomfort.

You don't need to follow any special dietary restrictions before your treatment. However, it's important to stay well-hydrated and get adequate rest before each infusion appointment.

How Long Should I Take Patisiran For?

Patisiran is typically a long-term treatment that you'll continue for as long as it's helping to control your hATTR symptoms and your body is tolerating it well. Most people need ongoing treatment to maintain the benefits.

Your doctor will monitor your progress through regular blood tests, nerve function assessments, and quality of life evaluations. These check-ups help determine whether patisiran is working effectively for you.

Some people begin to notice improvements in their symptoms within a few months of starting treatment, while others may take longer to see benefits. The medication works gradually, so patience is important during the initial treatment period.

Your healthcare team will discuss treatment goals with you and adjust your care plan based on how you're responding to the medication and any side effects you might experience.

What Are the Side Effects of Patisiran?

Like all medications, patisiran can cause side effects, though not everyone experiences them. Most side effects are manageable, and your healthcare team will monitor you closely during treatment.

The most common side effects you might experience include reactions during or shortly after your infusion. These can feel concerning, but your medical team is well-prepared to handle them if they occur.

Common side effects include:

• Swelling in your arms or legs (peripheral edema)
• Infusion-related reactions like flushing, back pain, or nausea
• Upper respiratory tract infections
• Muscle spasms or cramps
• Joint pain
• Fatigue or feeling more tired than usual
• Dizziness or lightheadedness
• Skin redness or rash

These common side effects are usually mild to moderate and often improve as your body adjusts to the treatment. Your healthcare team can provide strategies to help manage these symptoms.

More serious but rare side effects can include severe allergic reactions during infusion, significant drops in blood pressure, or unusual bleeding. While these are uncommon, your medical team monitors for them during every treatment.

Very rarely, some people may experience reduced levels of vitamin A in their blood, which can affect night vision. Your doctor will monitor your vitamin A levels and may recommend supplements if needed.

Who Should Not Take Patisiran?

Patisiran isn't suitable for everyone, even those with hATTR amyloidosis. Your doctor will carefully evaluate whether this medication is right for your specific situation.

You should not receive patisiran if you've had a severe allergic reaction to the medication or any of its ingredients in the past. This includes reactions like difficulty breathing, severe swelling, or dangerous drops in blood pressure.

People with certain medical conditions may need special monitoring or might not be candidates for patisiran treatment. Your doctor will need to know about your complete medical history before starting treatment.

Conditions that require careful consideration include:

• Severe heart problems or recent heart attacks
• Active infections or compromised immune system
• Liver disease beyond what's caused by hATTR
• Bleeding disorders or current use of blood thinners
• Pregnancy or plans to become pregnant
• Breastfeeding

If you're pregnant or planning to become pregnant, discuss this with your doctor immediately. The effects of patisiran on pregnancy aren't fully known, so careful consideration is needed.

Patisiran Brand Names

Patisiran is available under the brand name Onpattro. This is the only approved brand name for this medication in most countries, including the United States and Europe.

When you receive your treatment, the medication vial will be labeled as Onpattro, and this is the name you'll see on your medical records and insurance documentation. There are currently no generic versions of patisiran available.

If you're traveling or receiving care at different facilities, always mention both the generic name (patisiran) and brand name (Onpattro) to ensure clear communication with your healthcare providers.

Patisiran Alternatives

While patisiran is highly effective for hATTR amyloidosis, there are other treatment options available. Your doctor might consider alternatives based on your specific symptoms, disease progression, and individual circumstances.

Inotersen is another RNA-based medication that's given as a weekly injection under the skin. It works similarly to patisiran but has a different side effect profile and administration schedule.

Tafamidis is an oral medication that helps stabilize transthyretin proteins, preventing them from misfolding. It's particularly useful for people with heart involvement from hATTR.

Other supportive treatments might include:

• Medications for nerve pain and symptoms
• Physical therapy and occupational therapy
• Nutritional support and supplements
• Heart medications if cardiac involvement is present
• Liver transplantation in very severe cases

Your healthcare team will work with you to determine the best treatment approach based on your specific type of hATTR, symptom severity, and overall health status.

Is Patisiran Better Than Inotersen?

Both patisiran and inotersen are effective treatments for hATTR amyloidosis, but they have different advantages and considerations. The "better" choice depends on your individual circumstances and preferences.

Patisiran is given every three weeks through an IV infusion at a healthcare facility. This means fewer treatment days per year, but you'll need to visit a clinic for each dose. The medication has shown excellent results in clinical trials with significant reduction in disease progression.

Inotersen is given as a weekly injection under the skin that you can learn to give yourself at home. This offers more convenience and flexibility, but requires more frequent dosing and regular blood monitoring due to potential effects on platelets and kidney function.

In terms of effectiveness, both medications significantly reduce harmful transthyretin protein production. Studies suggest they're both highly effective, though direct comparison studies are limited.

Your doctor will help you weigh factors like your comfort with different administration methods, travel requirements, work schedule, and risk factors for specific side effects when choosing between these options.