Cardamyst (etripamil) is a nose spray that helps treat sudden episodes of fast heartbeats, known as paroxysmal supraventricular tachycardia (PSVT). PSVT is a type of abnormal heart rhythm where your heart suddenly beats very fast, often over 150 beats per minute. This can cause chest pain, dizziness, shortness of breath, or even fainting. PSVT episodes can happen without warning and may last from a few minutes to several hours.
Cardamyst can help your heartbeat return to normal if you have PSVT. It is the first self-administered medicine for PSVT approved by the FDA.
How Does Cardamyst Work for PSVT?
If your heart beats in a regular, organized way, it is called normal sinus rhythm (NSR). But during PSVT, the heart’s electrical system starts firing too quickly. Cardamyst blocks certain calcium channels in the heart to interrupt these fast signals. This helps your heartbeat return to normal.
When Do I Use Cardamyst?
Cardamyst is not meant to be used on a daily basis. Use Cardamyst only when you experience symptoms of PSVT. Use it as soon as possible after your PSVT symptoms begin. You can use up to two doses of Cardamyst in a single day (24-hour period).
How Do I Use Cardamyst?
Episodes of PSVT can be stressful. It is important to understand how to use Cardamyst so you feel comfortable using it when needed. Read and follow the instructions for use that come with the medicine before using it.
Cardamyst is a ready-to-use nasal spray. Each Cardamyst device contains two sprays, one spray for each nostril. Note that one dose equals one spray in each nostril (two sprays total). Do not test, prime, or press the plunger on your Cardamyst before you spray it into your nose.
Here are some tips to safely use Caramyst to treat episodes of PSVT:
- Sit down before using it, as PSVT can make you dizzy.
- Each device has two sprays (one for each nostril). Two sprays equal one dose.
- Do not test or press the plunger before using it.
- Hold the device upright with your thumb on the bottom of the plunger and the tip of the device between your index and middle fingers. Breathe normally, place the tip gently into one nostril, and spray once.
- Repeat with your other nostril. That counts as one full dose.
- Stay seated for 10 minutes with your head straight.
- You can wipe your nose, but don’t blow it.
- If you still have symptoms after 10 minutes, use a new device for your second dose.
- If you don’t feel better 20 minutes after the second dose, call your doctor or seek medical care.
- Throw away the used device, as it cannot be reused.
The drugmaker also has a video you can watch to help you understand how to use Cardamyst.
How Was Cardamyst Studied for PSVT?
The RAPID study is the key clinical trial that supported FDA approval of Cardamyst for the treatment of people with PSVT. The study included adults with episodes of PSVT that lasted at least 20 minutes. They were treated with either Cardamyst or a placebo (no medicine in it) device. The participants were given an electrocardiogram (EKG) monitor to track their heart’s electrical impulses. They were asked to attach the ECG monitor and use the Valsalva maneuver as soon as they noticed PSVT symptoms. If the symptoms did not get better with the Valsalva maneuver, participants used a dose of Cardamyst or a placebo. A second dose was used if the PSVT symptoms continued for 10 minutes after the first dose. Participants were told to seek medical treatment if the symptoms did not get better within 30 minutes of the first dose.
The main goal of the RAPID study was to see if participants treated with Cardamyst returned to normal sinus rhythm sooner than those treated with a placebo. A total of 99 participants were treated with Cardamyst, and 85 were treated with the placebo.The study participants had the following characteristics:
- Around 71% were women, and about 29% were men.
- Over 90% of the participants were White, while 3% or fewer belonged to each of the following groups: Black or African American, Asian, American Indian or Alaska Native, or other.
- The average age of participants was 54 years.
- The most common PSVT symptoms reported by the participants before they used the study medicine included a fast heartbeat, heart palpitations, and dizziness or lightheadedness.
- More than 60% of participants were also taking other medicines for PSVT, including beta-blockers or calcium channel blockers.
Another study, known as NODE-303, was done to test the safety and efficacy of Cardamyst when used for more than one PSVT episode. In this study, everyone used Cardamyst; there was no placebo (no medicine in it) to compare it to. A total of 312 participants were treated with Cardamyst for up to four PSVT episodes. Around 67% of the people in the study were female, and about 33% were male. About 86% of the participants were White, 9% were from other races, while 3% or fewer were Black or African American, Asian, Native Hawaiian or Pacific Islander, or did not report their race. The average age of participants was about 55 years. Almost 70% of the participants were also taking other medicines for PSVT, including beta-blockers or calcium channel blockers.
What Were the Benefits of Cardamyst in the Studies?
In the RAPID study, more people were able to get back to normal sinus rhythm (NSR) who used Cardamyst compared to those who used a placebo to treat an episode of PSVT. Also, people who used Cardamyst achieved normal sinus rhythm faster than those who used a placebo. You can see these results in the table below.
Cardamyst | Placebo | |
|---|---|---|
| Achieved NSR within 30 minutes | 64% | 31% |
| Median time (minutes) to NSR* | 17.2 minutes | 53.5 minutes |
*Median is the number that falls in the middle of a group when the numbers are arranged from smallest to largest.
In the NODE-303 study, across all PSVT episodes, 60% got back to NSR within 30 minutes and 69.9% within 60 minutes of using Cardamyst. It generally took about 17 minutes to get back to NSR. The results for each episode of PSVT are summarized in the table below.
| PSVT Episode | NSR within 30 minutes | NSR within 60 minutes | Median time (minutes) to NSR* |
|---|---|---|---|
| 1 | 59.9% | 70.5% | 18.3 |
| 2 | 61.6% | 73.5% | 14 |
| 3 | 54.9% | 57.7% | 19.1 |
| 4 | 66.7% | 77.8% | 15.6 |
*Median is the number that falls in the middle of a group when the numbers are arranged from smallest to largest.
Based on the results of the RAPID and NODE-303 studies, Cardamyst seems to work well to increase your chances of returning to NSR and works faster than a placebo. These benefits were seen even in people already taking other heart medicines, such as a beta-blocker and/or calcium channel blocker.
Note that your results may differ from the results seen in these studies.
How Do I Manage Side Effects of Cardamyst?
Cardamyst can cause dizziness or even fainting. Certain things can increase your risk for fainting. These include fainting with a past episode of PSVT, low blood pressure, or certain heart conditions. It is important for you to be seated in a safe area when you use Cardamyst so that you do not fall if you get dizzy, lightheaded, or faint. If you do get lightheaded or dizzy after using Cardamyst, you should lie down right away.
Other common side effects include nasal (nose) discomfort, stuffy nose, runny nose, throat irritation, or nosebleeds. These side effects are usually mild. The Cardamyst device should be gently inserted into your nostril to avoid damaging the inside of your nose. Also, be sure to follow your health care provider’s instructions to minimize possible side effects.
There may be other side effects of Cardamyst that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine.
What Are Other Unique Considerations to Be Aware Of?
The drugmaker of Cardamyst provides support when you have an episode of PSVT, but you must enroll in the Nurse Educator Support Program before using Cardamyst. The support program offers help with how to use Cardamyst during a PSVT episode, proper dosing, handling the device, and safety precautions. You need to be enrolled in the program to receive support, so consider enrolling as soon as you receive the medicine. To enroll, call the drugmaker at 844-805-5810.
Is There Any Cost Assistance Available?
You may be eligible for help with the cost of Cardamyst. Find out more by visiting this website or calling 877-557-5365.
