Cromolyn Sodium for Mast Cell Activation Syndrome

Cromolyn sodium oral (brand name Gastrocrom, but I’ll just refer to it as “cromolyn” for this article) is used to treat mast cell activation diseases, allergies, and asthma by reducing the release of mast cell mediators. It comes in other forms and can even be purchased as an over-the-counter nasal spray, but I’ll be discussing the oral suspension. It is classified as a mast cell stabilizer, although according to Dr. Theoharides, a pioneer in the study of mast cells and their role in inflammatory illnesses, this is a misclassification, as cromolyn does not inhibit the release of cytokines. Through an unknown mechanism, it inhibits the release of histamine and prostaglandin. People with mast cell activation disease can suffer from a number of symptoms due to being overwhelmed by mast cell mediators like histamine and prostaglandin, and cromolyn can provide relief. For some people, the relief is significant.

Before beginning cromolyn, there are some things you need to know.

1. Cromolyn is sensitive to light and temperature. It is important that its kept out of direct sunlight and in a dark place at room temperature. In the US, cromolyn oral comes in a big box that has foil containers inside. Within the foil containers are the plastic vials of cromolyn.
2. Do not take the cromolyn directly from the vial. Combine it with water and drink it slowly. Do not mix the cromolyn with water ahead of time, and only remove the vials from the foil when you’re ready to use them.
3. It is typically dosed at 800mg per day, divided among four doses. It is recommended that it’s taken thirty minutes before meals and before bed.
4. Cromolyn is a sticky molecule with poor absorption. Approximately 98% of it will stay in your gut, but not to worry, you want it to stick to the mast cells in your gut. It likes to stick to food and other medications, so it’s important to take it on an empty stomach for the best benefit.
5. START SLOW. Cromolyn can make you very sick by triggering a mast cell flare if you take too much too quickly. Because it comes in a liquid suspension in ampules, it’s easy to start out with a very small dose.
6. Expect to take at least eight weeks to get to full dose, increasing by 100mg per week. You can go as slow as you need to.
7. DO NOT suddenly stop taking cromolyn. Your mast cells have gotten used to its calming effects, so stopping it may make your condition worse. This can be extremely dangerous for someone who regularly experiences anaphylaxis.
8. While some patients feel better after the first dose, it may take up to six weeks to notice a benefit. Be patient.

It is currently not known why cromolyn triggers mast cell flares, but for doctors who have experience treating people with Mast Cell Activation Syndrome, this can be further confirmation of diagnosis. Taking too much too quickly can make us very sick.

I knew not to jump into taking the full dose when I started, but I still started with too much at 400mg. It was one of the worst flares I’ve experienced. If you’re an extremely sensitive individual, you can start with just a couple drops. It may take a long time to get to your full prescribed dose, but for many patients, it’s worth it. Some patients report the complete alleviation of symptoms after reaching their full dose. This may not be the case for you, but hopefully it is. Best of luck.