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Compounding for MCAS


Compounding for MCAS

Mast cell activation syndrome (MCAS) is a chronic condition that involves over-activation of mast cells. MCAS manifests in a variety of symptoms that can come and go over time. This makes it hard to “pin down” a diagnosis for many patients, who sometimes struggle for years before finding a doctor who can help them.  MCAS may be more prevalent than we now realize because of this difficulty. For patients who can get help, however, there are treatments available that can significantly improve quality of life.

What is MCAS?

MCAS involves the over-activation of mast cells, which leads to chronic inflammation. This is different from mastocystosis, which is a condition where a larger amount of mast cells are produced than are needed. With MCAS, there are a normal number of mast cells that are not activating normally. Mast cells produce mediators that are essential to the functioning of all other cells in the body.

When a mast cell senses a threat it starts producing mediators to help signal the body to manage it. With MCAS, the mast cells may start producing mediators when there is no threat or they may overreact to a threat that is not serious. The term MCAS encompasses any condition where mast cells are reacting abnormally but are not proliferating abnormally.

Dr. Lawrence Afrin has been pivotal in spreading awareness of mast cell activation syndrome. He has documented his experiences treating patients with mast cell disorders and discusses the research to-date in his book, “Never Bet Against Occam.” The articles he has written are a good start for anyone who has recently been diagnosed with MCAS.

MCAS Symptoms

The symptoms of mast cell activation syndrome are not completely universal across all diagnosed patients. There is some variety in symptoms and in the types of treatments that work for the individual. According to Dr. Afrin, “The clinician will face a series of MCAS patients, most of who will present as chronically unwell, though the details will differ so substantially across patients as to make the underlying pattern … very difficult to see.” Here are just some of the possible symptoms of MCAS:

  • Fatigue
  • Sense of always feeling cold
  • Sweats, flushing
  • Change in appetite
  • Weight gain or weight loss
  • Environmental sensitivities
  • Rashes, lesions, itching
  • Hearing problems
  • Rhinitis, sinusitis
  • Breathing problems, coughing

MCAS Treatment

There are no clinical trials that have compared the variety of treatments available for MCAS. It is only recently that the condition has become recognized and research is lacking. Doctors treating patients with this condition will usually start with the most affordable option first and work up to those that are more expensive.

Patients with MCAS may need to go through multiple types of treatments before finding one that works for them. This can take weeks, months, or even longer. A compounding pharmacy can be an integral part of an MCAS patient’s treatment. The most frequently prescribed medications that are obtained from a compounding pharmacy include ketotifen and cromolyn.  Both of these drugs inhibit mediator release and are referred to as mast cell stabilizers.

Cromolyn: Cromolyn is most effective at stabilizing mucosal mast cells with which it comes in contact. Its exact mechanism of action is not known but many patients find it to be effective. Within the first few days after starting cromolyn, there may be a temporary increase in the intensity of symptoms. After this they should be significantly reduced. Usually it will be prescribed in capsules that are taken orally, but a compounding pharmacy can also make cromolyn into a cream.

Ketotifen: Ketotifen is an antihistamine that has been used for treating asthma and allergies. In the U.S. the oral form is only available through a compounding pharmacy. Ketotifen is given in oral capsules and can be titrated up weekly until maximum efficacy is reached – usually not more than 6mg twice daily.

Non-steroidal anti-inflammatory drugs (NSAIDs): There are a variety of NSAIDs available both commercially and from a compounding pharmacy. Over-the-counter NSAIDs like aspirin are inexpensive and can also be titrated up slowly, starting at a low dose. If the smallest dosage available over the counter is still too high, a patient can use a compounding pharmacy to make a lower dose. COX-2 selective drugs like celecoxib are also NSAIDs and may be prescribed to treat MCAS.

Additional Benefits of Compounding

Environmental sensitivities and food sensitivities are common in MCAS patients. Commercially available medications often contain fillers and additives that can cause problems. A compounding pharmacy can often make a medication that is free of dyes and fillers that may trigger a mast cell flare-up.


  • Dr. Lawrence B. Afrin, “Presentation Diagnsosis, and Management of Mast Cell Activation Syndrome” – Read PDF Book
  • What is Mast Cell Activation Syndrome (MCAS)? – MastCellResearch.com

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  1. Pingback: Ketotifen for MCAS and mastocytosis | Mast Cell Activation Syndrome

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