SCM15: New Phosphate Binder: Chitosan?

Dr. Mujtaba Dr. Mujtaba HasnainHasnain, from Newark Beth Israel Medical Center, Newark, New Jersey, discusses his abstract for the National Kidney Foundation’s 2015 Spring Clinical Meetings (SCM15), Chitosan; A Novel Salivary Phosphorous Binder, with Dr. Kenar Jhaveri, AJKD Blog Editor.

AJKDblog: Why don’t you tell us a little about your research and abstract being presented at the NKF 2015 Spring Meetings?

In uremic patients, hyperphosphatemia is associated with cardiovascular calcification and increased cardiovascular mortality. Despite the use of phosphate binders, only half of hemodialysis (HD) patients achieve recommended serum phosphate levels. A hyperphosphoric salivary content, which correlates linearly with serum phosphate, has been reported in HD patients.

A 46-year-old woman presented for routine monthly follow up in peritoneal dialysis (PD) clinic. She was on peritoneal dialysis for the last 3 years. Her clearance was excellent (Kt/V 2.2) on continuous ambulatory peritoneal dialysis. Her serum calcium, PO4 and intact parathyroid hormone (iPTH) levels were 12 mg/dL, 7.0 mg/dL and 1117 pg/mL respectively. She has been non-adherent with low PO4 diet and refused to take all types of phosphate binders and sensipar due to unclear allergic reactions. She presented again one month later for routine follow up while maintained on same prescription of PD. Her laboratory data showed serum calcium of 12.1 mg/dL, while serum PO4 and iPTH levels improved to 6.7 mg/dL and 871 pg/mL respectively. On further questioning it was revealed that she started taking herbal capsules three weeks prior for weight loss. We requested that the patient to bring in those herbal capsules. We investigated it further and found “chitosan” in those capsules. This “chitosan” is an excellent phosphate binder in saliva. Further double blind, controlled trials are required to assess its precise efficacy and side effect profile. It can potentially help hundreds of thousands of dialysis patients whose serum phosphorous levels fall out of recommended levels.

AJKDblog: How does chitosan work as a potential binder?

Chitosan is an abundant natural polymer that is produced by the deacetylation of chitin obtained from crustacean shells. Its structure is similar to cellulose and is not cleaved by digestive enzymes. It has been used as a dietary fiber for weight reduction and hyperlipidemia. In HD patients, with high salivary PO4 content and average daily salivary production of 500 mL, a conservative estimate of at least 366 mg of bioavailable phosphate daily entering the gastrointestinal fluid could be proposed. Chitosan is an active salivary phosphate binder especially when chewed as a gum for prolonged time periods. It doesn’t need to be given with food which is a limitation with other binders; instead, it can be used in fasting periods.

AJKDblog: The improvement of phosphate levels in your patient appears very mild? Was the trend of phosphate over time downtrending on this agent?

Based on few trials which are available to date, it works very effectively if chewed as a gum. Initially, the drop in serum phosphate was less significant but the trend afterwards was more promising. This patient was taking herbal capsules which is potentially less efficacious in binding phosphate as compared to chewing gum for little extended time period. This might be the reason for milder drop of serum phosphate in our patient.

Click here for a full list of SCM15 abstracts of poster presentations.

Check out more AJKDblog coverage of the NKF’s 2015 Spring Clinical Meetings!

10 Comments on SCM15: New Phosphate Binder: Chitosan?

  1. What do you think its efficacy in HEMODYSLYDIS patients and CKD patients.

  2. Mujtaba Hasnain // March 27, 2015 at 4:23 pm // Reply

    i expect same efficacy in all subgroups of chronic renal disease. Again this is my observation which need to be tested in bigger trials!!

  3. Does it need to be taken with meals?

  4. Mujtaba Hasnain // March 28, 2015 at 10:04 am // Reply

    No, that is the beauty. Preferably it should be used during fasting (in between meals) as it binds endogenous phosphorous. All other bonds work on exogenous phosphate in diet. I would call it mega advantage.

  5. All other phosphate binders are with meals, why this one is irrespective of meals?

  6. sherif aly // March 29, 2015 at 6:00 pm // Reply

    Is it available in the market?

  7. All other phosphate binders are with meals, why this one is irrespective of meals?

    Answer: Because it binds to phosphate in saliva which is endogenous. Other binders bind to phosphate in diet which is exogenous.

  8. Is it available in the market?

    Answer: Yes available as herbal medicine. But not FDA approved yet

  9. Wheat Buckley // January 16, 2019 at 4:22 pm // Reply

    I am a bit late to this conversation, was wondering of any new information regarding chitosan as a binder. I had read in some journal that the chitosan gum wasn’t that great in reducing phosphate in the cohort. What about diagnostic strips for measuring salivary phosphate levels? That needs to exist. Seems like that would be an incredibly useful tool for managing phosphate. They exist for measuring phosphate in aquariums. I’m assuming the phosphate levels in the body are out of range of measuring aquarium phosphate levels.

  10. George Goldsmith // January 27, 2020 at 7:20 pm // Reply

    Unfortunately the excitement about chitosan chewing gum has fizzled out. The same results of single experiment that elicited excitement has never been duplicated despite repeated tries and in fact the original results were proven to be scientifically impossible; the amount of chitosan in the gum (20mg and 40mg) was ten times what would have been needed in terms of molecular weight to achieve the stated results. Chitosan capsules are available but do not offer the same reductions in phosphorus as a delivery vector that would have targeted saliva. The studies are easy to find on the internet. The original was the 2009 study; debunked or refuted in 2013, 14 and 15. I so wanted it to be true!!!

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