Exploring How Compound Phenytoin May Help Treat Macular Degeneration in Patients with MS

Exploring How Compound Phenytoin May Help Treat Macular Degeneration in Patients with MS

i-pillFor pharmacists treating patients with multiple sclerosis, the toughest part is finding medications to treat all the different ways MS robs patients of their quality of life. MS affects an estimated 2.5 million people worldwide and 400,000 people in the U.S., and as the debilitating disease progresses, one of the stages includes macular degeneration and eventual loss of sight. A study presented earlier this year at the April meeting of the American Academy of Neurology, however, may offer some hope in the form of a drug currently compounded to treat epilepsy. In a study, compound phenytoin was found to slow macular degeneration and improve treatment responses in cases of acute optic neuritis.

Researchers’ experimentation with compound phenytoin to treat MS optic conditions, completely unrelated to the API’s original intention as an anti-seizure drug, tracks with an overall trend in pharmacology today: testing existing and already approved formulations for new and varied purposes to avoid the costs associated with developing and bringing a new medication to market. Within the current regulatory environment, it can be difficult for companies to get new drugs approved by the Food and Drug Administration and to the market, and with strong research and clinical trials like Dr. Raj Kapoor’s phenytoin study, compounds can be safely formulated for new and exciting uses.1

Preserving Retinal Thickness with Phenytoin in MS Patients

The study conducted by Dr. Kapoor and associates at the National Hospital for Neurology and Neurosurgery in London involved 86 patients, all already diagnosed with both MS and acute optic neuritis. About half of all MS patients at some point in the progression of their disease experience some kind of vision impairment, usually the specific condition acute optic neuritis where the nerve that carries vision-related signals from brain to eye and back becomes inflamed and affects vision quality. The condition can also result in pain, as well as sudden blindness.

The 86 patients had all experienced their first symptoms of acute optic neuritis within two weeks of being selected for the trial, and were either given compound epilepsy drug phenytoin or a placebo as a treatment for three months. Patients who received the phenytoin showed, on average, 30 percent less damage to their overall retinal thickness compared with measurements from the beginning of the study and six months after the second measurement.2

Researchers cautioned that these results, while promising, do not mean that phenytoin is the answer to MS-related eye problems and eventual blindness. In the long-term, there was no difference between the control group and the group that received phenytoin in overall vision, despite the impressive 30 percent preservation of the retina following patients’ first vision attacks. The results do provide enough basis to justify future, larger trials that may yield more insight and eventual treatments for MS-related macular degeneration and acute optic neuritis.3

What Role Can Pharmacists Play in Treating MS Macular Degeneration?

Dr. Kapoor and his research team demonstrated the kind of creativity combined with careful testing that could help scientists, doctors and pharmacists everywhere improve outcomes for their patients with MS and many other chronic and progressive illnesses.

The study states that they were inspired to test anti-epilepsy drug phenytoin as a potential solution to acute optic neuritis by looking at the root causes of the condition and applying a medication with a proven response. One of the factors in the nerve fiber damage of acute optic neuritis is high levels of sodium within the fibers, and the team posited that preventing sodium entry could help protect the nerve fibers. Phenytoin functions as an anti-epilepsy drug by blocking sodium entry into specific cells.

Now that the Phase 2 study has concluded and generated cautious optimism after presentation on the national and world stage, the next steps will be larger trials and then perhaps the opportunity for specialty pharmacists to compound phenytoin into solutions for their MS patients. This process could take some time, of course, but in the meantime the thought process that led to this potential breakthrough for MS sufferers can certainly be applied to other conditions.

There are more and more recent examples of researchers working to find unconventional solutions to patient ailments using existing medication, including the use of the compound itraconazole, originally developed as an antifungal drug, to treat advanced forms of hormone-resistant prostate cancer due to its inherent qualities and responses.

The debate in pharmacology over the FDA process for developing and approving new medications is a complex one that cannot be reduced to simple arguments about safety and supply, but the end result of the current environment is that it is challenging to bring new formulations to market. Innovation in compounding and pharmacology like studying the use of phenytoin for the new purpose of protecting the optic nerve in MS patients can help pharmacists continue to improve outcomes for their patients living with a difficult and progressive condition like MS.4

For compounding pharmacists treating patients with macular degeneration from MS, not all of these solutions will come quickly enough for their patients, but they can still play a role in being up-to-date on all the current research and keeping their patients informed. A compound pharmacist can discuss potential upcoming options with patients and let them know that some positive outcomes have already happened based on new and exciting research into their condition. They may not be able to prescribe phenytoin for MS-related eyesight conditions now, but helping their patients understand all potential future treatment options ensures that the pharmacist continues to be a partner in the health care process.

Pharmaceutica North America is a premier provider of high-quality bulk and unit-dose APIs. Contact us to learn how we can help your pharmacy improve patient treatments for MS and epilepsy with phenytoin, or to learn more about our compounding kits and active kits.

Show 4 footnotes

  1. “Improving Outcomes in Multiple Sclerosis: Implications for the Specialty Pharmacist,” Dec. 12, 2013, https://www.pharmacytimes.org/landing/476
  2. “Neuroprotection With Phenytoin in Optic Neuritis,” Sept. 8, 2015, https://clinicaltrials.gov/ct2/show/NCT01451593
  3. “Epilepsy drug may preserve eyesight for people with multiple sclerosis,” April 16, 2015, http://www.sciencedaily.com/releases/2015/04/150416192534.htm
  4. “Too Much FDA Intervention Equals Too Few Drugs: Ramesh Ponnuru,” June 21, 2011, http://www.bloombergview.com/articles/2011-06-21/too-much-fda-intervention-equals-too-few-drugs-ramesh-ponnuru

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