Released Date: July 19, 2021
President’s Welcome
Welcome to all of our new and current GASPEN members!
GASPEN continues to strive to provide different education and programming to our members. Midway through 2021, GASPEN had already hosted a joint virtual meeting between SE SCCM and GASPEN in February, featured Dr. Paul Wischmeyer, who shared his expertise on “Nutrition and Metabolic Needs in COVID-19”. GASPEN has been in collaboration with Children’s Healthcare of Atlanta to provide monthly nutrition support professional development WebEx events which cover both pediatric and adult nutrition topics. If you are interested in participating in this monthly WebEx events, please send an email to GASPENGA@gmail.com.
The GASPEN board has been working hard on planning for our second virtual conference scheduled for Friday, August 27, 2021. We have an excellent program lined up for you. This conference will provide 4 hours of continuing education credits for dietitians, nurses, pharmacists, and physicians. This year's topics include enterocutaneous fistula management, micronutrients in the home parenteral nutrition patient, intestinal failure and rehab, and drug shortages and the Unapproved Drugs Initiative. Registration is available at http://nutritioncare.org/gaspenreg.
I am also excited to announce that we will be launching our website, GASPEN.org, by July 31st, 2021. You will soon have access to all GASPEN-related information in one central place. You can learn more about our board members and available committees, read our newsletters, register for upcoming events, and even listen to programs from past events through our GASPEN YouTube channel. Bookmark us NOW!
As always, we welcome any suggestions and comments from GASPEN members
on ways to improve our chapter and provide more benefits to our members. We are also calling for volunteers to help us grow! If you would like to share your ideas and/or if you are interested in volunteering as a committee member, please send an email to GASPENGA@gmail.com.
Thank you for being part of the GASPEN chapter!
Vivian Zhao
GASPEN President
Chronic metabolic acidosis-induced hypophosphatemia from topiramate: a case report
Alison Evans, RD, LD, CNSC | Optum Infusion Pharmacy, Marietta, GA
Purpose
Topiramate (Topamax®) is an FDA approved drug given orally to prevent and control seizures and prevent migraine headaches. Topiramate is also approved for use in multiple sclerosis (MS) to control neuropathic pain and slow disability progression.
A serious side effect of topiramate is metabolic acidosis, a buildup of acid in the blood, a side effect often unknown to the nutrition support clinician and interdisciplinary team. Symptoms may include increased respiratory rate, nausea, vomiting and lethargy.
Chronic metabolic acidosis can lead to metabolic bone disease, calcium nephrolithiasis and growth retardation. Metabolic acidosis induces renal wasting of phosphate disproportionate to its effect on mobilization of tissue phosphorous. Clinical features of moderate to severe hypophosphatemia may include muscle weakness, respiratory failure, heart failure, seizures, coma, rhabdomyolysis and increased mortality.
Methods
AJ, a 30 year old female with multiple sclerosis (MS), autonomic dysfunction, gastroparesis, and s/p gastric sleeve pyloroplasty was admitted for g-j tube dislodgement, subsequently removed due to local strangulated hernia, and small bowel resection with multiple revisions. Oral medications included topiramate 150 mg bid, gabapentin 200 mg tid, famotidine 20 mg bid, danazol 200 mg bid and baclofen 20 mg tid. The patient was later transitioned to infusion provider for home parenteral
nutrition (HPN).
At home, routine PN labs showed persistent chronic metabolic acidosis and mild hypophosphatemia of unclear etiology. The patient denied new medications or changes to current medications. Despite maximizing acetate salts in the PN formulation to correct metabolic acidosis, labs continued to reflect mild acidosis with serum chloride levels maintained in the range of 111-113 mmol/L (slightly elevated) and serum CO2 levels in the range of 18-22 mmol/L (low to low normal range). The PN formulation contained supratherapeutic amounts of phosphorous at 40-50 mMol daily which maintained serum phosphorous level in a low normal range of 3.2 - 3.3 mg/dL.
Results
PN patients are commonly treated
with multiple drugs for various
disease processes; therefore, are at risk for drug induced metabolic disturbances. The nutrition support clinician and interdisciplinary team must be aware of drug induced metabolic complications and recommend adjustments to the PN formulation accordingly. In this case, this patient was on multiple drugs for GI related disease processes, as well as neurological conditions.
Despite efforts to correct metabolic acidosis via PN, serum lab values improved but did not completely correct. The patient was eventually evaluated by a nephrologist, who determined that the persistent metabolic acidosis was topiramate induced chronic metabolic acidosis with hypophosphatemia. The topiramate dose was gradually reduced to 25 mg bid which was the lowest effective dose without exacerbating patient symptoms. Graph 1 and 2 show lab value changes once topiramate dose was decreased. Acetate and phosphorous amounts were eventually able to be decreased in the PN formulation.
Conclusion
Ongoing surveillance of patient’s medication profile by the interdisciplinary team is critical to safely managing HPN patients. A thorough understanding of underlying pathophysiologic mechanisms of drug induced metabolic aberrations and associated risk factors are of vital importance to ensure safe HPN support and prevention of complications.
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