OTC Case Studies: Diabetes

Pharmacy Times, September 2021 , Volume 87, Issue 9

This month's case studies include questions about continuous glucose monitoring, diabetes neuropathic pain, diabetes and colds, and smoking cessation.

Case 1: Continuous Glucose Monitoring

Q: MD is a 59-year-old woman who is looking to replace her glucose monitor. It has been 5 years since she last purchased a monitor, and she would like to upgrade to a continuous glucose monitor (CGM). MD has a 10-year history of diabetes and takes Lantus 10 U at bedtime and metformin 1000 mg daily. She does not take other medications. MD is technology-savvy. What should the pharmacist recommend?

A: Let MD know that most insurance plans have strict guidelines regarding the use of a CGM instead of conventional glucose testing. CGM products have proven to be beneficial at reducing A1C levels and hypoglycemia events. CGM products allows patients to track glucose levels day and night and alert them if they have hyperglycemia or hypoglycemia. Glucose monitors should be selected based on multiple factors, such as ease of cost and insurance coverage, flexibility, information retrieval, and of course, use. Certain CGM products also connect to insulin pumps, but because this is not a factor for MD, she can consider any product.1 CGM products in the United States include the Dexcom G6, FreeStyle Libre system from Abbott, and Medtronic's Guardian Sensor 3. Because MD uses insulin only at bedtime, most insurance companies will not cover CGM products. However, she has the option to select a CGM product and pay out of pocket if her insurance company does not cover it. According to Healthline, out-of-pocket prices for CGM supplies can range from $160 to $500 per month.2

Case 2: Diabetes Neuropathic Pain

Q: RM is a 58-year-old woman who is complaining of neuropathic pain related to diabetes. She has had diabetes for the past 15 years and her A1C levels usually range between 9 and 10. RM takes metformin 1000 mg twice daily but does not want to add additional prescription medications. Her doctor recently gave her a diagnosis of neuropathic pain, but she declined to add medications at the time. RM's friend said she started taking alpha-lipoic acid, which has helped reduce her pain. RM is hesitant to add a supplement, because she is worried about drug interactions. What recommendations should the pharmacist make?

A: RM should discuss the addition of alpha-lipoic acid with her prescriber. One study followed 460 patients over 4 years and found that alpha-lipoic acid was useful in preventing progression of neuropathy.3 RM could benefit with the addition of alpha-lipoic acid to prevent further progression. A meta-analysis evaluated the addition of alpha-lipoic acid and found improvements in neuropathic pain, when given intravenously. The study authors concluded that the benefit with oral administration is unclear.4 RM can see if it is beneficial but should also be advised that multiple prescription medications can also be beneficial with diabetic neuropathy.

Case 3: Diabetes Cold

Q: CS is a 38-year-old man who is looking for pseudoephedrine to clear his congestion. CS has been sick for the past 2 days with some congestion, but he does not have a cough or fever. His medical history includes diabetes and hypertension. CS takes lisinopril 10 mg daily, metformin 1000 mg twice daily, and regular insulin 10 U with each meal. He does not have seasonal allergies and has not tried any medications to relieve his congestion. What recommendations should the pharmacist make?

A: All OTC decongestants come with a caution label for patients who have diabetes or hypertension.5 Pseudoephedrine can increase blood pressure (BP), so patients are recommended to monitor their BP when taking a decongestant. In addition, patients with diabetes on insulin must monitor their BP more often and adjust diabetes medications if needed.6 In addition to using a nasal decongestant, CS can consider trying a dehumidifier or nasal saline to see if his congestion improves.

Case 4: Diabetes and Quitting Smoking

Q: YI is a 45-year-old man who wants to quit smoking. He has smoked 2 packs of cigarettes per day for the past 15 years. YI has tried to quit cold turkey a few times but has never succeeded. He has diabetes and takes metformin 1000 mg twice daily and regular insulin 20 U with each meal. YI wants information on OTC nicotine replacement products, such as the patch. What advice should the pharmacist give him?

A: Nicotine replacement products have been beneficial for patients who are trying to quit smoking. Because YI smokes 2 packs per day, his recommend dose would be 21 mg for 4 to 6 weeks, followed by 14 mg for 2 weeks, and completion of 7 mg for an additional 2 weeks. The most common adverse effects associated with the patch are skin reactions, such as burning or redness. YI should apply the patch to a clean, dry place on the upper arm or body every 24 hours. The patch should be applied to a different part of the skin each day to prevent skin reactions. One patch should not be used for more than 24 hours. YI can shower and swim with the patch on.7 Let him know. that when he quits smoking, he should monitor his blood sugar more often, because nicotine can alter cells that block insulin action, and hypoglycemia can occur.8 YI can also receive additional support by attending community smoking cessation support groups.

Rupal Patel Mansukhani, PharmD, FAPhA, NCTTP, is a clinical associate professor at Ernest Mario School of Pharmacy at Rutgers, The State University of New Jersey in Piscataway, and a transitions-of-care clinical pharmacist at the Morristown Medical Center in New Jersey.

Ammie J. Patel, PharmD, BCACP, BCPS, is a clinical assistant professor of pharmacy practice and administration at Ernest Mario School of Pharmacy at Rutgers, The State University of New Jersey in Piscataway, and an ambulatory care specialist at RWJBarnabas Health Primary Care in Shrewsbury and Eatontown, New Jersey.


1. Better blood glucose meters and more. American Diabetes Association. Accessed August 20, 2021. https://www.diabetes.org/healthy-living/devices-technology

2. Hoskins M. Buying CGM (continuous glucose monitor) supplies at the pharmacy. Healthline. April 3, 2021. Accessed August 22, 2021.https://www.healthline.com/diabetesmine/cgm-access-pharmacies

3. Ziegler D, Low PA, Litchy WJ, et al. Efficacy and safety of antioxidant treatment with alpha-lipoic acid over 4 years in diabetic polyneuropathy. Diab Care. 2011;34:2054-2060. doi:10.2337/dc11-0503

4. Mijnhout GS, Kollen BJ, Alkhalaf A, Kleefstra N, Bilo HJG. Alpha lipoic acid for symptomatic peripheral neuropathy in patients with diabetes: a meta-analysis of randomized controlled trials. Intl J Endocrinol. 2012:456279. doi:10.1155/2012/456279

5. Sudafed. SUDAFED sinus congestion. Accessed August 20, 2021.https://www.sudafed.com/products/sudafed-sinus-congestion

6. Drug interactions between Contac Day and Night Cold and Flu and insulin.Drugs.com. Accessed August 24, 2021. https://www.drugs.com/drug-interactions/contac-day-and-night-cold-and-flu-with-insulin-52-10276-1340-0.html

7. Nicotine replacement therapy to help you quit tobacco. American Cancer Society. Updated August 2, 2021. Accessed August 20, 2021. https://www.cancer.org/healthy/stay-away-from-tobacco/guide-quitting-smoking/nicotine-replacement-therapy.html

8. Smoking and diabetes. CDC. August 10, 2021. Accessed August 22, 2021. https://www.cdc.gov/diabetes/library/features/smoking-and-diabetes.html