Case Studies (December 2015)

CASE 1

MR is a 32-year-old woman who comes to the pharmacy with a new prescription for gabapentin 600 mg 3 times daily, which her physician prescribed for alcohol dependence. MR’s physician stated that this is an “off-label” use for gabapentin, which has made MR nervous. She has no other diagnosed psychological disorders. She most recently attempted to stop drinking 6 months ago when her physician prescribed naltrexone 50 mg daily. Unfortunately, her liver function test results kept coming back elevated and she had to discontinue the medication. She experienced a similar problem when she previously tried disulfiram. MR has an allergy to acamprosate, which results in hives. Currently, the only other medication she is taking is ethinyl estradiol/norethindrone (Junel) for birth control.

As the pharmacist, what do you tell MR about gabapentin’s role in the management of alcohol dependence?

CASE 2

JT, a 42-year-old man, is at an appointment with his new primary care physician (PCP) following Roux-en-Y gastric bypass surgery that he underwent last month. JT has been using vitamin samples from his bariatric surgeon but has run out and does not remember which vitamins he was asked to take, aside from the fact that he gets a monthly injection of vitamin B12. The surgeon is on vacation until next week, and JT’s chart reads only “Vitamin supplementation per instructions.” JT’s PCP calls the pharmacy asking what vitamin supplements are essential for JT to take following his Roux-en-Y gastric bypass surgery.

As the pharmacist, what do you recommend?

ANSWERS

Case 1: Gabapentin is not approved by the FDA for the treatment of alcohol dependence. The mechanism by which gabapentin prevents relapse is still unclear, but is hypothesized to be related to reduced hyperexcitability in the central nervous system during withdrawal due to the inhibition of glutamate and release of gamma-aminobutyric acid. FDA-approved therapy for the treatment of alcohol dependence includes naltrexone, acamprosate, and disulfiram; however, MR cannot take these agents due to previous elevated liver function test results and hypersensitivity reactions. The pharmacist could explain to MR that several small randomized control trials have demonstrated beneficial effects of higherdose (1800 mg/day) gabapentin on relapse rates and, in one recent trial, mood-effecting symptoms (such as insomnia, dysphoria, and craving) associated with relapse. The pharmacist should further advise MR not to discontinue the medication abruptly or without consulting her physician.

Case 2: Vitamin supplementation needs vary depending on the patient and type of bariatric surgery. Because JT underwent Roux-en-Y gastric bypass surgery, the American Society for Metabolic and Bariatric Surgery recommends that he take a multivitamin—mineral supplement with 200% of the daily value for at least two-thirds of nutrients, which means he will likely need to take 2 tablets of a multivitamin–mineral supplement with at least 18 mg of iron and 400 mcg of folic acid, as well as selenium and zinc. Calcium citrate 1500 mg daily with vitamin D is also recommended, which should be divided into 3 doses for best absorption. JT may need additional daily vitamin D to ensure his levels are higher than 30 ng/mL. Vitamin B12 supplementation is recommended, but JT is already receiving this with his monthly injection. JT may need to take additional supplements (eg, vitamin A or vitamin B6) depending on his lab values. For the first 6 weeks following the surgery, all tablets must be crushed and capsules opened to ensure absorption. Make sure JT knows he should not purchase formulations that are enteric-coated or delayed-release. Liquid formulations are available but often have high sugar content, so JT must read the label carefully and account for these carbohydrates in his diet.

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Ms. Hodgdon is a PharmD candidate from the University of Connecticut School of Pharmacy, Storrs, Connecticut. Dr. Nguyen is a post-PharmD Outcomes research fellow at Hartford Hospital, Hartford, Connecticut. Dr. Coleman is a professor of pharmacy practice at the University of Connecticut School of Pharmacy, Storrs, Connecticut.

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