Case Studies (October 2015)

CASE 1

JJ is a 30-year-old woman who comes to your pharmacy to get a refill of her oral contraceptive. She also hands you a new prescription for modafinil (Provigil) 200 mg orally, which she is to take 1 hour prior to the start of work. JJ started working the nightshift at a local hospital about 6 months ago and complains of being exhausted at night, which is when she needs to be awake. Looking at JJ’s pharmacy profile, you see that she has tried methylphenidate ER (Concerta) 18 mg once daily. Upon questioning, JJ tells you that medication did not help her stay awake at work. She also denies benefit from drinking coffee at work. JJ is otherwise in good health and has no known drug allergies.

As the pharmacist, would you make any recommendations for JJ?

CASE 2

FL, a 43-year-old man who had been camping in New Hampshire for the past 2 weeks, comes to your pharmacy with a tick that he claims was “on me for about 2 days.” He denies fatigue, fevers, or headaches and does not appear to have a red, ring-like rash (erythema migrans) on his neck where the tick bit him. You examine the engorged tick and are able to identify it as a blacklegged tick. You call his primary care physician, who asks for your recommendation in giving FL a medication for prophylaxis of Lyme disease. Although he tells you that he frequently takes antacids for heartburn, FL is otherwise healthy, with no medication allergies or intolerances. As the pharmacist, is FL a candidate for Lyme disease prophylaxis?

What would you recommend?

ANSWERS

Case 1: Modafinil is FDA-approved for shift work disorder and has been shown to improve nighttime alertness and decrease sleepiness; however, it also has been shown to reduce the efficacy of hormonal contraceptives. Ethinyl estradiol is partially metabolized via CYP3A4/5, and modafinil induces CYP3A4/5 enzyme activity. A pharmacokinetic study of modafinil and the ethinyl estradiol/norgestimate combination demonstrated that modafinil decreased the serum concentration of ethinyl estradiol by 18% (vs 4% with placebo). As such, alternative/concomitant methods of contraception should be recommended for women of childbearing age who are taking oral contraceptives in combination with modafinil. In addition, since the potential reduction in contraceptive effectiveness may continue for several weeks after discontinuation of modafinil, additional contraceptive measures should be continued for at least 1 month after stopping modafinil. Since caffeine has not been sufficient for JJ, modafinil is a reasonable choice for combatting her shift-work disorder. However, to prevent unplanned pregnancies, JJ also needs to be counseled to use an additional contraception method beyond her oral contraceptive.

Case 2: Based on guidelines from the Infectious Diseases Society of America, 4 conditions must be met before recommending Lyme disease antibiotic prophylaxis: • The tick (an adult or nymphal Ixodes scapularis, also called a deer tick or blacklegged tick) must be attached for ≥36 hours • Prophylaxis must be started within 72 hours of tick removal • The local rate of tick infection with Borrelia burgdorferi is ≥20% (common in parts of New England, the mid-Atlantic states, Minnesota, and Wisconsin) • Doxycycline treatment is not contraindicated (ie, pregnancy or age <8 years) As all of these conditions have been met, it is reasonable to recommend a single 200-mg dose of doxycycline for FL. Instruct FL to take the medication with a full glass of water to prevent esophageal erosion and recommend that he wear sunscreen when going outside, as doxycycline causes photosensitivity. You should also advise FL to separate his doxycycline and antacid doses by at least 2 to 4 hours, as divalent/trivalent cations (calcium, aluminum, magnesium) commonly found in antacids impair the absorption of tetracycline antibiotics.

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Dr. Kohn is an assistant professor at the University of Saint Joseph School of Pharmacy, Hartford, Connecticut. Dr. Coleman is professor of pharmacy practice, as well as codirector and methods chief, at Hartford Hospital Evidence-Based Practice Center at the University of Connecticut School of Pharmacy.

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