Ambien After Bariatric Surgery: What Patients and Prescribers Need to Know About Zolpidem Post-Op

Does bariatric surgery change how zolpidem is absorbed?

The closest evidence is a 2010 systematic review in Obesity Reviews of 26 studies: 15 case reports or case series covering 12 drugs and 11 non-randomized controlled studies covering 15 drugs [2]. Evidence of diminished absorption appeared in 15 of 22 jejunoileal bypass studies, 1 of 3 gastric bypass or gastroplasty studies and 0 of 1 biliopancreatic diversion study [2]. The review concluded that the effect of bariatric surgery on absorption appears drug-specific, that individual dose adjustment and therapeutic monitoring may be required, and that controlled studies of modern procedures were needed [2]. Its most consistent evidence of reduced absorption was for cyclosporine, thyroxine, phenytoin and rifampin [2].

What doses does the Ambien label specify?

Immediate-release zolpidem is dosed at 5 mg for women and 5 or 10 mg for men, once per night and not repeated the same night, to a maximum of 10 mg [1]. Ambien CR is dosed at 6.25 mg for women and 6.25 or 12.5 mg for men, maximum 12.5 mg, and the tablet is swallowed whole, not crushed, divided or chewed [3]. Both labels give 5 mg (Ambien) or 6.25 mg (Ambien CR) for older patients and for mild to moderate hepatic impairment [1][3]. The label says the starting doses differ because zolpidem clearance is lower in women [1].

What does the label warn about?

Complex sleep behaviors carry a boxed warning: sleep-walking, sleep-driving, eating, making phone calls or having sex while not fully awake can follow the first or any later dose at recommended doses, and patients usually do not remember them [1]. The boxed warning says some of these events have caused serious injuries, including death, and the label says to discontinue the drug immediately if one occurs and lists any prior episode as a contraindication [1]. FDA added the warning in April 2019 after reviewing reports from December 1992 through February 2018: 66 cases, 20 deaths, 46 serious injuries, and 22 with an earlier episode; such reports cannot establish how often these events occur [4][5].

The label also says Ambien with opioids may increase the risk of respiratory depression and that the dose and duration of combined use should be limited [1].

What about obstructive sleep apnea?

A 2015 Cochrane review included 14 randomized placebo-controlled trials of 10 drugs, among them zolpidem 10 mg and 20 mg, in 293 adults with confirmed obstructive sleep apnea; most had mild to moderate disease and all but three trials lasted one to three nights [6]. That review did not address bariatric surgery [6]. The Ambien label lists sleep apnea among the situations in which respiratory depression is a concern, says to re-evaluate if insomnia persists after 7 to 10 days, and says treatment should be as short as possible [1].

Is there a non-drug option?

The American College of Physicians recommends cognitive behavioral therapy for insomnia as the initial treatment for chronic insomnia in all adults (strong recommendation, moderate-quality evidence), adding medication through shared decision-making when CBT-I alone is unsuccessful (weak recommendation, low-quality evidence) [7].