Hypoglycemic effects of tramadol analgesia in hospitalized patients: a case-control study.

BACKGROUND: In outpatient populations, hypoglycemia has been associated with tramadol. We sought to determine the magnitude of risk for hypoglycemia associated with tramadol use in hospitalized patients. METHODS: During a 2-year period of observation, adult inpatients who received ≥1 dose of tramadol were identified and their medical records were reviewed. Patients were included if they had blood or plasma glucose (BG) concentrations measured on at least two occasions within five days after the initial administration of tramadol. A contemporary comparator group of hospitalized oxycodone recipients was similarly reviewed. RESULTS: Tramadol was administered to 2927 patients who met inclusion criteria. Among these, hypoglycemia (BG ≤70 mg/dL) was documented in 22 (46.8%) of 47 patients with type 1 diabetes, 113 (16.8%) of 673 patients with type 2 diabetes, and 103 (4.7%) of 2207 patients who did not have a diabetes mellitus diagnosis. In those without a diabetes diagnosis, the causality association between hypoglycemia and tramadol use was probable in 77 patients (3.5%). By comparison, hypoglycemia was documented in 8 (1.1%) of 716 matched oxycodone recipients without diabetes (p = 0.002). As compared with tramadol recipients who did not develop low BG concentrations, those who experienced tramadol-related hypoglycemia were relatively young (mean age 52.0 versus 59.8 years; p = 0.027) and predominantly female (74.0% versus 59.8%; p = 0.012). CONCLUSIONS: Tramadol use was causally associated with hypoglycemia in hospitalized patients. The proportion of patients without diabetes who developed hypoglycemia was higher among those who received tramadol than among those who received oxycodone. TRIAL REGISTRATION: Colorado Multiple Institutional Review Board Protocol № 15-2215. Registered/approved 8 December 2015.

Valproic acid-carbapenem interaction: report of six cases and a review of the literature.

AIM: To evaluate the drug interactions between valproic acid (VPA) and carbapenem antibiotics. METHODS: The effects of concurrent use of VPA and carbapenem antibiotics were evaluated in a retrospective observational study of hospitalized adults. Patients receiving both VPA and a carbapenem with at least two plasma VPA concentrations serially measured prior to, during, and/or after this combined treatment were included. RESULTS: Six critically ill VPA-treated patients were identified who concurrently received meropenem (n=4), imipenem (n=1), or ertapenem (n=1). As compared with values obtained while not receiving treatment with the carbapenem, mean plasma VPA trough concentrations decreased by 58% (from 51.7 [95% confidence interval {CI} 28.0-75.4] to 21.8 [95% CI 11.1-32.5] mg/L; p = 0.025). Estimated mean VPA clearance increased by 191% (from 0.0158 [95% CI 0.0041-0.0275] to 0.0302 [95% CI 0.0169-0.0591] L/h/kg; p = 0.007). All VPA concentrations measured during concurrent VPA-carbapenem treatment were below the lower boundary of the usual therapeutic range. Five patients (83%) experienced generalized seizures during concurrent VPA-carbapenem treatment, including two with no prior history of seizures or epilepsy. CONCLUSIONS: All recipients showed evidence of a complex pharmacokinetic and pharmacodynamic drug interaction between VPA and a carbapenem. Concurrent use of these medications should be avoided.

A randomized trial of nortriptyline combined with transdermal nicotine for smoking cessation.

BACKGROUND: Smoking cessation rates with current therapy are suboptimal. Tricyclic antidepressants improve cessation rates. We hypothesized that addition of nortriptyline hydrochloride to transdermal nicotine would enhance cessation rates. METHODS: We conducted a randomized, double-blind, placebo-controlled trial at a Department of Veterans Affairs medical center. Subjects were aged 18 to 65 years, smoked 10 or more cigarettes per day, and did not have current major depression. Nortriptyline hydrochloride or matched placebo was started at 25 mg 14 days before quit day, titrated to 75 mg/d as tolerated, and continued for 12 weeks after quit day. Transdermal nicotine (21 mg/d) was started on quit day and continued for 8 weeks. The behavioral intervention consisted of 12 brief, individual visits. Withdrawal symptoms were measured by means of a daily diary, and smoking cessation was defined as self-reported abstinence, expired carbon monoxide level of 9 ppm or less, and a 6-month urine cotinine level less than 50 ng/mL (284 nmol/L). RESULTS: A total of 158 patients were randomized (79 to nortriptyline and 79 to placebo). There was no significant reduction in withdrawal symptoms. The cessation rates at 6 months were 23% (18/79) and 10% (8/79), respectively (absolute difference, 13%; 95% confidence interval, 1.3%-24.5%; P = .052). Nortriptyline caused frequent side effects, including dry mouth (38%) and sedation (20%). CONCLUSIONS: Nortriptyline combined with transdermal nicotine resulted in an increased cessation rate with little effect on withdrawal symptoms. This combination may represent an option for smokers in whom standard therapy has failed.