anticonvulsants

The association between medication use and vitamin B12 deficiency in the elderly population: a cross- sectional study

Author/s: 
Monique P H Tillemans, Thijs J Giezen, Toine C G Egberts, Kees J Kalisvaart

Background
Vitamin B12 deficiency is common in the elderly population and can cause severe complications. The use of certain medication has in previous studies been associated with vitamin B12 deficiency in the general population. To identify elderly patients at risk for vitamin B12 deficiency due to medication use, we evaluated the association between medication use and vitamin B12 deficiency in the elderly population.

Methods
Hospitalized geriatric patients 65 years of age or over with a serum vitamin B12 measurement within one week of the admittance date were included. Patients were classified as either B12 normal (258–635 pmol/L) or B12 deficient (< 148 pmol/L). Upon hospital admission patients’ medication use was verified. The association between vitamin B12 deficiency and the use of antacid, antiepileptic, antidiabetic, lipid lowering and other medication was evaluated by univariate and multivariate analyses.

Results
Of the 7132 patients included in the study, 532 (7.5%) had vitamin B12 deficiency and 3433 (48.1%) patients had normal vitamin B12 concentrations. Metformin use was significantly and independently (adjusted OR 2.5; 95% CI 1.7–3.6) associated with a dose-dependent higher risk of vitamin B12 deficiency. The use of other medication evaluated in this study was not associated with vitamin B12 deficiency.

Conclusions
Metformin use is significantly associated with vitamin B12 deficiency in the elderly, and this risk rises with higher metformin doses. Monitoring and timely start of vitamin B12 supplementation along with the lowest possible metformin dose are essential to prevent complications.

Evidenced-Based Pharmacotherapies for Alcohol Use Disorder

Author/s: 
Fairbanks, J, Umbreit, A, Kolla, BP, Karpyak, VM, Schneekloth, TD, Loukianova, LL, Sinha, S

Pathologic alcohol use affects more than 2 billion people and accounts for nearly 6% of all deaths worldwide. There are three medications approved for the treatment of alcohol use disorder by the US Food and Drug Administration (FDA): disulfiram, naltrexone (oral and long-acting injectable), and acamprosate. Of growing interest is the use of anticonvulsants for the treatment of alcohol use disorder, although currently none are FDA approved for this indication. Baclofen, a γ-aminobutyric acid B receptor agonist used for spasticity and pain, received temporary approval for alcohol use disorder in France. Despite effective pharmacotherapies, less than 9% of patients who undergo any form of alcohol use disorder treatment receive pharmacotherapies. Current evidence does not support the use of pharmacogenetic testing for treatment individualization. The objective of this review is to provide knowledge on practice parameters for evidenced-based pharmacologic treatment approaches in patients with alcohol use disorder.

Nonopioid Pharmacologic Treatments for Chronic Pain. Comparative Effectiveness Review No. 228

Author/s: 
McDonagh, MS, Selph, SS, Buckley, DI, Holmes, RS, Mauer, K, Ramirez, S, Hsu, FC, Dana, T, Fu, R, Chou

Objectives. To evaluate the effectiveness and comparative effectiveness of nonopioid pharmacologic agents in patients with specific types of chronic pain, considering effects on pain, function, quality of life, and adverse events.

Data sources. Electronic databases (Ovid® MEDLINE®, Embase®, PsycINFO®, CINAHL®, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews) through September 10, 2019, reference lists, data requests, and previous reviews.

Review methods. Randomized controlled trials (RCTs) of nonopioid pharmacologic agents in patients with chronic pain were selected using predefined criteria and dual review. This review focused on seven common chronic pain conditions (neuropathic pain, fibromyalgia, osteoarthritis, inflammatory arthritis, low back pain, chronic headache, sickle cell disease), with effects analyzed at short term (1 to <6 months following treatment completion), intermediate term (≥6 to <12 months), and long term (≥12 months). Magnitude of effects were described as small, moderate, or large using previously defined criteria, and strength of evidence was assessed. Meta-analyses were conducted where data allowed, stratified by duration within each intervention type, using random effects models. We evaluated effect modification through subgroup and sensitivity analyses, including specific drug, dose, study quality, and pain type.

Results. We included 185 RCTs in 221 publications and 5 systematic reviews. In the short term, anticonvulsants (pregabalin, gabapentin, and oxcarbazepine for neuropathic pain, pregabalin/gabapentin for fibromyalgia), serotonin-norepinephrine reuptake inhibitor (SNRI) antidepressants (duloxetine for neuropathic pain, fibromyalgia, osteoarthritis, and low back pain, milnacipran for fibromyalgia), and nonsteroidal anti-inflammatory drugs (NSAIDs) (for osteoarthritis and inflammatory arthritis) were associated with mostly small improvements (e.g., 5 to 20 points on a 0 to 100 scale) in pain and function. Function was not found to be improved with duloxetine for low back pain or pregabalin/gabapentin for neuropathic pain. Moderate improvement in quality of life was seen with duloxetine in patients with neuropathic pain, and small improvements in patients with osteoarthritis, but evidence was insufficient to draw conclusions for other drugs and conditions. While most comparisons of drugs and doses did not identify differences, diclofenac improved pain and function moderately more than celecoxib. In the intermediate term, limited evidence (1 RCT) showed memantine moderately improved pain, function, and quality of life in patients with fibromyalgia; improvements in pain, but not function, were maintained in the intermediate term with duloxetine and milnacipran for fibromyalgia. Other drugs studied, including acetaminophen (osteoarthritis), capsaicin (neuropathic pain), cannabis (neuropathic pain), amitriptyline (fibromyalgia, neuropathic pain), and cyclobenzaprine (fibromyalgia) had no clear effects. Withdrawal from study due to adverse events was significantly increased with nonopioid drugs, with the greatest increase over placebo seen with cannabis. Large increases in risk of adverse events were seen with pregabalin (blurred vision, cognitive effects, dizziness, peripheral edema, sedation, and weight gain), gabapentin (blurred vision, cognitive effects, sedation, weight gain), and cannabis (nausea, dizziness). Dose viii reductions reduced the risk of some adverse events with SNRI antidepressants. In the short term small increases in risk of major coronary events and moderate increases in serious gastrointestinal events (both short and long term) were found with NSAIDs.

Conclusions. In the short term, small improvements in pain and/or function were seen with SNRI antidepressants for neuropathic pain, fibromyalgia, osteoarthritis, and low back pain; pregabalin/gabapentin for neuropathic pain and fibromyalgia; oxcarbazepine for neuropathic pain; and NSAIDs for osteoarthritis and inflammatory arthritis. Improvement in function was not found with duloxetine for low back pain and pregabalin/gabapentin for neuropathic pain. Intermediate- and long-term outcomes were mostly not assessed. Increased incidence of drug class–specific adverse events led to withdrawal from treatment in some patients, suggesting that careful consideration of patient characteristics is needed in selecting nonopioid drug treatments.

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