Acute pancreatitis secondary to tamoxifen-associated hypertriglyceridemia: A clinical update.

INTRODUCTION: Drug-induced pancreatitis has been increasingly recognized, but it is frequently encountered as an inconspicuous etiology. The underlying mechanisms of injury vary with different drugs. Tamoxifen is a frequently used anticancer drug that acts by selective modulation of the estrogen receptor in patients with breast cancer. Tamoxifen-induced hypertriglyceridemia is a relatively rare etiological factor for acute pancreatitis. However, acute pancreatitis secondary to this adverse effect remains an exceedingly important clinicopathologic entity. CASE REPORT: We hereby delineate a rare case of acute pancreatitis secondary to hypertriglyceridemia in a patient who was on tamoxifen treatment for the past 3 years. Her serum lipase and triglyceride levels were markedly elevated at 14,285 IU/L and 20,344 mg/dL, respectively. The diagnosis was considered based on the findings of a standard diagnostic workup and exclusion of alternative causes of acute pancreatitis. MANAGEMENT AND OUTCOME: The patient was instituted prompt treatment with intravenous insulin infusion and gemfibrozil. The clinical outcome was favorable with no complications. Tamoxifen was permanently discontinued and was replaced with letrozole. DISCUSSION: This article illustrates that acute pancreatitis should be considered in the differential diagnoses of abdominal pain and elevated pancreatic enzymes in patients undergoing tamoxifen treatment. It also underscores the importance of pre- and post-tamoxifen lipid screening, especially in patients with a history of dyslipidemia and diabetes mellitus. It will facilitate an expedient detection of hypertriglyceridemia, potentially saving patients from associated morbidity and mortality.

Gemfibrozil Induces Anemia, Leukopenia and Reduces Hematopoietic Stem Cells via PPAR-α in Mice.

Hypercholesterolemia, also called high cholesterol, is a form of hyperlipidemia, which may be a consequence of diet, obesity or diabetes. In addition, increased levels of low-density lipoprotein (LDL) and reduced levels of high-density lipoprotein (HDL) cholesterol are associated with a higher risk of atherosclerosis and coronary heart disease. Thus, controlling cholesterol levels is commonly necessary, and fibrates have been used as lipid-lowering drugs. Gemfibrozil is a fibrate that acts via peroxisome proliferator-activated receptor alpha to promote changes in lipid metabolism and decrease serum triglyceride levels. However, anemia and leukopenia are known side effects of gemfibrozil. Considering that gemfibrozil may lead to anemia and that gemfibrozil acts via peroxisome proliferator-activated receptor alpha, we treated wild-type and peroxisome proliferator-activated receptor alpha-knockout mice with gemfibrozil for four consecutive days. Gemfibrozil treatment led to anemia seven days after the first administration of the drug; we found reduced levels of hemoglobin, as well as red blood cells, white blood cells and a reduced percentage of hematocrits. PPAR-alpha-knockout mice were capable of reversing all of those reduced parameters induced by gemfibrozil treatment. Erythropoietin levels were increased in the serum of gemfibrozil-treated animals, and we also observed an increased expression of hypoxia-inducible factor-2 alpha (HIF-2α) and erythropoietin in renal tissue, while PPAR-alpha knockout mice treated with gemfibrozil did not present increased levels of serum erythropoietin or tissue HIF-2α and erythropoietin mRNA levels in the kidneys. We analyzed bone marrow and found that gemfibrozil reduced erythrocytes and hematopoietic stem cells in wild-type mice but not in PPAR-alpha-knockout mice, while increased colony-forming units were observed only in wild-type mice treated with gemfibrozil. Here, we show for the first time that gemfibrozil treatment leads to anemia and leukopenia via peroxisome proliferator-activated receptor alpha in mice.

Cumulative non-HDL-cholesterol burden in patients with hypertriglyceridemia receiving long-term fibrate therapy: Real life data from a lipid clinic cohort.

OBJECTIVE: Though epidemiological data suggest that an elevated triglyceride (TG) level may be a risk factor for coronary artery disease (CAD), there is still insufficient clinical evidence. This study was designed to evaluate the real-life efficacy and side effects of fibrate treatment for hypertriglyceridemia seen in a lipid clinic, as well as cardiovascular and diabetic outcomes. METHODS: This retrospective study evaluated patients who were followed-up for a diagnosis of hypertriglyceridemia at the lipid outpatient clinic of the Ege University Cardiology Department between 1997 and 2018. Data of demographic and clinical characteristics were obtained from hospital records. All patients (n=240) with at least 1 year of follow-up were included in the analysis. During follow-up, patients were treated with fenofibrate, and less frequently, gemfibrozile (14 patients), at different doses according to the TG level and disease severity. RESULTS: Of the study population, 23% had CAD, 21% were diabetic, and 52% were obese. On admission, 20% were using fibrates and 17% were on statins. The mean admission lipid levels were TG: 281±194 mg/dL, low-density lipoprotein cholesterol: 115±37 mg/dL, high-density lipoprotein (HDL) cholesterol: 43±13 mg/dL, and non-HDL cholesterol: 166±42 mg/dL. The mean length of follow-up was 5.3±4.7 years (range: 1-16 years). A total of 8 (4.3%) patients had adverse effects during follow-up (1 on statin combination and 7 on fibrates alone). The side effects observed were an elevation of liver enzymes in 3, myalgia in 2, insomnia in 1, malaise in 1, and a skin rash in 1 patient. No rhabdomyolysis or myopathy was seen. During follow-up, diabetes developed in 14 and cardiovascular disease (CVD) in 14 patients. The cumulative non-HDL cholesterol level was significantly high in patients who developed diabetes or CVD. Receiver operating curve analysis indicated that a cumulative non-HDL cholesterol value of 1016 mg/dL was predictive of the development of diabetes mellitus or CVD with 85% sensitivity and 70% specificity. CONCLUSION: In real life, long-term fibrate use is effective and safe. The cumulative non-HDL cholesterol burden can be used to assess the efficacy of treatment as a simple and easily calculated method. Large studies are needed to further clarify the value of this parameter in predicting the development of both diabetes and CVD.

SPPARM alpha: the Lazarus effect.

PURPOSE OF REVIEW: Atherogenic dyslipidaemia, characterized by high plasma triglycerides (a surrogate for triglyceride-rich remnant lipoproteins) and low high-density lipoprotein cholesterol (HDL-C), is prevalent in patients with type 2 diabetes mellitus (T2DM) and contributes to a high modifiable residual cardiovascular risk. Fibrates are effective in managing hypertriglyceridaemia but lack consistent cardiovascular benefit in clinical trials and exhibit pharmacokinetic interaction with statins (gemfibrozil) and renal and hepatic safety issues (fenofibrate). The selective peroxisome proliferator-activated receptor alpha modulator (SPPARMα) paradigm offers potential for improving potency, selectivity and the benefit-risk profile. RECENT FINDINGS: The present review discusses evidence for the novel SPPARMα agonist, pemafibrate. Clinical trials showed robust lowering of triglyceride-rich lipoproteins, elevation in HDL-C and nonlipid beneficial effects including anti-inflammatory activity. There was a favourable safety profile, with no increase in serum creatinine, evident with fenofibrate, and improved renal and hepatic safety. The cardiovascular outcomes study PROMINENT is critical to confirming the SPPARMα concept by validating reduction in residual cardiovascular risk in patients with T2DM and long-term safety. SUMMARY: SPPARMα offers a new paradigm for reducing residual cardiovascular risk in T2DM. PROMINENT will be critical to differentiating the first SPPARMα, pemafibrate, as a novel therapeutic class distinct from current fibrates.

Delayed presentation of severe rhabdomyolysis leading to acute kidney injury following atorvastatin-gemfibrozil combination therapy: a case report.

BACKGROUND: Rhabdomyolysis is a rare but serious complication of lipid-lowering therapy. Statin and fibrate combination increases the risk of rhabdomyolysis possibly by pharmacodynamic interactions. Advanced age, diabetes, hypothyroidism, polypharmacy, and renal impairment are known to increase the risk of rhabdomyolysis. Management strategies include fluid resuscitation and urine alkalinization. Renal indications such as refractory hyperkalemia, acidosis, fluid overload, or uremic complications mandate renal replacement therapy in rhabdomyolysis. CASE PRESENTATION: We report the case of a 62-year-old Sri Lankan Sinhalese man with dyslipidemia, type 2 diabetes mellitus with renal impairment, and hypothyroidism who was on atorvastatin; he was started on gemfibrozil and developed muscle symptoms. Although gemfibrozil was discontinued soon after, he presented with rhabdomyolysis with acute kidney injury 1 month later. He needed hemodialysis due to refractory hyperkalemia, metabolic acidosis, and fluid overload. CONCLUSIONS: Rhabdomyolysis is a rare but serious complication due to lipid-lowering therapy with statins and fibrates. Treating physicians should be aware and patients should be warned to report about muscle symptoms after starting statins or fibrates. Rhabdomyolysis may occur with mild symptoms and signs and may occur later, even after discontinuation of the drug.

Effect of gemfibrozil and rifampicin on the pharmacokinetics of selexipag and its active metabolite in healthy subjects.

AIMS: Based on in vitro data, there is evidence to suggest that cytochrome P450 (CYP) 2C8 is involved in the metabolism of selexipag and its active metabolite, ACT-333679. The present study evaluated the possible pharmacokinetic interactions of selexipag with gemfibrozil, a strong CYP2C8 inhibitor, and rifampicin, an inducer of CYP2C8. METHODS: The study consisted of two independent parts, each conducted according to an open-label, randomized, crossover design. The pharmacokinetics and safety of selexipag and ACT-333679 were studied following single-dose administration either alone or in the presence of multiple-dose gemfibrozil (part I) or rifampicin (part II) in healthy male subjects. RESULTS: Gemfibrozil had comparatively small effects on selexipag (less than 2-fold difference in any pharmacokinetic variable) but, with respect to ACT-333679, increased the maximum plasma concentration (Cmax ) 3.6-fold [90% confidence interval (CI) 3.1, 4.3] and the area under the plasma concentration-time curve from zero to infinity (AUC0-∞ ) 11.1-fold (90% CI 9.2, 13.4). The marked increased exposure to ACT-333679, which mediates the majority of the pharmacological activity of selexipag, was accompanied by significantly more adverse events such as headache, nausea and vomiting. Coadministration of rifampicin increased the Cmax of selexipag 1.8-fold (90% CI 1.4, 2.2) and its AUC0-∞ 1.3-fold (90% CI 1.1, 1.4); its effects on ACT-333679 were to increase its Cmax 1.3-fold (90% CI 1.1, 1.6), shorten its half-life by 63% and reduce its AUC0-∞ by half (90% CI 0.45, 0.59). CONCLUSION: Concomitant administration of selexipag and strong inhibitors of CYP2C8 must be avoided, whereas when coadministered with inducers of CYP2C8, dose adjustments of selexipag should be envisaged.

Safety and potential efficacy of gemfibrozil as a supportive treatment for children with late infantile neuronal ceroid lipofuscinosis and other lipid storage disorders.

Neuronal Ceroid Lipofuscinosis (NCL), also known as Batten disease, is a group of genetically distinct lysosomal disorders that mainly affect the central nervous system, resulting in progressive motor and cognitive decline primarily in children. Multiple distinct genes involved in the metabolism of lipids have been identified to date with various mutations in this family of diseases. There is no cure for these diseases but some new therapeutic approaches have been tested that offer more hope than the standard palliative care. Many of the therapeutic advances require invasive procedures but some progress in slowing the disease has been found and more options can be expected in the future. We also review the literature on children with disease/conditions other than NCL for the non-invasive use, safety, and tolerability of a lipid-lowering drug, gemfibrozil, as a potential treatment for NCLs. Gemfibrozil has shown efficacy in an animal model of NCL known as CLN2 (late infantile classic juvenile) and has been shown to be safe for lowering lipids in children. Among the 200 non-NCL children found in the published literature who were treated with gemfibrozil for NCL-related problems, only 3 experienced adverse events, including 2 with muscle pain and 1 with localized linear IgA bullous dermatitis. We conclude that gemfibrozil is safe for long-term use in children, causes minimal adverse events, is well tolerated, and may delay the progression of NCLs. Gemfibrozil may potentially be an alternative to more invasive therapeutic approaches currently under investigation and has the potential to be used in combination with other therapeutic approaches.

PPARα-dependent increase of mouse urine output by gemfibrozil and fenofibrate.

While gemfibrozil and fenofibrate are prescribed for anti-dyslipidemia treatment, a rational basis for the use of these drugs for treatment of dyslipidemia with concurrent metabolic syndrome has not been established. In this study, wild-type and Pparα-null mice were fed gemfibrozil- or fenofibrate-containing diets for 14 days. Urine output (24 h) was monitored, and urine, serum, and liver and kidney tissues were subjected to toxicity assessment. A 2-month challenge followed by a 2-week wash-out was performed for gemfibrozil to determine urine output and the potential toxicity. A therapeutically equivalent dose of gemfibrozil was more effective than fenofibrate in increasing urine output. This regulatory effect was not observed in Pparα-null mice. In contrast, hepatomegaly induced by fenofibrate was more pronounced than that of gemfibrozil. No significant toxicity was observed in liver or kidney in the 2-month treatment with gemfibrozil. These data demonstrated PPARα mediates the increased urine output by fibrates. Considering the relative action on hepatomegaly and the regulatory effect on urine output, gemfibrozil may be the preferable drug to increase urine output. These results revealed a new pharmacodynamic effect of clinically prescribed PPARα agonists and suggested the potential value of gemfibrozil in modification of blood pressure.

Pharmacological effects of gemfibrozil on some isolated smooth muscle preparations of experimental animals

Background: Gemfibrozil is a member of fibrates (gemfibrozil, fenofibrate, ceprofibrate, and benzafibrate) which is employed for treatment of dyslipidemia particularly hypertriglyceridemiae through its action on peroxisome proliflator activated receptors (PPAR-). Objective: The aim of this work was to study the site of action and pharmacololgical effects of different doses of gemfibrozil on some isolated smooth muscles preparations of experimental animals. Materials and Methods: The experiments were conducted on isolated jejunum of rabbits, isolated spiral tracheal and urinary bladder strips of guinea pigs. Results: I- On isolated rabbit jejunum, gemfibrozil produced a dose-dependent reduction on the amplitude of jejunal contractions. The inhibitory effect of gemfibrozil was not abolished after complete blockade of alpha and beta adrenergic receptors, while it was completely abolished after inhibition of nitric oxide synthase by N-methyl L-arginine. On the other hand the stimulatory effects of nicotine small dose, acetylcholine, calcium gluconate, histamine and serotonin were not abolished after administration of gemfibrozil. II- On isolated tracheal spiral strips of ginea pigs, gemfibrozil produced a dose- dependent relaxation on the basal tone and a dose-dependent reduction on the amplitude of acetylcholine-induced tracheal contractions of the tracheal strips. The inhibitory effect of gemfibrozil was completely abolished after inhibition of nitric oxide synthase by N-methyl L-arginine. Gemfibrozil completely abolished also serotonin-induced contraction, while it has no effect on histamine or calcium-induced tracheal contractions. III- On isolated urinary bladder strips of guinea pigs, gemfibrozil produced a dose-dependent reduction on the amplitude of urinary bladder contractions. The inhibitory effect of gemfibrozil was not abolished after complete blockade of beta adrenergic receptors, while it was completely abolished after inhibition of nitric oxide synthase by N-methyl L-arginine. On the other hand the stimulatory effects of acetylcholine and serotonin were not abolished after administration of gemfibrozil. Conclusion: Gemfibrozil (antidyslipidemic, PPAR- agonist) reduced jejunal and urinary bladder contractions and has a relaxant effect on tracheal basal tone. So it has a beneficial effect in obstructive airway diseases and cases of urgency and frequency of micturation and urinary incontinence. However, it may be used cauciously in cases of ,GIT disturbances as constipation and prostatic hypertrophy

Fracaso renal agudo por nefritis intersticial aguda con síndrome de Fanconi en relación con metamizol y gemfibrozilo / Acute renal failure secondary to interstitial acute nephritis and Fanconi syndrome for metamizole and gemfibrozil

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Screening, monitoring, and treatment of stage 1 to 3 chronic kidney disease: A clinical practice guideline from the American College of Physicians.

DESCRIPTION: The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations on the screening, monitoring, and treatment of adults with stage 1 to 3 chronic kidney disease. METHODS: This guideline is based on a systematic evidence review evaluating the published literature on this topic from 1985 through November 2011 that was identified by using MEDLINE and the Cochrane Database of Systematic Reviews. Searches were limited to English-language publications. The clinical outcomes evaluated for this guideline included all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, chronic heart failure, composite vascular outcomes, composite renal outcomes, end-stage renal disease, quality of life, physical function, and activities of daily living. This guideline grades the evidence and recommendations by using ACP's clinical practice guidelines grading system. RECOMMENDATION 1: ACP recommends against screening for chronic kidney disease in asymptomatic adults without risk factors for chronic kidney disease. (Grade: weak recommendation, low-quality evidence) RECOMMENDATION 2: ACP recommends against testing for proteinuria in adults with or without diabetes who are currently taking an angiotensin-converting enzyme inhibitor or an angiotensin II-receptor blocker. (Grade: weak recommendation, low-quality evidence) RECOMMENDATION 3: ACP recommends that clinicians select pharmacologic therapy that includes either an angiotensin-converting enzyme inhibitor (moderate-quality evidence) or an angiotensin II-receptor blocker (high-quality evidence) in patients with hypertension and stage 1 to 3 chronic kidney disease. (Grade: strong recommendation) RECOMMENDATION 4: ACP recommends that clinicians choose statin therapy to manage elevated low-density lipoprotein in patients with stage 1 to 3 chronic kidney disease. (Grade: strong recommendation, moderate-quality evidence).

Statin-associated polymyositis following omeprazole treatment.

Statins are an extensively used class of drugs, and myopathy is an uncommon, but well-described side effect of statin therapy. Inflammatory myopathies, including polymyositis, dermatomyositis, and necrotizing autoimmune myopathy, are even more rare, but debilitating, side effects of statin therapy that are characterized by the persistence of symptoms even after discontinuation of the drug. It is important to differentiate statin-associated inflammatory myopathies from other self-limited myopathies, as the disease often requires multiple immunosuppressive therapies. Drug interactions increase the risk of statin-associated toxic myopathy, but no risk factors for statin-associated inflammatory myopathies have been established. Here we describe the case of a man, age 59 years, who had been treated with a combination of atorvastatin and gemfibrozil for approximately 5 years and developed polymyositis after treatment with omeprazole for 7 months. Symptoms did not resolve after discontinuation of the atorvastatin, gemfibrozil, and omeprazole. The patient was treated with prednisone and methotrexate followed by intravenous immunoglobulin, which resulted in normalization of creatinine kinase levels and resolution of symptoms after 14 weeks. It is unclear if polymyositis was triggered by interaction of the statin with omeprazole and/or gemfibrozil, or if it developed secondary to long-term use of atorvastatin only.

Risk of hospitalized rhabdomyolysis associated with lipid-lowering drugs in a real-world clinical setting.

BACKGROUND: The occurrence of low rates of rhabdomyolysis among patients receiving lipid-lowering drugs (LLDs) in randomized clinical trials may be elucidated with population-based studies. OBJECTIVE: To determine the risk of hospitalized rhabdomyolysis associated with LLD therapy. METHODS: This observational study used claims data from 9 million members of five United States health plans to identify patients (≥18 years) who received >2 statin and nonstatin LLDs during July 2000 to December 2004. Inpatient International Classification of Diseases, Ninth Revision, Clinical Modification, codes for rhabdomyolysis (791.3, 728.89, and 728.88) were observed during the follow-up period; cases were confirmed with patients' medical records. Rhabdomyolysis events were reported per 10,000 person-years of LLD exposure; multivariate analysis was conducted. RESULTS: The study cohort (N = 473,343) received 490,988 and 11,624 person-years of LLD, and combination therapy, respectively. Medical charts were obtained for 104 of 144 eligible patients with rhabdomyolysis claims; 42 cases were confirmed. With atorvastatin as reference, rhabdomyolysis rates (95% confidence interval) were greatest for cerivastatin, 8.4 (2.3-21.7); no difference among available statins was observed. Rates for other LLD monotherapies were: niacin, 2.1 (0.3-7.7), ezetimibe, 2.1 (0.3-7.8), fenofibrate, 0 (0-1.7), and gemfibrozil, 2.0 (0.5-5.2). Multivariate analysis showed only cerivastatin with a significantly greater risk of rhabdomyolysis (odds ratio 4.74, 95% confidence interval 1.1-21.2, P = .041) versus atorvastatin among the statins. Combination therapies had increased rhabdomyolysis risk (OR 7.1, 1.6-31.6, P = .010) versus LLDs alone. CONCLUSION: The risk of habdomyolysis among hospitalized patients receiving statins was low; no difference among the available statins was evident. Further data are needed to establish the risk profile but current findings already offer guidance to physicians.

Statin-associated rhabdomyolysis with acute renal failure complicated by intradialytic NSTEMI: a review of lipid management considerations.

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are associated with myopathy, myalgias, myositis, and rhabdomyolysis. Rhabdoymyolysis is a rare complication and may cause acute renal failure, which may be fatal. In such cases, alternative therapies should be considered. In this review, we attempted to elucidate the lipid management options in patients with rhabdomyolysis and coronary artery disease. We also describe a case report of a patient who developed rhabdomyolysis from dual antilipid therapy followed by acute renal failure and non-ST elevation myocardial infarction. Such a complex case has not been reported in the literature, and lipid management options may include niacin, omega 3-fatty acids, or bile acid sequestrants. Once alternative therapies are initiated, monitoring a patient closely with evaluation for associated adverse events should be performed.

CYP2C metabolism of oral antidiabetic drugs--impact on pharmacokinetics, drug interactions and pharmacogenetic aspects.

INTRODUCTION: The cytochrome P4502C enzymes account for the metabolism of approximately 20% of therapeutic drugs including certain oral antidiabetic drugs (OADs). AREAS COVERED: This review focuses on the effect of CYP2C enzymes on metabolism of sulphonylureas (SUs), meglitinides, and thiazolidinediones (TZDs) discussing their impact on pharmacokinetics, drug interactions and toxicological profiles. Pharmacogenetic aspects reflecting individual gene variants and variable drug effects are also considered. EXPERT OPINION: Genetic polymorphisms of CYP2C9 enzymes (*2/*2, *2/*3, *3/*3) influence the glycaemic response to SUs and impair their substrate metabolism. Restricted data from small-sized studies with heterogenous definitions of hypoglycaemia revealed no clear association between CYP2C9 genotypes and the risk of hypoglycaemia. Functional polymorphisms of CYP2C8- and CYP2C9 drug metabolizing genes affect markedly pharmacokinetics of meglitinides. Compared to wild-type carriers, patients treated with TZDs and carrying the common CYP2C8*3 and *4 variants showed a reduced glycaemic control. The strong CYP2C8 and OATP1B1 inhibitor gemfibrozil increases substantially the plasma concentrations of repaglinide and TZDs. Numerous metabolic drug interactions exist between SUs and commonly prescribed drugs, especially anti-infectives. The complex pharmacokinetic and pharmacogenetic properties and the unfavourable short and long term risk profile of glibenclamide and glimepiride raise the question whether their use can be justified any longer.

Pharmacokinetic drug interaction between gemfibrozil and sitagliptin in healthy Indian male volunteers.

PURPOSE: To study the impact of gemfibrozil co-administration on the pharmacokinetics of sitagliptin in healthy Indian male volunteers. METHODS: A randomized open label two-period crossover study involving 12 healthy Indian male volunteers was conducted at a single center. In each phase, the volunteers were administered sitagliptin as 100 mg tablets, either alone or co-administered with gemfibrozil as 600 mg tablets twice daily for 3 days. There was a 2-week washout period between phases. The venous blood samples were serially collected at 0-12 h post-dose, and plasma concentrations of the study drugs were estimated by a validated high-performance liquid chromatography-ultraviolet method. RESULTS: Relative to the administration of sitagliptin alone, co-administration with gemfibrozil increased the AUC0₋12 (2,167 ± 82.9 vs. 2,970 ± 76.4 ng h/ml; p < 0.0001), AUC(0-∞) (3,621 ± 222.5 vs. 5,574 ± 249.6 ng h/ml; p < 0.0002), C(max) (282.9 ± 7.7 vs. 344.1 ± 5.9 ng/ml; p < 0.0001), and t(½) (7.4 ± 0.6 vs. 10 ± 0.6 h; p = 0.0076) to statistically significant levels. The interindividual differences in the pharmacokinetic parameters of sitagliptin were found to be within acceptable limits (coefficient of variation <20%). No adverse drug events associated with sitagliptin occurred in the subjects during the study period. CONCLUSION: Although the bioavailability of sitagliptin was increased by 54% when co-administered with gemfibrozil, this interaction may not have any clinical significance as sitagliptin has a wide therapeutic index. Hence, in clinical practice, sitagliptin as 100 mg tablets and gemfibrozil as 600 mg tablets may be co-prescribed without much threat of sitagliptin toxicity. However, these results may not hold if the dose of sitagliptin is increased or if is co-prescribed with other antidiabetic drugs and/or cytochrome P450 2C8/human organic anion transporter-3 inhibitors. Further studies are needed to confirm these results in patients.