Suicide attempt by an overdose of sitagliptin, an oral hypoglycemic agent: a case report and a review of the literature

Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Sitagliptin Phosphate Monohydrate

Sitagliptin is an antihyperglycemic drug used in adults for the treatment of diabetes Type 2. Literature data and in-house experiments were applied in this monograph to assess whether methods based on the Biopharmaceutics Classification System (BCS) could be used to assess the bioequivalence of solid immediate-release (IR) oral dosage forms containing sitagliptin phosphate monohydrate, as an alternative to a pharmacokinetic study in human volunteers. The solubility and permeability characteristics of sitagliptin were reviewed according to the BCS, along with dissolution, therapeutic index, therapeutic applications, pharmacokinetics, pharmacodynamic characteristics, reports of bioequivalence (BE) / bioavailability problems, data on interactions between the drug and excipients and other data germane to the subject. All data reviewed in this monograph unambiguously support classification of sitagliptin as a BCS Class 1 drug. In light of its broad therapeutic index and lack of severe adverse effects, the clinical risks associated with moderately supraoptimal doses were deemed inconsequential, as were the risks associated with moderately suboptimal doses. Taking all evidence into consideration, it was concluded that the BCS-based biowaiver can be implemented for solid IR oral drug products containing sitagliptin phosphate monohydrate, provided (a) the test product is formulated solely with excipients commonly present in solid IR oral drug products approved in ICH or associated countries and used in amounts commonly applied in this type of product, (b) data in support of the BCS-based biowaiver are obtained using the methods recommended by the WHO, FDA, EMA or ICH and (c) the test product and the comparator product (which is the innovator product in this case) meet all in vitro dissolution specifications provided in the WHO, FDA, EMA or ICH guidance.

Toxicology of Medications for Diabetes Mellitus

Medications used to treat diabetes mellitus are heterogeneous, with widely differing safety profiles in therapeutic use and in overdose. Insulin overdose may produce severe and prolonged hypoglycemia. Sulfonylurea poisoning should be treated with octreotide, sparing intravenous dextrose where possible. Acute metformin overdose may lead to life-threatening acidosis with elevated lactate concentrations, which may require hemodialysis. Glucagon-like peptide 1 agonists and dipeptidyl peptidase 4 inhibitors are benign in overdose in diabetic patients but may produce profound hypoglycemia in nondiabetic patients. Euglycemic diabetic ketoacidosis may develop in critically ill patients taking sodium-glucose co-transporter 2 inhibitors.

Dipeptidyl-peptidase IV (DPP-IV) inhibitor delays tolerance to anxiolytic effect of ethanol and withdrawal-induced anxiety in rats

Dipeptidyl-peptidase IV (DPP-IV) is an enzyme responsible for the metabolism of endogenous gut-derived hormone, glucagon-like peptide-1 (GLP-1). DPP-IV is known for its role in energy homeostasis and pharmacological blockade of this enzyme is a recently approved clinical strategy for the management of type II diabetes. Accumulating evidences suggest that enzyme DPP-IV can affect spectrum of central nervous system (CNS) functions. However, little is known about the role of this enzyme in ethanol-mediated neurobehavioral complications. The objective of the present study was to examine the impact of DPP-IV inhibitor, sitagliptin on the development of tolerance to anxiolytic effect of ethanol and anxiety associated with ethanol withdrawal in rats. A dose-response study revealed that sitaglitpin (20 mg/kg, p.o.) per se exhibit anxiolytic effect in the elevated plus maze (EPM) test in rats. Tolerance to anxiolytic effect of ethanol (2 g/kg, i.p.; 8 % w/v) was observed from 7(th) day of ethanol-diet (6 % v/v) consumption. In contrast, tolerance to anxiolytic effect of ethanol was delayed in rats that were treated daily with sitagliptin (20 mg/kg, p.o.) as tolerance was observed from 13(th)day since commencement of ethanol-diet consumption. Discontinuation of rats from ethanol-diet after 15-days of ethanol consumption resulted in withdrawal anxiety between 8 h and 12 h post-abstinence. However, rats on 15-day ethanol-diet with concomitant sitagliptin (20 mg/kg, p.o.) treatment exhibited delay in appearance (24 h post-withdrawal) of withdrawal anxiety. In summary, DPP-IV inhibitors may prove as an attractive research strategy against ethanol tolerance and dependence.

Tight glycemic control and cardiovascular effects in type 2 diabetic patients

Diabetes Mellitus (DM) with poor glycemic control is one of the leading causes for cardiovascular mortality in diabetic patients. Tight glycemic control with glycosylated haemoglobin of <7 gms% is recommended as a routine and < 6.5 gms% is recommended for young and newly diagnosed diabetics. Treatment goal aims at achieving near normal blood glucose level, and directed at management of other co morbid conditions such as obesity, hypertension and dyslipidemia. Oral hypoglycemic agents are the preferred drugs, alone or in combination. Preference for glitazones is declining due to the increasing evidences of associated adverse events. Gliptins appear as promising agents with lesser tendency to cause hypoglycemia, but their long term safety and efficacy is yet to be established. We emphasize the role of preventive measures in prediabetics and in established DM, treatment should be individualized and customized to minimize hypoglycemic effects and to retain quality of life.

Clinical effects of exposure to DPP-4 inhibitors as reported to the National Poison Data System

DPP-4 inhibitors (sitagliptin, saxagliptin, and linagliptin) are approved for the treatment of diabetes. They are considered safe due to their hyperglycemia dependent mechanism of action. We examined all isolated exposures to DPP-4 inhibitors reported to the National Poison Database System since 2006 to determine if significant toxicity occurs after exposure with attention to pediatric and intentional overdoses. NPDS data regarding DPP-4 ingestions in all age groups between January 2006 and March 2013 was collected. Cases were reviewed, and the following inclusion criteria applied: (1) reported ingestion of a DPP-4 inhibitor and (2) known clinical outcome. Exclusion criteria included the following: (1) exposure to more than a single substance, (2) no known outcome, and (3) clinical outcome judged to be unrelated to the exposure. One thousand four hundred seventy-six cases were reviewed while 826 were excluded. Of 650 included cases, 562 developed no clinical effects. Mild effects were noted in 77. There were no deaths. Moderate/major effect cases were investigated: two medication-naive nondiabetic individuals with accidental exposures developed clinically significant hypoglycemia requiring treatment. One diabetic patient on a DPP-4 inhibitor developed prolonged hypoglycemia requiring admission and continuous exogenous dextrose. Of 650 included exposures to DPP-4 inhibitors, 639 (98.3%) had either no or minor clinical effects. Three resulted in clinically significant hypoglycemia requiring intervention. None of the moderate or major clinical outcomes were the result of intentional overdoses for the purpose of self-injury. No exploratory ingestions resulted in moderate or major effects. Based on this data, exposure to DPP-4 inhibitors may rarely result in clinically significant hypoglycemia.

Diabetes mellitus and suicide

Relationship of diabetes mellitus (DM) with metal health disorders such as depression has been explored extensively in the published literatures. However, association of diabetes mellitus with suicidal tendencies has been evaluated less extensively. The present narrative review aimed to assess the literature relating to diabetes mellitus and suicide. As a part of the review, Pubmed and Google Scholar databases were searched for English language peer reviewed published studies with keywords relating to diabetes and suicide. Additional references were identified using cross-references. The available literature suggests that suicidal ideas and attempts are more frequent in patients with diabetes mellitus than healthy or medically ill controls. Although, a few studies report evidence to the contrary. Suicide accounts for a large proportion of deaths in patients with diabetes mellitus type I (T1DM), and their mortality rate is higher than that of age matched control population. Psychological morbidity, including depression, precedes suicidal ideas and attempts; though many other factors can be hypothesized to impact and modulate this association. A common method of suicide attempt in patients with diabetes includes uses of high doses of insulin and its congeners or medications to treat the disease. Regular screening and prompt treatment of depression and suicidality is suggested for patients with DM.

The pharmacokinetic considerations and adverse effects of DPP-4 inhibitors [corrected]

INTRODUCTION

Dipeptidyl-peptidase-4 (DPP-4) inhibitors are a class of anti-hyperglycemic agents with proven efficacy in patients with type 2 diabetes mellitus (T2DM).

AREAS COVERED

This review considers the pharmacokinetic profile, adverse effects and drug interactions of DPP-4 inhibitors. DPP-4 inhibitors have certain differences in their structure, metabolism, route of elimination and selectivity for DPP-4 over structurally related enzymes, such as DPP-8/DPP-9. They have a low potential for drug interactions, with the exception of saxagliptin that is largely metabolized by cytochrome CYP3A4/A5. Reports of pancreatitis and pancreatic cancer have raised concerns regarding the safety of DPP-4 inhibitors and are under investigation. Post-marketing surveillance has revealed less common adverse effects, especially a number of skin- and immune-related adverse effects. These issues are covered in the present review.

EXPERT OPINION

DPP-4 inhibitors are useful and efficient drugs. DPP-4 inhibitors have similar mechanism of action and similar efficacy. However, DPP-4 inhibitors have certain differences in their pharmacokinetic properties that may be associated with different clinical effects and adverse event profiles. Although clinical trials indicated a favorable safety profile, post-marketing reports revealed certain safety aspects that need further investigation. Certainly, more research is needed to clarify if the differences among DPP-4 inhibitors could lead to a different clinical and safety profile.

Attempted suicide with liraglutide overdose did not induce hypoglycemia

We document the first reported case of attempted suicide with the GLP-1 receptor agonist, liraglutide: a 33-year-old Japanese woman with type 2 diabetes reported subcutaneously injected 72 mg of liraglutide. She experienced gastrointestinal symptoms but no hypoglycemia.