Diabetes and Drug Treatments

Diabetes mellitus (DM) is a disorder in the body’s metabolism characterized by altered glucose conversion into energy for cell use, defects in insulin secretion, or increased insulin resistance (Antonioli, Blandizzi, Csoka, Pacher, & Hasko, 2015). DM can occur in children and adults and is diagnosed by measuring glycosylated hemoglobin (HbA1C) levels, fasting plasma blood sugar (FPG) levels, 2-hour plasma blood sugar levels during oral glucose tolerance testing, or random blood sugar level; however HbA1C provides a more accurate and long-term measure of blood sugar control (Huether & McCance, 2017).

Types of Diabetes

Type 1 diabetes mellitus (T1DM), presents during childhood approximately before age 10, with a classic clinical onset of high blood sugar, excessive thirst, excessive urination, and weight loss resulting from an autoimmune dysfunction activating the CD4, CD8 T cell, and macrophages infiltrating the pancreas leading to chronic inflammation, pancreatic B-cell dysfunction, destruction, and death (Antonioli et al., 2015). Genetic susceptibility increases the risk of close relatives to a T1DM patient as a result of gene polymorphisms, whereas environmental exposure can trigger an immune response to genetically susceptible individuals destroying the insulin-producing B-cells in the pancreas (Levitsky & Misra, 2019).

Type 2 diabetes mellitus (T2DM) develops in genetically predisposed individuals as a result of advancing age, inactivity, and obesity resulting in high levels of blood sugar due to the body’s inability to produce insulin, use enough insulin, or use glucose for energy with signs and symptoms of fatigue, weight gain, slow healing wounds, frequent infections, visual changes, and altered sensation (Blair, 2016). Chronic-low grade inflammation, immune system activation, and infiltration in the pancreas results in B-cell dysfunction and progressively increased insulin resistance (Antonioli et al., 2015).

Gestational diabetes mellitus is high blood sugar levels with the onset or first detected during pregnancy; however according to the American Diabetes Association (ADA) (as cited by

Heather & McCance, 2017), women with gestational diabetes may have had undiagnosed pre-existing diabetes, so the ADA recommends that these women should receive a  T1DM or T2DM diagnosis instead of gestational diabetes.

Metformin Administration in Type 2 Diabetes

Biguanides such as Metformin is the first line of therapy for T2DM unless contraindicated because it inhibits the liver’s glucose production and increases muscle tissue insulin sensitivity (Blair, 2016).  Metformin comes in two oral preparations: a)  initial adult dose for the immediate-release tablet is 500 mg orally once or twice daily or 850 mg daily; should be administered with a meal to decrease gastrointestinal (GI)  upset; and gradual dosage increases usually every seven days to minimize adverse GI effects; and b) initial adult dose for the extended-release Metformin is 500 mg to 1 gram once daily with the evening meal and gradual dose titration to minimize adverse GI effects (UpToDate, n.d.). Contraindications to Metformin use are hypersensitivity to Metformin or any of its components, patients with eGFR < 30 mL/minute as it can result in lactic acidosis, acute, or chronic metabolic acidosis, and death  (UpToDate, n.d.).

Short-Term and Long-Term Impact of Type 2 Diabetes and Effects of Drug Treatment

            Short-term impact of T2DM are : a) hypoglycemia in individuals taking secretagogues such as sulfonylurea agents or exogenous insulin that requires immediate glucose replacement by mouth or intravenously; b) hyperosmolar hyperglycemic nonketotic syndrome (HHNKS), is less common but can result in high mortality rate particularly in the elderly who have comorbidities such as infections, cardiovascular, or renal disease which is characterized by very high blood sugar level resulting in severe dehydration, electrolyte imbalance, and neurologic impairment (Huether & McCance, 2017).

The long-term impact of T2DM are categorized into: a) microvascular complications which are damages to small blood vessels leading to renal failure, retinopathy leading to blindness, and neuropathy leading to impotence and foot disorders; and b) macrovascular complications are damage to larger blood vessels leading to cardiovascular diseases (Blair, 2016).

Monitoring recommendation for Metformin use are : a) Vitamin B12 levels  every two to three years especially in individuals with peripheral neuropathy or anemia because long-term Metformin use can result in Vitamin B12 deficiency; b) initial and yearly hematologic and renal function studies; and c) Bi-annual urine glucose, fasting blood sugar, and hemoglobin A1C in patients with stable glucose control and every four months for individuals not meeting glycemic control (UpToDate, n.d.).