Introduction
The American Diabetes Association has classified diabetes into types 1 and 2. Type 1 is due to the destruction of beta cells leading to a deficiency of insulin production. Type 2 is due to defective insulin secretion from the beta cells. Furthermore, the medications used to treat diabetes are further classified as hypoglycemic and antihyperglycemic agents. Therefore, the overdose of these agents commonly results in hypoglycemia and other adverse effects.
How Are Antidiabetic Agents Classified?
How Does Drug Overdose Occur?
Overdose of a drug can be intentional or unintentional. The common reason for an intentional overdose may be an attempt to suicide or getting high. Unintentional overdose of a drug is more commonly noted in children. In addition, the mistakes such as over-dispensing, errors in prescribing, and medical interactions can also lead to overdose.
What Is the Common Presentation of Antidiabetic Drug Toxicity?
The most common presentation of antidiabetic drug toxicity is hypoglycemia. Hypoglycemia is when blood sugar levels drop below 60 mg/dL (milligrams per deciliter). In the case of mild hypoglycemia, the individual might have symptoms of dizziness, confusion, lightheadedness, and fatigue. It can lead to hypotension, epilepsy, and permanent neurological sequelae in severe cases. As it becomes worse, it can affect the central nervous system, and patients become comatose.
What Effects Does Sulfonylurea Toxicity Have?
The toxicity of sulfonylurea causes a direct increase in insulin secretion, causing lowered blood sugar levels, eventually leading to hypoglycemia. The signs of hypoglycemia include:
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Nausea.
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Tremor.
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Sweating.
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Difficulty speaking.
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Dizziness.
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Seizures.
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Lethargy.
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Hypothermia.
How to Manage Sulfonylurea Toxicity?
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Admit the individual to the hospital within 18 to 24 hours to prevent the hypoglycemic attack.
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Check glucose levels every hour.
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Provide a bolus of intravenous Dextrose to correct the hypoglycemic state.
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Activated charcoal can be administered within two hours of ingestion.
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If the patient is symptomatic, administration of Octreotide will help.
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Later, after stabilizing the blood glucose levels and discontinuing Octreotide, the individual is monitored for 24 hours and then discharged.
What Effects Does Metformin Toxicity Have?
To surprise, Metformin toxicity does not lead to a hypoglycemic state. Instead, it causes lactic acidosis. However, if Metformin accumulates in the blood, it can lead to severe lactic acidosis. In addition, the overdose of Metformin commonly causes gastrointestinal symptoms. The individual may present with nausea, vomiting, diarrhea, anorexia, and bloating. The major effects of Metformin toxicity are hypotension, seizures, and cardiac arrest.
How to Manage Metformin Toxicity?
If the lactic acid level is slightly increased, it returns to normal spontaneously. And Metformin toxicity can be treated through supportive care, and there is no antidote for it. The best method to remove lactic acid and Metformin is intermittent hemodialysis with a bicarbonate buffer. But if the patient cannot tolerate hemodialysis, continuous renal replacement therapy is indicated.
Other supportive care required is the treatment of hypotension with intravenous fluids and vasopressors. Though hypoglycemia is uncommon in Metformin toxicity, it can occur occasionally. In such a case, intravenous Dextrose is administered.
What Effects Does Thiazolidinediones Toxicity Have?
The commonly experienced adverse symptoms of excess thiazolidinediones intake are headache, weight gain, diarrhea, upper respiratory tract infection, back pain, sinusitis, myalgia, and pharyngitis. The long-term use of thiazolidinediones was found to cause liver failure, pulmonary edema, and anemia. In the case of hepatotoxicity, the symptoms were present after four months of ingestion. The signs of hepatotoxicity are nausea, vomiting, stomach pain, fatigue, jaundice, and loss of appetite. The progression of symptoms was noted in individuals who discontinued the medication. But in most cases, the condition resolves on discontinuation of the medicine. The Food and Drug Administration (FDA) recommends a liver function test every two months for individuals under thiazolidinediones. If the alanine transferase levels are elevated, it is recommended to stop the drug.
How to Manage Thiazolidinediones Toxicity?
There are no proper management guidelines for thiazolidinediones toxicity. And the presentation of a hypoglycemic state is uncommon in thiazolidinediones toxicity. But once ingested in higher doses, the individual is admitted and observed for 24 hours and administered intravenous Dextrose if blood sugar levels fall. Activated charcoal can also be administered in case of excess intake intentionally. In addition, a liver function test is recommended.
What Effects Does Meglitinide Toxicity Have?
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The toxicity of meglitinide can also lead to a hypoglycemic state similar to sulfonylurea.
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It can induce epilepsy, coma, and other neurological problems requiring medical attention.
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Individuals with hypoglycemia without loss of consciousness can present with drowsiness, profuse sweating, abdominal pain, and tachycardia.
How to Manage Meglitinide Toxicity?
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Activated charcoal can be administered in individuals who intentionally overdose on Meglitinide.
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Asymptomatic individuals can be observed for 24 hours.
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In severe cases, subcutaneous glucagon or intramuscular glucagon can be administered. If the individual fails to respond, 20 % glucose is administered intravenously.
What Effects Does Alpha-Glucosidase Inhibitor Toxicity Have?
The adverse effects of alpha-glucosidase inhibitor intake are primarily gastrointestinal symptoms like nausea, vomiting, diarrhea, flatulence, and abdominal pain. Acarbose can sometimes lead to hepatitis, so a liver function test is recommended. The symptoms are common in individuals taking a carbohydrate-rich diet as alpha-glucosidase inhibitor affects the metabolism of carbohydrates. The symptoms of hypoglycemia are uncommon in the case of alpha-glucosidase inhibitor toxicity.
How to Manage Alpha-Glucosidase Toxicity?
Since the individuals present with gastrointestinal symptoms due to alpha-glucosidase inhibitor overdose, electrolyte abnormalities, and dehydration may be noticed and should be treated accordingly. Oral glucose tablets can be administered in rare cases of hypoglycemia due to alpha-glucosidase inhibitor intake.
Conclusion
Not all overdose of oral antidiabetic agents leads to hypoglycemia. However, understanding the mechanism of action of drugs is essential in managing and monitoring the treatment plans for overdose patients. Therefore, the overdose of these drugs leading to hypoglycemia should be recognized earlier and treated.
