Phenytoin

Definition

Phenytoin is an antiepileptic medication primarily used to manage and prevent seizures, particularly in conditions such as epilepsy. It works by stabilizing neuronal membranes and inhibiting the spread of seizure activity in the brain, making it a critical drug for patients with seizure disorders.

5 Must Know Facts For Your Next Test

1. Phenytoin is typically administered orally or intravenously, with dosage adjusted based on patient response and therapeutic levels.
2. Common side effects of phenytoin include dizziness, drowsiness, and gingival hyperplasia, which is the overgrowth of gum tissue.
3. Phenytoin has a nonlinear pharmacokinetic profile, meaning small changes in dosage can lead to large changes in drug levels in the bloodstream.
4. Patients on phenytoin require regular monitoring for drug levels, especially since it interacts with many other medications that can affect its efficacy.
5. It is crucial to gradually adjust the dose when starting or stopping phenytoin to avoid potential seizure exacerbation or withdrawal symptoms.

Review Questions

• How does phenytoin function to help manage seizures in patients?
  • Phenytoin functions by stabilizing neuronal membranes and decreasing the excitability of neurons in the brain. It inhibits the repetitive firing of action potentials, which helps to prevent the spread of seizure activity. By effectively managing these electrical discharges, phenytoin plays a vital role in controlling seizures in individuals with epilepsy.
• Discuss the importance of monitoring phenytoin levels in patients undergoing treatment for seizure disorders.
  • Monitoring phenytoin levels is essential because it has a narrow therapeutic range and nonlinear pharmacokinetics. This means that small changes in dosage can significantly impact drug levels in the body, potentially leading to toxicity or ineffective treatment. Regular monitoring ensures that patients remain within the therapeutic range to maximize effectiveness while minimizing side effects.
• Evaluate the potential complications associated with long-term use of phenytoin for seizure management.
  • Long-term use of phenytoin can lead to several complications, including gingival hyperplasia, osteoporosis, and potential vitamin D deficiency due to impaired metabolism. Additionally, its interactions with other medications can complicate treatment regimens. Evaluating these complications is crucial as they can impact a patient's quality of life and overall health management, requiring comprehensive care approaches.

Related terms

Anticonvulsant: A class of medications used to prevent or treat seizures by reducing the excessive electrical activity in the brain.

Epilepsy: A neurological disorder characterized by recurrent seizures due to abnormal electrical activity in the brain.

Therapeutic Drug Monitoring:

The clinical practice of measuring specific drug levels in a patient's bloodstream to ensure optimal dosing and avoid toxicity.