Is it safe to switch from 200 mg of bupropion (Wellbutrin) sustained-release (SR) to 450 mg of bupropion (Wellbutrin) immediate-release (IR) in one day?

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Last updated: May 17, 2025View editorial policy

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From the Guidelines

No, it is not safe to increase from 200 mg sustained-release (SR) bupropion to 450 mg immediate-release (IR) bupropion in one day. This recommendation is based on the guidelines for managing depression and the use of bupropion, as outlined in a study published in the American Family Physician 1. The study suggests that bupropion should be started at a dose of 37.5 mg every morning, then increased by 37.5 mg every 3 days, with a maximum dose of 150 mg twice daily.

Key Considerations

  • The proposed dose increase is significant and could lead to dangerous side effects, including seizures, which is a known risk associated with bupropion use.
  • The change from sustained-release to immediate-release formulation could also cause more intense side effects, such as anxiety, insomnia, headache, dry mouth, and increased blood pressure.
  • The maximum recommended daily dose of bupropion IR is 450 mg, taken in divided doses (typically 150 mg three times daily), not as a single dose.

Recommendations for Safe Dose Adjustment

  • Bupropion dose changes should be gradual, typically increasing by no more than 100 mg increments with at least 3-4 days between adjustments.
  • Any changes to the bupropion regimen should only be made under direct supervision of a healthcare provider who can create a safe transition plan based on the patient's specific medical history and needs.
  • It is essential to monitor the patient for potential side effects and adjust the dose accordingly to minimize the risk of adverse reactions.

From the FDA Drug Label

To minimize the risk of seizure, increase the dose gradually [see Warnings and Precautions (5.3)]. When switching patients from WELLBUTRIN tablets (bupropion hydrochloride tablets) to bupropion hydrochloride extended-release tablets (XL) or from WELLBUTRIN SR sustained-release tablets (bupropion hydrochloride sustained-release tablets (SR)) to bupropion hydrochloride extended-release tablets (XL), give the same total daily dose when possible.

It is not safe to switch from 200 mg SR-12 welbutrin to 450 mg IR in one day. The FDA label recommends increasing the dose gradually to minimize the risk of seizure and suggests giving the same total daily dose when possible when switching between formulations. A sudden increase from 200 mg to 450 mg is not a gradual increase and may increase the risk of seizure. 2

From the Research

Bupropion Dosage and Seizure Risk

  • The studies suggest that bupropion can lower the seizure threshold, and the incidence of seizure at 300 mg per day is 1/1000 patients treated 3.
  • Seizures can occur even at therapeutic doses of bupropion, with 6.1% of new-onset seizures being drug-related, and bupropion being the third leading cause of drug-related seizures 4.
  • The risk of seizures is dose-dependent, and increasing the dose of bupropion can increase the risk of seizures 5, 6.

Switching from SR-12 Welbutrin to IR

  • There is no direct evidence in the provided studies to support the safety of switching from 200 mg SR-12 welbutrin to 450 mg IR in one day.
  • However, the studies suggest that bupropion can cause seizures even at therapeutic doses, and the risk of seizures increases with higher doses 3, 4, 5, 6.
  • It is essential to consider the potential risks and benefits of switching to a higher dose of bupropion and to monitor patients closely for signs of seizures or other adverse effects.

Potential Risks and Considerations

  • The studies highlight the importance of being aware of the seizure risk associated with bupropion, even in patients without a personal or family history of seizure disorders 7, 3.
  • Sleep deprivation, previous history of attention deficit disorder, and previous heavy alcohol use may increase the risk of seizures in patients taking bupropion 4.
  • Bupropion overdose can cause seizures, coma, and EEG burst-suppression, and requires acute intensive care treatment 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[Bupropion-induced epileptic seizures].

Revue neurologique, 2004

Research

Epileptic seizures, coma and EEG burst-suppression from suicidal bupropion intoxication.

Epileptic disorders : international epilepsy journal with videotape, 2017

Research

Single-Agent Bupropion Exposures: Clinical Characteristics and an Atypical Cause of Serotonin Toxicity.

Journal of medical toxicology : official journal of the American College of Medical Toxicology, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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