Summary

Bupropion and lansoprazole have a potential pharmacokinetic interaction where lansoprazole may inhibit the metabolism of bupropion, potentially leading to increased bupropion levels. This interaction is generally considered mild to moderate in clinical significance but requires monitoring for enhanced bupropion effects.

Introduction

Bupropion (brand names Wellbutrin, Zyban) is an atypical antidepressant and smoking cessation aid that works by inhibiting the reuptake of dopamine and norepinephrine. It belongs to the aminoketone class of antidepressants and is also used for seasonal affective disorder and as an adjunct for weight management. Lansoprazole (brand name Prilosec) is a proton pump inhibitor (PPI) commonly prescribed to reduce stomach acid production for conditions such as gastroesophageal reflux disease (GERD), peptic ulcers, and Zollinger-Ellison syndrome.

Mechanism of Interaction

The interaction between bupropion and lansoprazole occurs through hepatic enzyme inhibition. Lansoprazole can inhibit cytochrome P450 enzymes, particularly CYP2B6, which is the primary enzyme responsible for bupropion metabolism. When lansoprazole inhibits CYP2B6, it reduces the clearance of bupropion, potentially leading to increased plasma concentrations of bupropion and its active metabolites. This pharmacokinetic interaction may result in enhanced therapeutic effects or increased risk of bupropion-related adverse events.

Risks and Symptoms

The primary clinical risks of this interaction include an increased likelihood of bupropion-related side effects such as dry mouth, constipation, dizziness, headache, nausea, and insomnia. More concerning is the potential for increased risk of seizures, which is bupropion's most serious adverse effect, particularly in predisposed patients. The interaction may also lead to enhanced CNS stimulation, anxiety, or agitation. Patients with risk factors for seizures (history of head trauma, eating disorders, alcohol withdrawal, or concurrent medications that lower seizure threshold) may be at higher risk for complications.

Management and Precautions

Healthcare providers should monitor patients closely when bupropion and lansoprazole are used concurrently. Key management strategies include: starting with lower bupropion doses if lansoprazole is already established, monitoring for signs of bupropion toxicity (tremor, agitation, seizure activity), educating patients about potential side effects to report, considering alternative PPI options if clinically appropriate, and avoiding abrupt discontinuation of either medication. Regular follow-up appointments should assess therapeutic response and adverse effects. Patients should be counseled to avoid alcohol and report any unusual neurological symptoms immediately.

Bupropion interactions with food and lifestyle

Alcohol: Bupropion may lower the seizure threshold, and concurrent alcohol use can further increase seizure risk. Patients should avoid or limit alcohol consumption while taking bupropion. Sudden discontinuation of alcohol in patients with alcohol dependence may also increase seizure risk. Smoking cessation: While bupropion is used for smoking cessation, patients should be aware that nicotine withdrawal itself can affect seizure threshold. Close monitoring is recommended during the quit process. High-fat meals: Taking bupropion with high-fat meals may increase drug absorption and potentially increase side effects. Consider taking with light meals or on an empty stomach as tolerated.

Lansoprazole interactions with food and lifestyle

Lansoprazole should be taken on an empty stomach, preferably 30-60 minutes before meals, as food can significantly reduce its absorption and effectiveness. Alcohol consumption should be limited or avoided while taking lansoprazole, as alcohol can increase stomach acid production and counteract the medication's acid-reducing effects. Additionally, alcohol may worsen gastroesophageal reflux disease (GERD) symptoms that lansoprazole is intended to treat.