From the Guidelines
Bupropion is the antidepressant that doesn't cause hyponatremia, as it works through different mechanisms without significant serotonergic effects, making it a preferred option for patients at higher risk for hyponatremia. The evidence from the study 1 suggests that most second-generation antidepressants have similar adverse effects, but there is weak evidence indicating that certain antidepressants may be associated with specific risks, such as seizures or cardiovascular events. However, hyponatremia is not specifically mentioned as a common adverse event for most antidepressants, and bupropion is not associated with an increased risk for hyponatremia. Some key points to consider when prescribing bupropion include:
- Typical dosing ranges from 150-450 mg daily, often starting at 150 mg once daily and potentially increasing after several days
- Increased seizure risk, particularly at higher doses
- Common side effects include insomnia, headache, dry mouth, and agitation
- Contraindicated in patients with seizure disorders, eating disorders, or those undergoing abrupt discontinuation of alcohol or sedatives. It's essential to weigh the benefits and risks of bupropion and monitor patients closely, especially those with a history of seizures or other contraindications, as noted in the study 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Antidepressants and Hyponatremia
- There are no direct references to hyponatremia in the provided studies, making it challenging to determine which antidepressant does not cause hyponatremia based on the given evidence.
Bupropion's Mechanism of Action
- Bupropion is a dopamine-norepinephrine reuptake inhibitor with no appreciable activity on serotonin concentrations in the central nervous system 2.
- It has a unique pharmacology, inhibiting the reuptake of noradrenaline and dopamine, potentially providing pharmacological augmentation to more common antidepressants such as selective serotonergic reuptake inhibitors (SSRIs) 3.
- Bupropion acts via dual inhibition of norepinephrine and dopamine reuptake and is devoid of clinically significant serotonergic effects or direct effects on postsynaptic receptors 4.
Side Effects of Bupropion
- Bupropion is generally well tolerated, with very low rates of sexual dysfunction, and is more likely to cause weight loss than gain 3.
- Common side effects include agitation, dry mouth, insomnia, headaches, migraines, nausea, vomiting, constipation, and tremor 2.
- Bupropion has been reported to reverse adverse effects such as restless legs syndrome (RLS) induced by other medications 5.
Comparison to Other Antidepressants
- Bupropion has demonstrated efficacy comparable to that of other antidepressants, including SSRIs and serotonin-norepinephrine reuptake inhibitors (SNRIs) 6, 3.
- It has a unique clinical profile due to its dual norepinephrine and dopamine reuptake inhibition, which is associated with fewer common antidepressant-associated side effects 4.