From the Guidelines
It's generally safe to use Nuedexta (dextromethorphan and quinidine) with guaifenesin, but you should consult your healthcare provider before combining them. Nuedexta is a prescription medication used to treat pseudobulbar affect (PBA), while guaifenesin is an over-the-counter expectorant found in many cough medicines. These medications work through different mechanisms and don't have significant known interactions, as evidenced by the common combination of dextromethorphan and guaifenesin in many cough and cold products 1. However, Nuedexta contains quinidine, which can interact with many other medications, so it's essential to inform your doctor about all medications you're taking. Some key points to consider when using both medications include:
- Potential side effects from each - Nuedexta may cause dizziness, weakness, or gastrointestinal issues, while guaifenesin primarily causes mild gastrointestinal discomfort.
- Staying hydrated is important when taking guaifenesin as it helps thin mucus secretions, as described in the clinical practice guideline for adult sinusitis 1.
- Always follow prescribed dosages for Nuedexta and don't exceed recommended doses of guaifenesin. Given the lack of direct evidence on interactions between Nuedexta and guaifenesin, consulting a healthcare provider is crucial to ensure safe use and minimize potential risks.
From the Research
Interaction between Nuedexta and Guaifenesin
- There are no direct studies on the interaction between Nuedexta (dextromethorphan and quinidine) and guaifenesin.
- However, it is known that dextromethorphan is metabolized by the cytochrome P450 2D6 enzyme, and quinidine inhibits this enzyme, increasing dextromethorphan's bioavailability 2, 3.
- Guaifenesin is an expectorant that works by increasing the amount of water in the airways and reducing the viscosity of mucus, making it easier to cough up 4.
- Since guaifenesin does not affect the cytochrome P450 2D6 enzyme, it is unlikely to interact with Nuedexta in a way that would increase the risk of adverse effects.
- However, patients with pseudobulbar affect or other conditions being treated with Nuedexta may be taking multiple medications, and caution is warranted when initiating Nuedexta treatment, particularly in patients with underlying risk factors for torsade de pointes and in those receiving medications that may interact with Nuedexta 2.
Safety and Efficacy of Nuedexta
- Nuedexta has been shown to be effective in reducing the frequency and severity of pseudobulbar affect episodes in patients with amyotrophic lateral sclerosis, multiple sclerosis, and other neurological conditions 2, 3.
- The drug combination has also been studied for its efficacy in treating agitation in patients with Alzheimer's disease dementia, with significant reductions in agitation and aggression observed in clinical trials 4, 5.
- Nuedexta is generally well tolerated, but common adverse effects include dizziness, headache, and diarrhea 3, 4.
- Serious adverse effects, such as falls and urinary tract infections, have also been reported, particularly in older adults 4.