Does Dextromethorphan interact with Fluvoxamine? (+1 effect)

In this article, we will answer the question “Does Dextromethorphan interact with Fluvoxamine?”. We will also discuss the mechanism behind this interaction and some side effects associated with this combination.

Does Dextromethorphan interact with Fluvoxamine?

Yes, Dextromethorphan and Fluvoxamine interact with each other. They both are responsible for increasing the activity of serotonin in the brain.

Fluvoxamine is a selective serotonin reuptake inhibitor (SSRI) and its primary mechanism is to inhibit the reuptake of serotonin from the brain. On the other hand, Dextromethorphan also has a secondary mechanism of affecting serotonin levels to some extent. Both these medications, if combined, can increase the risk of serotonin syndrome in the individual taking the combination.

Fluvoxamine is approved by the FDA, for the treatment of individuals suffering from obsessive-compulsive disorder (OCD). This medication has also been used ‘off-label’  for the treatment of other depressive illnesses (1).

Dextromethorphan belongs to a class of medications called antitussives. It is used to provide relief from cough to patients. Dextromethorphan can only relieve cough and does not treat the underlying condition that causes it.

How does Dextromethorphan interact with Fluvoxamine?

Dextromethorphan is known to affect serotonin levels. It is a moderate inhibitor of serotonin reuptake as well as a promoter of serotonin release. Fluvoxamine has the same phenomenon of serotonin reuptake inhibition. Moreover, Dextromethorphan needs the enzyme CYP2D6 for metabolism and elimination. Fluvoxamine is a significant inhibitor of this enzyme and can cause increased levels of Dextromethorphan in the blood (2).

The increased amount of Dextromethorphan along with Fluvoxamine can cause dangerously increased levels of serotonin resulting in serotonin syndrome (SS). The SS can present with many symptoms, some of which are as follows:

• Agitation
• Nausea
• Loss of coordination
• Restlessness
• Insomnia
• Hallucinations
• Increased sweating
• Rapid heart rate
• Tremors

If you show any symptoms of SS you should immediately inform your healthcare provider. SS if left untreated can result in a coma or even death of the individual taking the combination.

What does research suggest?

Research suggests that the interaction of Dextromethorphan with Fluvoxamine and other SSRIs can be fatal if not treated at the right time. Data regarding this combination is limited but various studies and cases of SSRIs interacting with Dextromethorphan have been published supporting this information.

A case study of a patient being treated by an SSRI (Sertraline) reported that the use of an OTC product for his cough resulted in the occurrence of SS which had to be managed in the hospital for 2 days. The study also reported that due to this interaction, the SSRI was discontinued and replaced with a tricyclic antidepressant (TCA), Mirtazapine (2).

A clinical study reported that OTC medications containing Dextromethorphan have a risk of interacting with psychotropic medications including Fluvoxamine and causing potentially life-threatening side effects (3).

Another research, assessing the antidepressant side effect profile has reported the effect of SSRIs on medications metabolized by the CYP2D6 enzyme pathway, including Dextromethorphan. The SSRIs along with Dextromethorphan can cause SS, leading to many problems for the individual taking these medications (4).

Common additive side effects of Dextromethorphan and Fluvoxamine

The combination of Dextromethorphan and Fluvoxamine can result in additive side effects. Both patients and their healthcare providers need to understand the potential side effects so the combination of both medications can be used safely and effectively. Some of these are as follows:

• Dizziness
• Nausea
• Vomiting
• Diarrhoea
• Restlessness
• Nervousness
• Agitation
• Irritability

Both medications can cause these side effects individually and if used together these side effects can intensify. It is advisable to discuss the combination of Dextromethorphan and Fluvoxamine with your healthcare provider before taking these medications so your healthcare provider can give you proper guidance.

How to manage the additive side effects of Dextromethorphan and Fluvoxamine?

It is important to manage the additive side effects with the concurrent use of  Dextromethorphan and Fluvoxamine. Some tips to manage any potential side effects that may occur if your doctor has prescribed this combination are as follows:

Consult your doctor – You should contact your healthcare provider even if you have a cough. If you have taken an OTC medication, and experience any symptoms like agitation or restlessness you should immediately contact your doctor and ask for necessary adjustments.

Take medications in given doses – Your healthcare provider can provide you with alternative options to relieve your cough or if Dextromethorphan is essential, they may decrease the dosage of Fluvoxamine, to better suit your condition. Make sure to take your medications in the given doses and do not alter your medications without the permission of your doctor.

Monitor your condition – You should keep a close check on your symptoms and be vigilant about potential side effects. You should report immediately to your healthcare provider if you experience anything out of the ordinary.

Avoid alcohol – Alcohol can increase the nervous system side effects of both Dextromethorphan and Fluvoxamine. It is necessary to limit the use of alcohol when being treated with both these medications.

What alternatives exist to manage cough while on Fluvoxamine?

There are alternative medications as well as home remedies which can be used instead of Dextromethorphan when using Fluvoxamine.

Medications

OTC medications without Dextromethorphan are also available for use in cough. You can opt for an antitussive containing guaifenesin or even herbal ingredients like ivy leaf or thyme, to help relieve your cough.

Ginger and honey

Ginger and honey are two of the oldest home remedies that have been used to relieve cough. They can be used as infused in teas or as separate remedies. Ginger helps in increasing immunity and honey aids in soothing your irritated throat. 

Warm soups and broths

Warm drinks, soups and broths are soothing for an irritated or dry throat. You can use these remedies to provide you immediate relief from a scratchy or irritated throat.

Mint and turmeric tea

Both mint and turmeric have many benefits for your throat. Mint is good for clearing congestion and turmeric has antiseptic properties. Adding both or any one of these can help alleviate your symptoms.

Air purifiers and humidifiers

Having air purifiers or humidifiers in your room can do wonders. Air purifiers are helpful in purifying air and filtering out irritants, while humidifiers keep the room adequately humid so that your throat does not get dry.

In this article, we discussed the interaction between Dextromethorphan and Fluvoxamine. We also discussed the mechanism behind this interaction and how to manage side effects if your doctor has prescribed you this combination. We also discussed alternatives and different home remedies that can help you relieve your symptoms.

To the best of my knowledge and research, Dextromethorphan interacts with Fluvoxamine to cause a potentially life-threatening side effect, the serotonin syndrome (SS). It is essential to consult your doctor before taking this combination and also to keep a check on any potential side effects that may occur.

References