Can you use mirtazapine and Benadryl together? (5+ psychological side effects) 

In this blog post, we are going to answer the question, “Can you use mirtazapine and benadryl together?”. Mirtazapine is an antidepressant which is used to treat a number of mental health related problems. 

However, this antidepressant can interact with other medications. This blog will cover the safety and efficacy of the concomitant use of mirtazapine and benadryl. 

Can you use mirtazapine and Benadryl together?

No, it is not suitable to use mirtazapine and benadryl together. This is not an ideal combination and should only be used if absolutely necessary. Experts believe that there are other safer anti-allergy meds that can be taken with an antidepressant. 

The concomitant use can severely increase the risk of the following psychological side effects:

• Drowsiness
• Dizziness
• Low mental alertness
• Impaired motor functions
• Confusion
• Forgetfulness

It is not recommended to start using any medication without your doctor’s approval. Drug interactions should be an important consideration before taking two or more medicines together. Yes, drugs in combination are often used to achieve better therapeutic response but this is not the case with every interaction. 

Some drugs are highly incompatible with one another. They often cancel out each other’s effects or antagonise them. Some drugs are so incompatible that they end up changing the entire chemical composition of one another. 

Some interfere with metabolism or bioavailability (the rate and extent at which the active drug moiety enters systemic circulation/blood). This can lead to drug accumulation in different parts of the body. 

It is always advised to inform your healthcare provider of any medicine you take before getting a new prescription. Your doctor will make sure not to prescribe any such drug which might interfere with those you are already taking. 

Why are mirtazapine and benadryl incompatible with one another? 

Both mirtazapine and benadryl can act incompatibly because of their different mechanisms of action. 

Mirtazapine (Brand name: Remeron) is an antidepressant. It does not belong to any typical class of antidepressants and its mechanism of action is different from SSRIs and SNRIs. It does not block the reuptake of serotonin by any pathway. 

Mirtazapine belongs to the tetracyclic antidepressants. It has a dual mode of action. Mirtazapine is believed to be responsible for the activation of 5-HT1 receptors, which are one of the serotonin receptors. This antidepressant also acts on the noradrenergic system. 

Experts believe that mirtazapine enhances the stimulatory action of the noradrenergic system which increases the secretion of serotonin. It also prevents the inhibitory action of the noradrenergic system which hinders the release of serotonin. 

Benadryl, brand name for diphenhydramine, is basically an anti-allergic medication. It is used to help relieve the symptoms of an allergic reaction generated by your body in response to different stimuli including virus, bacteria, dust and pollen. 

It works by inhibiting histamine, which is an allergy mediator released from mast cells in response to an allergen. It also blocks acetylcholine which is responsible for increasing lacrimation (excess tear formation in response to an allergy), salivation and runny dose. 

Benadryl blocks histamine H1 receptors which is the biggest reason why this medicine causes sedation, drowsiness, dizziness or lightheadedness. Make sure you do not use this medication during the day time as it may hinder your daytime activities. 

What are the side effects associated with the use of mirtazapine and benadryl? 

Both mirtazapine and benadryl are associated with some side effects that can range from mild to severe depending on the tolerability of the person taking it. 

Experts suggest that side effects have a close relationship with the way your body responds when it gets exposed to one or the combination of meds. Preexisting health conditions can also play a huge role in determining the kind of side effects the meds will cause in you. 

Make sure you inform your healthcare provider if you exhibit any sign of an allergic reaction or any other unusual side effect. The most common side effects of mirtazapine include:

• Sleepiness or drowsiness 
• Excessive tiredness or fatigue 
• Dizziness or lightheadedness 
• Xerostomia or dry mouth 
• Anxiety 
• Agitation 
• Confusion 
• Gain of appetite
• Weight gain 
• Gastrointestinal side effects including nausea, vomiting and diarrhoea/Constipation 

Mirtazapine is also associated with some serious side effects, which may include:

• Allergic reaction associated with symptoms like redness of skin, itching, burning sensation, blisters, blue-purple patches, tightness of chest, wheezing, difficulty in breathing, hoarseness etc. 
• Convulsions 
• QT prolongation 
• Pain and tightness in chest
• Arrhythmia 
• Flu like symptoms 

Benadryl (Diphenhydramine) is also associated with some side effects. These include:

• Xerostomia or dry mouth 
• Dryness of nose and throat 
• Nausea 
• Vomiting 
• Drowsiness 
• Dizziness or lightheadedness 
• Fatigue or excessive tiredness 
• Loss of appetite 
• Chest congestion 
• Constipation 
• Nervousness 
• Forgetfulness 

Serious side effects include:

• Allergic reaction associated with symptoms like redness of skin, itching, burning sensation, blisters, blue-purple patches, tightness of chest, wheezing, difficulty in breathing, hoarseness etc. 
• Painful urination 
• Blurred vision with or without pain and irritation in eyes. 

Now, as you can see both of these meds are associated with some common side effects like dizziness, drowsiness, tiredness etc. This indicates that when these meds are used together, both of them can cause sedation and may compromise your mental alertness. 

At higher doses, this combination can lead to dangerous consequences and is capable of causing life threatening outcomes. Make sure you don’t use benadryl with your antidepressant without your doctor’s approval. 

This is because your doctor will weigh out the pros and cons of this combination first and then will determine if it’s okay for you to take these two together. If yes, then the dose will be adjusted in order to minimise these side effects. 

Never deviate from the prescribed dose and don’t share your medications with other people. The combination may work for you, but it definitely doesn’t mean it’s a good choice for everyone. 

How to ensure the proper use of mirtazapine and Benadryl? 

Immediately talk to your healthcare provider if you experience unusual side effects while taking mirtazapine and benadryl together. 

Do not recommend this combination to someone else and use it as long as your doctor has advised. 

Inform your doctor if you’re pregnant, trying to conceive. Benadryl should be used by pregnant women only if advised by the healthcare provider. Mirtazapine can also be dangerous for the fetus, especially when used in the third trimester. 

Inform your doctor if you’re a breastfeeding mother. Both of these drugs are capable of passing into the breastmilk and may cause side effects in newborns. 

Mirtazapine may induce suicidal behavior in users younger than 24 years of age. If you have someone who shows suicidal behavior or you see hopelessness in them, make sure you keep an eye on them and get medical attention as soon as you can. 

Do not stop mirtazapine and benadryl abruptly. If it’s time for you to stop one or both of these meds, your doctor will simply recommend a taper schedule for you, which should be followed vigilantly if you wish to keep withdrawal symptoms at bay. 

Report any problems with bleeding or bruising to your doctor. If you see any unexplained blisters or rashes on your body, or experience any problems with urination, or if you feel changes in your vision, immediately report to your healthcare provider.

Make sure you avoid certain activities when the concomitant use of these two meds make you feel sleepy or tired during the day time. These activities include:

• Do not drive when you’re feeling tired or drowsy. Driving requires your full physical and mental alertness and it’s in your best interest to avoid it when you’re tired and have low energy levels. If there’s somewhere you need to be, just ask a friend to drop you or book a ride. 

• If you’re an employee in some factory where you are supposed to operate heavy machinery, don’t! Your drowsiness might cause an accident and can make you or others around you severely injured. 

• Make sure you’re not taking any other medication that might be contributing to your drowsiness. Do not drink alcohol, or you’ll end up dulling your senses even more. Alcohol itself is responsible for causing fatigue and drowsiness.

Conclusion 

In this blog post, we have discussed the concomitant use of mirtazapine and benadryl. It is not recommended to use these two together. The concomitant use can severely increase the risk of drowsiness, dizziness, low mental alertness, impaired motor functions, confusion, forgetfulness etc. 

It is not recommended to start using any medication without your doctor’s approval. Both mirtazapine and benadryl are associated with some side effects that can range from mild to severe depending on the tolerability of the person taking it. 

Experts suggest that side effects have a close relationship with the way your body responds when it gets exposed to one or the combination of meds. Make sure you inform your healthcare provider if you exhibit any sign of an allergic reaction or any other unusual side effect.

FAQs: mirtazapine and benadryl 

Can you take Benadryl with antidepressants?

No, it is not suitable to use antidepressants and benadryl together. This is not an ideal combination and should only be used if absolutely necessary. Experts believe that there are other safer anti-allergy meds that can be taken with an antidepressant. The concomitant use can severely increase the risk of drowsiness, dizziness, low mental alertness, impaired motor functions, confusion, forgetfulness etc. 

What medications should not be taken with mirtazapine?

• Monoaminoxidase inhibitors (MAOIs). The combination use can increase the risk of serotonin syndrome. 
• Non-steroidal anti-inflammatory drugs (NSAIDS). The combination use can increase the risk of bleeding. 
• Pimozide. The concomitant use can increase the plasma concentration(availability of a drug in the blood) of pimozide to much higher levels. It can result in life-threatening arrhythmia.
• Controlled substances, including all narcotic analgesics. The concomitant use can cause severe psychological side effects. 
• Mood stabilisers 
• Alcohol 

Is there antihistamine in mirtazapine?

Mirtazapine is an antidepressant in nature and has a dual mode of action. Mirtazapine is believed to be responsible for the activation of 5-HT1 receptors, which are one of the serotonin receptors. This antidepressant also acts on the noradrenergic system. However, it does possess some antihistaminic properties because of its ability to inhibit H1 receptors. 

Do antidepressants interact with antihistamines?

Yes, antidepressants can interact with Antihistamines and it is recommended to not use these meds together. The concomitant use can severely increase the risk of drowsiness, dizziness, low mental alertness, impaired motor functions, confusion, forgetfulness etc. It is not recommended to start using any medication without your doctor’s approval. 

What should you not take with Benadryl?

• Antifungals and antivirals. They may inhibit the metabolism of clonazepam and cause toxicity. 
• Antiepileptics. The concomitant use may decrease the beneficial effects of clonazepam. 
• Anti-allergy medications. The concomitant use increases the risk of sedation 
• Narcotic analgesics or any other controlled substance. The concomitant use can cause serious CNS side effects. 
• Sleeping pills
• Anxiolytics and antidepressants. 

References 

• Drug Interactions between Benadryl and mirtazapine https://www.drugs.com/drug-interactions/benadryl-with-mirtazapine-896-1617-1640-0.html#:~:text=Interactions%20between%20your%20drugs&text=Using%20diphenhydrAMINE%20together%20with%20mirtazapine,%2C%20judgment%2C%20and%20motor%20coordination.
• National Library of Medicine – Mirtazapine https://medlineplus.gov/druginfo/meds/a697009.html 
• Mirtazapine Tablet – Uses, Side Effects, and More https://www.webmd.com/drugs/2/drug-13706-4047/mirtazapine-oral/mirtazapine-oral/details
• Diphenhydramine https://www.webmd.com/drugs/2/drug-5680/benadryl-oral/details 
• Sicari V, Zabbo CP. (2021) – Diphenhydramine https://www.ncbi.nlm.nih.gov/books/NBK526010/#_NBK526010_pubdet_