How long after Zyrtec can you take Benadryl?
By
Dr Drielli Vital-Fujii (PhD)
Author bio
Dr Drielli Vital-Fujii, PhD, is a Pharmacist with expertise in Drug Design and Development, Enzymes, Molecular Modelling, and Photodynamic Therapy. She writes and reviews content on these topics.
Dr Drielli Vital-Fujii’s Highlights:
- Postdoctoral fellow at the Department of Biochemistry at the University of São Paulo, emphasizing therapy of neglected diseases using light.
- PhD in Pharmaceutical Sciences focusing on drug design and development at the Faculty of Pharmaceutical Sciences of the University of São Paulo.
- Six months as an international researcher at the Center for Discovery and Innovation in Parasitic Diseases (University of California San Diego)
- Master’s degree in Pharmaceutical Sciences focusing on drug design and development at the Faculty of Pharmaceutical Sciences of the University of São Paulo.
- Bachelor of Pharmacy at the University of Mogi das Cruzes – São Paulo / Brazil
Professional Experience:
2012 – 2018 Project manager at University of São Paulo – Pharmacy Department
Dr Drielli Vital-Fujii has worked with computational studies, synthesis, biological evaluation, design, and development of new inhibitor candidates for Chagas Disease and Leishmaniasis.
2017 – 2017 International research fellow at University of California San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences – Center for Discovery and Innovation in Parasitic Diseases.
She used Virtual Screening (VS) and High-Throughput Screening (HTS) Integration in the Discovery of new drugs against neglected tropical diseases (NTDs).
2018 – 2019 Faculdades Oswaldo Cruz
Dr Drielli Vital-Fujii was a professor in the Faculty of Pharmacy, teaching the subjects of Pharmaceutical Chemistry and Drug Development.
2019 – 2021 Researcher in Biochemistry University of São Paulo – Biochemistry Department
She applied Photodynamic Therapy in Leishmaniasis Treatment, mentored undergraduate students in scientific activities, and wrote, executed, translated, and reported scientific projects with funding agencies.
2023-2023 UniPiaget – University Center.
Dr Drielli Vital-Fujii was a Biology, Nutrition, Physiotherapy, and Pharmacy professor.
Education:
2018 -2021 Postdoctoral at the Department of Biochemistry at the University of São Paulo
2013 -2018 PhD of Science: Drugs and Medicines at Department of Pharmacy at University of São Paulo
2012 -2013 M.Sc. of Sciences: Drugs and Medicines at the Department of Pharmacy at the University of São Paulo
2005-2008 Bachelor of Pharmacy at the University of Mogi das Cruzes
The leading publications of Dr Drielli Vital-Fujii are:
Vital-Fujii, D.G, Baptista, M.S. (2021). Progress in the photodynamic therapy treatment of Leishmaniasis. Brazilian Journal of Medical and Biological Research, 54, 1-11.
Gatti, F. M., Gomes, R.A., da Fonseca, A.L., Lima, E.J.C., Vital-Fujii, D.G., Taranto, A.G., Varotti, F.P., Trossini, G.H.G. (2020). Antiplasmodial activity of sulfonylhydrazones: in vitro and in silico approaches. Future medicinal chemistry, 13, 233-250.
Silva, E.J., Bezerra-Souza, A., Passero, L.F., Laurenti, M.D., Ferreira, G.M., Fujii, D.G.V., et al. (2018). Synthesis, leishmanicidal activity, structural descriptors and structure-activity relationship of quinoline derivatives. Future medicinal chemistry, 10, 2069-2085.
Leite, F.H.A., Froes, T.Q., da Silva, S.G., de Souza, E.I.M., Vital-Fuji,i D.G., Trossini, G.H.G., et al. (2017). An integrated approach towards the discovery of novel non-nucleoside Leishmania major pteridine reductase 1 inhibitors. European Journal of Medicinal Chemistry, 132, 322-332.
Vital, D.G., Damasceno, F.S., Rapado, L.N., Silber, A.M., Vilella, F.S., Ferreira, R.S., et al. (2017). Application of bioisosterism in design of the semicarbazone derivatives as cruzain inhibitors: a theoretical and experimental study. Journal of Biomolecular Structure and Dynamics, 35, 1244–1259.
Mello, J. F.R., Gomes, R.A., Vital-Fujii, D.G., Ferreira, G.M., Trossini, G.H.G. (2017). Fragment-based drug discovery as alternative strategy to the drug development for neglected diseases. Chemical Biology & Drug Design, 90, 1067-1078.
Pantaleao, S.Q., Fujii, D.G.V., Maltarollo, V.G., da C. Silva, D., Trossini, G.H.G., Weber, K.C., et al. (2017). The Role of QSAR and Virtual Screening Studies in Type 2 Diabetes Drug Discovery. Medicinal Chemistry, 13, 706-720.
Vital, D., Arribas, M., Trossini, G. (2014). Molecular Modeling and Docking Application to Evaluate Cruzain Inhibitory Activity by Chalcones and Hydrazides. Letters in Drug Design and Discovery, 11, 249-255.
Blau, L., Menegon, R.F., Trossini, G.H.G., Molino, J.V.D., Vital, D.G., Cicarelli, R.M.B., et al. (2013). Design, synthesis and biological evaluation of new aryl thiosemicarbazone as antichagasic candidates. European Journal of Medicinal Chemistry, 67, 142-151.
You can view some of Dr Drielli’s work below and links to her professional profile.
Orcid: https://orcid.org/0000-0001-9270-0466
Research Gate: https://www.researchgate.net/profile/Drielli-Gomes-Vital-Fujii
Scopus: https://www.scopus.com/authid/detail.uri?authorId=55829534000
Google Scholar: https://scholar.google.com/citations?user=F9U50AEAAAAJ&hl=pt-BR
Linkedin: linkedin.com/in/driellivital
Escavador: https://www.escavador.com/sobre/6101380/drielli-gomes-vital
CDIPD: https://cdipd.org/index.php/about-us/visiting-scientists
How long after Zyrtec can you take Benadryl?
You should wait for at least 24 hours after taking Zyrtec to take Benadryl. They both are antihistamines and work to fight against allergies.
Zyrtec, being a second-generation antihistamine, has a longer duration of action and it stays in your system for about 24 hours, during which I would not recommend taking Benadryl.
The concomitant use of these two antihistamines can increase the risk of side effects. However, if your health condition requires you to take these two together, your doctor will adjust the dose of one or both of these meds. In usual practice, only one of these antihistamines is used.
If it fails to achieve the therapeutic purpose, that’s when your doctor may advise you to switch to Benadryl, which is considered slightly better at resolving allergy symptoms. Just make sure you don’t take these meds concomitantly.
What are the side effects associated with the concomitant use of Zyrtec and Benadryl?
The concomitant use of Zyrtec and Benadryl is associated with a number of side effects as both antihistamines may cause the same kind of side effects. These include (1,2):
- Drowsiness
- Dry eyes
- Xerostomia or dry mouth
- Constipation
- Dizziness or lightheadedness
- Blurry vision
- Decreased mental alertness
- Forgetfulness
What to do if you have taken Zyrtec and Benadryl together?
If you have taken Zyrtec and Benadryl together, it might not significantly harm you. Occasional use is not something to worry about.
However, repeated use of these two together can increase the risk of side effects and that should be avoided. If you have a severe allergy and you think one medication may not be adequate, talk to your healthcare provider.
Your doctor will properly diagnose the condition and will determine the exact cause of your allergy. If your condition requires the use of two antihistamines, your doctor will prescribe them. He will also adjust the doses to make the concomitant use safer for you.
However, consistent use of any two antihistamines together should be avoided and Benadryl or Zyrtec- either of the anti-allergies should not be used with other similar medications like Claritin, Allegra, Dramamine, etc.
However, oral and nasal antihistamines can be used together for enhanced symptomatic relief without increasing the risk of adverse events.
Final words
To sum up, it is never a smart thing to take two antihistamines together unless your healthcare provider has prescribed a combination of these meds. One antihistamine is generally enough to help resolve your symptoms.
Taking two similar medications can increase the risk of side effects, which might end up causing you more trouble than helping you. However, if your symptoms are severe and one OTC antihistamine is not helping you much, please reach out to your doctor.
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References
1.-
Naqvi A, Gerriets V. Cetirizine. 2023 Jan 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 31747183. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549776/
2.-
Sicari V, Zabbo CP. Diphenhydramine. 2022 Jul 11. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 30252266. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526010/