What happens if you take two Venlafaxine? (3+ precautions)
By
Dr Milena Locci de Oliveira (PhD)
Author bio
Dr Milena Locci de Oliveira is a Pharmacist and Doctor of Philosophy in Sciences from the University of São Paulo (USP). She has experience in microbiology, analytical toxicology, and clinical pharmacokinetics. She writes and reviews content on these topics.
Dr Milena’s Highlights:
-PhD in Sciences, University of São Paulo, Brazil, 2019.
-University College London (UCL) – Semester of remote collaboration in the areas of Pharmacometrics and Population Pharmacokinetics, 2018.
-Bachelor in Biochemical Pharmacy, University of São Paulo, Brazil, 2013.
“Science can be translated, and it is essential that everyone has access to quality information to make informed decisions” – Dr Milena Oliveira, PhD.
Professional Experience:
With a decade-long career as a researcher, Dr Milena has amassed extensive experience in conducting research projects in microbiology, analytical toxicology, and clinical pharmacokinetics.
Her expertise also extends to the preparation of technical and scientific reports, literature reviews, data analysis, and scientific communication, both oral and written.
Dr Milena has served as a Clinical Pharmacist, providing expert supervision and guidance to teams during the challenging times of the COVID-19 pandemic, particularly in the ICUs of two reference hospitals for patient hospitalization.
In her most recent role, Dr Milena worked on the implementation of the deliberatives of the São Paulo State Government Pharmaceutical Assistance Coordination. These decisions were aimed at ensuring medication access within the Unified Health System.
A widely multidisciplinary background enabled Dr Milena to become a professional capable of integrating scientific knowledge into private initiatives, education, and healthcare, delivering consistent services in patient safety and population health.
Professional Memberships & Affiliations:
Dr Milena Oliveira is a member of the Regional Council of Pharmacy of the State of São Paulo, Brazil.
Education:
-PhD in Sciences, University of São Paulo, Brazil, 2019.
-University College London (UCL) – Semester of remote collaboration, 2018.
-Bachelor in Biochemical Pharmacy, University of São Paulo, Brazil, 2013.
Relevant Published Work & Citations:
Oliveira ML de, Rocha A, Nardotto GHB, Pippa LF, Simões BP, Lanchote VL. Analysis of daunorubicin and its metabolite daunorubicinol in plasma and urine with application in the evaluation of total, renal and metabolic formation clearances in patients with acute myeloid leukemia. Journal of Pharmaceutical and Biomedical Analysis. Nov 2020. 191:113-124.
Abstracts. CPT: Pharmacometrics & Systems Pharmacology. 2020 Nov; 9 (S1).
Pippa LF, Oliveira ML de, Rocha A, de Andrade JM, Lanchote VL. Total, renal and hepatic clearances of doxorubicin and formation clearance of doxorubicinol in patients with breast cancer: Estimation of doxorubicin hepatic extraction ratio. Journal of Pharmaceutical and Biomedical Analysis. 2020 Jun 5; 185:113-231.
Godoy ALPC, De Jesus C, De Oliveira ML, Rocha A, Pereira MPM, Larangeira DF, Lanchote VL, Barrouin-Melo SM. Determination of Allopurinol and Oxypurinol in Dogs Plasma by High-Performance Liquid Chromatography with an Ultraviolet Detector: Application for Pharmacokinetic Studies. J Chromatogr Sep Tech. 2017; 8 (4).
Clímaco EC, Oliveira ML de, Pitondo-Silva A, Oliveira MG, Medeiros M, Lincopan N, et al. Clonal complexes 104, 109 and 113 playing a major role in the dissemination of OXA-carbapenemase-producing Acinetobacter baumannii in Southeast Brazil. Infection, Genetics and Evolution. 2013 Oct;19:127–33.
Conference Papers:
Oliveira, M. L.; NARDOTTO, G. H. B.; PIPPA, L. F.; ROCHA, A.; SIMOES, B. P.; LANCHOTE, V. L. . Daunorubicin metabolism and urinary excretion in patients with acute myeloid leukemia. In: 84th Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT) and the 20th Annual Meeting of the Association of the Clinical Pharmacology Germany (VKliPha), 2018, Göttingen. Naunyn-Schmiedeberg’s Arch Pharmacol, 2018. v. 391. p. S76-S76.
Oliveira, M. L.; NARDOTTO, G. H. B. ; ROCHA, A. ; SIMOES, B. P. ; LANCHOTE, V. L. . The low contribution of urinary excretion in the elimination of daunorubicin and its metabolite daunorubicinol in patients with acute myeloid leukemia. In: 49th Brazilian Congress of Pharmacology and Experimental Therapeutics., 2017, Ribeirão Preto. Livro de Resumos, 2017. p. 64-64.
Oliveira, M. L.; PIPPA, L. F. ; ROCHA, A. ; SIMOES, B. P. ; LANCHOTE, V. L. . Quantification of daunorubicin and its metabolite daunorubicinol in human plasma by LC-MS/MS. In: I International Meeting of Environmental Health and Toxicology (IMEHTOX), 2016, Ribeirão Preto. Livro de Resumos, 2016.
Oliveira, M. L.; Clímaco, E.C. ; OLIVEIRA, M. G. ; Lincopan, N. ; Darini A.L.C. . PFGE typing of Carbapenem-Resistant Acinetobacter baumannii isolated from different University Hospitals. In: V International Postgraduate and Research Symposium, 2012.
Clímaco, E.C. ; SILVA, A. P. ; Oliveira, M. L. ; OLIVEIRA, M. G. ; Lincopan, N. ; Darini A.L.C. Relação clonal entre linhagens de Acinetobacter baumannii produtoras de carbapenemases da família OXA em quatro hospitais no Brasil. In: XXI Latin American Congress of Microbiology, 2012, Santos. XXI Latin American Congress of Microbiology, 2012.
Oliveira, M. L.; Clímaco, E.C. ; OLIVEIRA, M. G. ; Darini A.L.C. . Dissemintion of OXA carbapenemases genes in carbapenem-resistant Acinetobacter baumannii in University Hospital of Juiz de Fora, MG. In: 8th CIFARP – International Congress of Pharmaceutical Sciences, 2011, Ribeirão Preto.
Clímaco, E.C. ; Oliveira, M. L. ; OLIVEIRA, M. G. ; Darini A.L.C. . Avaliação do sequenciamento parcial do gene rpoB e de seus flanqueadores para identificação de espécies de Acinetobacter na rotina laroratorial. In: 2° International Symposium on Clinical Microbiology, 2010, Florianópolis.
You can view some of Dr Milena’s work below and links to her professional profile.
Linkedin: https://www.linkedin.com/in/dra-milena-locci-de-oliveira-28986042/?locale=en_US
ResearchGate: https://www.researchgate.net/profile/Milena-Oliveira-6
Escavador: https://www.escavador.com/sobre/5394254/milena-locci-de-oliveira
Lattes: https://buscatextual.cnpq.br/buscatextual/busca.do
Scopus: https://www.scopus.com/authid/detail.uri?authorId=57199779361
Scholar: https://scholar.google.com/citations?view_op=list_works&hl=pt-BR&user=1YUBDIQAAAAJ
In this article, we aim to provide helpful information regarding the potential risks of taking two venlafaxine pills while also outlining the possible side effects that may arise. Additionally, we will discuss how to prevent any potential issues when consuming venlafaxine.
What happens if you take two venlafaxine?
Taking two venlafaxine will increase the risk of side effects caused by venlafaxine. Taking a high dose of venlafaxine twice will cause an overdose, and you may experience some serious side effects which can be life-threatening.
The overdose side effects of venlafaxine are: (1)
- Vomiting
- Increase or decrease in heart rate
- Change in the level of consciousness (ranging from somnolence to coma)
- Mydriasis
- Seizures
- Electrocardiogram changes
- Hypotension
- Rhabdomyolysis
- Vertigo
- Liver necrosis
- Serotonin syndrome
It is safe to consume two 75mg Venlafaxine tablets if your physician has prescribed a daily dosage of 150mg. However, taking two pills when you are advised to take only one can increase the risk of experiencing unwanted side effects.
The common side effects of venlafaxine include: (2)
- Headache
- Nausea
- Insomnia
- Dizziness
- Hypotension/Hypertension
- Anorexia
- Drowsiness
- Dry mouth
- Lack of energy
- Impotence
- Decreased libido/anorgasmia
- Constipation/Diarrhea
- Abdominal pain
- Anxiety
- Tremor
- Seizures
- Serotonin syndrome
What does the research say?
A case report by Marie et al. reported a 39-year-old woman presented with symptoms of serotonin syndrome and hypoglycemia due to a very high dose of venlafaxine. (3)
A study involving 369 individuals, out of which 273 of these individuals had experienced an overdose. The average ingested dose of venlafaxine was 1.5g. Tachycardia was reported by 54%, hypotension by 5%, and hypertension by 40%. (4)
Another study revealed cardiovascular toxicity related to venlafaxine overdose. A total of 235 patients who had ingested a dose ranging from 919-2800 mg of venlafaxine reported experiencing common symptoms such as tachycardia, high blood pressure and mydriasis. Abnormal QT prolongation was seen in 24 patients, and 3 patients experienced transient arrhythmia. (5)
When can you take two venlafaxine?
If your physician has prescribed you 150mg/day of venlafaxine, you can take two 75mg pills if a 150mg tablet is not available. Venlafaxine is available in immediate-release (25mg, 37.5mg, 50mg, 75mg, and 100mg) and extended-release tablets (37.5mg, 75mg, 150mg and 225mg) (2)
The starting dose of venlafaxine is 75 mg/day, and it can be increased up to 375 mg depending upon the patient’s condition and response to the drug. Venlafaxine is always started with a low dose to avoid unwanted side effects. If your body is not responding to 75mg venlafaxine, then 75mg more is added to your regimen after four days or every four days till your body responds to the drug. (2)
When should you not take two venlafaxine?
Avoid venlafaxine if you are hypersensitive to venlafaxine HCl or its excipients in the formulations. If you are being medicated with any other antidepressants, such as monoamine oxidase inhibitors, do not take venlafaxine, as it will increase the risk of serotonin syndrome. (1)
Methylene blue has a significant drug interaction with venlafaxine and can lead to an increase in serotonin syndrome. (6) Precautions should be taken when using venlafaxine with sedative medications and alcohol, as they may cause drowsiness. (7)
Avoid taking venlafaxine if you have a seizure disorder; it can increase the risk of seizures. (2) Avoid taking venlafaxine if you experience worsening of depression, anxiety, suicidal ideation, or psychosis.
What to do if you took two venlafaxine?
If you accidentally take two pills of venlafaxine, here are some measures to follow:
Consult your healthcare provider: Call your healthcare provider or an emergency helpline. They will provide guidance on how to proceed based on your specific situation. Seek immediate medical attention
Do not panic: Most double-dosing situations can be managed with proper medical attention.
Watch for symptoms: Monitor for any unusual or severe symptoms. Taking two doses of venlafaxine may increase the risk of side effects such as dizziness, rapid heart rate, higher blood pressure, etc.
How to ensure safe and effective use of venlafaxine?
| Tips | Description |
| Dosage | Venlafaxine is usually taken as a single dose once daily, with or without food. The dose may vary depending on your condition. Do not miss the venlafaxine dose. Ensure you discuss with your physician about your medication and proper dosing. |
| Pill Organiser | You can use a pill organiser to prevent accidental double dosing of the medication in the future. |
| Follow instructions |
Adhere to your medication; do not increase or decrease your dose without consulting your physician. Read the instruction manual carefully. |
| Monitor side effects |
Venlafaxine may cause side effects. It is important to monitor your symptoms and consult your healthcare provider if you experience any side effects. |
| Regular check-ups |
Do not miss any appointments; attend all follow-ups to monitor your progress and the duration of the course. Patients with glaucoma should undergo regular eye check-ups to prevent increased intraocular pressure, which can be induced by the use of venlafaxine.
|
| Avoid alcohol | Avoid the use of alcohol as it increases the side effects of venlafaxine |
| Avoid driving or operating machinery | Venlafaxine can make you drowsy. Be cautious when you are driving or operating machinery. |
Conclusion:
To sum it up, taking two high doses of venlafaxine can be dangerous. In my experience, if the dose of venlafaxine is too low, you may experience some mild side effects, which will subside after a period of time. However, if you take a large dose of venlafaxine, it can result in an overdose and lead to severe side effects. I suggest maintaining a proper routine to take your medication.
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References
1.-
Effexor XR [package insert]. Philadelphia: Wyeth Pharmaceuticals Inc; 2017. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/020699s107lbl.pdf
2.-
Singh D, Saadabadi A. Venlafaxine. Available from: https://www.ncbi.nlm.nih.gov/books/NBK535363/
3.-
Francino MC, Deguigne MB, Badin J, Turcant A, Perrotin D. Hypoglycaemia: a little known effect of Venlafaxine overdose. Clinical Toxicology. 2012 Mar 1;50(3):215-7. Available from: https://www.tandfonline.com/doi/abs/10.3109/15563650.2012.660696
4.-
Isbister GK. Electrocardiogram changes and arrhythmias in venlafaxine overdose. British journal of clinical pharmacology. 2009 May;67(5):572-6. Available from: https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2125.2009.03382.x
5.-
Howell C, Wilson AD, Waring WS. Cardiovascular toxicity due to venlafaxine poisoning in adults: a review of 235 consecutive cases. British journal of clinical pharmacology. 2007 Aug;64(2):192-7. Available from: https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2125.2007.02849.x
6.-
Gilbert B, Akamune IE. A case of serotonin syndrome caused by the concomitant utilization of methylene blue and venlafaxine in an oncological patient. Journal of Pharmacy Practice. 2020 Oct;33(5):705-7. Available from: https://pubmed.ncbi.nlm.nih.gov/31232145/
7.-
Brubacher JR, Hoffman RS, Lurin MJ. Serotonin syndrome from venlafaxine-tranylcypromine interaction. Veterinary and human toxicology. 1996 Oct 1;38(5):358-61. Available from: https://pubmed.ncbi.nlm.nih.gov/8888541/
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