How long does Namenda stay in your system? (+3 factors)
By
Ivan Kahwa
Author bio
Mr Ivan Kahwa is a chemist and phytopharmaceutical scientist with expertise in chemistry, pharmacology, phytochemistry, and Nanobiotechnology. He writes and reviews content on these topics.
Mr Ivan Kahwa’s Highlights:
Guest Researcher at the University of Leipzig, Senior Research Fellow/Scientist, and Lecturer at the Department of Pharmacy, Faculty of Medicine, Mbarara University of Science and Technology.
Professional Experience:
Mr Ivan joined PHARMBIOTRAC as a research fellow/scientist during his master of science tenure. He contributed to the development of most of the phytopharmaceutical products in the project. Furthermore, he participated in carrying out the pharmacological activities of the developed products in laboratory animals such as mice and rats in order to develop proper doses hence leading to pre-clinical studies.
With the above relevant research experience, Ivan started to work with the University of Leipzig on collaborative projects with Mbarara University to develop the chemistry of Ugandan Medicinal plants and their pharmacological activities. This was coupled with several consultative positions by different German NGOs. Mr. Kahwa is also a supporting in the teaching and learning at the Departments of Pharmacy and Pharmaceutical Sciences, Faculty of Medicine, Mbarara University of Science and Technology.
With the increase in antimicrobial resistance globally, Ivan retooled his thinking towards developing new naturally derived antibiotic regimens from Ugandan propolis with the assistance of nanotechnology to improve their delivery to microbial cells. Kahwa has also published over 28 articles in peer-reviewed journals and he is currently reviewing for many journals.
Education:
2023-2027: PhD in Pharmaceutical Sciences (ongoing) with a focus on Pharmaceutical Microbiology and Nanobiology at Mbarara University of Science and Technology.
2022: 2Msc. in Pharmacognosy and Natural Medicine Science at Mbarara University of Science and Technology.
2018: Bachelor of Science (Chemistry) at Mbarara University of Science and Technology.
Publications:
▪ Iqbal, S., Jabeen, F., Kahwa, I., & Omara, T. 2023. Suberosin Alleviates Thiazolidinedione-Induced Cardiomyopathy in Diabetic Rats by Inhibiting Ferroptosis via Modulation of ACSL4-LPCAT3 and PI3K-AKT Signaling Pathways. Cardiovascular Toxicology. https://doi.org/10.1007/s12012-023-09804-7
▪ Gupta, A. K., Yadav, R., Sharma, S., Sawale, J., & Kahwa, I. 2023. Anti-ageing Activity and Antioxidant Activity of Methanol Extracts of Leaves and Flowers of Salvia officinalis and Rosmarinus officinalis. Journal of Young Pharmacists, 15(3), 448–455. https://doi.org/10.5530/jyp.2023.15.60
▪ Tolo, C.U., Kahwa, I., Nuwagira, U., Weisheit, A. and Ikiriza, H., 2023. Medicinal plants used in treatment of various diseases in the Rwenzori Region, Western Uganda. Ethnobotany Research and Applications, 25, pp.1-16.
https://ethnobotanyjournal.org/index.php/era/article/view/4683
▪ Kahwa, I., Ajayi, C.O., Yadav, R., Chauhan, N.S., Shah, K., Abdelgadir, A.A., Shegena, E.A., Daniel, S., Omara, T., Asiimwe, J.B. and Ikiriza, H., 2023. Pharmacognostic and phytochemical studies as an invaluable approach for correct identification of medicinal plants: The case of Artemisia vulgaris L. substituted for Artemisia annua L. in Western Uganda. TMR Integr Med, 7, p.e23004.
https://doi.org/10.53388/TMRIM202307004
▪ Nalimu, F., Oloro, J., Kahwa, I. and Ogwang, P.E., 2021. Review on the phytochemistry and toxicological profiles of Aloe vera and Aloe ferox. Future Journal of Pharmaceutical Sciences, 7, pp.1-21.
https://doi.org/10.1186/s43094-021-00296-2
▪ Elamin, O.H.S., Ali, M.A., Elgezuli, I.A.A., Bashir, M.A. and Kahwa, I., 2021. Diagnosis of pre-and post-treatment of echinococcus granulosus with counter current immune electrophoresis and bacterial co-agglutination. Journal of Microbiology and Infectious Diseases, 11(02), pp.88-94.
https://doi.org/10.5799/jmid.951600
Published book Chapter
▪ Kahwa, I., Ayesiga, I., Nakalema, S., Alinaiswe, R., Mbabazi, R. and Iqbal, S., 2023. Natural products in the management of onchocerciasis. In Natural Products in Vector-Borne Disease Management (pp. 63-80). Academic Press. Book Chapter.
https://doi.org/10.1016/B978-0-323-91942-5.00012-4
Submitted manuscripts Under Review:
▪ Comparison of the Wound Healing Activity of the Leaf and Leaf Ash Extracts of Vernonia amygdalina in Rats. Journal name: Clinical Phytoscience
▪ Ethnobotanical Survey of Medicinal plants used in the management of cancer in Uganda. Journal name: Journal of Herbal Medicine
▪ Ethnobotanical survey and phytochemical screening of medicinal plants used in treatment of epilepsy by PROMETRA-Uganda Traditional Health Practitioners in Mpigi District, Uganda. Journal name: Journal of Ethnopharmacology
Submitted book chapters under review
1.Book title: Algae as a Natural Solution for Water-Food-Energy Nexus, Section 4: Microalgae and cyanobacteria for food applications, Chapter 4.6: Safety, toxicological and allergenic aspects of using algae for food. Authors: Christine Kyarimpa, Tom Omute, Caroline K. Nakiguli, Alice V. Khanakwa4, Christopher Angiro, Ivan Kahwa, Fortunate Ahumuza, Timothy Omara*. Publisher: Springer Nature Singapore Pte Ltd. 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore.
2.Book title: Nutraceuticals Inspiring the Contemporary Therapy for Lifestyle Diseases. Chapter: Nutraceutical applications of Seaweeds and their Phytocompounds in Nutrition and Treatment of Diseases. Authors: Ivan Kahwa, Timothy Omara , Innocent Ayesiga , Gael Noel Neh Neba Ambe , Zehbanaz Javidbhai Panwala , Rachel Mbabazi , Shabnoor Iqbal , Christine Kyarimpa , Christine Betty Nagawa , Kamal Shah ,Nagendra Singh Chauhan* Publisher: CRC Press
You can view my works on the following professional sites:
Research Gate: https://www.researchgate.net/profile/Ivan-Kahwa
Google Scholar: https://scholar.google.com/citations?user=tOwrvqoAAAAJ&hl=en
ORCID: https://orcid.org/0000-0002-6440-3437
Linkedin: https://de.linkedin.com/in/ivan-kahwa-865450159
In this article, we will discuss the stay of Namenda in your system. We will also discuss some factors which may affect the stay of Namenda in your system and the withdrawal symptoms if you discontinue the use of Namenda abruptly.
How long does Namenda stay in your system?
Namenda may stay in your body for about a week after the last dose is taken. Namenda has a terminal half-life of 60-80 hours. The average peak plasma concentration is achieved within 3-7 hours.
The stay of Namenda in the system may vary depending on the age, weight, dosage strength, dosing frequency, concomitant administration of other drugs, and other underlying health conditions.
Patients with renal and liver disease may require dose adjustment. Most of the drug (75-90% of the dose) is eliminated via the kidney as an unchanged form of Namenda. Therefore, it may require several days to achieve steady plasma drug concentration (1).
What is the half-life of Namenda?
The half-life of Namenda is 60-80 hours. This means that the drug requires 60-80 hours to reduce to half of its initial drug concentration. After this time, the remaining concentration further reduces to half in the next 60-80 hours.
This process continues until all of the drug is excreted from your system. Namenda may require up to three months to start working, but the onset of action varies from one person to another.
Factors affecting the time taken by Namenda to leave your system
Several factors can affect the stay time of Namenda in your system, including:
Dose
The initial dose of Namenda is 5 mg/day which can be increased to 20 mg/day. Higher doses of Namenda generally require more time to get eliminated from the body as compared to the lower dose.
Genitourinary condition
Conditions that raise the pH of urine decrease the urinary elimination of Namenda. The plasma concentration of Namenda hence increases. This increases the plasma concentration of the drug and prolongs its stay in the body (2).
Severe hepatic impairment
The dose of Namenda should be adjusted if the patient has severe hepatic impairment. However, dose adjustment is not required in the case of mild or moderate liver dysfunction (3).
Severe renal impairment
Severe renal impairment may reduce the clearance of Namenda from your system, especially under alkaline conditions. However, dose adjustment is not required in the case of mild to moderate renal dysfunction (4).
Drugs which make urine alkaline
Drugs, such as carbonic anhydrase inhibitors and sodium carbonate make the urine alkaline. This may increase the accumulation of Namenda in the system as alkaline pH decreases the urinary elimination of Namenda.
Age and gender
The elimination rate of Namenda may be affected by age and gender due to the overall health condition of the patient. However, such changes are not significant. Dose adjustment is necessary in the elderly with liver and renal dysfunction (5).
Antidepressants
Coadministration of Namenda with sertraline may induce a pronounced antidepressant effect than either drug used alone. This increases the stay of Namenda in the system and increases the risk of side effects associated with sertraline such as fatigue and night sweats (6).
Can Namenda cause withdrawal symptoms?
Namenda can cause withdrawal symptoms so you should not stop taking Namenda abruptly. You should talk to your doctor if you feel your condition is not improving or side effects are affecting your quality of life (7).
| Withdrawal symptom | Effect |
| Cognitive disturbance | Memory impairment, trouble following a conversation, and social phobia. |
| Insomnia | Sleep disturbance includes difficulty in falling asleep, waking up frequently, irritation, and feeling tired after waking up. |
| Worsening of neuropsychiatric problems | Anxiety, mood swings, sleep disturbance, and possible tic disorder. |
| Aggressive behaviour | Disorganized thinking, irritability, poor judgement, and threatening behaviour. |
| Visual hallucinations | Seeing objects move when they are stagnant and seeing complex scenarios of people that are not present. |
What to do if Namenda is not working?
Namenda is prescribed to treat moderate to severe dementia due to Alzheimer’s disease. Namenda may take up to three months to show its effect. After three months if you still think Namenda is not working for you then consult your doctor.
Talk to your doctor
If Namenda is not working for you or your condition is worsening even after taking a high dose of Namenda, your doctor may prescribe you another medication. But first, he will take your medical history and identify the possible reason why Namenda is not showing its desired effects.
Alternatives to Namenda
The Food and Drug Administration (FDA) has approved five medications for the management of dementia associated with Alzheimer’s disease, including Namenda, donepezil, tacrine, galantamine, and rivastigmine.
Except for Namenda, the rest of the drugs belong to the class of acetylcholinesterase inhibitors (AchEI). These drugs are prescribed for mild to moderate Alzheimer’s disease. However, donepezil can be used for the treatment of advanced stages of Alzheimer’s disease.
As a pharmacist, I would advise you to follow the directions of your doctor for the safe and effective use of Namenda. Although, you may not feel any changes at first, with time your condition will begin to improve.
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References
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HBr G. Drugs to treat aLZHeIMer’s DIsease. https://www.proquest.com/openview/0759cfae5f38f1773a0d162121146e2d/1?pq-origsite=gscholar&cbl=35532
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Amidfar M, Réus GZ, Quevedo J, Kim YK, Arbabi M. Effect of co-administration of memantine and sertraline on the antidepressant-like activity and brain-derived neurotrophic factor (BDNF) levels in the rat brain. Brain Research Bulletin. 2017 Jan 1;128:29-33. https://www.sciencedirect.com/science/article/abs/pii/S0361923016302672
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Kwak YT, Han IW, Suk SH, Koo MS. Two cases of discontinuation syndrome following cessation of memantine. Geriatrics & gerontology international. 2009 Jun;9(2):203-5. https://onlinelibrary.wiley.com/doi/10.1111/j.1447-0594.2009.00519.x
