Jun 6, 2023 · Benadryl may cause serious side effects including: pounding heartbeats or fluttering in your chest, painful or difficult urination, little or no urination, confusion, lightheadedness, tightness in your neck or jaw, and. uncontrollable movements of your tongue. Get medical help right away, if you have any of the symptoms listed above. Apr 8, 2023 · The main long-term side effects of Plaquenil are eye-related. ... To manage your symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine ... Aug 15, 2023 · It can sometimes cause a decrease in memory, confusion, and thinking issues. These side effects are more common in elders. In addition, taking Benadryl long-term might increase the risk of dementia. People aged> 65 who took medications such as Benadryl daily for over three years had an increased risk of dementia. Extrapyramidal side effects (EPS), commonly referred to as drug-induced movement disorders are among the most common adverse drug effects patients experience from dopamine-receptor blocking agents. It was first described in 1952 after chlorpromazine-induced symptoms resembling Parkinson disease.[1] A variety of movement phenotypes has since been described along the EPS spectrum, including ...Diphenhydramine (Benadryl) is a common over-the-counter allergy medication. It’s part of a class of drugs called anticholinergics that research has linked to dementia in older people.Apr 8, 2023 · The main long-term side effects of Plaquenil are eye-related. ... To manage your symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine ... Jan 24, 2018 · Taking an over-the-counter sleep aid with diphenhydramine once in a while is generally not going to cause problems, other than a possible hangover the next day. Older people, however, can get confused when taking diphenhydramine because it also blocks a brain chemical called acetylcholine, which plays a big role in attention and short-term memory. Overdosing on diphenhydramine (Benadryl) can also lead to more serious side effects like severe confusion, seizures, low blood pressure, involuntary muscle spasms, hallucinations (seeing things that aren't there), and heart rhythm problems. In fact, the FDA released a warning to avoid high doses of diphenhydramine.Jul 9, 2020 · This video examines the question and remark: Benadryl long term side effects! I WISH I had KNOWN! Benadryl is a common OTC medication and is also known as D... Uses Diphenhydramine is an antihistamine used to relieve symptoms of allergy, hay fever, and the common cold. These symptoms include rash, itching, watery eyes, itchy eyes /nose/throat, cough,... Jul 9, 2015 · Higher dosage or long-term use of common drugs with anticholinergic effects is linked to significantly increased risk of dementia - including Alzheimer’s - says large study. Benadryl helps reduce the effects of natural chemicals in the body called histamines. It is used to treat the side effects of an allergic reaction, including: Benadryl can be taken to relieve the symptoms of hayfever (seasonal allergies) and motion sickness. It can also be taken to induce sleep and treat certain symptoms of Parkinson's disease.The phase IV clinical study analyzes which people take Benadryl and have Peripheral neuropathy. It is created by eHealthMe based on reports of 70,795 people who have side effects when taking Benadryl from the FDA, and is updated regularly. You can use the study as a second opinion to make health care decisions.Apr 23, 2021 · Hives. Swelling and inflammation. Redness. Runny nose and eyes. Coughing. Sneezing. Anaphylactic reaction. One of the side effects of Benadryl is drowsiness, which can help to calm anxious dogs ... Apr 11, 2023 · In the drug realm, antihistamines such as diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton), cetirizine (Zyrtec), and loratadine (Claritin) can help with a stuffy nose are safe for the heart. Nasal sprays deliver a decongestant right where you need it. In theory, this should minimize cardiovascular effects. Benadryl may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly. Drinking alcohol can increase certain side effects of diphenhydramine. Ask a doctor or pharmacist before using any other cold, cough, allergy, or sleep medicine.January 19, 2022. By Harvard Health Publishing Staff. A report published in JAMA Internal Medicine several years ago highlighted a link between long-term use of anticholinergic medications like Benadryl and dementia. While this study and other observational studies have also found this association, it doesn't prove that these drugs cause dementia.Oct 3, 2022 · Some dosage forms listed on this page may not apply to the brand name Benadryl Allergy. Summary. More frequent side effects include: sedated state and thickening of bronchial secretions. Continue reading for a comprehensive list of adverse effects. Applies to diphenhydramine: oral capsules and tablets, parenteral injection. Side effects include: “Atarax (hydroxyzine) and Benadryl (diphenhydramine) were routinely administered in the chemotherapy I received for breast cancer. After 5 months of chemo, I attributed my loss of mental function to a condition I read about called “chemo brain” — and chalked it up as another price paid in side affects for the benefit of staying alive.Apr 8, 2023 · The main long-term side effects of Plaquenil are eye-related. ... To manage your symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine ... May 17, 2018 · Answer From Eric J. Olson, M.D. It's unlikely you'll become dependent on zolpidem (Ambien). Ambien and similar sleep medications can be effective, and they're much less likely to be habit-forming than some other drugs sometimes prescribed for sleep problems — for example, benzodiazepines, such as alprazolam (Xanax), lorazepam (Ativan) or ... May 13, 2021 · The active ingredient in Benadryl is called diphenhydramine. Like any medication, Benadryl has several side effects. Some of the most common are: feeling sleepy or drowsy. dry mouth or throat ... Benadryl may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly. Drinking alcohol can increase certain side effects of diphenhydramine. Ask a doctor or pharmacist before using any other cold, cough, allergy, or sleep medicine.Jun 28, 2021 · Experts say skip antihistamines. Dana Benson. 713-798-8267. Houston, TX - Jun 28, 2021. Share this article. For people who take an antihistamine such as Benadryl for a cold or allergies, drowsiness is often a welcome side effect. But a Baylor College of Medicine sleep expert cautions against turning to this type of medication as a sleep aid. Diphenhydramine blocks the effects of histamine in your brain and this reduces symptoms. It enters the brain in large quantities and this can make you feel drowsy. Diphenhydramine also blocks the effects of another chemical called acetylcholine. This can help a cough or runny nose but can also cause side effects such as a dry mouth and dry nose.Nov 15, 2019 · Central side effects. Since these actions are disrupted by sedating antihistamines, these drugs produce sedation, drowsiness, tiredness, lack of concentration, difficulty in learning and memory ... Aug 1, 2023 · skin rash. swollen joints. stomach discomfort, upset or pain. tender swollen glands in neck. tremor. unusual excitement, nervousness, restlessness, or irritability. vomiting. Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional. Benadryl and Depression. Although there is no direct effect of Benadryl on depression, regular and daily use of Benadryl does result in severe depression in the individual. It is believed to be helpful only for the short term, however, long term use of Benadryl results in certain depressive symptoms in the individual.Sleep aids: The options. Sleep aids available without a prescription are widely available. Common choices and the potential side effects include: Diphenhydramine (Benadryl). Diphenhydramine is a sedating antihistamine. Side effects might include daytime drowsiness, dry mouth, constipation and urinary retention. Doxylamine (Unisom).Oct 3, 2022 · Applies to diphenhydramine: compounding powder, injectable solution, oral capsule, oral disintegrating strip, oral liquid, oral tablet, oral tablet chewable, oral tablet disintegrating. General The most commonly reported side effects included somnolence, dizziness, and incoordination. When corrected based on the number of drugs with anticholinergic effects an individual was taking, the odds ratio for cognitive impairment was 1.46 with a p value of .0181. However, overall the authors conclude that their data did not support the hypothesis that the use of anticholinergic medications increased the risk of alzheimer’s dementia ...Apr 8, 2023 · The main long-term side effects of Plaquenil are eye-related. ... To manage your symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine ... Some dosage forms listed on this page may not apply to the brand name Benadryl Allergy. Summary. More frequent side effects include: sedated state and thickening of bronchial secretions. Continue reading for a comprehensive list of adverse effects. Applies to diphenhydramine: oral capsules and tablets, parenteral injection. Side effects include:Effects of Long-Term Diphenhydramine Use The information regarding the effects of prolonged Benadryl use is once again not known, as prospective studies analyzing its prolonged use do not exist. There are some exceptions to the above statement, however, the following are related to the long-term use of any antihistamine medication and ...Jul 5, 2023 · Benadryl is an antihistamine that can be used to treat allergic reactions, relieve motion sickness, as a sleep aid, and relieve some symptoms of Parkinson's disease. Sedation is a common side effect. 5. Tips. Benadryl may be taken with or without food. Take exactly as directed. You may take an antihistamine every day to keep long-term allergy symptoms under control. Types of antihistamines. Second-generation antihistamine. If you take an antihistamine frequently or daily, your health care provider may recommend a second-generation antihistamine as they are less likely to cause side effects like sleepiness and fatigue ...Apr 9, 2020 · Diphenhydramine, brand name Benadryl ®, is one of the oldest and most frequently used over-the-counter medications for children. However, many better options are now widely available, all of which are faster acting, longer lasting, with less side effects. Antihistamines counteract the effect of histamine throughout the body, and treat a range ... Benadryl is an antihistamine that can be used to treat allergic reactions, relieve motion sickness, as a sleep aid, and relieve some symptoms of Parkinson's disease. Sedation is a common side effect. 5. Tips. Benadryl may be taken with or without food. Take exactly as directed.and readily penetrates the blood-brain-barrier. Thus side effects such as grogginess, drowsiness, and memory loss are common. Diphenhydramine is also used for motion sickness and extrapyramidal symptoms in Parkinson’s disease patients. Potential harm to the brain: Long-term anticholinergic use has been associated with increased 1. McMillan JM, Aitken E, Holroyd-Leduc JM. Management of insomnia and long-term use of sedative- hypnotic drugs in older patients. CMAJ 2013;185:1499–505. [ PMC free article] [ PubMed] [ Google Scholar] 2. Gray SL, Anderson ML, Dublin S, et al. Cumulative use of strong anticholinergics and incident dementia: a prospective cohort study.Answer (1 of 2): Here is one long term study: “These drugs are called anticholinergics, among them the first-generation antihistamines that are now marketed as sleep aids.Long-Term Side Effects of Diphenhydramine Abuse. Continued diphenhydramine use can cause long-term adverse side effects that result in permanent damage. Not only will prolonged use cause harm, but it can lead to other aspects such as dependence on the medication. Common long-term side effects of prolonged diphenhydramine use include: Dependence. Apr 11, 2018 · Benadryl is a first-generation antihistamine, meaning it is one of the earlier drugs developed in this category of medications. First-generation antihistamines, like Benadryl, are often noted for their sedative side effects as they have the ability to travel to your brain (i.e. crosses the blood-brain barrier), which is why they can make you ... When corrected based on the number of drugs with anticholinergic effects an individual was taking, the odds ratio for cognitive impairment was 1.46 with a p value of .0181. However, overall the authors conclude that their data did not support the hypothesis that the use of anticholinergic medications increased the risk of alzheimer’s dementia ...General The most commonly reported side effects included somnolence, dizziness, and incoordination. [ Ref] Nervous system Common (1% to 10%): Sedation/somnolence/sleepiness, drowsiness, unsteadiness, dizziness, headache, attention disturbance Rare (0.01% to 0.1%): Extrapyramidal effects, tremor, convulsionsBenadryl may cause serious side effects including: pounding heartbeats or fluttering in your chest, painful or difficult urination, little or no urination, confusion, lightheadedness, tightness in your neck or jaw, and. uncontrollable movements of your tongue. Get medical help right away, if you have any of the symptoms listed above.Diphenhydramine blocks the effects of histamine in your brain and this reduces symptoms. It enters the brain in large quantities and this can make you feel drowsy. Diphenhydramine also blocks the effects of another chemical called acetylcholine. This can help a cough or runny nose but can also cause side effects such as a dry mouth and dry nose.IV administration of 50 mg of DPH resulted in immediate improvement of tremor, rigidity, tachycardia, and eye versions. The patient was started on oral DPH 50 mg 4 times a day and the dose was reduced by 25% every 3 days. Oral clonidine 0.1 mg 3 times a day and a weekly 0.1 mg transdermal patch was added to mitigate sympathetic side effects.May 17, 2018 · Answer From Eric J. Olson, M.D. It's unlikely you'll become dependent on zolpidem (Ambien). Ambien and similar sleep medications can be effective, and they're much less likely to be habit-forming than some other drugs sometimes prescribed for sleep problems — for example, benzodiazepines, such as alprazolam (Xanax), lorazepam (Ativan) or ... Oct 9, 2018 · Many older adults may take sleeping pills because pain, nerve problems or other health issues are keeping them up at night, she says. For these people, a sleeping pill is standing in the way of ... Aug 23, 2021 · Symptoms can be mild or serious and can include: skin rash. itchiness. flushing (temporary warmth, redness, or deepening of skin color) swelling under your skin, typically in your eyelids, lips, hands, or feet. swelling of your mouth, tongue, or throat, which can make it hard to breathe. A 2017 study revealed that 10% of adults aged 18-45 use OTC sleep aids while 17.5% of people 65 years and older do. Most over-the-counter options are considered safe when used occasionally—as long as the medication is compatible with any medical conditions you have and other medications you take. But when taken night after night, trouble can ...Common Side Effects of Diphenhydramine. Diphenhydramine is considered an H1 receptor antagonist, and it works by blocking the effect of histamine in the body. The chemical reactions that diphenhydramine trigger in the body can cause other potentially significant sedative side effects on the central nervous system (CNS).Sep 14, 2022 · Benadryl helps reduce the effects of natural chemicals in the body called histamines. It is used to treat the side effects of an allergic reaction, including: Benadryl can be taken to relieve the symptoms of hayfever (seasonal allergies) and motion sickness. It can also be taken to induce sleep and treat certain symptoms of Parkinson's disease. Addiction and Misuse. Another cause of overdose is an addiction to Diphenhydramine. Patients can become addicted to Benadryl after taking it for an extended period or when it is used for recreational purposes. Side effects of Diphenhydramine overdose often cause long-term damage, which can be fatal to patients ingesting it.Oct 9, 2018 · Many older adults may take sleeping pills because pain, nerve problems or other health issues are keeping them up at night, she says. For these people, a sleeping pill is standing in the way of ... Diphenhydramine, which is the active ingredient in ZzzQuil, can cause side effects in some people. The most common side effects of diphenhydramine include: drowsiness. dizziness. loss of ...“Atarax (hydroxyzine) and Benadryl (diphenhydramine) were routinely administered in the chemotherapy I received for breast cancer. After 5 months of chemo, I attributed my loss of mental function to a condition I read about called “chemo brain” — and chalked it up as another price paid in side affects for the benefit of staying alive.Benadryl is an antihistamine that can be used to treat allergic reactions, relieve motion sickness, as a sleep aid, and relieve some symptoms of Parkinson's disease. Sedation is a common side effect. 5. Tips. Benadryl may be taken with or without food. Take exactly as directed.Children's Benadryl Allergy - Uses, Side Effects, and More Generic Name(S): diphenhydramine HCl, diphenhydramine citrate ... (such as long-acting tablets/capsules) are not recommended for use in ...Effects of Long-Term Diphenhydramine Use The information regarding the effects of prolonged Benadryl use is once again not known, as prospective studies analyzing its prolonged use do not exist. There are some exceptions to the above statement, however, the following are related to the long-term use of any antihistamine medication and ...Apr 8, 2022 · People who take too much Benadryl start to experience many of the medication’s side effects. These can include mild symptoms, such as dry mouth, constipation, and tiredness. Usually, the more Benadryl a person takes, the worse these side effects become. In more severe Benadryl overdose cases, symptoms like seizures, irregular heartbeats, and ... May 19, 2022 · Yes, certain side effects are possible after using Benadryl long term. For example, long-term use of Benadryl may cause: an increased risk of dementia; withdrawal symptoms after the drug is stopped* However, keep in mind that doctors typically don’t recommend taking Benadryl as a long-term treatment. You may take an antihistamine every day to keep long-term allergy symptoms under control. Types of antihistamines. Second-generation antihistamine. If you take an antihistamine frequently or daily, your health care provider may recommend a second-generation antihistamine as they are less likely to cause side effects like sleepiness and fatigue ...Applies to diphenhydramine: compounding powder, injectable solution, oral capsule, oral disintegrating strip, oral liquid, oral tablet, oral tablet chewable, oral tablet disintegrating. General The most commonly reported side effects included somnolence, dizziness, and incoordination.Benadryl may cause serious side effects including: pounding heartbeats or fluttering in your chest, painful or difficult urination, little or no urination, confusion, lightheadedness, tightness in your neck or jaw, and. uncontrollable movements of your tongue. Get medical help right away, if you have any of the symptoms listed above.Oct 9, 2018 · Many older adults may take sleeping pills because pain, nerve problems or other health issues are keeping them up at night, she says. For these people, a sleeping pill is standing in the way of ... Benadryl is an antihistamine that can be used to treat allergic reactions, relieve motion sickness, as a sleep aid, and relieve some symptoms of Parkinson's disease. Sedation is a common side effect. 5. Tips. Benadryl may be taken with or without food. Take exactly as directed.Feb 18, 2010 · One Benadryl per night seems to be enough to keep the ears dry & the resulting nausea at bay. I must admit that I'm not sure this is still even a problem for me. The last time I stopped to see if I still needed it was about 2 years ago. After 3 days, the dizziness/nausea/inner ear issues came back, so I promptly started taking the nightly ... While it may work to help you fall asleep for a few days, long-term use of Benadryl as a sleep-aid likely isn't effective and is associated with several side effects like next-day drowsiness. Additionally, the long-term use of drugs like Benadryl in those 65 years old and over is linked with an increased risk of dementia.Apr 11, 2018 · Benadryl is a first-generation antihistamine, meaning it is one of the earlier drugs developed in this category of medications. First-generation antihistamines, like Benadryl, are often noted for their sedative side effects as they have the ability to travel to your brain (i.e. crosses the blood-brain barrier), which is why they can make you ... May 8, 2019 · Answer. While Benadryl ( diphenhydramine) can safely be used once in a while as a sleep aid, long-term use is not recommended for multiple reasons. Even the intermittent use of Benadryl for sleep isn't generally recommended if you are elderly (over 65). Studies show that the elderly population doesn't metabolize Benadryl as quickly and are far ... In the drug realm, antihistamines such as diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton), cetirizine (Zyrtec), and loratadine (Claritin) can help with a stuffy nose are safe for the heart. Nasal sprays deliver a decongestant right where you need it. In theory, this should minimize cardiovascular effects.General The most commonly reported side effects included somnolence, dizziness, and incoordination. [ Ref] Nervous system Common (1% to 10%): Sedation/somnolence/sleepiness, drowsiness, unsteadiness, dizziness, headache, attention disturbance Rare (0.01% to 0.1%): Extrapyramidal effects, tremor, convulsionsMay 7, 2021 · There is evidence that the use of diphenhydramine among older adults or the elderly may result in serious side effects. This holds true esp. if you are older than age 65. The older a person becomes, the greater the risk of adverse effects. Benadryl is listed as potentially Inappropriate Medication in Older Adults ( also known as Beers criteria) People who take too much Benadryl start to experience many of the medication’s side effects. These can include mild symptoms, such as dry mouth, constipation, and tiredness. Usually, the more Benadryl a person takes, the worse these side effects become. In more severe Benadryl overdose cases, symptoms like seizures, irregular heartbeats, and ...Effects of Long-Term Diphenhydramine Use The information regarding the effects of prolonged Benadryl use is once again not known, as prospective studies analyzing its prolonged use do not exist. There are some exceptions to the above statement, however, the following are related to the long-term use of any antihistamine medication and ...Aug 1, 2023 · What are the side effects of Benadryl ... Diphenhydramine is only for short-term use until your symptoms clear up. ... (such as a long car ride, airplane or boat travel, amusement park rides, etc ... May 17, 2018 · Answer From Eric J. Olson, M.D. It's unlikely you'll become dependent on zolpidem (Ambien). Ambien and similar sleep medications can be effective, and they're much less likely to be habit-forming than some other drugs sometimes prescribed for sleep problems — for example, benzodiazepines, such as alprazolam (Xanax), lorazepam (Ativan) or ... Answer From Eric J. Olson, M.D. It's unlikely you'll become dependent on zolpidem (Ambien). Ambien and similar sleep medications can be effective, and they're much less likely to be habit-forming than some other drugs sometimes prescribed for sleep problems — for example, benzodiazepines, such as alprazolam (Xanax), lorazepam (Ativan) or ...In the drug realm, antihistamines such as diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton), cetirizine (Zyrtec), and loratadine (Claritin) can help with a stuffy nose are safe for the heart. Nasal sprays deliver a decongestant right where you need it. In theory, this should minimize cardiovascular effects.General The most commonly reported side effects included somnolence, dizziness, and incoordination. [ Ref] Nervous system Common (1% to 10%): Sedation/somnolence/sleepiness, drowsiness, unsteadiness, dizziness, headache, attention disturbance Rare (0.01% to 0.1%): Extrapyramidal effects, tremor, convulsions
May 25, 2023 · Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes. Not able to pass urine or change in how much urine is passed. A very bad skin reaction ( Stevens-Johnson syndrome / toxic epidermal necrolysis) may happen. . Rtxuv
It can sometimes cause a decrease in memory, confusion, and thinking issues. These side effects are more common in elders. In addition, taking Benadryl long-term might increase the risk of dementia. People aged> 65 who took medications such as Benadryl daily for over three years had an increased risk of dementia.Inhaled corticosteroids are often used daily as part of treatment for asthma caused or complicated by reactions to airborne allergy triggers (allergens). Side effects are generally minor and can include mouth and throat irritation and oral yeast infections. Some inhalers combine corticosteroids with long-acting bronchodilators.Aug 25, 2021 · Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision ... General The most commonly reported side effects included somnolence, dizziness, and incoordination. [ Ref] Nervous system Common (1% to 10%): Sedation/somnolence/sleepiness, drowsiness, unsteadiness, dizziness, headache, attention disturbance Rare (0.01% to 0.1%): Extrapyramidal effects, tremor, convulsionsJan 6, 2023 · Diphenhydramine is a common ingredient in sleeping aids; it is also used to treat allergies. While effective, the risk of serious diphenhydramine side effects—including confusion, dizziness, urinary retention, and liver or kidney issues—is increased in people age 65 and older. Long term use of some antihistamines may increase your risk of dementia. Diphenhydramine (Benadryl®) blocks the effects of a neurotransmitter called acetylcholine. This neurotransmitter is vital for memory and learning. Diphenhydramine increased the risk of dementia by 54% in one 3,000 patient study followed for seven years. May 7, 2021 · There is evidence that the use of diphenhydramine among older adults or the elderly may result in serious side effects. This holds true esp. if you are older than age 65. The older a person becomes, the greater the risk of adverse effects. Benadryl is listed as potentially Inappropriate Medication in Older Adults ( also known as Beers criteria) Jan 6, 2023 · Diphenhydramine is a common ingredient in sleeping aids; it is also used to treat allergies. While effective, the risk of serious diphenhydramine side effects—including confusion, dizziness, urinary retention, and liver or kidney issues—is increased in people age 65 and older. May 17, 2018 · Answer From Eric J. Olson, M.D. It's unlikely you'll become dependent on zolpidem (Ambien). Ambien and similar sleep medications can be effective, and they're much less likely to be habit-forming than some other drugs sometimes prescribed for sleep problems — for example, benzodiazepines, such as alprazolam (Xanax), lorazepam (Ativan) or ... Aug 25, 2021 · Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision ... Benadryl is a first-generation antihistamine, meaning it is one of the earlier drugs developed in this category of medications. First-generation antihistamines, like Benadryl, are often noted for their sedative side effects as they have the ability to travel to your brain (i.e. crosses the blood-brain barrier), which is why they can make you ...May 13, 2021 · The active ingredient in Benadryl is called diphenhydramine. Like any medication, Benadryl has several side effects. Some of the most common are: feeling sleepy or drowsy. dry mouth or throat ... Long term use of some antihistamines may increase your risk of dementia. Diphenhydramine (Benadryl®) blocks the effects of a neurotransmitter called acetylcholine. This neurotransmitter is vital for memory and learning. Diphenhydramine increased the risk of dementia by 54% in one 3,000 patient study followed for seven years.Mar 21, 2023 · There is very little scientific research about the long-term effects of Benadryl. Some side effects that may occur with long-term use include: constipation; blurred vision Uses Diphenhydramine is an antihistamine used to relieve symptoms of allergy, hay fever, and the common cold. These symptoms include rash, itching, watery eyes, itchy eyes /nose/throat, cough,...Benadryl may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly. Drinking alcohol can increase certain side effects of diphenhydramine. Ask a doctor or pharmacist before using any other cold, cough, allergy, or sleep medicine..