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. Side effects of antihistamines that make you drowsy can include: sleepiness (drowsiness) and reduced co-ordination, reaction speed and judgement – do not drive or use machinery after taking these antihistamines. dry mouth. blurred vision. difficulty peeing. Side effects of non-drowsy antihistamines can include: headache. 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.Diphenhydramine is contraindicated in premature infants and neonates, as well as people who are breastfeeding. It is a pregnancy Category B drug. Diphenhydramine has additive effects with alcohol and other CNS depressants. Monoamine oxidase inhibitors prolong and intensify the anticholinergic effect of antihistamines. OverdoseFeb 6, 2023 · Benadryl is an over-the-counter antihistamine that contains the active ingredient diphenhydramine. People often use it to treat allergies. Because it causes drowsiness, some people take it as a ... Long-term use may also lead to harmful side effects. The inability to fall or stay asleep can have a significant, negative impact on your mood, productivity, and overall health. Insomnia can also ...Anxiety. Asthma. Car Sickness. Insomnia. Motion sickness. Reactions to Vaccines. Because one of the common side effect of Benadryl in dogs is drowsiness, your vet may use it to alleviate dog anxiety, particularly associated with traveling and motion sickness that may occur during plane rides or car trips.Oct 3, 2022 · Adults and children ≥12 years of age receiving conventional or orally disintegrating tablets: Headache, somnolence, fatigue, dry mouth. Fixed combination loratadine (the active ingredient contained in Claritin) pseudoephedrine sulfate preparations: Insomnia, dry mouth, headache, somnolence, nervousness, dizziness, fatigue. Diphenhydramine is a type of medicine called an antihistamine. It is used in some allergy and sleep medicines. Overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or on purpose. This article is for information only. DO NOT use it to treat or manage an actual overdose. Yes, certain side effects may be possible with long-term use of Benadryl. However, doctors usually don’t recommend Benadryl for long-term use. Instead, they typically advise short-term use of the drug to ease certain symptoms. The drug’s label information* for Benadryl does not specify any long-term side effects for this drug.Jun 5, 2019 · Moderate and Severe Benadryl Side Effects. If patients are using Benadryl for an allergic reaction, and experience any of the following moderate to severe Benadryl side effects they should consult their medical doctor or contact emergency medical services to minimize injury to their health: Contact and Atopic dermatitis ~1.0-10.0%; Confusion Jun 5, 2019 · 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. 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. Side Effects Of Benadryl. Overall, Benadryl is well tolerated and side effects are generally mild in severity. If they do occur, they should subside 4 to 6 hours after dosing, although this can be extended in those with kidney disease and in the elderly. Below, we discuss the most common side effects associated with Benadryl.May 22, 2013 · 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 ... Anxiety. Asthma. Car Sickness. Insomnia. Motion sickness. Reactions to Vaccines. Because one of the common side effect of Benadryl in dogs is drowsiness, your vet may use it to alleviate dog anxiety, particularly associated with traveling and motion sickness that may occur during plane rides or car trips.Diphenhydramine is a type of medicine called an antihistamine. It is used in some allergy and sleep medicines. Overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or on purpose. This article is for information only. DO NOT use it to treat or manage an actual overdose. 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. Diphenhydramine is a type of medicine called an antihistamine. It is used in some allergy and sleep medicines. Overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or on purpose. This article is for information only. DO NOT use it to treat or manage an actual overdose.Diphenhydramine, which is available as an over-the-counter medication, is a first-generation antihistamine that is used in a variety of conditions to treat and prevent dystonias, insomnia, pruritis, urticaria, vertigo, and motion sickness. It also possesses local anesthetic properties for those patients who have allergies to other, more commonly used local anesthetics; however, this is an off ...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 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 3, 2022 · Applies to diphenhydramine: oral capsules and tablets, parenteral injection. Side effects include: Sedation, sleepiness, dizziness, disturbed coordination, epigastric distress, thickening of bronchial secretions. 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.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 ...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).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 ... 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.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.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.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. 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 ... Jun 5, 2019 · Moderate and Severe Benadryl Side Effects. If patients are using Benadryl for an allergic reaction, and experience any of the following moderate to severe Benadryl side effects they should consult their medical doctor or contact emergency medical services to minimize injury to their health: Contact and Atopic dermatitis ~1.0-10.0%; Confusion 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. 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 ...• Common side effects of montelukast include upper respiratory infection, fever, headache, sore throat, cough, stomach pain, diarrhea, earache or ear infection, flu, runny nose, and sinus infection. Jun 5, 2019 · The Major Antihistamine Effects of Diphenhydramine Prevents Histamine-Mediated: constriction of respiratory smooth muscle. rapid vasodilation in blood vessels. increased capillary permeability and subsequent edema. sensations of itching, pain, and “flare” formation. increase in heart rate and strength of contraction. Jun 5, 2019 · Moderate and Severe Benadryl Side Effects. If patients are using Benadryl for an allergic reaction, and experience any of the following moderate to severe Benadryl side effects they should consult their medical doctor or contact emergency medical services to minimize injury to their health: Contact and Atopic dermatitis ~1.0-10.0%; Confusion The symptoms you have noticed are very likely the result of long-term heavy antihistamine use. Antihistamines tend to dry up the nose, which is why they are so effective in humans with allergic rhinitis, but the way they do that is by making the secretions thicker. In dogs, we are not worried much about a runny nose, but we are concerned about ...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 ...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. May 17, 2019 · 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 ... Benadryl is a brand of diphenhydramine. As far as long term effects. Look up Benadryl or diphenhydramine and dementia on google then come back to me. I am a 10 year 50mg daily user of diphenhydramine and am slowly stopping this stuff. The past few weeks I have been reducing to 1/2. Trust me, take this for long term and you increase risk of ...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.Diphenhydramine or : Benadryl (diphenhydramine) may cause sedation the next day (due to its long half-life), decreased alertness, diminished cognitive function, delirium, ... Read More. Created for people with ongoing healthcare needs but benefits everyone. Learn how we can help. 5k views Reviewed >2 years ago. 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.Jun 15, 2016 · 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. • Common side effects of montelukast include upper respiratory infection, fever, headache, sore throat, cough, stomach pain, diarrhea, earache or ear infection, flu, runny nose, and sinus infection. Diphenhydramine is contraindicated in premature infants and neonates, as well as people who are breastfeeding. It is a pregnancy Category B drug. Diphenhydramine has additive effects with alcohol and other CNS depressants. Monoamine oxidase inhibitors prolong and intensify the anticholinergic effect of antihistamines. OverdoseMay 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) Jun 14, 2023 · The symptoms you have noticed are very likely the result of long-term heavy antihistamine use. Antihistamines tend to dry up the nose, which is why they are so effective in humans with allergic rhinitis, but the way they do that is by making the secretions thicker. In dogs, we are not worried much about a runny nose, but we are concerned about ... Side Effects Of Benadryl. Overall, Benadryl is well tolerated and side effects are generally mild in severity. If they do occur, they should subside 4 to 6 hours after dosing, although this can be extended in those with kidney disease and in the elderly. Below, we discuss the most common side effects associated with Benadryl.Benadryl is a brand of diphenhydramine. As far as long term effects. Look up Benadryl or diphenhydramine and dementia on google then come back to me. I am a 10 year 50mg daily user of diphenhydramine and am slowly stopping this stuff. The past few weeks I have been reducing to 1/2. Trust me, take this for long term and you increase risk of ...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 ...Long-term use may also lead to harmful side effects. The inability to fall or stay asleep can have a significant, negative impact on your mood, productivity, and overall health. Insomnia can also ...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. 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 ...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 ... 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.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 ... Jun 23, 2009 · The most common side effect is drowsiness, causing mild disorientation or dementia. An elderly person may fall asleep during normal activities. This sedating effect can cause unsteadiness. A person over 60 should get up slowly from a sitting or prone position to avoid fainting. If you take an anti-anxiety drug, it is not advisable to use ... Diphenhydramine is contraindicated in premature infants and neonates, as well as people who are breastfeeding. It is a pregnancy Category B drug. Diphenhydramine has additive effects with alcohol and other CNS depressants. Monoamine oxidase inhibitors prolong and intensify the anticholinergic effect of antihistamines. OverdoseDear Alice, I've experimented with the abuse of Benadryl on a few occasions now and have been absolutely blown off to another world, I was just curious as to what the side affects, long or short-term, can look like, and what the dangers are of abusing this drug (acetaminophen free).Diphenhydramine is a type of medicine called an antihistamine. It is used in some allergy and sleep medicines. Overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or on purpose. This article is for information only. DO NOT use it to treat or manage an actual overdose. Side effects of antihistamines that make you drowsy can include: sleepiness (drowsiness) and reduced co-ordination, reaction speed and judgement – do not drive or use machinery after taking these antihistamines. dry mouth. blurred vision. difficulty peeing. Side effects of non-drowsy antihistamines can include: headache. The symptoms you have noticed are very likely the result of long-term heavy antihistamine use. Antihistamines tend to dry up the nose, which is why they are so effective in humans with allergic rhinitis, but the way they do that is by making the secretions thicker. In dogs, we are not worried much about a runny nose, but we are concerned about ...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)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. 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 ...Diphenhydramine or : Benadryl (diphenhydramine) may cause sedation the next day (due to its long half-life), decreased alertness, diminished cognitive function, delirium, ... Read More. Created for people with ongoing healthcare needs but benefits everyone. Learn how we can help. 5k views Reviewed >2 years ago. Jan 10, 2023 · hoarseness. lack or loss of strength. pain in the lower back or side. swelling of the hands, feet, or lower legs. trembling or shaking. Common side effects that do require medical attention ... Diphenhydramine, which is available as an over-the-counter medication, is a first-generation antihistamine that is used in a variety of conditions to treat and prevent dystonias, insomnia, pruritis, urticaria, vertigo, and motion sickness. It also possesses local anesthetic properties for those patients who have allergies to other, more commonly used local anesthetics; however, this is an off ...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, runny ...Yeah, look at r/dph.Datura is even worse. It's like dph, but way more likely to kill you or make you go blind. Shadow people and spiders and having full conversations with people who don't exist usually only happens in the 400+ category. Between 150mg and there, it's usually just having to piss but being unable to, dysphoria/fear, be 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. 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,...“The antihistamine diphenhydramine is only approved for management of short-term or temporary sleep difficulties, particularly in those people who have problems falling asleep,” Dr. What are the negative effects of Benadryl? Drowsiness, dizziness, constipation, stomach upset, blurred vision, or dry mouth/nose/throat may occur. If any of ...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 ...Jun 8, 2022 · 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). While there are cases of misuse and abuse, withdrawal symptoms from Benadryl are rare, even with long term use. Nevertheless, Benadryl has strong anticholinergic effects, and there have been reports of 'anticholinergic withdrawal' in some individuals taking Benadryl for extended periods of time. Potential symptoms include:Feb 6, 2023 · Benadryl is an over-the-counter antihistamine that contains the active ingredient diphenhydramine. People often use it to treat allergies. Because it causes drowsiness, some people take it as a ... 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 ...The Major Antihistamine Effects of Diphenhydramine Prevents Histamine-Mediated: constriction of respiratory smooth muscle. rapid vasodilation in blood vessels. increased capillary permeability and subsequent edema. sensations of itching, pain, and “flare” formation. increase in heart rate and strength of contraction.
Section snippets Sedation. The sedation associated with diphenhydramine is one of the most acknowledged effects of this medication. Indeed, it is frequently used as a medication to treat insomnia. 3 The sedative effect of diphenhydramine is related to its easy penetration of the blood-brain barrier. 4 In the brain, diphenhydramine interferes with H 1 receptors, which causes drowsiness and .... Buffet mas cercano
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.Take one to two 50mg tablets at least 30 minutes prior to bedtime. The maximum dose of two tablets works best for sleep. You can take Dramamine with or without food, but make sure you take a dose with a full glass of water 1 2. Swallow tablets whole; don't crush or chew. Plan on taking Dramamine four to six hours prior to waking for the next ...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.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.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.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.Nov 14, 2022 · 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 ... Jun 15, 2016 · 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. Jun 15, 2016 · 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 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. 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.hoarseness. lack or loss of strength. pain in the lower back or side. swelling of the hands, feet, or lower legs. trembling or shaking. Common side effects that do require medical attention ...There could be both short- and long-term consequences. Worried about the side effects of Ambien, Lunesta or other sleep aids? ... Diphenhydramine is an anticholinergic drug, which means it blocks ....