Stroke Survivors: Is Diphenhydramine Safe?

Diphenhydramine is a first-generation antihistamine used to treat allergies, insomnia, and symptoms of the common cold. It is also used to treat nausea and tremors in parkinsonism. It is available as a generic medication and is sold under various brand names, including Benadryl. While it is effective in treating allergies and insomnia, its use is not recommended in young children or the elderly, and it is included on the Beers list of drugs to avoid in the elderly due to its strong anticholinergic effects. Diphenhydramine has also been associated with an increased risk of stroke, with one study finding a 46% to 65% increased risk for individuals taking over-the-counter sleep medication containing diphenhydramine for 1-14 or 15+ days per month, respectively. Therefore, it is essential to consult a doctor or pharmacist before taking diphenhydramine, especially for individuals who have had a stroke or are at risk of stroke.

Diphenhydramine's side effects

Diphenhydramine may cause several side effects. Some of these may be serious, so if you experience any of the following, you should call your doctor immediately:

• Difficulty or pain when urinating
• Mental or mood changes, such as restlessness or confusion
• Fast or irregular heartbeat
• Seizures
• Allergic reaction, including rash, itching or swelling of the face, tongue or throat
• Severe dizziness or trouble breathing

Other side effects may include:

• Dry mouth, nose or throat
• Increased chest congestion
• Excitement (especially in children)
• Dizziness
• Drowsiness
• Loss of coordination
• Constipation
• Upset stomach
• Dry eyes
• Blurred vision
• Daytime drowsiness or "hangover" feeling after night-time use

Diphenhydramine's contraindications

Diphenhydramine is an antihistamine drug used to treat allergic reactions, insomnia, cough, motion sickness, and Parkinsonism. It is available under various brand names, including Benadryl, Nytol, and Sominex. While generally safe, it does have some contraindications and side effects that users should be aware of.

Hypersensitivity

Diphenhydramine should not be taken by individuals with a hypersensitivity or allergy to the drug or other antihistamines of similar chemical structure.

Conditions and Pre-Existing Health Issues

Those with the following conditions should use diphenhydramine with caution:

• Lower respiratory tract diseases, such as acute asthma (the use of diphenhydramine in such cases is controversial)
• Angle-closure glaucoma
• Prostatic hypertrophy
• Stenosing peptic ulcer
• Pyloroduodenal obstruction
• Thyroid dysfunction
• Cardiovascular disease
• Hypertension
• Liver or kidney disease
• Bladder obstruction or other urination problems
• A colostomy or ileostomy
• Heart disease
• Low blood pressure
• A thyroid disorder

Pregnancy and Breastfeeding

The use of diphenhydramine during pregnancy may be acceptable, but only if clearly needed, as there are no adequate and well-controlled studies in pregnant women. It is recommended that women who are pregnant or breastfeeding consult a doctor before taking this medication.

Age

Diphenhydramine is not recommended for premature infants, neonates, or children under the age of two. Older adults may also be more likely to experience side effects.

Drug Interactions

Diphenhydramine may interact with other medications, including:

• Eliglustat (severe interaction)
• At least 11 other drugs (serious interactions)
• At least 265 other drugs (moderate interactions)
• At least 34 other drugs (minor interactions)

Additionally, it may increase the effects of alcohol and other central nervous system depressants, such as sedatives, hypnotics, and tranquilizers.

Other

Diphenhydramine may cause drowsiness and dizziness and may impair driving or the operation of heavy machinery. It should not be used to make a child sleepy.

Diphenhydramine's interactions with other medicines

Diphenhydramine is known to interact with several medicines, including prescription and over-the-counter drugs, vitamins, and herbal products. It is important to consult a doctor or pharmacist before taking diphenhydramine with any other medication to avoid potential drug interactions. Here are some of the key interactions to be aware of:

• Central nervous system depressants: Diphenhydramine can cause drowsiness and dizziness. When combined with other central nervous system depressants, such as opioid pain relievers, alcohol, marijuana, sleep aids, anxiety medications, muscle relaxants, or other antihistamines, these effects may be enhanced.
• Medications for specific conditions: Diphenhydramine may interact with medicines for various conditions. For example, it can interact with codeine (an opioid pain reliever), lorazepam (an anxiety medication), ondansetron (an anti-nausea medication), and lorazepam (a seizure medication).
• Anticholinergics: Diphenhydramine has anticholinergic properties, which means it can block the action of acetylcholine, a neurotransmitter in the body. When taken with other anticholinergic medications, the anticholinergic effects may be enhanced, leading to side effects such as dry mouth, blurred vision, constipation, and urinary retention.
• CYP450 enzymes: Diphenhydramine is metabolized by CYP450 enzymes in the liver, including CYP2D6, CYP1A2, CYP2C9, and CYP2C19. Inhibitors or inducers of these enzymes may affect the metabolism of diphenhydramine and alter its effectiveness or side effects.
• Other antihistamines: Diphenhydramine should not be taken with other antihistamines, including topical antihistamines applied to the skin, as this may lead to an increased risk of side effects.
• Medications affecting the heart: Diphenhydramine can have cardiovascular effects, so it is important to use caution when taking it with medications that affect the heart, such as those for heart disease, low blood pressure, or high blood pressure.
• Medications affecting the liver or kidneys: Diphenhydramine is metabolized by the liver and excreted by the kidneys. Therefore, it is important to use caution when taking it with medications that affect liver or kidney function, as this may impact the metabolism and excretion of diphenhydramine.

Diphenhydramine's overdose effects

Diphenhydramine is an antihistamine medication that can be purchased over the counter and is used to treat allergies, hay fever, and the common cold. It can also be used to treat motion sickness and insomnia. However, it is important to be aware of the dangers of overdose when taking this medication.

Diphenhydramine overdose can occur accidentally or on purpose and can have life-threatening consequences. The symptoms of a diphenhydramine overdose include:

• Difficulties urinating
• Increased heart rate
• Tachycardia
• Blurred vision
• Dry mouth
• Nausea
• Constipation
• Impotence
• Urinary retention
• Hyperthermia
• Decreased bowel sounds
• Delirium/psychosis
• Seizures
• Coma
• Death

If someone is displaying any of these symptoms and you suspect a diphenhydramine overdose, it is important to call emergency services immediately. The recommended course of action in the event of a suspected overdose is to call 911 or poison control, which can be reached by calling the Poison Help Hotline at 1-800-222-1222.

The treatment for diphenhydramine overdose may include general condition management and symptomatic treatments. Benzodiazepines may be administered for convulsions, physostigmine for acetylcholinesterase inhibition, sodium bicarbonate for ventricular arrhythmia, and VA-ECMO for hemodynamic support. It is important to note that there is currently no antidote specifically for diphenhydramine toxicity.

Diphenhydramine's effects on children

Diphenhydramine is an antihistamine medication that can be used to treat allergies, hay fever, and the common cold in children aged 6 and above. It can also be used to treat nausea, vomiting, and dizziness caused by motion sickness. It is important to note that diphenhydramine should not be used to cause sleepiness in children.

When used in children, diphenhydramine may cause side effects such as excitement, dry mouth, nose, and throat, increased chest congestion, and blurred vision. It can also cause drowsiness, dizziness, and loss of coordination, which may impair their ability to perform hazardous activities. Therefore, caution must be exercised when giving diphenhydramine to children, and it should only be administered under the advice and supervision of a doctor or pharmacist.

The dosage of diphenhydramine for children depends on their age, medical condition, and response to treatment. It is available in various forms, including tablets, capsules, liquids, and creams, and should be taken as directed by a healthcare professional. It is important to carefully follow the dosage instructions and not to give diphenhydramine to children below the recommended age, as it can cause serious side effects or even death in very young children.

In summary, diphenhydramine can be an effective treatment for allergies, hay fever, and motion sickness in children when used appropriately under medical supervision. However, it is essential to be cautious about its side effects and potential interactions with other medications.

Frequently asked questions