Benadryl Allergy/ Cold Side Effects, Before Using & Usefull Information

Benadryl is a more common name for diphenhydramine, an antihistamine, mainly used for the treatment of allergies. It is recommended widely by doctors to fight symptoms of hay fever or other allergies such as runny or clogged nose, itchy face, and hands, watery eyes and congestion. It is also used to treat insomnia, motion sickness, symptoms of common cold and tremor is Parkinsonism.

The medicine’s mode of function is blocking a naturally occurring substance in our bodies called histamine which the body makes during allergic reactions. The medicine can be used orally, injected into a vein and taken via injection to muscle.



This product does not entirely cure or reduce the length of the common cold, and it may lead to serious side effects. It is not recommended to give this medicine or any similar medicine to children under the age of 6 unless the doctor specifically advises you to.


Side Effects:

Common Side Effects:

The list includes few of the more common and mild side effects experienced while administrating the medicine. They are likely to be experienced towards the beginning stages and usually stop on own with time. If they persist for too long, call your doctor.

  • Drowsiness
  • Dry mouth
  • Dry nose and throat
  • Dizziness
  • Nausea
  • Headache
  • Feeling jittery (especially in children)
  • Tightness in the chest
  • Weakness
  • Constipation
  • Loss of appetite
  • Blurred vision


Rare Side Effects:

These are rare but very serious. Upon experiencing any, directly report to the ER to get treatment for them as they can have an everlasting impact.

  • Change in vision
  • Trouble passing urine
  • Trouble breathing
  • Rash
  • Swelling of the face or hands


How to use:

Follow the guidelines that the medicine comes with. If you are taking the medicine with your doctor’s prescription, then follow his instructions. Take the tablet, liquid form or capsule orally, with or without food. It is advised to measure the liquid form of this medicine by a measuring spoon rather than a household one to prevent the risk of under or overdosing on it.

The dissolvable tablet should be allowed to be dissolved on the tongue and then swallowed, with or without water. The chewable one should be chewed well before swallowing it for effectiveness.

The dosage is determined by age, medical history, and response to treatment. Do not take more or less than the prescribed amount of dose.

To prevent motion sickness, take the medicine 30 minutes prior to carrying out any traveling activities. Similarly, to sleep, take the medicine 30 minutes before bedtime. In case you don’t see any changes even after taking the medicine for 2 weeks, consult your doctor.




You should not give a child this medicine to make him sleepy. It is strictly advised to not give this medicine or similar ones to children under 2 for the common cold and flu-like symptoms. It can prove to be fatal for them.

Before using the product, tell your doctor about any allergies you might have. This medicine may contain inactive ingredients that can cause allergic reactions in people. Also, tell your doctor before using this drug if you have a medical history of the following:

  • Difficulty urinating
  • Breathing problems (asthma, emphysema)
  • High blood pressure
  • Heart problems
  • Intestine or stomach problems
  • Overactive thyroid
  • Seizures
  • Problems in liver

This drug can make you dizzy, cause blurred vision, and sleepiness so, do not try to drive or operate heavy machinery while using this medicine. The liquid solution, dissolvable tablet, chewable tablets, and strips may contain sugar which can increase the glucose levels of diabetics. Talk to your doctor if you are diabetic before administering this medicine.

Old people and children alike are more sensitive to the side effects of this drug such as sleepiness, drowsiness, constipation, and dizziness.

It is not suitable for expecting women and should only be used under dire conditions. It does pass into the breast milk and could potentially harm the infant so, talk to your doctor before breastfeeding your child while on this medicine.