Diphenhydramine is used to fight irritation, redness and itchy eyes, watery eyes, sneezing and runny nose associated with allergies or colds. It is also used to treat mild coughs caused by irritation to the throat and respiratory tract.

 

Among its other possible uses include prevention and treatment of motion sickness, insomnia, tremors associated with the early stages of Parkinson’s disease or movement problems that appear as a side effect of the drug.  

 

What is Diphenhydramine?

Diphenhydramine is an antihistamine drug. It works by blocking the activity of histamine, which is the substance responsible for the appearance of allergy symptoms.

 

How should Diphenhydramine be taken?

Typically, Diphenhydramine is taken when needed, however, in some cases your doctor may prescribe regular intake. Among possible pharmaceutical forms include tablets (also buccal tablets), capsules, powders and solutions. Sometimes, it is sold in combination with other medications (painkillers, antipyretics or decongestants).

 

Typically, for relieving allergy symptoms, it is recommended to take Diphenhydramine every 4-6 hours; whereas, for fighting sickness, it should be taken 30 minutes before a meal and eventually intake may need to be repeated. For treatment against insomnia, Diphenhydramine should be taken 30 minutes before bedtime. Lastly, for treatment against uncontrollable movements, four doses are recommended daily.  

 

Side effects associated with Diphenhydramine

Possible side effects include the following:

  • Drying of mouth, nose and throat
  • Drowsiness
  • Dizziness
  • Nausea
  • Vomiting
  • Loss of appetite
  • Constipation
  • Increased chest congestion
  • Headache
  • Muscle weakness
  • Excitation (especially in children)
  • Nervousness

 

It is important to contact a doctor immediately in the case in which the drug triggers:

  • Vision problems
  • Difficult or painful urination

 

 

 

Contraindications and warnings associated with the use of Diphenhydramine

Diphenhydramine can cause dangerous drowsy while driving or operating dangerous machinery. Alcohol can exacerbate this side effect.

Products containing diphenhydramine used to treat coughs and colds should not be given to children under the ages of 4. For children up to 11 years old, caution must also be used.

Diphenhydramine medications may also be contraindicated in case of phenylketonuria.

 

Before taking Diphenhydramine, it is important to inform your doctor:

  • If you have any allergies to the active substance, its excipients or any other drug
  • If you are taking any other medications, herbal remedies or supplements. Mentioning in particular:  products containing diphenhydramine, other medicines for colds or allergies, anxiety medications, medication for depression or seizures, muscle relaxants, narcotics, sedatives, sleeping pills and tranquilizers
  • If you suffer (or have suffered) from asthma, emphysema, chronic bronchitis, other lung diseases, glaucoma, ulcers, urination difficulty associated with prostatic hypertrophy, heart disease, high blood pressure, seizures, phenylketonuria or hyperthyroidism
  • If you have to follow a low-sodium diet
  • If you are pregnant or breastfeeding

 

 

It is important to inform surgeons and dentists of any ongoing treatment with Diphenhydramine.