• Tablets: Swallow Durahist D tablets whole with water. Can be taken with or without food.
• Liquid: When liquid is taken, use measuring device to measure dose. Shake the bottle well before each dose.

• Use Durahist D as directed by your doctor. Take Durahist D every 4-6 hours as needed for pain relief, but do not take more than the maximum number of doses per day.
• If you forget to take a dose, take the dose when you remember and do not double doses to catch up on a missed dose.
• Reminder: Do not take Durahist D just before going to bed unless you don’t mind being sleepy as a result of the diphenhydramine.

Durahist D contains two active components with different mechanisms of action for prevention and relief from allergic symptoms and reactions:

• Diphenhydramine (Antihistamine): Diphenhydramine inhibits the action of histamine, a chemical the body releases when an allergic response occurs. Histamine leads to itching, sneezing, runny nose, and watery eyes. Inhibiting the histamine receptors in the body, diphenhydramine prevents such allergy symptoms.

• Pseudoephedrine (Decongestant): Pseudoephedrine is a decongestant sympathomimetic drug. It achieves this effect by contracting the blood vessels of the nose, and this causes nasal swelling and decrease in congestion. This makes breathing easier through the nose and eliminates sinus pressure.

Both active ingredients combined work to both help relieve the allergic symptoms (e.g., sneezing, nasal discharge, and itching) and the nasal congestion usually experienced with these.

Although Durahist D possesses the capability to alleviate allergic symptoms, it has side effects, which are:

Common Side Effects:

• Drowsiness: Diphenhydramine induces drowsiness and makes it hard to stay awake. This is particularly common when taking Durahist D during the day.
• Dry Mouth and Throat: Dry throat and mouth are one of the usual side effects of the antihistamine drug, diphenhydramine.
• Dizziness: Others will dizzy, particularly when getting up from a lying position or sitting up or when changing positions too rapidly.

Serious Side Effects:

• Rapid or Irregular Heartbeat: Pseudoephedrine can lead to increased heart rate or irregular heartbeat in some people.
• Urination Difficulty: Trouble urinating is experienced by elderly individuals, particularly those with prostate conditions.
• Severe Allergic Reactions: Certain people may experience allergic reactions such as swelling, rash, or difficulty in breathing in some rare instances. Immediately seek medical help if any of these are experienced.

 If you are suffering from violent drowsiness, respiratory distress, or other symptoms of an acute life-threatening allergic reaction, stop using Durahist D and talk to your doctor.

Before taking Durahist D, you should be aware of the following precautions:

• Alcohol and Sedatives: Drink alcohol and other sedative medications under Durahist D administration because the effect would enhance sedative activity by diphenhydramine.
• Medical Conditions: Ask your physician before using Durahist D if you have any heart ailment, hypertension, glaucoma, or liver or kidney disease.
• Pregnancy and Breastfeeding: Do not use Durahist D during pregnancy, particularly the third trimester. When breast-feeding, consult your doctor to assess risks.
• Children: Durahist D should not be given to children under the age of 6 unless instructed by your doctor. It may cause drowsiness in children.

• Other Antihistamines: Combination with other antihistamines or with cold and allergy products will add to the risk of drowsiness, dry mouth, and dizziness.
• Monoamine Oxidase Inhibitors (MAOIs): Durahist D combined with MAOIs (depression medication) will cause harmful interactions and should not be used.
• Blood Pressure Medicine: Pseudoephedrine is a blood pressure drug and may be taken with blood pressure medication. If you are taking a blood pressure medication, you should speak to your physician before taking Durahist D.
• Alcohol: Alcohol will increase the sedative effect of diphenhydramine and must not be used with treatment with Durahist D.

Dosage of Durahist D varies with the age of the patient and the seriousness of the symptoms:

• Adults and Children 12 years and over: One tablet or one dose of liquid every 4 to 6 hours as necessary. Not more than 6 doses a day.
• Children 6 to 12 years: Half adult dose, and not exceeding 3 doses a day.
• Children under 6 Years: Durahist D should not be used in children under 6 years old unless on prescription by a physician.

• Durahist D is an over-the-counter drug, but it is advisable that one sees a doctor before using it, particularly if one has underlying medical conditions, is pregnant, or is using other drugs. Durahist D must be used as indicated by the manufacturer or as advised by a doctor.

• What is Durahist D used for?
  It treats runny or stuffy nose, sneezing, watery/itchy eyes, and sinus congestion from colds, flu, or allergies. 

• What active ingredients are in Durahist D?
  It contains dexchlorpheniramine, methscopolamine, and pseudoephedrine. 

• How does each ingredient work?
  Dexchlorpheniramine is an antihistamine; methscopolamine reduces secretions; pseudoephedrine is a decongestant. 

• Which drug classes does Durahist D belong to?
  It falls under substituted alkylamines, sympathomimetics, ophthalmic anticholinergics, and belladonna alkaloids (semisynthetic, quaternary ammonium compounds).

• Is Durahist D a controlled substance?
  No, it is not a controlled substance. 

• Is Durahist D available in generic form?
  The components are generic, but the brand Durahist D itself appears discontinued. 

• Is Durahist D still available on the market?
  No, it has been discontinued. 

• What are common side effects of Durahist D?
  Side effects include dry mouth, blurred vision, dizziness, nausea, restlessness, and urinary difficulty. 

• Are there serious warnings associated with Durahist D?
  Yes—avoid if recently on MAO inhibitors. Alcohol and stimulants may worsen side effects, and do not use beyond 7 days. 

• Can children safely use Durahist D?
  Caution is advised; some formulations may not be safe for children under 6 or 12 years.

• Does Durahist D cure the common cold or flu?
  No—it helps relieve symptoms but does not cure or shorten illness duration. 

• How should Durahist D be dosed?
  The typical form is extended-release tablets; specific dosing depends on the product—follow medical guidance. 

• What are key drug interactions for Durahist D?
  Important interactions include MAO inhibitors and other cold/allergy meds containing antihistamines or decongestants. 

• Can Durahist D cause cardiovascular issues?
  Yes—potential effects include irregular heart rate, palpitations, or hypotension. 

• Does Durahist D affect the nervous system?
  Possible effects include drowsiness, nervousness, insomnia, dizziness, or tremors. 

• Are ocular issues possible with Durahist D?
  Yes, blurred vision and dryness of eyes/nose may occur. 

• What gastrointestinal symptoms can Durahist D cause?
  Nausea, bloating, heartburn, constipation, and dry mouth or throat have been reported. 

• Can Durahist D affect urinary function?
  Yes—difficulty urinating or urinary retention, especially in those with prostatic hypertrophy. 

• Is Durahist D suitable during pregnancy?
  Risk data is available, but discontinuation suggests consult a healthcare provider before any use. 

• When should one seek a doctor’s advice regarding Durahist D use?
  If symptoms persist, worsen, cause fever, or if serious side effects appear.