What is Diphenhydramine and how is it made?

Diphenhydramine is an antihistamine used to control allergy symptoms such as itchy, watery eyes, airway irritation, sneezing, and coughing. It can also be used for insomnia and is often included in such antihistamines as Benadryl®. This versatile antihistamine can also be used to treat motion sickness and involuntary movements in the early stages of Parkinson's disease. It should never be used to cause drowsiness in children younger than 12 years of age as it could cause serious side effects. One should follow a doctor's advice when dosing young children with any antihistamine.

Diphenhydramine Used as an Antihistamine

Diphenhydramine comes in a variety of antihistamine forms and can be taken every four to six hours. It can be purchased as an antihistamine tablet, timed-release tablet, liquid-filled gel capsule, liquid, dissolving strips, and a powder. If it is being used to control motion sickness, it should be taken 30 minutes before departure and before meals. It can also be used as an injection for cases when an oral dose is impractical.

What form is Diphenhydramine available?

Diphenhydramine comes alone or combined with cold and flu antihistamine remedies. One should be sure to check product labels before buying more than one antihistamine to avoid and overdose. This over-the-counter antihistamine is recommended for adults and should never be given to young children unless directed by a physician.

When taking the liquid form, one should follow the directions on the antihistamine package and never use a regular spoon from their silverware to measure the dosage. If one does not have a medicine spoon or cup, they should use a cooking measuring spoon to get the prescribed amount of the antihistamine.

Dissolving strips and tablets of the antihistamine should be placed on the tongue. Once the strip or tablet has dissolved, then they are swallowed. If one wishes, an individual may follow it with a bottle of water.

Tablets, liquid gels, and capsules should be swallowed whole with water. Do not try to cut, crush or break them in half.

How is Diphenhydramine Hydrochloride Made?

Diphenhydramine Hydrochloride is a white crystalline power that is both odorless and tasteless. It is soluble in both alcohol and water. It is produced as a power or liquid and can be formed into antihistamine capsules or tablets.

Inactive ingredients in the antihistamine usually include magnesium stearate, lactose monohydrate, and anhydrous lactose.

Antihistamine Process in the Body

A single dose of the antihistamine is quickly absorbed and the active ingredients reach full effect in approximately one hour and usually last four to six hours. Very little of the antihistamine is excreted through the urine, and it is widely distributed throughout the body. However, some degraded antihistamines appear in the urine that has undergone a metabolic conversion.

Diphenhydramine Summary

Taken properly, Diphenhydramine is a safe, effective antihistamine that can be taken during allergy and hay fever season without harmful side effects. It can lessen the symptoms of a cold or flu and provide much needed rest. Pregnant women and nursing mothers should avoid using any antihistamine unless recommended by their physician.