What is the Difference Between Diphenhydramine and Doxylamine

The key difference between diphenhydramine and doxylamine is that diphenhydramine is a stronger medication, whereas doxylamine is a smoother medication.

Diphenhydramine and doxylamine are antihistamine medications useful in treating allergic reactions. However, these drugs have different efficiencies and different side effects.

CONTENTS

1. Overview and Key Difference
2. What is Diphenhydramine  
3. What is Doxylamine
4. Diphenhydramine vs Doxylamine in Tabular Form
5. Summary – Diphenhydramine vs Doxylamine

What is Diphenhydramine?

Diphenhydramine is a medication that is useful as an antihistamine. It is important in treating allergic reactions. We can also use this medication to treat insomnia and some symptoms of the common cold, tremors in parkinsonism, and nausea. This drug can act as a first-generation H1-antihistamine, which can work by blocking certain effects of histamine. Moreover, this medication is useful as an anticholinergic medicine.

We can administrate this antihistamine drug through oral administration, injection into a vein, injection into a muscle, or we can simply apply it on the skin as a topical treatment. As a maximum, the effects of this drug start at around 2 hours and can last for about 7 hours.

The most common side effects of diphenhydramine medication include sleepiness, dizziness, blurred vision, and an upset stomach. Moreover, this medication is not recommended for children and the elderly. Although there is no evidence of any harm, this drug is not given to pregnant women or breastfeeding women.

The bioavailability of diphenhydramine is about 40-60%, and its protein binding ability is about 99%. Its metabolism takes place in the liver, and the excretion occurs through urine or faeces. In healthy adults, the elimination half-life of diphenhydramine is 2.4-9.3 hours.

What is Doxylamine?

Doxylamine is a medication that is useful as an antihistamine and as a short-time sedative and a hypnotic. Moreover, it is useful in combination with other compounds and provides night-time allergy and cold relief.

Generally, doxylamine provides a calmative effect in drug preparations and contains the analgesics paracetamol and codeine. Typically, this drug is prescribed along with vitamin B6 in order to avoid morning sickness during pregnancy. The major route of administration for this drug is oral. However, it can be administered through the intranasal method. Administering it as an intranasal drug gives a high bioavailability (about 70%). The metabolism of this medication occurs as hepatic metabolism. The excretion of this medication occurs through urine and feces. The elimination half-life of this drug is about 10 to 12 hours.

There can be some side effects which include dry mouth, ataxia, urinary retention, drowsiness, memory problems, inability to concentrate, hallucination, etc.

What is the Difference Between Diphenhydramine and Doxylamine?

Diphenhydramine and doxylamine are antihistamine medications useful in treating allergy reactions. The key difference between diphenhydramine and doxylamine is that diphenhydramine is a stronger medication, whereas doxylamine is a smoother medication. Moreover, the efficiency of diphenhydramine is higher than the efficiency of doxylamine. However, both these medications show side effects; the side effects of diphenhydramine include sleepiness, poor condition, and upset stomach and the most common side effects of doxylamine include dry mouth, ataxia, urinary retention, drowsiness, memory problems, inability to concentrate, hallucination, etc.

The following infographic lists the differences between diphenhydramine and doxylamine in tabular form for side by side comparison.

Summary – Diphenhydramine vs Doxylamine

Diphenhydramine and doxylamine are antihistamine medications useful in treating allergy reactions. The key difference between diphenhydramine and doxylamine is that diphenhydramine is a stronger medication, whereas doxylamine is a smoother medication. In addition, the efficiency of diphenhydramine is higher than the efficiency of doxylamine.

Reference:

1. Don Makaveli. “Misc – Doxylamine Succinate vs Diphenhydramine?” Bluelight.org, 5 Mar. 2013.

Image Courtesy:

1. “Diphenhydramine 2D skeletal” By Fvasconcellos (talk · contribs) – Own work (Public Domain) via Commons Wikimeida
2. “Doxylamine” (Public Domain) via Commons Wikimedia