- 10 Common Allergy Triggers Slideshow Pictures
- Take the Quiz on Allergies
- Nasal Allergy Relief Products Slideshow
- What are antihistamine shots, and what are the medical uses for this type of drug?
- What are examples of generic and brand names of antihistamine injections available in the US?
- What are the side effects of antihistamine shots?
- Which drugs interact with antihistamine shots?
- What formulations of antihistamine injections are available?
- Is it safe to have antihistamine shots during pregnancy or while breastfeeding?
What are antihistamine shots, and what are the medical uses for this type of drug?
Antihistamine shots are prescription medications that are used for the rapid medical treatment of conditions such as:
- Allergic reactions (a severe allergy to a substance)
- Motion sickness
- To induce sedation when injected into a patient
Antihistamine shots also are used to alleviate extra pyramidal symptoms of antipsychotic medications.
Histamine is a chemical that causes many signs and symptoms of allergy. Histamine is released from histamine-storing cells (mast cells) and attaches to other cells that have receptors for histamine on their surfaces. Histamine stimulates the cells to release chemicals that produce effects that we associate with allergy. Antihistamines blocks histamine receptors and thus prevent activation of cells with histamine receptors by histamine.
What are examples of generic and brand names of antihistamine injections available in the US?
Examples of the brand and generic names for this type of medication include:
- diphenhydramine (Benadryl)
- promethazine (Phenergan)
- hydroxyzine hydrochloride (Restall, Vistacot)
- dimenhydrinate (Dramamine, Driminate)
The formulation of this drug is available by prescription only to treat a patient with a specific condition. It is not available over-the-counter (OTC). Other formulations of antihistamine drugs are available over-the-counter that treat medical conditions such as:
Examples of OTC medicine available over-the-counter include:
What are the side effects of antihistamine shots?
The common side effects of this type of medication include:
Which drugs interact with antihistamine shots?
Antihistamine injections have additive effects if used with alcohol or other central nervous system depressant medications such as:
- alprazolam (Xanax)
- clonazepam (Klonopin)
- diazepam (Valium)
- zolpidem (Ambien)
- zaleplon (Sonata)
- butalbital/acetaminophen/caffeine (Fioricet)
- morphine (MSIR)
- hydromorphone (Dilaudid)
- buprenorphine (Buprenex)
- azelastine (Astelin)
Effects of antihistamines are prolonged if combined with monoamine oxidase inhibitors (MAOIs) such as:
- phenelzine (Nardil)
- selegiline (Zelapar, Emsam, and Eldepryl)
- tranylcypromine (Parnate)
- procarbazine (Matulane)
- rasagiline (Azilect)
- isocarboxazid (Marplan).
Antihistamine injections should be used with caution if the patient under medical care and receiving treatment with an MAOI drug.
What formulations of antihistamine injections are available?
- Prescription antihistamine injections are available in injection form.
- Diphenhydramine, promethazine, and dimenhydrinate are administered intramuscularly and intravenously.
- Hydroxyzine hydrochloride is administered only intramuscularly.
- Antihistamine injections are not recommended for administration via subcutaneous route.
Is it safe to have antihistamine shots during pregnancy or while breastfeeding?
- FDA lists diphenhydramine and dimenhydrinate as Pregnancy Category B and promethazine as Pregnancy Category C. Hydroxyzine does not have a Pregnancy Category. These categories mean that the safe and effective use of any antihistamine injection drug is not established in during pregnancy; therefore, if a patient is pregnant, medical treatment with this drug should be used only if clearly needed.
- It is not known whether an injected antihistamine drug enters breast milk; therefore, patients who are pregnant should seek medical advise and use caution before treatment with a prescription antihistamine injection medication in women who are breastfeeding.
Quick GuideBad Bugs: Identify Bug Bites From Mosquitos, Spiders and More
Antihistamine shots or injections are prescription drugs used to treat a patient for the rapid treatment of allergic reactions, anxiety, nausea, vomiting, motion sickness, and induce sedation. Side effects of allergy shots include:
- Increased or decreased blood pressure
- Abnormal heart rate
- Trouble breathing
- Tiredness (fatigue)
- Drowsiness (sleepiness)
Multimedia: Slideshows, Images & Quizzes
Balance Disorders: Vertigo, Motion Sickness, Labyrinthitis, and More
What is vertigo? What causes dizziness? Understand different balance disorders and symptoms such as vertigo, motion sickness,...
Could I Be Allergic? Discover Your Allergy Triggers
Allergies are an overreaction of the immune system where the body's defenses react to substances such as pollen, food and more....
Anxiety Disorder Pictures: Symptoms, Panic Attacks, and More with Pictures
Learn about generalized anxiety disorder (GAD). See if your worries are normal or something more by learning about symptoms,...
The Most Common Food Allergies for Kids and Adults
What common food allergens cause the most problems for adults and children? See this list of common food allergies and learn to...
Nasal Allergy Attack: Causes, Triggers, Treatments
What causes allergies? What are your allergy triggers? Discover how allergies work, why our bodies react to them, whether...
Home Allergy Quiz: Is Your Home Allergy-Proof?
Take this home allergy quiz and test your knowledge on allergens, dust mites, pollens and more to see how allergy-proof your home...
Related Disease Conditions
The word "rash" means an outbreak of red bumps on the body. The way people use this term, "a rash" can refer to many different...
Nosebleeds are common in dry climates during winter months, and in hot dry climates with low humidity. People taking blood...
Eustachian Tube Problems (Ear Tube Dysfunction, Blockage)
The Eustachian tube is a membrane lined tube that connects the middle ear space to the back of the nose. Symptoms of Eustachian...
Hives (Urticaria & Angioedema)
Hives, also called urticaria, is a raised, itchy area of skin that is usually a sign of an allergic reaction. The allergy may be...
What Is Mucus?
Mucus is a normal substance produced by lining tissues in the body. Excess mucus or mucus that is yellow, green, brown, or bloody...
Sore throat (throat pain) usually is described as pain or discomfort in the throat area. A sore throat may be caused...
Motion sickness is a feeling of unwellness caused by the inner ear and balance systems. Motion sickness can include sea...
An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. ...
Panic attacks are sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep....
Hay Fever (Allergic Rhinitis)
Hay fever (allergic rhinitis) is an irritation of the nose caused by pollen and is associated with the following allergic...
Anaphylaxis is a serious allergic reaction that affects a number of different areas of the body at one time, and can be fatal....
The most common food allergies are to eggs, nuts, milk, peanuts, fish, shellfish, strawberries and tomatoes. Symptoms and signs...
Drug Allergy (Medication Allergy)
Drug or medication allergies are caused when the immune system mistakenly creates an immune response to a medication. Symptoms of...
Allergy Treatment Begins At Home
Avoiding allergy triggers at home is one of the best ways to prevent allergy symptoms. Controlling temperature, humidity, and...
Latex allergy is a condition where the body reacts to latex, a natural product derived from the rubber tree. The reaction can...
Treatment & Diagnosis
Medications & Supplements
Prevention & Wellness
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.