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- 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:
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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.
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Related Disease Conditions
Hives, also called urticaria, is a raised, itchy area of skin that is usually a sign of an allergic reaction. The allergy may be to food or medications, but usually the cause of the allergy (the allergen) is unknown.
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 skin conditions. The most common of these are scaly patches of skin and red, itchy bumps or patches all over the place.
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 may indicate a problem. Mucus production may increase when allergies, a cold, flu, cough, or sore throat are present. Antihistamines and cold and flu medications may help alleviate excess mucus. A neti pot may be used to decrease nasal congestion and clear mucus.
Nosebleeds are common in dry climates during winter months, and in hot dry climates with low humidity. People taking blood clotting medications, aspirin, or anti-inflammatory medications may be more prone to nosebleeds. Other factors that contribute to nosebleed are trauma (including nose picking, especially in children), rhinitis (both allergic and nonallergic), and high blood pressure. First-aid treatments for a nosebleed generally do not need medical care. Frequent or chronic nosebleeds may require medical treatment such as over-the-counter (OTC) medication, and prevention of nose picking.
Sore throat (throat pain) usually is described as pain or discomfort in the throat area. A sore throat may be caused by bacterial infections, viral infections, toxins, irritants, trauma, or injury to the throat area. Common symptoms of a sore throat include a fever, cough, runny nose, hoarseness, earaches, sneezing, and body aches. Home remedies for a sore throat include warm soothing liquids and throat lozenges. OTC remedies for a sore throat include OTC pain relievers such as ibuprofen or acetaminophen. Antibiotics may be necessary for some cases of sore throat.
An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. When these allergens come in contact with the body, it causes the immune system to develop an allergic reaction in people who are allergic to it. It is estimated that 50 million North Americans are affected by allergic conditions. The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Common allergic disorders include hay fever, asthma, allergic eyes, allergic eczema, hives, and allergic shock.
Panic attacks are sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep. A person experiencing a panic attack may believe that he or she is having a heart attack or that death is imminent. The fear and terror that a person experiences during a panic attack are not in proportion to the true situation and may be unrelated to what is happening around them. Most people with panic attacks experience several of the following symptoms: racing heartbeat, faintness, dizziness, numbness or tingling in the hands and fingers, chills, chest pains, difficulty breathing, and a feeling of loss or control. There are several treatments for panic attacks.
Eustachian Tube Dysfunction
The Eustachian tube is a membrane lined tube that connects the middle ear space to the back of the nose. Symptoms of Eustachian tube dysfunction or blockage include popping and/or clicking in the ear, and ear fullness and/or pain. Causes of Eustachian tube dysfunction or blockage include allergies, sinus infections, ear infections, and the common cold. Treatment includes home remedies to relieve pain and several maneuvers (swallowing, chewing gum, yawning etc.), which can be done to improve Eustachian tube function. In severe cases surgery may be necessary.
Motion sickness is a feeling of unwellness caused by the inner ear and balance systems. Motion sickness can include sea sickness, car sickness, and train or plane sickness. Symptoms include, headache, nausea, vomiting, fatigue, dizziness, cold sweats, and pale skin. Treatment for motion sickness includes home remedies such as ginger, avoiding large or fatty meals prior to traveling, and OTC and prescription medications.
Anaphylaxis is a serious allergic reaction that affects a number of different areas of the body at one time, and can be fatal. Causes of anaphylaxis can be food allergy, latex allergy, allergy to insect or but stings/bites, asthma, or other materials or conditions. Symptoms include flushing, itching, hives, anxiety, rapid or irregular pulse. Severe symptoms may be throat and tongue swelling, swallowing, and difficulty breathing. Some disorders appear similar to anaphylaxis such as fainting, panic attacks, blood clots in the lungs, heart attacks, and septic shock. If you think that you may be having an anaphylactic reaction, seek emergency care or call 911 immediately.
Lice vs. Fleas
Lice and fleas are small wingless insects. Lice are parasites that can crawl and infest the human skin and scalp. Although they can bite people, fleas are parasites that mainly feed on non-human hosts and can jump from one host to another. Lice infestations and fleabites are treatable and typically do not cause long-term problems with proper treatments for home, people, and pets.
The most common food allergies are to eggs, nuts, milk, peanuts, fish, shellfish, strawberries and tomatoes. Symptoms and signs of a food allergy reaction include nausea, vomiting, diarrhea, abdominal pain, itching, hives, eczema, asthma, lightheadedness, and anaphylaxis. Allergy skin tests, RAST, and ELISA tests may be used to diagnose a food allergy. Though dietary avoidance may be sufficient treatment for mild allergies, the use of an Epipen may be necessary for severe food allergies.
Hay Fever (Allergic Rhinitis)
Hay fever (allergic rhinitis) is an irritation of the nose caused by pollen and is associated with the following allergic symptoms: nasal congestion, runny nose, sneezing, eye and nose itching, and tearing eyes. Avoidance of known allergens is the recommended treatment, but if this is not possible, antihistamines, decongestants, and nasal sprays may help alleviate symptoms.
Allergy Treatment Begins at Home
Avoiding allergy triggers at home is one of the best ways to prevent allergy symptoms. Controlling temperature, humidity, and ventilation are a few ways to allergy-proof the home. Cleaning, vacuuming, and using HEPA air filters also helps control allergies.
Drug Allergy (Medication Allergy)
Drug or medication allergies are caused when the immune system mistakenly creates an immune response to a medication. Symptoms of a drug allergic reaction include hives, rash, itchy skin or eyes, dizziness, nausea, diarrhea, fainting, and anxiety. The most common drugs that people are allergic to include penicillins and penicillin type drugs, sulfa drugs, insulin, and iodine. Treatment may involve antihistamines or corticosteroids. An EpiPen may be used for life-threatening anaphylactic symptoms.
Latex allergy is a condition where the body reacts to latex, a natural product derived from the rubber tree. The reaction can either be delayed and cause a skin rash or immediate, which can lead to anaphylaxis. Avoiding latex is the most effective way to prevent an allergic reaction.
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