Allergy Drugs: Prescription and OTC

Allergies occur when the body's immune system responds to a substance it considers an "invader." Substances that provoke the immune system into an allergic response are known as allergens. There is no such thing as a universal allergen. What might trigger a life-threatening allergic response in one person might cause absolutely no harm in another.

The physiological mechanism of allergic reactions is the same, however, in everyone. Allergens enter the body -- either through ingestion, inhalation or contact with the skin or mucous membranes. This causes white blood cells to release an antibody which then binds to what are known as mast cells. The mast cells rupture – and in the process, release biochemical substances including histamine.

Mild allergy symptoms include itchy, watery eyes, a runny nose, scratchy throat and a rash. More severe, life-threatening allergy symptoms include swelling of the throat, wheezing and difficulty breathing.

How They Work:

Antihistamines used to treat allergy symptoms fall into two broad categories: sedating and non-sedating. The first category includes the older antihistamines. These allergy drugs relieve allergy symptoms but cause drowsiness and other side effects, including dry mouth. Newer antihistamines are said to be non-sedating, although some users may experience drowsiness even from these.

All antihistamines work in the same way: by competing with histamine to prevent or reduce the characteristic signs and symptoms of an allergic reaction: swelling, tearing, itching, and increase in bronchial and other secretions.

In addition to oral dosage forms, antihistamines come as creams, lotions, nasal sprays, and eye drops; the latter to relieve symptoms associated with allergic conjunctivitis.

Other types of allergy drugs include:

Corticosteroids: These come as nasal sprays, topical creams and ointments, tablets, injectables and eye preparations. Corticosteroids work by reducing inflammation.

Mast cell stabilizers: These can help prevent allergic reactions from happening when taken regularly. During an allergic reaction, mast cells release histamine and other substances. Mast cell stabilizers, such as cromolyn sodium, keep these cells intact.

Leukotriene inhibitors: Other substances released during an allergic reaction are leukotrienes, which can aggravate allergic conditions and asthma. Some drugs target leukotriene receptors to reduce allergic symptoms.

Nasal anticholinergics: A runny nose is a common complaint among those with allergic rhinitis. Anticholinergic nasal sprays reduce discharge from the nose, but though they do not relieve a stuffy nose.

Decongestants: These relieve a stuffy nose by constricting blood vessels, which limits the amount of secretions coming from the inner lining of the nose. They are available as nasal sprays, pills, and liquids. They don't relieve other allergy symptoms such as itching and sneezing.

Immunomodulators: These are topical medications used to treat skin allergies. They are often used if other agents are ineffective or intolerable.

Autoinjectable epinephrine: This is used to treat a life-threatening allergic reaction known as anaphylaxis, which may be caused by severe allergic response to foods, drugs, or insect stings.

Over-the-counter allergy medications

Antihistamines (sedating)

• Brompheniramine (Dimetane)
• Chlorpheniramine (Chlor-Trimeton)
• Diphenhydramine (Benadryl)

Antihistamines (non-sedating)

• Cetirizine (Zyrtec, Zyrtec-D)
• Clemastine (Tavist)
• Fexofenadine (Allegra, Allegra D)
• Loratadine (Claritin, Claritin D, Alavert)

Eye Drops: Antihistamine

• Antazoline/Naphazoline (Vasocon A)
• Ketotifen fumarate (Zaditor, Alaway, Zyrtec, Claritin Eye and Refresh Eye)
• Naphazoline/Pheniramine (Naphcon-A, Opcon-A, Visine A)

Eye Drops: Mast cell stabilizer

• Cromolyn (Opticrom)

Nasal Sprays: Decongestants

• Oxymetazoline (Afrin)

Nasal Spray: Corticosteroid

• Triamcinolone acetonide (Nasacort)
• Fluticasone propionate (Flonase)
• Budesonide (Rhinocort)

Nasal Spray: Mast cell stabilizer

• Cromolyn sodium (Nasalcrom)

Prescription allergy medication

Antihistamines

• Acrivastine (Semprex-D)
• Carbinoxamine (Palgic)
• Cyproheptadine (Periactin)
• Desloratadine (Clarinex)
• Hydroxyzine (Vistaril)
• Levoceterizine (Xyzal)

Eye Drops: Antihistamine

• Azelastine (Optivar)
• Emadastine (Emadine)
• Epinastine (Elestat)
• Olopatadine (Patanol, Pataday, Pazeo)

Inhalers: Mast cell stabilizer

• Cromolyn Sodium (Intal)

Eye Drops: Mast cell stabilizer

• Lodoxamine (Alomide)
• Nedocromil (Alocril)
• Pemirolast (Alamast)

Eye Drops: Anti-Inflammatory

• Loteprednol (Alrex)
• Ketorolac (Acular)

Nasal Sprays: Antihistamine

• Azelastine (Astelin, Astepro)
• Azelastine and fluticasone (Dymista)
• Olopatadine (Patanase)

Nasal Sprays: Corticosteroid

• Beclomethasone dipropionate (QNasl)
• Budesonide (Rhinocort)
• Ciclesonide (Omnaris, Zetonna)
• Flunisolide
• Fluticasone furoate (Veramyst)
• Fluticasone propionate (Flonase)

Nasal Sprays: Anticholinergic

• Ipratropium Bromide (Atrovent)

Corticosteroids

• Prednisone
• Prednisolone
• Cortisol
• Methylprednisolone

Leukotriene Inhibitor

• Montelukast (Singulair)

Topical Immunomodulators

• Tacrolimus (Protopic Ointment)
• Pimecrolimus (Elidel Cream)

Older antihistamines are associated with drowsiness, dizziness, constipation, upset stomach, blurry vision, a dry mouth/nose and throat, and difficulty urinating. The newer antihistamines are usually well tolerated but can cause drowsiness, dry mouth, and stomach problems.

Nasal corticosteroids can cause nasal dryness or irritation, nosebleed, throat irritation, headache, nausea, vomiting, cough, and fungal infections of the throat with long-term use.

Mast cell stabilizers can cause a short-lived stinging sensation inside the nose.

Leukotriene inhibitors are associated with unusual weakness, upset stomach, earache, dizziness, cough, headache, trouble sleeping. Serious but unlikely side effects include flu-like symptoms.

Nasal decongestants may cause a temporary burning, stinging, or dryness in the nose, a runny nose, and sneezing. Oral decongestants may cause dizziness, headache, nervousness, fast heartbeat, increased blood pressure, loss of appetite, and sleep problems.

Nasal anticholinergics can cause a bloody or dry nose, nasal congestion, dry mouth and irritated throat, bad taste in the mouth, dizziness, and nausea.

Topical corticosteroids for skin allergies can cause burning, itching, redness, and changes to skin color and thinning of skin.

Topical immunomodulators for skin allergies may cause stinging, burning, irritation, and itching at the application site. They may also cause headache and flu symptoms.

Antihistamines may interact with:

Other drugs that cause drowsiness, such as sleeping medications, narcotic pain medications, sedatives, muscle relaxants, antidepressants and seizure medications.

Drugs with anticholinergic activity such as amitryptiline and other tricyclic antidepressants, antipsychotics like chlorpromazine, certain drugs to prevent vomiting (prochlorperazine and promethazine.

Corticosteroids may interact with:

Drugs affecting metabolism of corticosteroids, such as ketoconazole (Nizoral, Xolegel, Extina, Ketoconazole Cream) and ritonavir (Kaletra Capsules, Kaletra Tablets, Norvir).

Leukotriene inhibitors may interact with:

Drugs that stimulate liver metabolism, such as phenytoin (Dilantin,) phenobarbital, and carbamazepine (Tegretol) – as well as the antibiotic Rifampin.

Oral decongestants may interact with:

Antidepressants, other cold or allergy medications, drugs used to treat migraines and high blood pressure.

Topical immunomodulators may interact with:

Certain antibiotics, antifungals, calcium channel blockers, and cimetidine (Tagamet).

The best choice of allergy medication is one which relieves symptoms without interfering with everyday tasks. Many allergy sufferers are finding that the newer, non-sedating antihistamines meet both these important parameters. It's also important to find an allergy medication that can safely be used for the long term, since for many, allergies last an entire season – if not the entire year. And finally, allergy medications should minimally react with other medications.

Allergy shots, also known as immunotherapy, may eliminate or lessen allergy symptoms if medications are ineffective or intolerable. Immunotherapy works by reducing sensitivity to allergens. Each shot contains a small, but increasing, amount of allergen. This challenges the body to build up tolerance over time. The drawbacks to immunotherapy include use of shots, cost and the fact it may take many months to complete.

Allergy medications are not recommended for use in children under the age of two years without out the advice of a physician. In this group, mild symptoms can be managed using non-drug methods such as saline spray for a stuffy or dry nose and/or a vaporizer/humidifier for congestion. If the allergy is in the form of a rash, emollient creams may offer some relief. For more severe allergy symptoms – widespread rash, wheezing, red, watery eyes – parents should consult a pediatrician.

Many over-the-counter antihistamines are safe for use in children beginning at the age of two – and several come in a liquid dosage form (loratadine, diphenhydramine) which makes them easy to administer. Parents should pay careful attention to dosing.

Older (first-generation) antihistamines:

• Diphenhydramine (Benadryl)
• Chlorpheniramine (Chlor-Trimeton)
• Brompheniramine (Dimetapp, Dimetane)
• Carbinoxamine (Palgic)
• Clemastine (Tavist)
• Cyproheptadine (Periactin)
• Hydroxyzine (Vistaril)

Newer (second-generation) antihistamines:

• Cetirizine (Zyrtec)
• Desloratadine (Clarinex)
• Fexofenadine (Allegra)
• Loratadine (Claritin)
• Levocetirizine (Xyzal)

Antihistamine nasal sprays:

• Azelastine (Astelin, Astepro)
• Azelastine and fluticasone (Dymista)
• Olopatadine (Patanase)

Antihistamine/Decongestant combinations:

• Acrivastine (Semprex-D)
• Cetirizine (Zyrtec-D)
• Fexofenadine (Allegra-D)
• (Loratadine) Claritin-D

Eyedrops:

• Azelastine (Optivar)
• Emadastine (Emadine)
• Naphazoline/pheniramine (Naphcon-A, Opcon-A, Visine-A)
• Epinastine (Elestat)
• Ketotifen (Zaditor, Alaway)
• Olopatadine (Patanol, Pataday)
• Loteprednol (Alrex, Lotemax)
• Naphazoline (AK-Con, Casocon, Albalan)
• Cromolyn (Crolom)
• Lodoxamine (Alomide)
• Nedocromil (Alocril)
• Pemirolast (Alamast)
• Ketorolac (Acular)

Nasal corticosteroids:

• Beclomethasone Dipropionate (QNasl)
• Budesonide (Rhinocort Aqua)
• Ciclesonide (Omnaris)
• Flunisolide
• Fluticasone furoate (Veramyst)
• Fluticasone propionate (Flonase)
• Mometasone furoate (Nasonex)
• Triamcinolone acetonide (Nasacort AQ)
• Beclomethasone dipropionate (Beconase AQ)

Mast cell stabilizers:

• Cromolyn sodium (Nasalcrom nasal spray)

Leukotriene drugs used for allergies:

• Montelukast (Singulair)

Nasal anticholinergics:

• Ipratropium bromide (Atrovent nasal spray)

Decongestants (Nasal):

• Oxymetazoline (Afrin)

Decongestants (Oral):

• Pseudoephedrine (Sudafed)
• Phenylephrine

Topical steroids for skin allergy:

• Aclometasone
• Fluocinolone
• fluocinonide (Lidex, Vanos)
• Hydrocortisone
• Triamcinolone (Nasacort)
• flurandrenolide (Cordran Lotion, Cordran Tape)
• fluticasone (Cutivate)
• mometasone (Elocon Ointment, Elocon, Elocon Lotion)
• prednicarbate (Dermatop Ointment, Dermatop Emollient Cream)
• Amcinonide
• betamethasone valerate (Luxiq, Cultivate Cream)
• desoximetasone (Topicort)
• halcononide (Halog Cream, Halog-E Cream)
• betamethasone dipropionate (Halog Ointment)
• clobetasol propionate (Halog Solution)
• halobetasol propionate (Ultravate Cream, Ultravate Ointment, Cortaid)

Immunomodulators for skin allergy:

• Pimecrolimus (Elidel)
• Tacrolimus (Protopic)

REFERENCES:

Allergy and Asthma Foundation of America http://www.aafa.org/display.cfm?id=9&cont=79

American Academy of Allergy, Asthma and Immunology http://www.aaaai.org/conditions-and-treatments/treatments/drug-guide/allergy-medications.aspx

https://www.medicinenet.com/antihistamines-oral/page2.htm

http://www.protopic.com/default.aspx#

http://elidel-us.com/hcp/#isi

http://www.merck.com/product/usa/pi_circulars/s/singulair/singulair_ppi.pdf

http://www.nlm.nih.gov/medlineplus/steroids.html

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a695021.html

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a695021.html

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a601241.html

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a602002.html

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a602002.html

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682713.html

http://familydoctor.org/familydoctor/en/diseases-conditions/allergic-rhinitis/treatment/allergy-shots-could-they-help-your-allergies.printerview.all.html

http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm273617.htm

http://www.mayoclinic.org/drugs-supplements/antihistamine-oral-route-parenteral-route-rectal-route/before-using/drg-20070373