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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Non-Standardized Pollen Allergenic Extract [EPC]
Elymus Repens Pollen is a non-standardized allergenic extract used in the diagnosis and treatment of grass-pollen induced allergic rhinitis and conjunctivitis. It belongs to the class of Non-Standardized Pollen Allergenic Extracts [EPC].
Name
Elymus Repens Pollen
Raw Name
ELYMUS REPENS POLLEN
Category
Non-Standardized Pollen Allergenic Extract [EPC]
Drug Count
9
Variant Count
10
Last Verified
February 17, 2026
About Elymus Repens Pollen
Elymus Repens Pollen is a non-standardized allergenic extract used in the diagnosis and treatment of grass-pollen induced allergic rhinitis and conjunctivitis. It belongs to the class of Non-Standardized Pollen Allergenic Extracts [EPC].
Detailed information about Elymus Repens Pollen
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Elymus Repens Pollen.
Elymus Repens Pollen, commonly known as Quackgrass or Couch Grass pollen, is a biological substance utilized in clinical immunology for the diagnosis and treatment of allergic diseases. It belongs to the pharmacological class known as Non-Standardized Pollen Allergenic Extracts [EPC]. These extracts are derived from the pollen of the Elymus repens plant, a common perennial grass in the Poaceae family. In the United States, the Food and Drug Administration (FDA) regulates these extracts as biological products. Unlike 'standardized' extracts, which have a defined potency in Bioequivalent Allergy Units (BAU), non-standardized extracts like Elymus Repens are typically labeled by weight/volume (w/v) concentration or Protein Nitrogen Units (PNU).
Healthcare providers utilize Elymus Repens Pollen primarily for allergen immunotherapy (AIT), also known as 'allergy shots.' This therapeutic approach involves the repeated administration of specific allergens to patients with IgE-mediated (Immunoglobulin E) hypersensitivity. The goal is to induce immunological tolerance, thereby reducing the symptoms associated with allergic rhinitis (hay fever), allergic conjunctivitis, and allergic asthma triggered by grass pollen exposure. According to the FDA-approved labeling for allergenic extracts, these products are indicated for patients whose symptoms are not adequately controlled by environmental avoidance or pharmacotherapy (such as antihistamines and nasal corticosteroids).
The mechanism of action for Elymus Repens Pollen in immunotherapy is complex and involves a fundamental shift in the patient's immune response. When a person with an allergy is exposed to Quackgrass pollen naturally, their immune system mistakenly identifies the pollen proteins as a threat, triggering a Th2-biased (T-helper cell type 2) response. This leads to the production of IgE antibodies, which bind to mast cells and basophils. Upon subsequent exposure, the allergen cross-links these IgE antibodies, causing the release of inflammatory mediators like histamine, leukotrienes, and cytokines, resulting in the classic symptoms of sneezing, itching, and congestion.
Allergen immunotherapy with Elymus Repens Pollen works by reversing this process through a process called desensitization. By introducing gradually increasing doses of the pollen extract subcutaneously (under the skin), the immune system is 'retrained.' At the molecular level, this involves:
The pharmacokinetics of allergenic extracts like Elymus Repens Pollen differ significantly from traditional small-molecule drugs. Because these are complex mixtures of proteins and glycoproteins administered subcutaneously, their 'disposition' is measured by immunological activity rather than plasma concentration.
Elymus Repens Pollen extracts are FDA-approved for two primary clinical purposes:
Off-label, some clinicians may use these extracts in customized 'cocktails' for multi-allergen immunotherapy, although the efficacy of mixing non-standardized extracts depends on the compatibility of the specific proteins involved.
Elymus Repens Pollen is available in the following dosage forms:
> Important: Only your healthcare provider can determine if Elymus Repens Pollen is right for your specific condition. Immunotherapy should only be administered in a clinical setting equipped to treat anaphylaxis.
Dosage for Elymus Repens Pollen is highly individualized and must be determined by an allergy specialist (allergist/immunologist). There is no 'standard' dose because the extract is non-standardized, and patient sensitivity varies by several orders of magnitude. The treatment is divided into two distinct phases:
During this phase, the patient receives injections once or twice weekly. The starting dose is typically a very dilute solution (e.g., 0.05 mL of a 1:100,000 w/v or 1:10,000 w/v dilution). The volume and concentration are gradually increased based on the patient's local reaction and systemic tolerance. This phase usually lasts 3 to 6 months.
Once the 'maintenance dose' (the highest dose tolerated by the patient that provides clinical benefit) is reached, the frequency of injections is decreased. Maintenance injections are typically administered every 2 to 4 weeks. A common maintenance volume is 0.5 mL of a 1:20 or 1:10 w/v extract, though this varies significantly.
Elymus Repens Pollen immunotherapy is generally considered safe and effective for children, typically starting around age 5. Younger children may be treated if the clinician determines the benefit outweighs the risk and the child can cooperate with the injection and observation process. Dosing schedules for children follow the same build-up and maintenance principles as adults, though the starting dose may be more conservative if the child is highly sensitive.
No dosage adjustments are required for patients with renal impairment, as the proteins are not cleared by the kidneys in a manner that affects systemic toxicity.
No dosage adjustments are required for patients with hepatic impairment.
Caution is advised in elderly patients. While there is no specific age-based dose adjustment, older adults are more likely to have underlying cardiovascular disease. This increases the risk associated with the use of epinephrine if an emergency treatment for anaphylaxis becomes necessary.
Elymus Repens Pollen is administered exclusively by subcutaneous injection, usually in the posterior aspect of the upper arm. It should never be injected intravenously.
If a dose is missed during the build-up phase, the next dose may need to be reduced or the previous dose repeated to maintain safety. If a dose is missed during the maintenance phase:
An 'overdose' in the context of immunotherapy usually refers to an injection of a concentration higher than the patient's current tolerance level. Signs of an overdose are identical to a severe systemic allergic reaction:
Emergency measures: Immediate administration of epinephrine (1:1000) intramuscularly, followed by oxygen, IV fluids, and antihistamines as directed by the emergency protocol. Patients should be transported to an emergency department immediately.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or frequency without medical guidance.
Most patients undergoing immunotherapy with Elymus Repens Pollen will experience local reactions at the site of injection. These are generally not dangerous but can be uncomfortable.
> Warning: Stop taking Elymus Repens Pollen and call your doctor immediately if you experience any of these symptoms of anaphylaxis.
There are no known long-term 'toxic' effects of Elymus Repens Pollen. The primary long-term effect is the desired modulation of the immune system. However, patients should be monitored for the development of 'new' sensitivities, although immunotherapy for one allergen does not typically cause allergies to others. In rare cases, chronic local inflammation could lead to minor skin changes at the injection site.
While specific 'Black Box' formatting varies by manufacturer, all FDA-approved allergenic extracts carry a prominent warning regarding Anaphylaxis.
Summary of Warning: Elymus Repens Pollen extract can cause severe, life-threatening systemic reactions, including anaphylaxis. These reactions may occur even in patients who have previously tolerated the treatment well. Injections must be administered by healthcare professionals prepared to treat anaphylaxis. Patients with unstable asthma are at increased risk for fatal reactions. Patients taking beta-blockers may be resistant to the effects of epinephrine used for emergency treatment.
Report any unusual symptoms to your healthcare provider, especially those occurring within the first few hours after an injection.
Elymus Repens Pollen is a potent biological agent. Its use requires strict adherence to safety protocols to prevent life-threatening allergic reactions. Patients must be honest with their providers about their current health status, especially regarding asthma symptoms or recent illnesses, before receiving each injection.
No FDA black box warnings for Elymus Repens Pollen are specifically listed in the same format as oral medications like antidepressants; however, the Anaphylaxis Warning is the functional equivalent. It states that allergenic extracts should only be used by physicians experienced in the diagnosis and treatment of allergic diseases and should only be administered in settings where emergency equipment and personnel are available to treat systemic reactions.
Elymus Repens Pollen does not typically cause drowsiness. However, if you experience a systemic reaction or are given antihistamines/epinephrine for a reaction, you should not drive or operate machinery until you are fully recovered and cleared by a medical professional.
While there is no direct chemical interaction between alcohol and the pollen extract, alcohol consumption can cause vasodilation (widening of blood vessels). This could potentially increase the rate of allergen absorption or mask the early signs of an allergic reaction. It is generally advised to avoid alcohol for several hours before and after an injection.
Immunotherapy is usually a 3-to-5-year commitment. Stopping early may result in the return of allergy symptoms. There is no 'withdrawal syndrome' associated with stopping Elymus Repens Pollen, but the immunological benefits will gradually fade if the maintenance phase is not completed.
> Important: Discuss all your medical conditions with your healthcare provider before starting Elymus Repens Pollen.
There are no specific food interactions with Elymus Repens Pollen. However, patients with 'Oral Allergy Syndrome' (OAS) may experience itching in the mouth when eating certain fruits (like melons or oranges) that contain proteins similar to grass pollen. Receiving immunotherapy may eventually improve these food-related symptoms, but you should not change your diet without consulting your doctor.
There are no well-documented interactions between Elymus Repens Pollen and herbal supplements. However, supplements that have 'anti-inflammatory' or 'immune-boosting' claims (such as Echinacea or high-dose Vitamin C) should be discussed with your allergist, as they could theoretically influence the immune system's response to the desensitization process.
For each major interaction, the primary concern is not a chemical reaction between the drugs, but rather a pharmacodynamic interaction that either increases the risk of an allergic event or makes the emergency treatment of such an event more difficult.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.
Elymus Repens Pollen must NEVER be used in the following circumstances:
Conditions requiring careful risk-benefit analysis by the allergist:
Elymus Repens (Quackgrass) is part of the Poaceae family. Patients allergic to Quackgrass are almost always cross-sensitive to other 'Northern' grasses, such as:
If you have had a reaction to any of these grass extracts, you are at high risk for a reaction to Elymus Repens Pollen.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Elymus Repens Pollen.
FDA Pregnancy Category: C (based on general allergenic extract classification).
It is not known whether the components of Elymus Repens Pollen or the antibodies it induces are excreted in human milk. However, since the allergens are proteins that are digested in the infant's stomach, the risk to a nursing infant is considered negligible. Breastfeeding is generally considered safe during immunotherapy.
Renal function does not affect the safety or efficacy of Elymus Repens Pollen. No dose adjustments are necessary for patients with chronic kidney disease or those on dialysis.
Hepatic function does not play a role in the clearance of allergenic proteins. No dose adjustments are needed for patients with liver cirrhosis or other hepatic conditions.
> Important: Special populations require individualized medical assessment by an immunology specialist.
Elymus Repens Pollen acts as a biological response modifier. Its primary molecular target is the T-cell receptor (TCR) on naive T-cells. By presenting Quackgrass-specific peptides in a controlled, low-dose manner, the extract induces the following:
| Parameter | Value |
|---|---|
| Bioavailability | Local absorption (Subcutaneous) |
| Protein Binding | N/A (Proteins are processed by APCs) |
| Half-life | Immunological effect: Years; Protein half-life: Hours |
| Tmax | Local tissue peak: 1-2 hours |
| Metabolism | Proteolysis (non-CYP) |
| Excretion | Cellular degradation products |
Elymus Repens Pollen is classified as a Non-Standardized Pollen Allergenic Extract. It is grouped with other grass pollen extracts used for both 'in vivo' diagnostics and immunotherapy. It is distinct from 'Standardized' extracts like Timothy Grass, which have a potency expressed in Bioequivalent Allergy Units (BAU).
Common questions about Elymus Repens Pollen
Elymus Repens Pollen is used as an allergenic extract for both diagnosing and treating allergies to Quackgrass. In diagnostic settings, it is applied during skin prick tests to see if a patient develops a localized allergic reaction. For treatment, it is used in allergen immunotherapy (allergy shots) to gradually desensitize the immune system. This process helps reduce symptoms of hay fever and allergic asthma over time. It is specifically indicated for patients who do not get enough relief from standard allergy medications.
The most common side effects are localized reactions at the site of the injection, occurring in nearly all patients at some point. These include redness, itching, and swelling (a 'wheal') where the shot was given. These reactions usually appear within minutes and fade within a few hours. Some patients may also experience a mild flare-up of their typical allergy symptoms, like sneezing or itchy eyes. While these are common, they are generally not dangerous and can be managed with over-the-counter antihistamines.
It is generally recommended to avoid alcohol on the days you receive an Elymus Repens Pollen injection. Alcohol causes blood vessels to dilate (expand), which could theoretically cause the allergen to be absorbed more quickly into your bloodstream, increasing the risk of a systemic reaction. Additionally, being under the influence of alcohol can make it harder for you to notice or describe early symptoms of an allergic reaction. To ensure maximum safety, wait at least several hours after your injection before consuming alcohol. Always follow the specific guidance provided by your allergist.
Allergen immunotherapy is usually not started during pregnancy because of the risk of a severe allergic reaction (anaphylaxis), which could deprive the baby of oxygen. However, if a woman is already on a stable maintenance dose and becomes pregnant, many doctors choose to continue the treatment at that same dose. There is no evidence that the pollen extract itself causes birth defects. The decision to continue or stop therapy is made on a case-by-case basis. You must inform your allergist immediately if you become pregnant or are planning to conceive.
Immunotherapy with Elymus Repens Pollen is a long-term treatment and does not provide immediate relief. Most patients begin to notice a reduction in their allergy symptoms after 3 to 6 months, once they reach the maintenance phase. The full clinical benefit is typically seen after one or two full grass pollen seasons. For the best and most lasting results, a full course of treatment usually lasts between 3 and 5 years. This long duration is necessary to 'retrain' the immune system permanently.
Yes, you can stop taking Elymus Repens Pollen injections at any time without experiencing physical withdrawal symptoms. However, stopping the treatment before the recommended 3-to-5-year course is finished often means your allergy symptoms will eventually return. The immune system may 'forget' the tolerance it was building, and you may find yourself needing daily allergy medications again. If you are considering stopping because of side effects or scheduling issues, talk to your doctor first. They may be able to adjust your dose or schedule to make the treatment more manageable.
If you miss a dose, you should contact your allergist's office as soon as possible to reschedule. Do not simply wait for your next scheduled appointment. Because the treatment involves building tolerance, missing a dose for too long can make the next injection less safe. Depending on how many weeks have passed, your doctor may need to repeat your last dose or even reduce the dose slightly for your next visit. Consistency is key to both the safety and the effectiveness of allergen immunotherapy.
There is no scientific evidence or clinical data suggesting that Elymus Repens Pollen extracts cause weight gain. The extract consists of a very small amount of proteins and glycerin, which do not have metabolic or caloric effects on the body. If you experience weight changes while on immunotherapy, it is likely due to other factors such as lifestyle changes or other medications you may be taking, such as oral corticosteroids. Always discuss any unexpected physical changes with your primary care physician.
Elymus Repens Pollen can be taken alongside most standard allergy medications like antihistamines and nasal sprays. In fact, these medications are often used to manage the minor side effects of the injections. However, it can have dangerous interactions with certain heart and blood pressure medications, specifically beta-blockers. These drugs can make a severe allergic reaction much harder to treat. You must provide your allergist with a complete list of all medications, including eye drops and supplements, before starting treatment.
The concept of 'generic' drugs does not apply to allergenic extracts in the same way it does to pills. Elymus Repens Pollen is a biological product, and different manufacturers may produce their own versions of the extract. While these extracts are similar, they are not considered 'interchangeable' by the FDA. This means that if you switch brands, your doctor may need to restart your build-up phase or adjust your dose to ensure safety. Always check with your provider if the source of your extract changes.