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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Non-Standardized Food Allergenic Extract [EPC]
Rheum Officinale Root is a non-standardized plant and food allergenic extract used primarily in the diagnosis and treatment of specific hypersensitivity reactions. It belongs to the class of allergenic extracts used for skin testing and immunotherapy.
Name
Rheum Officinale Root
Raw Name
RHEUM OFFICINALE ROOT
Category
Non-Standardized Food Allergenic Extract [EPC]
Drug Count
12
Variant Count
21
Last Verified
February 17, 2026
About Rheum Officinale Root
Rheum Officinale Root is a non-standardized plant and food allergenic extract used primarily in the diagnosis and treatment of specific hypersensitivity reactions. It belongs to the class of allergenic extracts used for skin testing and immunotherapy.
Detailed information about Rheum Officinale Root
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Rheum Officinale Root.
Rheum Officinale Root, commonly known as Chinese Rhubarb, is a botanical substance that, in a clinical and pharmacological context, is classified as a Non-Standardized Plant Allergenic Extract [EPC] and a Non-Standardized Food Allergenic Extract [EPC]. While the plant itself has a multi-millennial history in traditional pharmacopeias for its laxative and astringent properties, its modern clinical application in the United States and Europe often centers on its role as an allergenic diagnostic and therapeutic agent. As an allergenic extract, Rheum Officinale Root is used by healthcare providers—specifically allergists and immunologists—to identify individuals who have developed a Type I hypersensitivity (allergic) reaction to the proteins found within the rhubarb plant.
In the regulatory framework of the Food and Drug Administration (FDA), Rheum Officinale Root extracts are categorized under the broader umbrella of allergenic products. These products are unique because they are often 'non-standardized,' meaning their potency is not measured by a specific biological activity unit (like Bioequivalent Allergy Units or BAU) but is instead defined by the weight of the source material relative to the volume of the extracting fluid (Weight/Volume or w/v) or by the Protein Nitrogen Unit (PNU) content. This classification is critical for clinicians to understand, as it necessitates a highly individualized approach to dosing and administration compared to standardized medications. Rheum Officinale Root belongs to a class of drugs called allergenic extracts, which are designed to interact directly with the patient's immune system to either elicit a diagnostic response or to induce immunological tolerance through subcutaneous injections.
The mechanism of action for Rheum Officinale Root as an allergenic extract is rooted in the fundamental principles of immunology. When used for diagnostic purposes, such as in percutaneous (skin prick) or intradermal testing, the extract introduces specific rhubarb proteins directly into the skin. If a patient is sensitized to these proteins, their immune system will have already produced specific Immunoglobulin E (IgE) antibodies that are 'loaded' onto the surface of mast cells and basophils in the skin and blood.
Upon exposure to the Rheum Officinale Root extract, these IgE antibodies recognize the rhubarb allergens and trigger a process called 'cross-linking.' This cross-linking causes the mast cells to degranulate, releasing potent chemical mediators such as histamine, leukotrienes, and prostaglandins. This localized chemical release results in the 'wheal and flare' reaction—a raised, itchy bump surrounded by redness—which the clinician measures to confirm an allergy. In the context of immunotherapy (allergy shots), the mechanism shifts toward immunomodulation. By administering gradually increasing doses of the Rheum Officinale Root extract, the body is encouraged to shift its immune response from a Th2-mediated (allergic) pathway to a Th1-mediated (protective) pathway, while also stimulating the production of 'blocking' antibodies (IgG4) and regulatory T-cells that suppress the allergic cascade.
Unlike traditional systemic drugs (such as tablets or intravenous antibiotics), the pharmacokinetics of Rheum Officinale Root allergenic extracts are not typically characterized by standard absorption, distribution, metabolism, and elimination (ADME) studies. This is because the extract is a complex mixture of proteins, glycoproteins, and polysaccharides, and its therapeutic action is intended to be localized or focused on the immune system's signaling pathways.
Rheum Officinale Root extracts are indicated for several specific clinical scenarios, always under the supervision of an allergy specialist:
Rheum Officinale Root is typically available in the following specialized forms:
> Important: Only your healthcare provider can determine if Rheum Officinale Root is right for your specific condition. The use of allergenic extracts carries a risk of severe systemic reactions, including anaphylaxis, and must only be performed in facilities equipped to handle medical emergencies.
Dosage for Rheum Officinale Root is highly individualized and does not follow a 'one size fits all' approach. For Diagnostic Skin Prick Testing, a single drop of the 1:10 or 1:20 w/v concentrate is applied to the skin (usually the forearm or back), and the skin is pricked through the drop. A positive control (histamine) and a negative control (saline) are always used simultaneously for comparison.
For Intradermal Testing, if the skin prick test is negative but a high clinical suspicion remains, a dose of 0.02 mL to 0.05 mL of a highly diluted extract (e.g., 1:1000 w/v) is injected into the top layer of the skin.
In the rare instance of Immunotherapy, the dosage follows a 'Build-up Phase' and a 'Maintenance Phase.' The build-up phase starts with an extremely low dose (often 0.05 mL of a 1:100,000 dilution) and increases weekly until the 'Maintenance Dose' is reached (typically 0.5 mL of a 1:100 or 1:10 dilution). Your doctor will determine the exact concentration based on your sensitivity level.
Rheum Officinale Root extracts may be used in children, but extreme caution is required. There is no specific age-based dosage; instead, the dose is determined by the child's sensitivity, similar to adults. However, many clinicians prefer to avoid intradermal testing in very young children (under age 5) due to the increased discomfort and the risk of systemic reactions. The safety and efficacy of immunotherapy in children under the age of 5 have not been fully established, and the decision to proceed must be based on a careful risk-benefit analysis by a pediatric allergist.
No specific dosage adjustments are required for patients with kidney disease, as the amount of protein administered is minimal and does not place a significant burden on renal clearance. However, if a patient is experiencing an acute uremic episode, testing should be postponed.
No dosage adjustments are necessary for patients with liver disease. The metabolic breakdown of the allergenic proteins occurs primarily through tissue proteases rather than hepatic CYP450 enzymes.
Elderly patients (over age 65) may have reduced skin reactivity, which can lead to false-negative results in diagnostic testing. Furthermore, elderly patients are more likely to be taking medications (like beta-blockers) that could make a potential allergic reaction more difficult to treat. Dosing should be approached conservatively.
Rheum Officinale Root extract is never self-administered by the patient at home. It must be administered in a clinical setting:
If you miss a scheduled immunotherapy injection of Rheum Officinale Root, contact your allergist immediately. Do not 'double up' the dose at your next visit. If the interval between doses has been too long, your doctor may need to reduce the dose to ensure your safety and then gradually build it back up.
An overdose of Rheum Officinale Root extract usually occurs due to a calculation error or a 'dose escalation' that is too rapid for the patient's immune system to tolerate.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or skip observation periods without medical guidance.
The most common side effects of Rheum Officinale Root extract are localized to the site of administration. These are often expected as part of the diagnostic process:
> Warning: Stop taking Rheum Officinale Root and call your doctor immediately if you experience any of these symptoms of a systemic allergic reaction (anaphylaxis).
When used correctly for immunotherapy, Rheum Officinale Root does not typically cause 'long-term' side effects in the traditional sense (like organ damage). However, the primary long-term risk is the development of a persistent 'delayed-type hypersensitivity,' where the patient becomes more sensitive to the extract over time rather than less. There is also a theoretical risk of developing autoimmune-like symptoms if the immune system is excessively stimulated, though this is extremely rare and not well-documented for this specific plant extract.
While Rheum Officinale Root specifically may not have a unique black box warning, the FDA requires a Class Black Box Warning for all allergenic extracts, including non-standardized plant extracts.
Summary of Warning: Allergenic extracts can cause severe life-threatening systemic reactions, including anaphylaxis. Patients with unstable or severe asthma are at higher risk for fatal outcomes. Extracts should only be administered by clinicians trained in the management of anaphylaxis. Patients should be observed for at least 30 minutes. Some patients may experience 'delayed' systemic reactions after leaving the clinic.
Report any unusual symptoms to your healthcare provider. Even a 'minor' systemic symptom like itchy palms or a scratchy throat can be a precursor to a severe reaction.
Rheum Officinale Root allergenic extract is a potent biological product. It is intended only for use by physicians who are experienced in the administration of allergenic extracts and the treatment of the resulting complications. Patients must be informed that the use of this extract carries an inherent risk of systemic reactions. You must provide a complete medical history, especially regarding any history of asthma, heart disease, or previous severe allergic reactions to foods or plants.
No FDA black box warnings for Rheum Officinale Root specifically, however, it is subject to the general black box warning for all Allergenic Extracts. This warning emphasizes that these products can cause severe, life-threatening anaphylaxis. It mandates that the product be used only in settings where emergency resuscitative equipment (including epinephrine) and trained personnel are immediately available. It also warns that patients with poorly controlled asthma are at a significantly higher risk of death if a systemic reaction occurs.
There are no standard laboratory tests (like blood counts) required for Rheum Officinale Root. Monitoring is clinical:
Rheum Officinale Root does not typically cause sedation. However, if you experience a systemic reaction, you may feel dizzy, weak, or confused. It is generally safe to drive to and from your appointment unless you experience a reaction, in which case you should not drive until cleared by your doctor.
Alcohol should be avoided for several hours before and after receiving an allergenic extract. Alcohol causes vasodilation (widening of the blood vessels), which can speed up the absorption of the allergen and potentially increase the severity of an allergic reaction.
If you decide to stop Rheum Officinale Root immunotherapy, you can usually do so without 'withdrawal' symptoms. However, the benefits of the treatment (allergy desensitization) will gradually diminish, and your original allergy symptoms will likely return. Always discuss discontinuation with your allergist to ensure a safe exit strategy.
> Important: Discuss all your medical conditions with your healthcare provider before starting Rheum Officinale Root.
There are few 'absolute' drug contraindications, but certain combinations are extremely dangerous due to how they interact with the treatment of a potential side effect:
Rheum Officinale Root does not typically interfere with standard blood chemistry or hematology tests. However, it will directly affect:
For each major interaction, the mechanism is usually pharmacodynamic (how the drugs affect the body's response to the allergen or the emergency treatment) rather than pharmacokinetic (how the body processes the drug). The management strategy is always to disclose your full medication list to your allergist before the first dose.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.
Rheum Officinale Root must NEVER be used in the following circumstances:
These conditions require a careful risk-benefit analysis by the healthcare provider:
Rheum Officinale Root is part of the Polygonaceae family. Patients who are allergic to rhubarb may also show cross-reactivity to:
If you have a known severe allergy to buckwheat, your doctor will exercise extreme caution when testing you with Rheum Officinale Root, as the similar protein structures can trigger a cross-allergic reaction.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Rheum Officinale Root.
Rheum Officinale Root extract is classified as FDA Pregnancy Category C. This means that animal reproduction studies have not been conducted, and it is not known whether the extract can cause fetal harm or affect reproduction capacity.
It is not known whether the allergenic components of Rheum Officinale Root are excreted in human milk. Because most of the components are large proteins that are digested in the infant's gut, the risk to a nursing infant is considered low. However, if the mother experiences a systemic reaction, the physiological stress and any medications required (like epinephrine or antihistamines) could temporarily affect milk production or the infant. Consult your doctor before continuing treatment while breastfeeding.
Rheum Officinale Root is used in the pediatric population for allergy diagnosis. However, children are at a higher risk for 'silent' systemic reactions because they may not be able to articulate early symptoms like an itchy throat or a feeling of 'impending doom.'
In patients over age 65, several factors must be considered:
No specific studies have been conducted in patients with renal impairment. However, since the dose of protein is minuscule (microgram range), no adjustment is typically required. Patients on dialysis should ideally receive their injections on non-dialysis days to ensure they are at their physiological baseline.
Liver disease does not significantly impact the processing of Rheum Officinale Root allergenic extracts. No dosage adjustments are recommended based on Child-Pugh classification.
> Important: Special populations require individualized medical assessment to ensure the highest level of safety.
Rheum Officinale Root extract functions as an immunological probe. Its molecular mechanism involves the interaction between exogenous plant proteins (allergens) and the endogenous immune system. Specifically, the extract contains various proteins, some of which may be pathogenesis-related (PR) proteins or profilins.
In a sensitized individual, these proteins bind to specific IgE antibodies attached to high-affinity receptors (FcεRI) on the surface of mast cells. This binding causes the receptors to cluster (cross-link), which activates an intracellular signaling cascade involving tyrosine kinases (like Syk). This leads to the rapid release of pre-formed mediators (histamine) and the synthesis of new mediators (leukotrienes), resulting in the classic allergic response.
| Parameter | Value |
|---|---|
| Bioavailability | N/A (Local/Subcutaneous) |
| Protein Binding | Primarily to IgE and IgG antibodies |
| Half-life | Minutes (proteins) to Days (immune signaling) |
| Tmax | 15-20 minutes (for skin reaction) |
| Metabolism | Tissue proteases |
| Excretion | Renal (metabolites) |
Rheum Officinale Root extract is a complex aqueous-glycerin solution.
Rheum Officinale Root is classified as a Non-Standardized Plant Allergenic Extract. It is related to other extracts in the Polygonaceae family, such as Buckwheat extract, and shares the therapeutic class of 'Biologicals, Allergenic Extracts.'
Medications containing this ingredient
Common questions about Rheum Officinale Root
In a clinical setting, Rheum Officinale Root extract is primarily used as a diagnostic tool to identify whether a patient has a specific allergy to rhubarb. This is done through skin prick testing or intradermal testing performed by an allergist. If a patient is found to be allergic, the extract can also be used in some cases for allergen immunotherapy, which involves giving small, increasing doses to build up tolerance. It is not used as a medication to treat other diseases in this specific extract form. Always consult an allergy specialist to see if this testing is appropriate for your symptoms.
The most common side effects are localized to the area where the extract was applied or injected. You can expect to see a 'wheal and flare' reaction, which looks like a mosquito bite—a raised, itchy bump surrounded by a red area. This is a normal part of the diagnostic process and usually disappears within a few hours. Some patients may also experience mild swelling or tenderness at the injection site for a day or two. Systemic side effects like hives or sneezing are less common but require monitoring. Talk to your doctor if you experience any discomfort that lasts longer than 24 hours.
It is strongly recommended that you avoid alcohol for at least 24 hours before and after receiving a Rheum Officinale Root skin test or immunotherapy injection. Alcohol can cause your blood vessels to dilate, which might speed up the absorption of the allergen into your bloodstream. This increases the risk of a more severe or systemic allergic reaction. Additionally, alcohol can mask some of the early warning signs of anaphylaxis, such as dizziness or flushing. Always follow the specific 'pre-injection' instructions provided by your allergy clinic. Discuss your alcohol consumption habits with your healthcare provider to ensure your safety.
The use of Rheum Officinale Root extract during pregnancy is generally approached with extreme caution. While the extract itself is not known to be toxic to the fetus, a severe allergic reaction (anaphylaxis) in the mother can lead to a dangerous drop in blood pressure and oxygen levels, which can harm the baby. For this reason, most allergists will postpone diagnostic skin testing until after delivery. If you are already on a stable maintenance dose of immunotherapy, your doctor may choose to continue it but will likely not increase the dose. Always inform your allergist immediately if you become pregnant or are planning to become pregnant.
If you are undergoing diagnostic testing, the results are almost immediate; the skin reaction typically peaks within 15 to 20 minutes of the test being performed. If you are receiving immunotherapy (allergy shots), the process takes much longer. It usually takes 3 to 6 months of weekly injections to reach a 'maintenance dose' where you might start to notice a reduction in your allergy symptoms. A full course of immunotherapy typically lasts 3 to 5 years for long-lasting protection. Your healthcare provider will monitor your progress and adjust your schedule based on your individual response.
Yes, you can stop receiving Rheum Officinale Root injections or testing at any time without experiencing physical withdrawal symptoms. However, stopping immunotherapy before the recommended 3-to-5-year period usually means that your allergy symptoms will eventually return. If you miss several doses, you cannot simply restart at the same level; your doctor will need to lower the dose to ensure you don't have a reaction. It is important to discuss your reasons for wanting to stop with your allergist. They can help you weigh the pros and cons of continuing the treatment versus managing your symptoms with other medications.
If you miss an immunotherapy appointment, you should call your allergy clinic as soon as possible to reschedule. Do not try to make up for the missed dose by taking a higher dose later. The safety of allergenic extracts depends on a very specific timing and escalation schedule. If you miss only one week, your doctor may give you your usual dose. If you miss several weeks, they will likely need to reduce the dose and then gradually increase it again to keep you safe. Consistently missing doses can significantly delay the effectiveness of the treatment.
There is no scientific evidence to suggest that Rheum Officinale Root allergenic extract causes weight gain. Unlike some other medications like systemic corticosteroids or certain antidepressants, allergenic extracts do not interfere with your metabolism, appetite, or fat storage. The amount of protein and glycerin in each injection is extremely small and has no caloric significance. If you notice weight changes while undergoing treatment, they are likely due to other factors such as lifestyle changes, other medications, or an underlying health condition. You should discuss any unexpected weight changes with your primary care physician.
Rheum Officinale Root can interact with several types of medications, particularly those that affect how your body responds to an allergic reaction or its treatment. Antihistamines and certain antidepressants can block the results of skin tests, making them appear negative even if you are allergic. More importantly, medications like beta-blockers can make it very difficult for doctors to treat you if you have a severe reaction to the extract. You must provide your allergist with a complete and updated list of every medication you take, including over-the-counter drugs and supplements. They will determine if any of your current medications make the treatment unsafe for you.
The concept of 'generic' vs. 'brand name' is slightly different for allergenic extracts. Because Rheum Officinale Root is a 'non-standardized' biological product, different manufacturers may produce their own versions of the extract, but they are not considered identical generics in the way a generic ibuprofen tablet is to a brand-name one. Each manufacturer's extract may have slightly different protein concentrations. Therefore, if your doctor switches you from one manufacturer's extract to another, they will often reduce your dose slightly to ensure safety. Always ensure your treatment is being managed by a qualified specialist who understands these differences.