Viscum Album Fruit

Dosage for Viscum Album Fruit allergenic extract is highly individualized and must be determined by an allergy specialist based on the patient's sensitivity levels. There is no 'standard' dose for all patients.

• Diagnostic Testing: Typically, a single drop of a 1:10 or 1:20 w/v (weight/volume) concentration is used for prick testing. If intradermal testing is required, the concentration is significantly more dilute (often 1:1000 or 1:10,000).
• Immunotherapy Build-up Phase: Treatment usually begins with a very low dose (e.g., 0.05 mL of a 1:100,000 dilution). Doses are increased weekly or bi-weekly by 50% to 100% until the 'Maintenance Dose' is reached. This phase can take 3 to 6 months.
• Maintenance Phase: Once the maximum tolerated dose is reached (often 0.5 mL of a 1:100 or 1:10 concentration), injections are spaced out to every 2 to 4 weeks. This phase typically continues for 3 to 5 years to ensure long-term desensitization.

Viscum Album Fruit extracts may be used in children, provided they are old enough to cooperate with the procedure and have a clearly defined allergy.

• Dosing: Pediatric dosing follows the same escalation principles as adult dosing, though the starting dose may be even more conservative depending on the child's weight and the severity of their allergic history.
• Safety: Children must be monitored even more closely for signs of systemic reactions, as they may not be able to articulate early symptoms of anaphylaxis.

Renal Impairment

No specific dose adjustments are typically required for patients with renal impairment, as the proteins are metabolized proteolytically. However, the patient's overall health must be considered before starting immunotherapy.

Hepatic Impairment

No dose adjustments are standardized for hepatic impairment. The metabolic pathway of allergenic extracts does not rely on the cytochrome P450 system.

Elderly Patients

Elderly patients may be at higher risk for complications if a systemic reaction occurs, particularly if they have underlying cardiovascular disease. Healthcare providers may choose a slower dose escalation for patients over age 65.

Viscum Album Fruit extract is never self-administered by the patient at home. It must be administered in a clinical setting.

• Administration: The injection is given subcutaneously, usually in the posterior aspect of the upper arm.
• Observation Period: Patients must remain in the doctor's office for at least 30 minutes following every injection. This is the period when life-threatening systemic reactions (anaphylaxis) are most likely to occur.
• Storage: Vials must be stored in a refrigerator between 2°C and 8°C (36°F to 46°F). They should never be frozen.

If a dose in the build-up phase is missed, the next dose may need to be reduced rather than increased.

• If 1 week is missed: Repeat the last dose.
• If 2-3 weeks are missed: Reduce the dose by one or two levels.
• If more than 4 weeks are missed: Consult the allergist, as the build-up may need to be restarted from a much lower concentration to avoid a reaction.

An 'overdose' in the context of allergenic extracts usually refers to an injection of a concentration higher than what the patient's immune system can currently tolerate.

• Signs: Rapid onset of hives, swelling of the throat, wheezing, drop in blood pressure, or loss of consciousness.
• Emergency Measures: Immediate administration of epinephrine (adrenaline), followed by antihistamines, corticosteroids, and emergency transport to a hospital.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance. Ensure you inform your doctor of any new medications or illnesses before receiving your injection.

Most patients receiving Viscum Album Fruit extracts will experience localized reactions at the site of the injection or test. These are generally considered a sign that the immune system is responding to the extract.

• Local Redness (Erythema): A red patch at the injection site that may feel warm to the touch. This usually appears within minutes and fades within a few hours.
• Swelling (Edema): A small bump or 'wheal' at the site. If the swelling is smaller than the size of a half-dollar (approx. 3 cm), it is usually considered normal.
• Itching (Pruritus): Intense itching at the injection site is very common and can be managed with topical cold compresses or oral antihistamines.

• Large Local Reactions: Swelling that extends beyond the immediate injection site, sometimes involving the entire upper arm. This may indicate that the next dose should not be increased.
• Fatigue: Some patients report feeling unusually tired for 24 hours following an immunotherapy injection.
• Mild Nasal Congestion: A slight increase in allergy-like symptoms (sneezing, runny nose) shortly after the injection.

• Generalized Hives (Urticaria): Itchy welts appearing on parts of the body far from the injection site.
• Angioedema: Swelling of the deeper layers of the skin, often around the eyes or lips.
• Persistent Cough: A dry, hacking cough that may signal the beginning of a systemic respiratory reaction.

> Warning: Stop taking Viscum Album Fruit treatments and call your doctor or emergency services immediately if you experience any of these symptoms of anaphylaxis.

• Difficulty Breathing: Wheezing, chest tightness, or a feeling that the throat is closing.
• Hypotension (Low Blood Pressure): Feeling faint, dizzy, or suddenly weak. This can lead to fainting (syncope).
• Rapid or Weak Pulse: A sign that the cardiovascular system is struggling during a systemic allergic reaction.
• Nausea and Vomiting: Sudden gastrointestinal distress following an injection is often a precursor to a severe systemic reaction.
• Cyanosis: A bluish tint to the lips or fingernails, indicating a lack of oxygen.

There are no known long-term 'toxic' effects of Viscum Album Fruit extracts when used correctly. The primary long-term effect is the intended modulation of the immune system. However, patients who receive immunotherapy for many years should be monitored for any changes in their baseline allergic profile or the development of new sensitivities.

While specific Viscum Album Fruit extracts may not always carry a standalone black box warning, the class of Allergenic Extracts as a whole carries a significant warning regarding anaphylaxis.

FDA Class Warning Summary:

• Allergenic extracts can cause severe life-threatening systemic reactions, including anaphylaxis.
• Extracts should only be administered by physicians who are exceptionally experienced in the treatment of systemic reactions.
• Patients must be observed for at least 30 minutes in the office after administration.
• Patients with unstable asthma are at a significantly higher risk for fatal reactions.

Report any unusual symptoms to your healthcare provider. Even a 'large' local reaction should be reported, as it may necessitate a dose adjustment for your safety.

Viscum Album Fruit extract is a potent biological agent. Its use is restricted to diagnostic and therapeutic scenarios where the benefit of identifying or treating an allergy outweighs the inherent risk of triggering an allergic reaction. Patients must be in their baseline state of health when receiving injections; for example, if a patient is currently experiencing an asthma flare or a severe viral infection, the injection should be postponed.

No specific FDA black box warning exists for Viscum Album Fruit individually, but the following applies to the EPC class of Allergenic Extracts:

"WARNING: This product can cause severe systemic reactions, including anaphylaxis, which may be fatal. Patients should be informed of the risks and must be observed for at least 30 minutes following administration. Healthcare providers must have emergency equipment, including epinephrine, immediately available."

• Allergic Reactions / Anaphylaxis Risk: This is the primary risk. Anaphylaxis can occur even in patients who have previously tolerated the extract without issue. Risk factors include high dose, rapid escalation, and high degree of patient sensitivity.
• Asthma Status: Patients with poorly controlled or unstable asthma are at the highest risk for a fatal outcome if they experience a systemic reaction to Viscum Album Fruit. A peak flow meter may be used to verify lung function before the injection is given.
• Cardiovascular Health: Patients with significant heart disease may not be able to tolerate the physiological stress of a systemic reaction or the effects of the epinephrine used to treat it.

• Pre-Injection Screening: Before every dose, the provider will ask about any reactions to the previous dose, current medications (especially beta-blockers), and current health status.
• Post-Injection Observation: A strict 30-minute wait time is mandatory.
• Lung Function: For asthmatic patients, regular monitoring of FEV1 or peak expiratory flow is recommended throughout the course of immunotherapy.

Viscum Album Fruit does not typically cause sedation. However, if a patient experiences a systemic reaction or receives epinephrine, they should not drive or operate machinery until they have fully recovered and been cleared by a medical professional.

Alcohol should be avoided for several hours before and after an injection. Alcohol causes vasodilation (widening of the blood vessels), which can increase the rate of allergen absorption and potentially increase the severity of a systemic reaction.

Immunotherapy can be discontinued at any time, but the benefits of desensitization will be lost if the course is not completed (usually 3-5 years). There is no 'withdrawal' syndrome, but the patient's allergy symptoms will likely return to their baseline level over time.

> Important: Discuss all your medical conditions with your healthcare provider before starting Viscum Album Fruit, especially if you have heart problems or asthma.

• Beta-Blockers (e.g., Propranolol, Atenolol): These medications are generally contraindicated in patients receiving Viscum Album Fruit immunotherapy. Beta-blockers can make a systemic allergic reaction (anaphylaxis) much more difficult to treat because they block the effects of epinephrine, the primary rescue medication. If a patient on a beta-blocker experiences anaphylaxis, they may suffer from refractory (unresponsive) hypotension and bradycardia.

• ACE Inhibitors (e.g., Lisinopril, Enalapril): These blood pressure medications may increase the risk of more severe systemic reactions or interfere with the body's natural compensatory mechanisms during an allergic event. While not strictly contraindicated, they require a careful risk-benefit analysis.
• MAO Inhibitors (e.g., Phenelzine): These can potentiate the effects of epinephrine used in emergencies, leading to dangerously high blood pressure.

• Other Immunotherapy: If a patient is receiving multiple different allergenic extracts (e.g., grass pollen and Viscum Album Fruit), the risk of a systemic reaction is cumulative. Doses may need to be staggered.
• Antihistamines: While often used to manage local reactions, regular use of antihistamines can mask the early 'warning signs' of a systemic reaction, potentially leading to a delay in recognizing anaphylaxis.

• Alcohol: As mentioned, alcohol increases blood flow to the skin and can accelerate the systemic absorption of the injected extract, increasing reaction risk.
• Large Meals: It is generally advised not to receive an injection immediately after a very heavy meal, as gastrointestinal symptoms of anaphylaxis could be confused with simple indigestion.

• St. John's Wort: May theoretically affect the metabolism of other medications used to treat allergic reactions, though direct evidence with allergenic extracts is limited.
• Immune Stimulants (e.g., Echinacea): These may theoretically interfere with the 'immune deviation' goal of immunotherapy by promoting a non-specific immune response.

• Skin Testing: Viscum Album Fruit treatment will eventually cause a decrease in the size of the wheal-and-flare reaction during subsequent skin tests. This is the intended effect and is used to monitor the progress of the therapy.
• Total IgE: Some patients may see a transient rise in total IgE levels early in treatment, followed by a long-term decline.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. A complete list is vital for your safety during immunotherapy.

Viscum Album Fruit must NEVER be used in the following circumstances:

• Previous Severe Systemic Reaction: If a patient has had a life-threatening reaction to a previous dose of Viscum Album Fruit, further use is generally prohibited unless in a highly specialized desensitization protocol.
• Unstable or Severe Asthma: Patients whose asthma is not well-controlled (e.g., FEV1 consistently below 70% of predicted) are at an unacceptable risk for fatal anaphylaxis.
• Acute Infection: Injections should never be given during an active fever or respiratory infection, as this lowers the threshold for a systemic allergic reaction.

Conditions requiring careful risk-benefit analysis include:

• Beta-Blocker Therapy: As noted, this makes treating anaphylaxis difficult.
• Severe Autoimmune Disease: There is a theoretical risk that stimulating the immune system with allergenic extracts could exacerbate conditions like systemic lupus erythematosus (SLE) or rheumatoid arthritis.
• Malignancy: While some use mistletoe investigatively in cancer, standard allergenic extracts are usually avoided in patients with active, unstable malignancies unless specifically indicated.
• Pregnancy (Initiation): Immunotherapy is typically not started during pregnancy due to the risk of anaphylaxis-induced fetal hypoxia.

Patients allergic to Viscum Album Fruit may show cross-reactivity with other members of the Santalaceae family. Furthermore, because mistletoe is a parasite that grows on host trees (like Apple, Oak, or Pine), poorly purified extracts might contain trace amounts of host tree proteins, potentially triggering reactions in patients with those specific tree allergies.

> Important: Your healthcare provider will evaluate your complete medical history before prescribing Viscum Album Fruit to ensure no contraindications are present.

Viscum Album Fruit is classified as Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women.

• Risk: The primary risk to the fetus is not the extract itself, but the potential for maternal anaphylaxis. A severe drop in maternal blood pressure can lead to uterine hypoperfusion and fetal distress or death.
• Clinical Practice: Most allergists will not start a new course of Viscum Album Fruit immunotherapy during pregnancy. However, if a woman is already on a stable maintenance dose and is tolerating it well, the doctor may choose to continue the therapy at the same or a slightly reduced dose.

It is not known whether the allergenic proteins in Viscum Album Fruit are excreted in human milk. However, because these are large proteins that are broken down in the mother's body, the risk to a nursing infant is considered extremely low. The decision to continue immunotherapy while breastfeeding should be made based on the mother's clinical need for allergy control.

Viscum Album Fruit extracts are used in the pediatric population.

• Age Limit: There is no specific age cutoff, but it is rarely used in children under age 5 because they may be unable to communicate the early symptoms of a reaction.
• Growth Effects: There is no evidence that allergenic extracts affect growth or development in children.

Patients over age 65 may receive Viscum Album Fruit, but caution is warranted.

• Comorbidities: Older adults are more likely to have cardiovascular disease, which increases the risk of complications from anaphylaxis.
• Medications: The higher prevalence of beta-blocker and ACE-inhibitor use in the elderly makes them a higher-risk group for immunotherapy.

Renal impairment does not significantly alter the clearance of allergenic proteins. No specific dosage adjustments are published, but clinicians should ensure the patient is hemodynamically stable before administration.

Hepatic impairment does not affect the proteolytic breakdown of the proteins in Viscum Album Fruit. No dose adjustments are required based on Child-Pugh classification.

> Important: Special populations require individualized medical assessment. Always inform your specialist of your full health status.

Viscum Album Fruit extract acts as an immunomodulator. On a molecular level, the extract contains various allergens that are processed by Antigen Presenting Cells (APCs), such as dendritic cells. these APCs present the mistletoe peptides to naive T-cells. In an allergic individual, this normally promotes a Th2 (T-helper 2) response.

Immunotherapy with Viscum Album Fruit works by forcing the immune system to tolerate the allergen. This is achieved through the induction of Regulatory T-cells (Tregs) that produce IL-10 and TGF-beta. These cytokines suppress the allergic inflammation and signal B-cells to switch production from IgE to IgG4. IgG4 acts as a 'blocking antibody,' preventing the allergen from binding to IgE on the surface of mast cells and basophils, thus preventing the allergic cascade.

The pharmacodynamic effect of Viscum Album Fruit is not immediate. While a skin test shows a reaction within 15-20 minutes, the therapeutic effect (desensitization) takes months to develop. The duration of effect can last for several years after the completion of a 3-5 year treatment course, though some patients may eventually require 'booster' injections.

| Parameter | Value |

|---|---|

| Bioavailability | N/A (Subcutaneous/Epicutaneous) |

| Protein Binding | Minimal (interacts with IgE/IgG) |

| Half-life | Hours (Proteins); Years (Immune Memory) |

| Tmax | 1-2 hours (Systemic absorption of proteins) |

| Metabolism | Proteolysis (Proteases) |

| Excretion | Renal (as amino acids/metabolites) |

Viscum Album Fruit extract is a mixture of proteins, glycoproteins, and polysaccharides. Key active constituents include:

• Viscotoxins: Small, cysteine-rich proteins (approx. 5 kDa) that have cytotoxic and immunostimulatory properties.
• Mistletoe Lectins (ML I, II, III): Type II ribosome-inactivating proteins that consist of an A-chain (inhibits protein synthesis) and a B-chain (binds to cell surfaces).
• Molecular Weight: Ranges from 5 kDa to over 60 kDa depending on the specific protein component.

Viscum Album Fruit is categorized as a Non-Standardized Plant Allergenic Extract. It is related to other plant extracts like Ragweed, Timothy Grass, and Oak extracts, all of which are used in the field of allergen immunotherapy.