Anser Anser Feather

Dosage for Anser Anser Feather must be highly individualized based on the patient's sensitivity level and the specific clinical objective (diagnosis vs. treatment).

Diagnostic Dosing

• Skin Prick Test (SPT): A single drop of the 1:10 or 1:20 w/v extract is applied to the skin, followed by a puncture through the drop. A positive control (histamine) and negative control (saline/glycerin) are used for comparison.
• Intradermal Test: If the SPT is negative, 0.02 mL of a 1:1000 w/v or 1:100 w/v dilution may be injected into the intradermal layer of the skin.

Immunotherapy Dosing

Immunotherapy follows a two-phase schedule:

1. 1Build-up Phase: Starting with an extremely dilute solution (e.g., 0.05 mL of a 1:100,000 w/v dilution), doses are increased weekly or bi-weekly. The volume increases (0.1, 0.2, 0.5 mL) until the patient reaches the next concentration level.
2. 2Maintenance Phase: Once the 'maintenance dose' is reached (the highest dose tolerated without significant side effects), the frequency of injections is reduced to every 2 to 4 weeks. This phase typically continues for 3 to 5 years.

Anser Anser Feather is used in pediatric populations, though the safety and efficacy are generally extrapolated from adult data. Children follow similar weight/volume dosing protocols as adults, but the starting dose in the build-up phase may be even more conservative in highly sensitive children. There is no specific age cutoff, but skin testing is rarely performed on infants under 6 months of age due to reduced skin reactivity.

Renal Impairment

No specific dosage adjustments are required for patients with renal impairment, as the systemic protein load is negligible. However, if a systemic reaction occurs, the use of emergency medications (like epinephrine) may require caution in patients with underlying kidney-related electrolyte imbalances.

Hepatic Impairment

No dosage adjustments are necessary for hepatic impairment. The metabolism of allergenic proteins is not dependent on liver function.

Elderly Patients

Elderly patients may have reduced skin reactivity, leading to potential false-negative results in diagnostic testing. Furthermore, the risk of systemic reactions to immunotherapy must be weighed against the patient's cardiovascular health, as they may be less able to tolerate the physiological stress of anaphylaxis or the administration of epinephrine.

Anser Anser Feather is never for self-administration. It must be administered by a trained healthcare professional in a clinical setting equipped to handle anaphylaxis.

1. 1Preparation: The skin (usually the forearm or back) is cleaned with alcohol.
2. 2Administration: For testing, the skin is pricked. For immunotherapy, the injection is given subcutaneously in the upper arm.
3. 3Observation: The patient must remain in the clinic for at least 30 minutes after any injection or test to monitor for signs of a systemic allergic reaction.
4. 4Storage: Vials must be stored in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze, as this can denature the allergenic proteins and render the extract ineffective.

In immunotherapy, consistency is vital. If a dose is missed during the build-up phase, the next dose may need to be reduced or the previous dose repeated, depending on how much time has passed. If the maintenance dose is missed by more than 2 weeks, the allergist will typically step back the dose to ensure safety.

An 'overdose' in the context of allergenic extracts refers to the administration of a dose that exceeds the patient's current tolerance level, potentially leading to a systemic reaction. Symptoms of an overdose include generalized hives, swelling (angioedema), wheezing, or a drop in blood pressure. Immediate treatment with epinephrine, antihistamines, and potentially corticosteroids is required.

> Important: Follow your healthcare provider's dosing instructions exactly. Do not attempt to adjust your dose or the frequency of your injections without medical guidance.

The most frequent side effects associated with Anser Anser Feather are localized to the site of administration. These are expected responses to the allergen in sensitized individuals.

• Local Wheal and Flare: A raised, itchy bump (wheal) surrounded by redness (flare) at the test site. This typically appears within 15–20 minutes and resolves within a few hours.
• Injection Site Swelling: In immunotherapy, it is common to experience swelling and redness at the injection site that may last 24–48 hours. This is often referred to as a 'local reaction.'
• Pruritus (Itching): Intense itching at the site of the skin test or injection.

• Large Local Reactions (LLR): Swelling at the injection site that exceeds 5–10 cm in diameter. While not dangerous, it may indicate that the next dose should not be increased.
• Fatigue: Some patients report feeling unusually tired or 'drained' for several hours after an immunotherapy injection.
• Nasal Congestion or Sneezing: A mild systemic 'flare' of the patient's typical allergy symptoms.

• Generalized Urticaria: Hives appearing on parts of the body away from the injection site.
• Angioedema: Swelling of the deeper layers of the skin, often around the eyes or lips.
• Persistent Granuloma: A small, firm bump under the skin at the injection site that may persist for weeks.

> Warning: Stop the administration process and call your doctor or seek emergency care immediately if you experience any of the following symptoms of Anaphylaxis:

• Respiratory Distress: Difficulty breathing, shortness of breath, or a tight feeling in the throat.
• Wheezing or Persistent Coughing: Signs of bronchial constriction.
• Cardiovascular Collapse: Dizziness, lightheadedness, rapid or weak pulse, or fainting (indicating a drop in blood pressure).
• Swelling of the Tongue or Throat: This can obstruct the airway and is a life-threatening emergency.
• Nausea and Vomiting: Systemic involvement of the gastrointestinal tract during an allergic reaction.
• Sense of Impending Doom: A psychological symptom often associated with the onset of severe anaphylaxis.

There are no known long-term 'toxic' effects of Anser Anser Feather extract, as it is a biological protein mixture. However, the long-term benefit is the 'disease-modifying' effect, which can reduce the risk of developing asthma in children with allergic rhinitis. Some patients may develop persistent sensitivity at the injection site over years of treatment.

While Anser Anser Feather may not have a specific individual black box warning for the 'Goose' variety, the FDA requires a Class Black Box Warning for all allergenic extracts.

Summary of Warning:

• Allergenic extracts can cause severe life-threatening systemic reactions, including anaphylaxis.
• Extracts should only be administered by healthcare professionals prepared to treat anaphylaxis.
• Patients with unstable asthma are at higher risk for severe reactions.
• Patients taking beta-blockers may be resistant to the effects of epinephrine used to treat reactions.

Report any unusual symptoms or delayed reactions (occurring hours after the injection) to your healthcare provider immediately.

Anser Anser Feather extract is intended only for use by physicians specializing in allergy and immunology. Because it contains active allergens, the risk of an acute allergic reaction is always present. Patients must be informed of the risks and benefits before beginning either diagnostic testing or immunotherapy.

No FDA black box warnings specifically unique to Anser Anser Feather exist beyond the standard class warning for all allergenic extracts. This warning emphasizes that the product can cause anaphylaxis and must be administered in a setting where emergency resuscitation equipment and trained personnel are immediately available. Patients must be observed for at least 30 minutes post-injection.

• Anaphylaxis Risk: This is the primary concern. Risk factors include high levels of sensitivity, a history of previous systemic reactions, and administration during peak allergy seasons when the patient's 'allergic load' is already high.
• Asthma Status: Patients with symptomatic or poorly controlled asthma should not receive immunotherapy or skin testing until their asthma is stabilized. Severe, even fatal, reactions are more common in patients with compromised lung function.
• Cardiovascular Disease: Patients with significant heart disease may be at increased risk if a systemic reaction occurs, as the physiological stress of anaphylaxis and the subsequent treatment with epinephrine can strain the heart.
• Autoimmune Disorders: The use of immunotherapy in patients with active autoimmune diseases (e.g., Lupus, Rheumatoid Arthritis) is controversial and requires a careful risk-benefit analysis, as it may theoretically exacerbate the underlying condition.

• Pre-injection Assessment: Before every immunotherapy dose, the provider must check for current allergy symptoms, asthma stability (potentially using a peak flow meter), and any reactions to the previous dose.
• Post-injection Observation: A mandatory 30-minute wait time in the clinic.
• Skin Test Interpretation: Diagnostic tests must be read at the appropriate time (15–20 minutes) to avoid false negatives or false positives.

Most patients can drive after the 30-minute observation period. However, if a patient experiences a systemic reaction or receives antihistamines/epinephrine, they should not operate heavy machinery or drive until the symptoms and the effects of the emergency medications have completely resolved.

Alcohol consumption should be avoided on the day of an immunotherapy injection. Alcohol can cause vasodilation (widening of blood vessels), which may theoretically increase the rate of allergen absorption and heighten the risk or severity of a systemic reaction.

Immunotherapy is typically discontinued if the patient experiences a life-threatening reaction that cannot be managed by dose reduction. It may also be stopped if no clinical improvement is seen after 1–2 years of maintenance therapy. There is no 'withdrawal syndrome' associated with stopping allergenic extracts.

> Important: Discuss all your medical conditions, especially respiratory or heart problems, with your healthcare provider before starting Anser Anser Feather.

There are no absolute drug-drug contraindications that prevent the use of Anser Anser Feather, but certain medications make its use significantly more dangerous.

• Beta-Blockers (e.g., Propranolol, Atenolol): These are often considered a relative contraindication. If a patient on a beta-blocker has an anaphylactic reaction to the feather extract, the beta-blocker may prevent epinephrine from working effectively. This can lead to 'epinephrine-resistant anaphylaxis,' which is difficult to treat and potentially fatal.

• ACE Inhibitors (e.g., Lisinopril): Some studies suggest that patients taking ACE inhibitors may be at a higher risk for more severe systemic reactions to allergenic extracts due to interference with the body's ability to degrade bradykinin (an inflammatory mediator).
• MAO Inhibitors (e.g., Phenelzine): These can potentiate the effects of epinephrine, leading to severe hypertension if epinephrine is needed to treat a reaction.

• Antihistamines (H1 Blockers): Medications like cetirizine (Zyrtec), loratadine (Claritin), and diphenhydramine (Benadryl) must be stopped 3–7 days before diagnostic skin testing. These drugs block the H1 receptors on the skin, preventing the 'wheal and flare' reaction and leading to false-negative results. They do not, however, need to be stopped for immunotherapy injections.
• Tricyclic Antidepressants (e.g., Amitriptyline): These drugs have potent antihistamine properties and can also interfere with skin test results for several days.
• H2 Blockers (e.g., Famotidine): While less potent than H1 blockers, they can also slightly reduce skin reactivity and should ideally be discontinued before testing.
• Topical Corticosteroids: Applying steroid creams to the test site can suppress the local inflammatory response and should be avoided for at least 2–3 weeks prior to testing.

• Bird-Egg Syndrome: There is a known cross-reactivity between bird dander/feathers and egg yolk. Patients allergic to goose feathers may experience allergic symptoms when eating eggs. While not a direct 'interaction' with the drug, healthcare providers must be aware of this clinical link.
• Alcohol: As mentioned, alcohol can increase the risk of systemic reactions to injections.

• St. John's Wort: May theoretically affect the metabolism of medications used to treat anaphylaxis, though this is not well-documented.
• High-dose Vitamin C: Some believe it has mild antihistamine effects, which could theoretically interfere with skin testing, though clinical evidence is sparse.

Anser Anser Feather does not interfere with standard blood chemistry or hematology tests. However, it will directly affect:

• Specific IgE (RAST/ImmunoCAP): Successful immunotherapy will eventually lead to changes in goose-specific IgE and IgG4 levels in the blood, which is the intended therapeutic effect.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, especially any heart or blood pressure medications.

Anser Anser Feather must NEVER be used in the following circumstances:

• Recent Anaphylaxis: If a patient has recently suffered a severe systemic reaction to the same or a similar extract, administration should be delayed until they are fully recovered and the cause is investigated.
• Unstable Asthma: Patients with an FEV1 (Forced Expiratory Volume) consistently below 70% of predicted value or those with frequent acute exacerbations are at an unacceptably high risk for fatal anaphylaxis.
• Acute Infection: Injections should be deferred if the patient has a fever or a significant respiratory infection, as this can lower the threshold for a systemic reaction.

Conditions requiring careful risk-benefit analysis include:

• Severe Atopic Dermatitis: If the skin is too inflamed, diagnostic skin testing may be impossible to interpret accurately.
• Pregnancy (Initiation): While maintenance immunotherapy is often continued during pregnancy, starting a new build-up phase is generally avoided due to the risk of maternal anaphylaxis, which can cause fetal hypoxia (lack of oxygen).
• Malignancy or Immunodeficiency: The immune system's ability to respond appropriately to immunotherapy may be compromised in patients with cancer or HIV/AIDS.

Patients allergic to goose feathers often show cross-sensitivity to:

• Other Avian Species: Duck, chicken, and turkey feathers/dander.
• Egg Proteins: Specifically the serum albumin (Gal d 5) found in egg yolks, a phenomenon known as 'bird-egg syndrome.'

> Important: Your healthcare provider will evaluate your complete medical history, including your current asthma control and medication list, before prescribing Anser Anser Feather.

FDA Pregnancy Category C. There are no adequate and well-controlled studies of Anser Anser Feather in pregnant women.

• Risk Summary: The primary risk during pregnancy is not the extract itself, but the potential for maternal anaphylaxis. A severe allergic reaction can lead to uterine contractions and placental hypoperfusion (reduced blood flow), potentially harming the fetus.
• Clinical Practice: Allergists typically do not start immunotherapy during pregnancy. However, if a patient is already on a stable maintenance dose and is tolerating it well, the treatment is often continued at that dose (without further increases) to maintain the patient's allergic stability.

It is not known whether the allergenic proteins from Anser Anser Feather are excreted in human milk. However, because these are large proteins that are degraded into amino acids, it is highly unlikely that they would be absorbed intact by the nursing infant. Immunotherapy is generally considered safe for breastfeeding mothers, provided they are monitored for systemic reactions as usual.

• Safety: Allergen immunotherapy is considered safe and effective for children, usually starting around age 5. Younger children may be tested if symptoms are severe.
• Benefits: Early intervention with immunotherapy in children with allergic rhinitis has been shown in studies (like the GAP trial) to reduce the later development of asthma.
• Considerations: Children may be more frightened by the frequent injections, and their ability to communicate the early symptoms of a systemic reaction (like an itchy throat) may be limited.

• Cardiovascular Risk: Patients over 65 are more likely to have underlying hypertension or coronary artery disease, making them more vulnerable to the side effects of epinephrine if a reaction occurs.
• Skin Reactivity: Reduced mast cell density in aging skin can lead to smaller wheal sizes during testing, requiring careful interpretation.
• Polypharmacy: Older adults are more likely to be on beta-blockers or ACE inhibitors, which complicate the management of allergic reactions.

No dosage adjustments are required. The proteins are naturally degraded by proteases and do not rely on renal clearance for their primary therapeutic effect. However, clinicians should monitor for fluid balance if high-volume systemic resuscitation is ever required for anaphylaxis.

No adjustments are necessary. Liver function does not impact the efficacy or safety of subcutaneous allergenic extracts.

> Important: Special populations require individualized medical assessment. Always inform your allergist if you become pregnant or develop new health conditions during treatment.

Anser Anser Feather acts as a specific immunomodulator. At the molecular level, the extract contains various proteins (such as serum albumins and keratins) that act as antigens.

1. 1Diagnostic Phase: The antigens cross-link pre-existing IgE antibodies on the surface of mast cells and basophils. This cross-linking triggers a signal transduction pathway involving tyrosine kinases (like Lyn and Syk), leading to the influx of calcium and the release of pre-formed mediators like histamine.
2. 2Therapeutic Phase: Repeated subcutaneous exposure to the antigen induces the production of Regulatory T-cells (Tregs). These cells secrete IL-10 and TGF-beta, which suppress the Th2 allergic response. Furthermore, B-cells are stimulated to switch production from IgE to IgG4. IgG4 acts as a 'blocking antibody' by binding to the goose allergen before it can reach the IgE on mast cells.

• Dose-Response: In skin testing, the size of the wheal is generally proportional to the degree of sensitization, up to a plateau. In immunotherapy, higher maintenance doses are generally associated with better long-term clinical outcomes.
• Onset of Effect: Skin test results are visible in 15–20 minutes. The clinical benefits of immunotherapy usually take 6–12 months to become noticeable.
• Duration: The diagnostic effect is transient. The therapeutic effect of a completed 3–5 year course of immunotherapy can last for many years after discontinuation.

| Parameter | Value |

|---|---|

| Bioavailability | Low (Subcutaneous/Epicutaneous) |

| Protein Binding | N/A (Interacts with Antibodies) |

| Half-life | Minutes to hours (Proteins) |

| Tmax | 15-30 minutes (Local) |

| Metabolism | Proteolytic degradation |

| Excretion | Renal (Peptide fragments) |

• Composition: A sterile liquid containing the water-soluble proteins and dander extracted from Anser anser feathers.
• Solubility: Highly soluble in aqueous buffers or glycerin-saline solutions.
• Molecular Weight: Variable; contains a mixture of proteins ranging from 10 kDa to over 70 kDa (e.g., serum albumins are ~67 kDa).

Anser Anser Feather is classified as a Non-Standardized Animal Allergenic Extract. It shares this class with other avian extracts (duck, chicken) and mammalian extracts (cat, dog, horse) that are not measured by BAU.