Agrostis Alba

FDA Drug Information • Also known as: Standardized Redtop Grass, Standardized Redtop Pollen

Brand Names: Standardized Redtop Grass, Standardized Redtop Pollen
Route: INTRADERMAL, PERCUTANEOUS, SUBCUTANEOUS
Dosage Form: SOLUTION
Product Type: STANDARDIZED ALLERGENIC

⚠ Boxed Warning (Black Box)

WARNINGS This product is intended for use by physicians who are experienced in the administration of allergenic extract or for use under the guidance of an allergy specialist. In previously untreated patients, the initial dose must be based on skin testing as described in the dosage and administration section of this insert. Patients being switched from alum-adsorbed or other types of precipitated extracts to this extract should be started as though they were coming under treatment for the first time. Patients should be instructed to recognize adverse reaction symptoms and cautioned to contact the physician's office if symptoms occur. As with all allergenic extracts, severe systemic reactions may occur and in certain individuals these reactions may be lifethreatening or cause death. Patients should be observed for at least 20 minutes following treatment. Emergency measures as well as personnel trained in their use should be immediately available in the event of a life-threatening reaction. Patients being switched to a new lot of extract from the same manufacturer should have the dose reduced 75 percent. For dose selection in switching patients from unstandardized to standardized extract, physicians may refer to Table 3 as a guide (see CLINICAL PHARMACOLOGY). Extracts labeled in BAU/mL are not directly interchangeable with any other grass pollen product. Patients receiving beta-blocking drugs may be refractive to the usual dose of epinephrine, in the event that epinephrine is required to control an adverse allergic reaction to this product. Caution must be exercised in testing and treating patients with steroid-dependent or labile asthma. This product should never be injected intravenously. See also WARNINGS and ADVERSE REACTIONS below. Serious adverse reactions to this product should be reported to VAERS at 1-800-822-7967 or www.vaers.hhs.gov.

Description

DESCRIPTION Standardized grass pollen extract is a sterile solution containing the extractables of grass pollen in 0.25% sodium chloride, 0.125% sodium bicarbonate, 50% glycerol v/v and 0.4% phenol w/v. Standardized grass pollen extracts include Bermuda Grass ( Cynodon dactylon ), June Grass ( Poa pratensis ), Meadow Fescue Grass ( Festuca elatior ), Orchard Grass ( Dactylis glomerata ), Perennial Rye Grass ( Lolium perenne ), Redtop Grass ( Agrostis alba ), Sweet Vernal Grass ( Anthoxanthum odoratum ) and Timothy Grass ( Phleum pratense ). The extract may be administered by the scratch, prick, puncture, or intradermal methods of skin testing for diagnostic purposes and subcutaneously for therapeutic purposes as directed under Dosage and Administration. The potency of standardized grass pollen extracts is expressed in Bioequivalent Allergy Units per mL (BAU/mL) and is determined by an in vitro ELISA Competition Assay comparing the extract to a U.S. reference grass pollen extract available from the Center for Biologics Evaluation and Research (CBER), U.S. Food and Drug Administration. Bioequivalent Allergy Units per mL (BAU/mL) have been assigned to the reference extract based on quantitative skin testing (see CLINICAL PHARMACOLOGY). CBER reference extract labeled 100,000 BAU/mL can be diluted 1:5 million and yield a 50 mm sum of erythema diameter response intradermally in highly puncture reactive subjects. CBER reference extract labeled 10,000 BAU/mL can be diluted 1:500,000 for the same response (12). Allermed's standardized grass pollen extracts labeled in BAU/mL are not interchangeable with alum-precipitated grass pollen extracts, grass pollen extracts labeled in AU/mL or non-standardized grass pollen extracts.

What Is Agrostis Alba Used For?

INDICATIONS AND USAGE Standardized grass pollen extract is indicated for use in the diagnosis of grass allergy in patients with a history of allergic symptoms that occur during grass pollination. Skin tests with standardized grass pollen extract should be done first by the puncture method using 10,000 BAU/mL extract. If these tests are negative, they may be repeated by the puncture method with 100,000 BAU/mL extract, or by the intradermal method using an appropriate dilution (see DOSAGE AND ADMINISTRATION). The extract also is indicated for use in the treatment of allergic symptoms by immunotherapy in patients with a history of grass pollen allergy and established sensitivity to grass pollen extract by skin testing. The availability of 10,000 and 100,000 BAU/mL extracts facilitates dose selection for safe switching to standardized grass pollen extracts. Previously untreated patients should be initially treated with appropriately diluted 10,000 BAU/mL. If tolerated, higher doses may be indicated. The use of grass pollen extract for the above purposes should be made only by physicians with special familiarity and knowledge of allergy as described in a standard allergy textbook (13). Allermed's standardized grass pollen extracts labeled in BAU/mL are not interchangeable with alum-precipitated grass pollen extracts, grass pollen extracts labeled in AU/mL or non-standardized grass pollen extracts.

Dosage and Administration

DOSAGE AND ADMINISTRATION Parental drug products should be inspected visually for particulate matter and discoloration prior to adminitration, whenever solution and container permit. The product should be discarded if discoloration or particles are observed. DIAGNOSTIC USE: Standardized grass pollen extract may be used to diagnose sensitivity to grass pollen by performing skin tests on persons with a history of grass pollen allergy. Due to the risk of adverse reactions occuting in highly sensitive persons, it is mandatory to initially test all patients percutaneously using the scratch, prick or puncture method. If a properly performed percutaneous test is negative, an intradermal test may be used with caution. PUNCTURE TEST: The punture test should be performed first with 10,000 BAU/mL extract. Data for the puncture test using 10,000 BAU/mL extract are summarized in Table 1 under CLINICAL PHARMOCOLOGY. If the puncture test to 10,000 BAU/mL extract is negative, the test may be repeated using 100,000 BAU/mL extract. Appropriate positive and negative controls for skin test interpretation are necessary. Reactions are quarntified based on size of erythema and wheal in reaction to controls. INTRADERMAL TEST: An intradermal test should only be performed after a puncture test has been properly administered with a negative result. It is usually safe to initiate intradermal testing with a 1:1,000 v/v diluton of the extract to which a negative puncture test was observed. For example, if a puncture test is done with 10,000 BAU/mL extract and is negative, the intradermal test may be performed with 0.05 mL of 10 BAU/mL extract. The dose may be increased to 0.05 mL of 100 BAU/mL extract if the intradermal test with 10 BAU/mL extract is negative. THERAPEUTIC USE: The dosage of grass pollen extract administered by subcutaneous injection during immunotherapy is highly individualized and varies according to the patient. In patients who appear to be highly sensitive by history and skin test, the initial dose of the extract should be low, such as 0.1 mL of a 0.01 BAU/mL dilution. The amount of extract is increased at each injection, but not more than 50%-100% of the previous amount, and the next increment is governed by the response to the last injection. Local reactions that persist longer than 24 hours are undesirable and any systemic reaction is an indication that the dose should be reduced (at least 50%). The upper limits of dosage have not been established, but doses larger than 0.2 mL of concentrate containing 50% glycerol may be painful due to the glycerol in the extract. The potency of each standardized grass pollen in a final mixture should not exceed that obtained from using a 10,000 BAU/mL stock concentrate of each grass included in the mix. Concentrate containing 100,000 BAU/mL should be diluted to 10,000 BAU/mL extract before being used to prepare final mixtures, or alternatively, the volume of 100,000 BAU/mL extract added to the mixture should be...

Side Effects (Adverse Reactions)

ADVERSE REACTIONS Local reactions consisting of erythema, itching, swelling, tenderness and sometimes pain may occur at the injection site. These reactions may appear within a few minutes to hours and persist for several days. Local cold applications and oral antihistamines may be effective treatment. For marked and prolonged local reactions, steroids may be helpful. Adverse systemic reactions usually occur within minutes and consist primarily of allergic symptoms such as generalized skin erythema, urticaria, pruritus, angioedema, rhinitis, wheezing, laryngeal edema and hypotension. Less commonly, nausea, emesis, abdominal cramps, diarrhea and uterine contractions may occur. Severe reactions may cause shock and loss of consciousness and fatalities have occurred (14). The treatment of systemic allergic reactions is somewhat dependent upon the symptom complex. Epinephrine hydrochloride 1:1,000 aqueous, in an adult dose of 0.3 - 0.5 mL (or 0.01 mL per kg. for children) administered subcutaneously in the opposite arm is the immediate treatment of choice. A tourniquet should be placed above the site of the injection if the injection was done on the extremities. Antihistamines may offer relief of recurrent urticaria, associated skin reactions and gastrointestinal symptoms. Persistent wheezing may necessitate intravenous aminophylline treatment in addition to inhaled bronchodilators. For profound shock and hypotension, intravenous fluids, vasopressors and oxygen also may be needed. Maintenance of an open airway is critical if upper airway obstruction is present. Corticosteroids may provide benefit if symptoms are prolonged or recurrent. Serious adverse reactions to this product should be reported to MEDWATCH, Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20852-9782. Telephone (800) 332-1088.

Warnings and Precautions

WARNINGS Standardized grass pollen extract must be diluted prior to first use on a patient for immunotherapy or intradermal testing (see DOSAGE AND ADMINISTRATION). Grass pollen extract is manufactured to assure high potency and has the ability to cause serious local and systemic reactions, including death in sensitive patients (14). Patients should be informed of this risk and precautions should be discussed prior to initiating skin testing and immunotherapy (see PRECAUTIONS). Grass pollen extract should be temporarily withheld from a patient if any of the following conditions exist: (a) severe symptoms of rhinitis and/or asthma; (b) infection or flu accompanied by fever; (c) exposure to excessive amounts of grass pollen allergen prior to a scheduled injection. SWITCHING PATIENTS TO STANDARDIZED GRASS POLLEN EXTRACT: The same precautions that are recommended in switching from an old to a new lot of non-standardized grass pollen extract should be followed in switching from non-standardized to standardized grass pollen extract, i.e., the dose of the new lot of standardized grass pollen extract should be reduced 75% of the dose given from an old lot of non-standardized grass pollen extract. Under certain circumstances, it may be advisable to compare the relative potency of the standardized and non-standardized extract by side by side skin testing using comparable v/v dilutions of the concentrates. When switching from alum precipitated grass pollen extract to standardized grass pollen extract, the patient should be managed as a new patient coming under treatment for the first time.

Contraindications

CONTRAINDICATIONS Immunotherapy should not be started in patients until a specific diagnosis of Type I allergy to grass pollen has been made from the patient's allergy history and from a positive skin test to grass pollen extract. Other contraindications include: EXTREME SENSITIVITY TO GRASS POLLEN: Patients who experience serious adverse reactions to grass pollen extract from skin testing and/or immunotherapy should not be given the product. AUTOIMMUNE DISEASE: Individuals with autoimmune disease may be at risk, due to the possibility of routine immunizations exacerbating symptoms of the underlying disease. MYOCARDIAL INFARCTION: Patients who have experienced a recent myocardial infarction may not be able to tolerate adverse reactions resulting from skin testing or immunotherapy. The benefit-torisk ratio must be carefully evaluated in these patients. CHILDREN WITH NEPHROTIC SYNDROME: Children with nephrotic syndrome require careful consideration and probably should not receive immunotherapy, due to a variety of seemingly unrelated events that may cause an exacerbation of nephrotic disease. BLEEDING DIATHESIS: Injections of grass pollen extract should not be administered in the presence of diseases characterized by a bleeding diathesis.

Overdosage

OVERDOSAGE A strong local reaction to the injection of extract may be treated with oral antihistamines and the local application of a cold compress. The dosage must be reduced and additional extract must not be given until all evidence of the reaction has disappeared. A systemic reaction following the injection of extract must be treated immediately with Epinephrine hydrochloride 1:1,000 aqueous and other measures as appropriate (see ADVERSE REACTIONS, paragraph 3 above).

How Supplied

HOW SUPPLIED Standardized grass pollen extract containing 10,000 BAU/mL is supplied in 1 and 5 mL dropper vials and in 10 mL, 30 mL and 50 mL multidose vials. Bermuda Grass is only supplied as 10,000 BAU/mL. Other standardized grass pollen extracts are available at 100,000 BAU/mL in 10 mL, 30 mL and 50 mL vials.

About This Information

This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.

What are side effects?

Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.

What are drug interactions?

Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.