GENERAL: The risk of a severe allergic reaction usually can be reduced by eliciting the patient's allergy history and by percutaneous testing by the scratch, prick or puncture method. If a scratch, prick or puncture skin test is negative, it usually is safe to perform an intradermal test with a one thousand-fold dilution of the extract used for the percutaneous test. If there is a history of unusual sensitivity, it is advisable to use a weaker dilution of the extract for skin testing. 

Systemic allergic reactions may occur as a result of immunotherapy. The risk can be reduced by adherence to a careful injection schedule, which starts with a low concentration of extract and is increased slowly. The physician must be prepared to treat anaphylaxis should it occur and have the necessary drugs and equipment on hand to treat serious adverse reactions. Extracts should not be administered by the patient or by other individuals who are not prepared to treat anaphylaxis, should it occur.

Extract must be injected subcutaneously during immunotherapy. It must not be given intravenously. A separate sterile tuberculin syringe graduated in 0.01 mL should be used for each injection.

INFORMATION FOR PATIENTS: Because most serious reactions occur within 20 minutes after the injection of allergenic extract the patient should remain under observation for this length of time. The patient also should be instructed to report any unusual reactions to the physician, such as swelling and/or tenderness at the injection site or rhinorrhea, sneezing, coughing, wheezing, shortness of breath, nausea, dizziness or faintness following the injection of extract. 

CARCINOGENESIS, MUTAGENESIS, IMPAIRMENT OF FERTILITY: Long term studies in animals have not been conducted with standardized grass pollen extract to determine the potential for carcinogenicity, mutagenicity or impairment of fertility. 

PREGNANCY CATEGORY C: Animal reproduction studies have not been conducted with standardized grass pollen extract. It is also not known whether standardized grass pollen extract can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Caution should be exercised in testing or treating pregnant females, because a systemic reaction might conceivably cause uterine muscle contractions leading to abortion. Standardized grass pollen extract should be given to a pregnant woman only if clearly needed 15. 

PEDIATRIC USE: The dose of allergenic extract recommended for children is the same as for adults. Allowances may be made in the injection of large doses of extract for treatment. In this case, it may be advisable to modify the dose and frequency of injections, so that the discomfort is minimized. 

NURSING MOTHERS: It is not known whether standardized grass pollen extract is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when allergenic extract is administered to a nursing woman. 

DRUG INTERACTION: Antihistamines and hydroxyzine can inhibit the immediate skin test reaction. Patients being treated with delayed absorption antihistamine tablets should be free of such medication for 48 hours before testing. Non-sedating antihistamines, such as terfenadine and astemizole, may variably suppress the skin response for longer periods of time up to six weeks. Epinephrine injection inhibits the immediate skin test reaction for several hours. Beta-blocking drugs may make a patient refractory to the usual dose of epinephrine, in the event epinephrine is required to treat an adverse allergic reaction.