2 DOSAGE AND ADMINISTRATION At the onset of an attack, administer onto or under the tongue. Repeat every 5 minutes as needed ( 2.1 ). Do up to three metered sprays within a 15-minute period. If chest pain persists, advise prompt medical attention ( 2.1 ). May be used prophylactically 5 to 10 minutes prior to engaging in activities that might precipitate an acute attack ( 2.1 ). 2.1 Recommended dosage Instruct the patient to administer one or two metered sprays (400 mcg of nitroglycerin per spray) at the onset of an attack onto or under the tongue. A spray may be repeated approximately every five minutes as needed. No more than three metered sprays are recommended within a 15-minute period. If the chest pain persists after a total of three sprays , advise prompt medical attention. Nitroglycerin Lingual Spray may be used prophylactically 5 to 10 minutes prior to engaging in activities that might precipitate an acute attack. 2.2 Priming The pump must be primed prior to the first use. Each metered spray of Nitroglycerin Lingual Spray delivers 48 mg of solution containing 400 mcg of nitroglycerin after an initial priming of five sprays. It will remain adequately primed for 6 weeks. If the product is not used within 6 weeks it can be adequately re-primed with one spray. If the product is not used within 3 months it can be adequately re-primed with up to five sprays. There are 60 or 200 metered sprays per bottle. The total number of available doses is dependent, however, on the number of sprays per use (1 or 2 sprays), and the frequency of priming. There are 60 or 200 metered sprays per bottle. The total number of available doses is dependent, however, on the number of sprays per use (1 or 2 sprays), and the frequency of priming. 2.3 Administration Instruct patients that during administration, the patient should rest, ideally in the sitting position. Hold the container vertically with the valve head uppermost and the spray orifice as close to the mouth as possible. Spray the dose preferably onto or under the tongue by pressing the grooved-button firmly and the mouth closed immediately after each dose. THE SPRAY SHOULD NOT BE INHALED. The medication should not be expectorated or the mouth rinsed for 5 to 10 minutes following administration. Instruct patients to familiarize themselves with the position of the spray orifice, which can be identified by the finger rest on top of the valve, in order to facilitate orientation for administration at night [see Patient Information (17) ]. The amount of liquid remaining in the container should be checked periodically. The transparent container can be used for continuous monitoring of the consumption. With the container upright and level, check to be sure the end of the center tube extends below the level of the liquid. Once fluid falls below the level of the center tube, remaining sprays will not deliver intended dose.