NITROGLYCERIN

Nitroglycerin is 1,2,3,-propanetriol trinitrate, an organic nitrate whose structural formula is as follows: and whose molecular weight is 227.09. Nitroglycerin ointment, USP, 0.4% contains 0.4% nitroglycerin w/w (4 mg nitroglycerin/1 g ointment), propylene glycol, lanolin, sorbitan sesquioleate, paraffin wax, and white petrolatum. Nitroglycerin ointment, USP, 0.4% is available in tubes with a one-inch dosing line on the carton allowing the measurement of approximately 375 mg of nitroglycerin ointment 0.4% (1.5 mg nitroglycerin) for application. image-structure

Nitroglycerin ointment, 0.4% is indicated for the treatment of moderate to severe pain associated with chronic anal fissure. Nitroglycerin ointment, 0.4% is a nitrate vasodilator indicated for the treatment of moderate to severe pain associated with chronic anal fissure ( 1 ).

Apply 1 inch of ointment (375 mg of ointment equivalent to 1.5 mg of nitroglycerin) intra-anally every 12 hours for up to 3 weeks. A finger covering, such as plastic-wrap, disposable surgical glove or a finger cot, should be placed on the finger to apply the ointment. To obtain a 1.5 mg dose of nitroglycerin, the covered finger is laid alongside the 1-inch dosing line on the carton. Refer to carton for accurate dosage guide. The tube is gently squeezed until a line of ointment the length of the measuring line is expressed onto the covered finger. The ointment is gently inserted into the anal canal using the covered finger no further than to the first finger joint and the ointment is applied around the side of the anal canal. If this cannot be achieved due to pain, application of the ointment should be made directly to the outside of the anus. Treatment may be continued for up to three weeks. Nitroglycerin ointment, 0.4% is not for oral, ophthalmic, or intravaginal use. Hands should be washed after application of the ointment. See Patients Instruction for Use . Apply 1 inch of ointment (375 mg of ointment equivalent to 1.5 mg of nitroglycerin) intra-anally every 12 hours for up to 3 weeks ( 2 ). Nitroglycerin ointment 0.4% is not for oral, ophthalmic, or intravaginal use ( 2 ). Tube-1

Use of PDE5 inhibitors (e.g. sildenafil, vardenafil and tadalafil) as these are shown to potentiate the hypotensive effects of organic nitrates. ( 4.1 ). Severe anemia ( 4.2 ) Increased intracranial pressure ( 4.3 ) Known hypersensitivity to nitroglycerin, other nitrates and nitrites, or any components of the ointment. ( 4.4 ) 4.1 PDE5 Inhibitor Use Administration of nitroglycerin ointment, 0.4% is contraindicated in patients who are using a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), such as sildenafil, vardenafil, and tadalafil, as these are shown to potentiate the hypotensive effects of organic nitrates [see 7.1 DRUG INTERACTIONS ]. 4.2 Severe Anemia Nitroglycerin ointment, 0.4% is contraindicated in patients with severe anemia. 4.3 Increased Intracranial Pressure Nitroglycerin ointment, 0.4% is contraindicated in patients with increased intracranial pressure. 4.4 Hypersensitivity Nitroglycerin ointment, 0.4% is contraindicated in patients who have shown hypersensitivity to it or to other nitrates or nitrites. Skin reactions consistent with hypersensitivity have been observed with organic nitrates.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The most common adverse reaction of nitroglycerin ointment, 0.4% applied to the anal canal is headache. Headache may be recurrent following each dose. Headaches are typically of short duration and can be treated with an analgesic, e.g. acetaminophen, and are reversible upon discontinuation of treatment. In Study REC-C-001, a double-blind, placebo-controlled trial in patients with a painful chronic anal fissure, the most frequent (≥ 2%) adverse reactions reported were as follows (Table 1): Table 1: Incidence of Adverse Reactions (≥ 2%) in Study REC-C-001 Nitroglycerin Ointment N = 123 Placebo N = 124 System Organ Class Preferred term Patients n (%) Events n Patients n (%) Events n Nervous system disorders Headache 79 (64) 938 51 (41) 225 Dizziness 6 (5) 26 0 0 Most common adverse reactions are headache and dizziness. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact TruPharma LLC at 1-877-541-5504 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Hypotension Transient episodes of light-headedness, occasionally related to blood pressure changes, also may occur. Hypotension (including orthostatic hypotension) occurs infrequently, but in some patients may be severe enough to warrant discontinuation of therapy. Allergic Reactions Flushing, allergic reactions, and application site reactions (including drug rash and exfoliative dermatitis) have been reported rarely. Methemoglobinemia In rare cases, therapeutic doses of organic nitrates have caused methemoglobinemia (see 10 OVERDOSAGE ).

PDE5 inhibitors: potentiation of hypotensive effects of organic nitrates; concomitant use is contraindicated. ( 4.1 , 7.1 ) Antihypertensives: possible additive hypotensive effects. ( 7.2 ) Aspirin: increased nitroglycerin levels. ( 7.3 ) Tissue-type Plasminogen Activator (t-PA): decreased thrombolytic effect. ( 7.4 ) Heparin: anticoagulant effect of heparin may be reduced. Monitor APTT. ( 7.5 ) Ergotamine: increased bioavailability of ergotamine. ( 7.6 ) Alcohol: Additive vasodilatory effects to nitroglycerin. Consumption of alcohol should be avoided. ( 7.7 ) 7.1 PDE5 Inhibitors Phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil, vardenafil, and tadalafil have been shown to potentiate the hypotensive effects of organic nitrates. The time course of the interaction appears to be related to the half-life of the PDE5 inhibitor, however, the dose dependence of this interaction has not been studied. Use of nitroglycerin ointment, 0.4% within a few days of PDE5 inhibitors is contraindicated. 7.2 Antihypertensives Patients receiving antihypertensive drugs, beta-adrenergic blockers, and other nitrates should be observed for possible additive hypotensive effects when using nitroglycerin ointment, 0.4%. Marked orthostatic hypotension has been reported when calcium channel blockers and organic nitrates were used concomitantly. Beta-blockers blunt the reflex tachycardia produced by nitroglycerin without preventing its hypotensive effects. If beta-blockers are used with nitroglycerin ointment, 0.4% in patients with angina pectoris, additional hypotensive effects may occur. 7.3 Aspirin Coadministration of aspirin (at doses between 500 mg and 1000 mg) and nitroglycerin has been reported to result in increased nitroglycerin maximum concentrations by as much as 67% and AUC by 73% when administered as a single dose. The pharmacological effects of nitroglycerin ointment, 0.4% may be enhanced by concomitant administration of aspirin. 7.4 Tissue-type Plasminogen Activator (t-PA) Intravenous administration of nitroglycerin decreases the thrombolytic effect of tissue-type plasminogen activator (t-PA). Plasma levels of t-PA are reduced when coadministered with nitroglycerin. Therefore, caution should be observed in patients receiving nitroglycerin ointment, 0.4% during t-PA therapy. 7.5 Heparin Although an interaction has been reported between intravenous heparin and intravenous nitroglycerin (resulting in a decrease in the anticoagulant effect of heparin), the data are not consistent. If patients are to receive intravenous heparin and nitroglycerin ointment, 0.4% concurrently, the anticoagulation status of the patient must be checked. 7.6 Ergotamine Oral administration of nitroglycerin markedly decreases the first-pass metabolism of dihydroergotamine and consequently increases its oral bioavailability. Ergotamine is known to precipitate angina pectoris. Therefore the possibility of ergotism in patients receiving nitroglycerin ointment, 0.4% should be considered. 7.7 Alcohol The vasodilating effects of nitroglycerin have been shown to be additive to the effects observed with alcohol.