Pactorin400 mcg/spray

Pactorin is an organic nitrate vasodilator used mainly for the management of angina pectoris (chest pain) caused by coronary artery disease.

Established/FDA-approved uses

• Acute relief of angina attacks (sublingual tablet, sublingual/translingual spray): taken at the onset of an anginal attack.
• Prophylaxis (prevention) of angina before activities known to provoke an attack (sublingual tablet/spray taken 5-10 minutes beforehand; extended-release oral tablets/capsules and transdermal patches for longer-term prevention).
• Intravenous Pactorin is FDA-approved for control of blood pressure in perioperative hypertension, for treatment of congestive heart failure associated with acute myocardial infarction, for treatment of angina pectoris that has not responded to sublingual Pactorin and beta-blockers, and for producing controlled hypotension during surgical procedures.

Guideline-supported / adjunct uses

• Adjunct therapy in acute coronary syndrome and acute decompensated heart failure with pulmonary congestion, in combination with other standard therapies, under close medical supervision.

Pactorin does not replace the need for evaluation and long-term management of underlying coronary artery disease.

Each formulation of Nitroglycerin contains the active ingredient Nitroglycerin in varying strengths depending on the dosage form:

• Sublingual tablets: commonly 0.3 mg, 0.4 mg, or 0.6 mg per tablet.
• Sublingual/translingual spray: commonly 0.4 mg per metered spray.
• Extended-release oral tablets/capsules: commonly 2.5 mg, 2.6 mg, 6.4 mg, or 9 mg.
• Transdermal patch: delivers Nitroglycerin at a controlled rate (e.g. 0.2-0.8 mg/hour) over 24 hours.
• Intravenous infusion: supplied as a concentrate for dilution, commonly 5 mg/mL.
• Topical ointment: commonly 2% Nitroglycerin ointment.

Inactive ingredients vary by manufacturer and formulation; refer to the specific product label for details.

Pactorin is an organic nitrate ester and a potent smooth-muscle relaxant belonging to the nitrovasodilator class of drugs. It has been used for over a century in the management of angina pectoris.

Pactorin is available in multiple dosage forms, including sublingual tablets, sublingual/translingual spray, extended-release oral tablets/capsules, transdermal patches, topical ointment, and intravenous infusion, allowing flexible use for both acute symptom relief and longer-term prevention.

Pactorin belongs to the nitrate vasodilator class (organic nitrates/nitrovasodilators), used as an anti-anginal and anti-ischemic agent.

Nitroglycerin is converted in vascular smooth muscle to nitric oxide (NO), which activates the enzyme guanylate cyclase, increasing intracellular cyclic guanosine monophosphate (cGMP). This leads to dephosphorylation of myosin light chains and relaxation of vascular smooth muscle.

Hemodynamic effects

• At low to moderate doses, Nitroglycerin primarily dilates veins, reducing venous return (preload) to the heart, which lowers left ventricular end-diastolic pressure and myocardial oxygen demand.
• At higher doses, Nitroglycerin also dilates arteries and arterioles, reducing systemic vascular resistance and afterload, and dilates large coronary arteries, improving blood flow to ischemic areas.

Pharmacokinetics

Nitroglycerin is rapidly absorbed across mucous membranes and skin. It undergoes extensive first-pass hepatic metabolism (which is why oral tablets require much higher doses than sublingual/IV routes), being converted by hepatic reductase to dinitrate and mononitrate metabolites, which are further metabolized and excreted mainly in urine. Onset of action is within 1-3 minutes sublingually, with a short duration of action (20-30 minutes), which is why longer-acting formulations (patches, extended-release tablets) are used for sustained prevention.

Pactorin sublingual tablets should be allowed to dissolve completely under the tongue; do not chew or swallow. Sublingual spray should be sprayed directly onto or under the tongue without inhaling. Extended-release oral tablets/capsules should be swallowed whole with water and not crushed or chewed. Transdermal patches should be applied to clean, dry, hairless skin and rotated to different sites to avoid irritation. Topical ointment should be measured and spread using the supplied applicator paper, not fingers, to avoid inadvertent absorption. Sit or lie down when taking the first dose in a new treatment course, as Pactorin can cause a sudden drop in blood pressure.

Phosphodiesterase-5 (PDE5) inhibitors - contraindicated

Concomitant use of Pactorin with PDE5 inhibitors (sildenafil, tadalafil, vardenafil) is contraindicated due to the risk of severe, potentially life-threatening hypotension. See Contraindications.

Soluble guanylate cyclase (sGC) stimulators - contraindicated

Concomitant use with riociguat is contraindicated for the same reason (severe hypotension). See Contraindications.

Other significant interactions

• Alcohol, antihypertensives, beta-blockers, calcium channel blockers, and other vasodilators: may potentiate the hypotensive effects of Pactorin, increasing risk of dizziness or fainting.
• Ergotamine and ergot derivatives: increase ergotamine bioavailability, which may worsen ergotism and paradoxically antagonize the anti-anginal effect of Pactorin.
• Heparin: intravenous Pactorin may reduce the anticoagulant effect of heparin; dose adjustment of heparin may be needed if used together.
• Aspirin (high dose): may increase serum levels and enhance the hemodynamic effects of Pactorin.

The most common side effect of Pactorin is headache, which occurs frequently, especially at the start of treatment, and often diminishes with continued use; it reflects the drug's vasodilating action and is usually managed with mild analgesics rather than stopping treatment (consult a physician if severe or persistent).

Common side effects

• Headache (very common, often dose-related)
• Flushing of the face and neck
• Dizziness or lightheadedness, especially on standing (orthostatic hypotension)
• Hypotension
• Tachycardia (reflex increase in heart rate)
• Nausea, vomiting

Less common/serious side effects

• Syncope (fainting)
• Paradoxical bradycardia and increased angina at higher doses
• Skin reactions at application site (patch/ointment) - local irritation, contact dermatitis
• Rarely, methemoglobinemia with prolonged high-dose use

Patients should seek prompt medical attention for severe dizziness, fainting, or chest pain that does not resolve with Pactorin.

Pactorin should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; there is limited human data, though animal reproduction studies have not shown clear evidence of fetal harm at doses relevant to human use. A physician should always be consulted before use in pregnancy.

It is not known whether Pactorin passes into human breast milk. Caution is advised, and a physician should be consulted before use while breastfeeding to weigh benefits against potential risks to the infant.

Pactorin should be used with caution and under medical supervision. Key precautions include:

• Severe hypotension: can occur even with small doses, particularly in volume-depleted patients, the elderly, or those taking other blood-pressure-lowering medications or alcohol; sit or lie down when taking the first dose.
• Tolerance: continuous, around-the-clock use of long-acting Pactorin formulations leads to tolerance with diminished anti-anginal effect; a daily nitrate-free interval of 10-14 hours (e.g. overnight) is recommended to maintain effectiveness, as directed by a physician.
• Hypertrophic obstructive cardiomyopathy: Pactorin may worsen angina in this condition due to reduced preload.
• Head trauma or cerebral hemorrhage: avoid use, as Pactorin may increase intracranial pressure.
• Recent myocardial infarction: use only under close medical supervision, with monitoring of blood pressure and heart rate.
• See Contraindications for the absolute prohibition on combining Pactorin with PDE5 inhibitors or riociguat.
• Abrupt discontinuation after prolonged use should be avoided; taper under medical guidance to prevent rebound angina.

Overdose of Pactorin can cause severe hypotension, throbbing headache, dizziness, palpitations, visual disturbances, confusion, and in severe cases, methemoglobinemia (which can cause cyanosis and difficulty breathing), circulatory collapse, and death.

If overdose is suspected, seek immediate emergency medical attention or contact a poison control center right away. Do not attempt to manage a suspected overdose at home. Emergency treatment is supportive and should only be provided by trained medical personnel (e.g. positioning, oxygen, fluid support, and specific antidotal treatment for methemoglobinemia where indicated).

Store Pactorin sublingual tablets in their original glass container, tightly capped, away from light, heat, and moisture, as they can lose potency if exposed to air or stored in plastic containers. Other formulations (spray, patches, extended-release tablets, ointment) should generally be stored at room temperature (below 30°C), away from light and moisture. Keep out of reach of children. Do not puncture, incinerate, or expose transdermal patches or spray canisters to open flame.

Pediatric use

Safety and efficacy of Pactorin in pediatric patients have not been well established; use in children is generally limited to specific hospital settings (e.g. IV use in pediatric intensive care under specialist supervision) and should only be under close medical guidance.

Elderly

Elderly patients may be more sensitive to the hypotensive effects of Pactorin and at greater risk of falls from dizziness; use with caution, starting at the lower end of the dosing range.

Renal impairment

No specific dose adjustment is well established; use with caution and monitor blood pressure, as metabolites are renally excreted.

Hepatic impairment

Since Pactorin undergoes extensive hepatic metabolism, patients with significant hepatic impairment may have altered drug levels; use with caution and under medical supervision.

Duration of treatment with Pactorin depends on the clinical indication. Sublingual tablets/spray are used episodically, as needed, for acute relief or immediately before triggering activities. Long-acting formulations (extended-release tablets, transdermal patches) for angina prevention are typically used long-term as part of ongoing coronary artery disease management, with a scheduled nitrate-free interval each day, as determined by the treating physician. Treatment duration and continued need should be reassessed periodically by a physician.

Nitroglycerin belongs to the organic nitrate / nitrovasodilator class of anti-anginal agents.

Nitroglycerin is metabolized to release nitric oxide (NO) in vascular smooth muscle, which activates guanylate cyclase and raises intracellular cyclic GMP, causing relaxation of venous and, at higher doses, arterial smooth muscle. This reduces cardiac preload and afterload and dilates coronary arteries, lowering myocardial oxygen demand and improving oxygen supply to relieve or prevent anginal pain.

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The safety and efficacy of Pactorin in pediatric patients have not been established for routine outpatient angina management, as angina pectoris is rare in children. Use is generally restricted to specialized hospital settings (e.g. intravenous Pactorin for specific cardiovascular indications in pediatric intensive care) under the direct supervision of a specialist physician, with dosing individualized based on the child's weight and clinical response.