tetracaine/oxymetazoline intranasal

Action and Spectrum

Actions and Spectrum: 

tetracaine and oxymetazoline are two different medications with different mechanisms of action and spectrums of activity when used intranasally. 

tetracaine: 

Mechanism of Action: tetracaine is a local anesthetic that blocks nerve impulses’ initiation and conduction. When applied intranasally, tetracaine numbs the nasal mucosa, temporarily relieving pain or discomfort. 

Spectrum of Activity: tetracaine’s spectrum of activity is limited to its local anesthetic effect. It primarily targets the sensory nerves in the nasal mucosa, reducing pain and irritation associated with conditions such as nasal congestion, sinusitis, or post-nasal drip. 

oxymetazoline: oxymetazoline is a nasal decongestant that constricts the blood vessels in the nasal passages. This constriction reduces blood flow to the swollen nasal tissues, relieving congestion and allowing easier breathing. 

• Mechanism of Action: oxymetazoline is an alpha-adrenergic agonist, explicitly targeting the alpha-1 receptors in the smooth muscles of blood vessels in the nasal mucosa. Activating these receptors leads to vasoconstriction, reducing blood flow and relieving nasal congestion. 
• Spectrum of Activity: oxymetazoline’s spectrum of activity primarily focuses on alleviating nasal congestion caused by various conditions such as allergies, colds, or sinusitis. It provides temporary relief by reducing swelling and congestion in the nasal passages, facilitating improved airflow. 

tetracaine is primarily used as a local anesthetic to relieve pain, while oxymetazoline is a nasal decongestant to alleviate nasal congestion. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Nasal congestion (32%) 

Oropharyngeal pain (14%) 

Rhinorrhea (52%) 

Nasal discomfort (26%) 

Lacrimation increased (13%) 

1-10% 

Pharyngeal hypoesthesia (10%) 

Throat irritation (9%) 

Rhinalgia (6%) 

Sneezing (4%) 

Hypertension (3%) 

Sinus headache (3%) 

Sensory disturbance (2%) 

Nasal dryness (2%) 

Intranasal hypoesthesia (10%) 

Headache (10%) 

Dysgeusia (8%) 

Systolic BP increased (5%) 

Diastolic BP increased (3%) 

Bradycardia (3%) 

Dizziness (3%) 

Epistaxis (2%) 

Oral discomfort (2%) 

Black Box Warning

Black box warning: 

None 

Contraindication / Caution

Contraindications/caution: 

Contraindications: 

tetracaine Intranasal: 

• Hypersensitivity: tetracaine should not be used if an individual has a known hypersensitivity or allergy to tetracaine or other local anesthetics. 
• Methemoglobinemia: tetracaine should be avoided in individuals with a history of methemoglobinemia or known methemoglobin reductase deficiency. tetracaine can increase the risk of methemoglobin formation, leading to a potentially severe condition. 

oxymetazoline Intranasal: 

• Hypersensitivity: oxymetazoline should not be used if an individual has a known hypersensitivity or allergy to oxymetazoline or other ingredients in the product. 
• Severe hypertension: Individuals with severe uncontrolled hypertension (high blood pressure) should avoid using oxymetazoline, which can potentially increase blood pressure. 
• Narrow-angle glaucoma: oxymetazoline should be used with caution or avoided in individuals with narrow-angle glaucoma, as it may elevate intraocular pressure and worsen the condition. 
• Monoamine oxidase inhibitors (MAOIs): oxymetazoline should not be used within 14 days of discontinuing treatment with MAOIs or other medications that can increase blood pressure, as it can lead to a hypertensive crisis. 
• Children under six years old: oxymetazoline intranasal formulations are generally not recommended for children under 6 unless specifically directed by a healthcare professional. 

Caution: 

tetracaine intranasal: 

• Avoid excessive use: tetracaine should be used as directed and in the recommended dosage. Excessive or prolonged use can lead to adverse effects or complications. 
• Avoid eye contact: tetracaine should not encounter the eyes, as it can cause irritation or corneal injury. Care should be taken to prevent accidental contact with the eyes during application. 
• Limited duration of use: tetracaine intranasal preparations are intended for short-term use to relieve temporary pain or discomfort. Prolonged or frequent use may lead to the development of tolerance or dependence. 

oxymetazoline intranasal: 

• Limited duration of use: oxymetazoline nasal sprays are generally recommended for short-term use, usually up to 3-5 days. Prolonged or frequent use can lead to a rebound effect, where nasal congestion worsens after discontinuation. 
• Avoid excessive use: oxymetazoline should be used as directed and in the recommended dosage. Overuse or prolonged use can result in nasal dryness, irritation, or a condition called rhinitis medicamentosa (rebound congestion). 
• Pre-existing medical conditions: Individuals with certain medical conditions, such as cardiovascular disease, diabetes, thyroid disorders, or prostate problems, should use oxymetazoline with caution and under the guidance of a healthcare professional. 
• Age restrictions: oxymetazoline nasal sprays may have specific age restrictions. Some formulations are not recommended for children under a certain age.

Pregnancy / Lactation

Pregnancy consideration: Insufficient data available 

Lactation: Excretion of the drug in human breast milk is unknown 

Pregnancy category: 

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

• tetracaine is a local anesthetic of the ester type. When applied intranasally, tetracaine works by blocking sodium channels, which are responsible for the initiation and conduction of nerve impulses. This action prevents the generation and transmission of pain signals from the sensory nerves in the nasal mucosa.  
• tetracaine’s onset of action is relatively rapid, providing local anesthesia and numbing effect on the nasal mucosa. It has a duration of action typically lasts for a short period, allowing temporary relief from pain or discomfort associated with nasal conditions. 
• oxymetazoline is a selective alpha-adrenergic agonist. It acts primarily on alpha-1 adrenergic receptors in the smooth muscle cells of blood vessels in the nasal mucosa. When administered intranasally, oxymetazoline causes vasoconstriction, or narrowing of the blood vessels, in the nasal passages. 
• The vasoconstrictive effect of oxymetazoline reduces blood flow to the swollen nasal tissues, resulting in decreased congestion and improved nasal airflow. This helps alleviate symptoms of nasal congestion caused by various conditions, such as allergies, colds, or sinusitis. 
• oxymetazoline’s onset of action is usually rapid, relieving nasal congestion within minutes of administration. Its duration of action can vary depending on the formulation but is generally several hours, allowing for sustained relief of nasal congestion. 

Pharmacodynamics: 

• The primary pharmacodynamic effect of tetracaine intranasal is the numbing or anesthetic effect on the nasal mucosa. This provides temporary relief from pain, discomfort, or irritation associated with nasal conditions such as congestion, sinusitis, or post-nasal drip. 
• The pharmacodynamic effect of oxymetazoline intranasal is vasoconstriction. Activation of the alpha-1 receptors by oxymetazoline causes the smooth muscle cells to constrict, narrowing blood vessels in the nasal passages. This reduces blood flow to the swollen nasal tissues, decreasing congestion and improving nasal airflow.

Pharmacokinetics: 

Absorption 

tetracaine is absorbed locally through the nasal mucosa after intranasal administration. The formulation, concentration, and contact time with the nasal mucosa can influence the absorption rate. oxymetazoline is absorbed through the nasal mucosa after intranasal administration. It is readily absorbed into the systemic circulation, resulting in local and systemic effects. The rate and extent of absorption can be influenced by factors such as formulation, concentration, and contact time with the nasal mucosa.  

Distribution 

After absorption, tetracaine distributes locally in the nasal tissues, where it exerts its anesthetic effect. Systemic distribution is minimal due to its local application. oxymetazoline is distributed throughout the body via the bloodstream after systemic absorption. It can bind to alpha-adrenergic receptors in various tissues, including nasal blood vessels, leading to vasoconstrictive effects. 

Metabolism 

tetracaine is metabolized primarily in the liver through hydrolysis and esterase enzymes. It undergoes biotransformation into inactive metabolites, including para-aminobenzoic acid (PABA).oxymetazoline undergoes extensive metabolism in the liver through enzymatic processes, primarily via oxidation and conjugation. The significant metabolites include 6- and 8-hydroxy oxymetazoline and conjugated metabolites.  

Elimination and Excretion 

The elimination of tetracaine and its metabolites occurs mainly through renal excretion. The same half-life of tetracaine can vary based on factors such as the specific formulation and individual patient characteristics. oxymetazoline and its metabolites are eliminated mainly through renal excretion. The same half-life of oxymetazoline can vary based on factors such as the specific formulation and individual patient characteristics. 

Adminstartion

Administration: 

Nasal Route of Administration  

Only for intranasal usage  

• Provide the medication in the nostril on the same side as the maxillary tooth that will be the site of the dental operation.  
• Ten minutes after administering an anesthetic, a diagnostic drill should be performed to establish that the affected tooth is numb.  
• A patient may not feel the same tingling or numbness of the lips and cheeks, typical with injectable dental anesthetics. 

Storage 

• Store at 2-8°C (36-46°F); excursions permissible at 0-15°C (32-59°F).  
• Any unused solution should be discarded.  
• Do not use if the medication has been at room temperature for more than five days. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: tetracaine/oxymetazoline intranasal 

Why do we use tetracaine/oxymetazoline intranasal? 

tetracaine and oxymetazoline intranasal preparations are used for different purposes. Here are the common uses for each medication: 

• Nasal Procedures: tetracaine may be used intranasally to provide local anesthesia for minor nasal procedures, such as nasal endoscopy or packing. It helps numb the nasal mucosa and alleviate discomfort during these procedures. 
• Nasal congestion: oxymetazoline relieves nasal congestion caused by various conditions, including allergies, colds, sinusitis, or hay fever. It constricts the blood vessels in the nasal passages, reducing swelling and improving airflow. 
• Nasal Allergies: oxymetazoline can temporarily relieve nasal congestion associated with allergic rhinitis or seasonal allergies. 
• Sinusitis: oxymetazoline can be an adjunctive treatment for sinusitis to alleviate nasal congestion and facilitate sinus drainage. 
• Pre- and Post-Sinus Surgery: In some cases, oxymetazoline may be recommended before and after sinus surgery to reduce nasal congestion, improve surgical access, or promote healing.