antipyrine/benzocaine/phenylephrine

Action and Spectrum

Actions and Spectrum 

Action of antipyrine: antipyrine, also known as phenazone, exerts its pharmacological action primarily through its analgesic and antipyretic properties. As a pyrazolone derivative, it inhibits the synthesis of prostaglandins by blocking the activity of cyclooxygenase enzymes. By doing so, antipyrine reduces pain and fever in the affected area. In otic preparations, it is mainly utilized for its analgesic effect in alleviating ear pain. 

Action of benzocaine: benzocaine, a local anesthetic and ester-type compound, reversibly inhibits the voltage-gated sodium channels in the neuronal membranes. This mechanism impedes the initiation and conduction of nerve impulses, resulting in temporary loss of sensation. In otic formulations, benzocaine is employed for its local anesthetic effect, providing relief from ear discomfort and pain. 

Action of phenylephrine: phenylephrine, a sympathomimetic agent with alpha-adrenergic agonist properties, acts on alpha-adrenergic receptors present in the vasculature. By stimulating these receptors, phenylephrine induces vasoconstriction, leading to reduced mucosal edema and nasal congestion. 

Spectrum of antipyrine/benzocaine/phenylephrine: The combination of antipyrine, benzocaine, and phenylephrine in otic preparations yields a broad therapeutic spectrum that targets multiple aspects of otic conditions. These ingredients provide analgesic, anesthetic, decongestant, and anti-inflammatory effects. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Local hypersensitivity reaction 

burning in ear canal 

Temporary stinging 

Black Box Warning

Black Box Warning:  

None  

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity or Allergic Reactions: The drug combination is contraindicated in individuals who have a known hypersensitivity or allergic reaction to any of its active ingredients or other similar substances.  

Severe Cardiovascular Disease: Patients with severe cardiovascular diseases, such as severe hypertension, coronary artery disease, or congestive heart failure, should avoid the use of this drug combination. 

Narrow-Angle Glaucoma: The drug combination should be contraindicated in individuals with narrow-angle glaucoma. due to its sympathomimetic properties, phenylephrine can lead to pupillary dilation and potentially increase intraocular pressure.  

Recent Otitis Media Surgery or Trauma: Patients who have recently undergone surgery or experienced trauma involving the ear, such as tympanic membrane perforation, should avoid using this drug combination. The presence of open wounds or damaged tissue in the ear may increase the risk of systemic absorption of the medication and lead to unwanted side effects or complications. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: C 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

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:  

antipyrine/benzocaine/phenylephrine is a combination drug widely used for its analgesic, anesthetic, and decongestant properties. It comprises three active components: antipyrine, a non-opioid analgesic; benzocaine, a local anesthetic; and phenylephrine, a sympathomimetic decongestant. 

Pharmacodynamics:  

antipyrine exerts its analgesic and anti-inflammatory effects by inhibiting prostaglandin synthesis, thereby reducing pain and inflammation. benzocaine acts as a local anesthetic by inhibiting voltage-gated sodium channels, thereby blocking nerve impulses responsible for pain transmission. phenylephrine, a selective α1-adrenergic receptor agonist, stimulates vasoconstriction, reducing nasal congestion and improving airflow.   

Pharmacokinetics: 

Absorption 

antipyrine is readily absorbed following oral administration, with peak plasma concentrations achieved within 1-3 hours. benzocaine, primarily used as a topical anesthetic, exhibits poor systemic absorption. In contrast, phenylephrine, commonly employed as a nasal decongestant, displays variable oral absorption due to extensive first-pass metabolism. 

Distribution 

antipyrine exhibits a relatively large volume of distribution, indicating extensive tissue distribution. It readily crosses the blood-brain barrier and placenta, with limited protein binding. benzocaine has limited distribution beyond the application site, primarily due to its low systemic absorption. phenylephrine has a moderate volume of distribution, with approximately 95% protein binding. 

Metabolism 

antipyrine undergoes extensive hepatic metabolism through the cytochrome P450 enzyme system. benzocaine undergoes minimal metabolism and is predominantly eliminated unchanged. phenylephrine undergoes extensive first-pass metabolism, primarily mediated by sulfotransferases and monoamine oxidases. 

Excretion and Elimination 

antipyrine and its metabolites are primarily excreted via the kidneys, with approximately 90% eliminated within 24 hours. benzocaine is primarily eliminated through renal excretion, with minimal systemic clearance. phenylephrine and its metabolites are primarily excreted in the urine, with a small fraction eliminated through feces. 

Adminstartion

Administration:  

When administered as directed, antipyrine/benzocaine/phenylephrine is applied topically to the affected ear canal. Prior to administration, it is crucial to ensure the ear is free of any obstructions or ruptured eardrums.   

A suitable amount of the medication is instilled into the ear, and gentle pressure is applied to facilitate proper distribution within the canal. Following administration, patients are advised to remain in a reclined position for several minutes to allow optimal contact and absorption of the medication. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: antipyrine/benzocaine/phenylephrine 

Why do we use antipyrine/benzocaine/phenylephrine?  

The drug is a composite pharmaceutical preparation, combines the therapeutic properties of antipyrine, benzocaine, and phenylephrine. This formulation is utilized for its analgesic, antipyretic, vasoconstrictive properties and helps in reducing inflammation, congestion, and pain. The combined action of these active ingredients enables the drug to effectively address multiple symptoms and conditions.  

Analgesic Effect: The analgesic property of drug is predominantly attributed to the presence of benzocaine. It acts as a local anesthetic, providing temporary relief from minor pain and discomfort associated with various conditions such as minor cuts, abrasions, and irritations of the mucous membranes.  

Antipyretic Effect: antipyrine, a pyrazolone derivative, contributes to the antipyretic effect of this combination product. It assists in reducing fever by acting on the hypothalamic heat-regulating center. The drug can be used to manage fever in patients suffering from infectious diseases, post-vaccination reactions, or other pyrexial conditions.  

Vasoconstrictive Effect: phenylephrine, a sympathomimetic amine, serves as a potent vasoconstrictor in this formulation. The vasoconstrictive effect of antipyrine/benzocaine/phenylephrine is employed to alleviate nasal congestion associated with common cold, sinusitis, and allergic rhinitis.