Pharmacology of Otic Products - Veterinary Medicine

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary responsibility of the cochlea in the inner ear?

Cleaning the ear canal

Balance

Sound amplification

Hearing (correct)

Which characteristic of ear canal cleaners helps prevent microbial proliferation?

Maintaining a high pH

Incorporating surfactants

Emulsifying debris

Incorporating antimicrobial agents (correct)

What is a common symptom of otitis externa?

Hearing loss

Pain or discomfort in the ear (correct)

Dizziness

Ruptured tympanic membrane

Which substance is NOT considered safe for use when there is a ruptured tympanic membrane?

Surfactants (B) Signup and view all the answers

Ceruminolytics are primarily used to:

Soften and dissolve cerumen (A) Signup and view all the answers

What type of agents are astringents used in ear cleaners designed to prevent?

Maceration (B) Signup and view all the answers

Which of the following is a correct statement regarding ear cleaners?

Some can be ototoxic and are unsafe with ruptured tympanic membranes. (C) Signup and view all the answers

Which of the following describes the outer ear?

Comprises the pinna and ear canal (D) Signup and view all the answers

What is the primary function of surfactants in ear cleaning?

To emulsify and break up debris (B) Signup and view all the answers

Which of the following is a contraindication for using certain detergents in ear cleaning?

Ruptured tympanic membrane (B) Signup and view all the answers

What effect do foaming agents like urea have in ear cleaning?

They release oxygen to disperse debris (D) Signup and view all the answers

Which compound is NOT commonly classified as astringent for ear cleaning?

Carbamide peroxide (D) Signup and view all the answers

What is the role of chlorhexidine in ear cleaning solutions?

It serves as an antimicrobial agent (A) Signup and view all the answers

Which of the following best characterizes the safe use of chlorhexidine in ear cleaning?

0.05% concentration did not cause ill effects (C) Signup and view all the answers

Which of the following is a potential side effect of cleaning fluids in ear care?

Inflammation of the middle ear mucosa (D) Signup and view all the answers

What is the main advantage of using solutions that maintain a low pH in ear cleaners?

They have antimicrobial effects (B) Signup and view all the answers

What should be avoided when cleaning the ear canal to prevent pushing debris back into the vertical ear canal?

Using cotton tipped applicators (D) Signup and view all the answers

Which of the following drugs is NOT considered ototoxic?

Gentamycin (A) Signup and view all the answers

Which step should be taken first when cleaning a dog's ear canal?

Gently pull the earflap up and slightly back (D) Signup and view all the answers

Which of the following ingredients is commonly found in products used for treating bacterial and Malassezia otitis?

Fluoroquinolones (C) Signup and view all the answers

What indicates that the medication has successfully entered the horizontal ear canal during cleaning?

A squishing sound is heard (D) Signup and view all the answers

Which of the following topical antimycotics is used against Malassezia?

Miconazole (C) Signup and view all the answers

In the absence of firm information about the integrity of the tympanic membranes, what should be exercised?

Caution (B) Signup and view all the answers

Which topical antibiotic is part of the fluoroquinolone class used in ear treatments?

Marbofloxacin (B) Signup and view all the answers

Study Notes

Otic Products Pharmacology

Course: Pharmacology and Therapeutics II, Integrated Master in Veterinary Medicine 2024-25
Lecturer: Ana Oliveira, MV, MSc, Dip ECVD, PhD, EBVS European Specialist in Veterinary Dermatology
Topic: Pharmacology of Otic Products

Ear Anatomy

The ear has three parts: outer, middle, and inner.
Outer ear: Includes the pinna and ear canal.
Ear canal: Carries sound to the tympanic membrane (eardrum).
Ear canal shape: "L" shaped, where cerumen and secretions accumulate.
Middle ear: Includes the tympanic membrane, auditory ossicles (transmit & amplify vibrations), and eustachian tube.
Inner ear: Includes the cochlea (hearing) and vestibular apparatus (balance).

Otitis Externa

Symptoms of External Ear Canal Problems: Pruritus (itching), pain, inflammation, shaking of the head, excess cerumen, and change in smell.

Ear Canal Cleaners

Types: Ear canal cleaners
Medication to treat otitis: Include treatments for infections

Characteristics of Ear Canal Cleaners

Ceruminolytics/Surfactants: Used to clean the ear canal, emulsify debris, break it up, keep it in solution.
Astringents: Dry the ear canal surface, preventing maceration.
Low pH & Antimicrobials: Maintaining a low pH along with antimicrobial agents inhibit microbial proliferation.
Ototoxicity: Some ear cleaners (not water, saline, or squalene) can be ototoxic (harmful to the ear).

Ceruminolytics

Composition: Organic oils and solvents (propylene glycol, lanolin, glycerin, squalane, etc.).
Use: Effective in mildly waxy or dirty ears, relatively safe for routine at-home cleaning when the tympanic membrane is intact.

Surfactants

Action: Efficient with both ceruminous and purulent debris. Emulsify debris, keeping it in solution.
Precautions: Some detergents can annoy the middle ear mucosa and are not appropriate if the ear drum is ruptured.
Examples: Dioctyl sodium sulfosuccinate (DSS or docusate), calcium sulfosuccinate, and other detergents.

Foaming Agents

Action: Release oxygen in situ, dispelling debris and aerating canals.
Potential concern: Causes anxiety in some animals.
Availability: Not available in all countries.

Astringents

Action: Dry the ear canal surface, prevent maceration.
Combination: Often used together with keruminolytics and surfactants.
Examples: Isopropyl alcohol, boric acid, benzoic acid, salicylic acid, sulfur, aluminium acetate, and silicon dioxide.

Antimicrobial Effect

Purpose: Inhibit microbial proliferation.
Active compounds: Some ear cleaners contain potent antimicrobial components like chlorhexidine and parachlorometaxylenol (PCMX).

Contraindications and Side Effects

Inflammation: Some cleaning fluids can cause inflammatory reactions, especially if introduced into the middle ear.
Examples of fluids: Propylene glycol, DSS, carbamide peroxide, and triethanolamine often cause inflammation of the middle ear mucosa in normal dogs.
Chlorhexidine: Generally regarded as ototoxic; ototoxicity usually depends on the concentration, formulation and presence of tympanic membrane.

How to Clean the Ear Canal

Owner Instruction: Steps to clean, involving pulling the ear flap, applying medication to the ear canal entrance, gently manipulating and massaging the ear canal, and then allowing the animal to shake its head. Avoid using cotton tipped applicators because of the damage they can cause to the vertical ear canal.

General Pharmacology for Infectious Otitis (Ear Infections)

Composition: Typically combine an antibiotic, antifungal, and glucocorticoid.
Uses: Treatment of bacterial and Malassezia otitis.

Topical Antibiotics

Types: Fluoroquinolones (enrofloxacin, orbifloxacin, marbofloxacin), aminoglycosides (gentamycin, amicacin, neomycin, tobramycin), and large spectrum penicillins (polymixina B).

Antimysotics against Malassezia

Effectiveness: Topical antimycotics are very efficient.
Examples: Miconazole, clotrimazole, posaconazole, and nistatin.

Ototoxicity

Ototoxic Drugs: Polimixine B, Tobramycin, and Neomycin.
Potentially Safe: Gentamycin and Amicacin. Ototoxicity could depend on formulation and the presence of the tympanic membrane
Safe: Fluoroquinolones, anti-fungals.
Important: The vehicle of the preparation can also be ototoxic.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the pharmacology of otic products relevant to veterinary medicine, focusing on ear anatomy, otitis externa, and ear canal cleaners. Test your knowledge on the structures of the ear and the treatments for common ear conditions in animals.