Cerumenolytic

{{Short description|Ear wax softening agent}} {{Infobox drug class | Name =  | Image = File:Cerumenolytic used in right ear.jpg | Alt = | Caption = Hydrogen peroxide, a common cerumenolytic, bubbles after being administered into a person's ear. | Pronounce = | Synonyms =  | Use = | ATC_prefix = | Mode_of_action = | Mechanism_of_action = | Biological_target = | Chemical_class =  | Drugs.com =  | Consumer_Reports = | medicinenet = | rxlist =  | MeshID = }} A '''cerumenolytic''' is an ear wax (cerumen) softening agent. Common cerumenolytics such as hydrogen peroxide and hydrogen peroxide - urea (also called carbamide peroxide) are topical preparations used to facilitate the removal of ear wax. Their side effects tend to be mild, including ear discomfort, transient loss of hearing, dizziness, and local irritation.

==Medical uses== Cerumenolytics are used to soften and break up ear wax. Using a cerumenolytic can reduce the need for flushing the ear with irrigants for wax removal. Additionally, cerumenolytics can also facilitate the manual removal of ear wax.<ref name="AAOHNSF 2017 CPG">{{cite journal | vauthors = Schwartz SR, Magit AE, Rosenfeld RM, Ballachanda BB, Hackell JM, Krouse HJ, Lawlor CM, Lin K, Parham K, Stutz DR, Walsh S, Woodson EA, Yanagisawa K, Cunningham ER | title = Clinical Practice Guideline (Update): Earwax (Cerumen Impaction) | journal = Otolaryngology–Head and Neck Surgery | volume = 156 | issue = 1_suppl | pages = S1–S29 | date = January 2017 | pmid = 28045591 | doi = 10.1177/0194599816671491 | doi-access = free }}</ref> Overall, all cerumenolytics are considered to be equivalent in efficacy.<ref name="Pediatric Primary Care 2017">{{cite book|chapter-url=https://books.google.com/books?id=OOSxCwAAQBAJ|title=Pediatric Primary Care|last=Petersen-Smith|first=Ann M.|publisher=Elsevier|year=2017|isbn=978-0-323-24338-4|editor-last=Burns|editor-first=Catherine|edition=6th|location=USA|page=741|chapter=30, Ear Disorders|editor-last2=Dunn|editor-first2=Ardys|editor-last3=Brady|editor-first3=Margaret A.|editor-last4=Barber Starr|editor-first4=Nancy|editor-last5=Blosser|editor-first5=Catherine G.|editor-last6=Garzon Maaks|editor-first6=Dawn Lee}}</ref> Cerumenolytics are administered directly into the ear, which is a form of topical administration that can be specified as "ototopical."<ref name="DefinitionOtotopical">{{cite web|title=ototopical – definition – English|url=https://glosbe.com/en/en/ototopical|website=Glosbe|publisher=Glosbe|accessdate=2 April 2018|language=en}}</ref><ref name="SafeMed Otic Admin">{{cite web | title = How to Use Ear Drops Properly | url = http://www.safemedication.com/safemed/MedicationTipsTools/HowtoAdminister/HowtoUseEarDropsProperly | work = Safe Medications | publisher = American Society of Health-System Pharmacists | access-date = 24 March 2018 }}</ref> Generally, the use of a cerumenolytic involves instilling several drops of the product into the affected ear once or twice daily for a treatment duration of 3 to 5 days.<ref name="AAOHNSF 2017 CPG" /><ref name="SafeMed Otic Admin"/> Each instillation is relatively quick (less than 5 minutes) and can be done either at home or in a clinical setting. However, like all ear wax treatments, the ear wax can reaccumulate in the ear after treatment, necessitating further treatment.<ref name="AAOHNSF 2017 CPG" /> Cerumenolytics are not recommended in children less than 3 years-old.<ref name="AAOHNSF 2017 CPG" />

===Available forms and classification=== Cerumenolytics are available as topical preparations intended for installation into the ear.<ref name="AAOHNSF 2017 CPG" /> Cerumenolytics can be classified based upon the formulation of their constituents: water based, oil based, or neither.<ref name="AAOHNSF 2017 CPG" /> {| class="wikitable" |+ Available cerumenolytics<ref name="AAOHNSF 2017 CPG" /> ! Classification !Product/preparation !Active chemical constituents |- ! Water based | style="text-align: center;"| #Acetic acid #Cerumenex #Colace #Hydrogen peroxide #Sodium bicarbonate #Sterile saline solution | style="text-align: center;"| #Aqueous acetic acid #Triethanolamine polypeptide oleate-condensate #Docusate sodium #Hydrogen peroxide solution #Sodium bicarbonate #Water |- ! Oil based |style="text-align: center;"| #Almond oil #Peanut oil #Earex #Olive oil #Mineral oil/liquid petrolatum |style="text-align: center;"| #Almond oil #Peanut oil #Peanut oil, almond oil, rectified camphor oil #Olive oil #Liquid petrolatum |- ! Neither |style="text-align: center;"| #Audax #Debrox |style="text-align: center;"| #Choline salicylate, glycerine #Carbamide peroxide (urea-hydrogen peroxide) |- |}

[[File:Army Spc Taryn Emery cleans the ear of an Iraqi child 061127-M-5585B-016.jpg|thumb|right|A member of the U.S. Army cleans the ear of an Iraqi child.]]

==Contraindications== Cerumenolytics should not be used in ears that in which the ear drum has been perforated or is otherwise nonintact.<ref name="AAOHNSF 2017 CPG" /> Cerumenolytics should also be avoided in ears that are actively infected due to the lack of research in this area (i.e. people with otitis externa, a type of ear infection).<ref name="AAOHNSF 2017 CPG" />

==Adverse effects== In general, cerumenolytics can cause ear discomfort, transient loss of hearing, dizziness, and local irritation.<ref name="AAOHNSF 2017 CPG" /> Local reactions are least frequent with cerumenolytics that lack organic chemicals, such as a saline.<ref name="AAOHNSF 2017 CPG" />

==Overdose== Using the cerumenolytic hydrogen peroxide as an example, no adverse effects are expected with overdose of an otic administered preparation.<ref name="H2O2 UK">{{cite web | title = Otex Ear Drops – Summary of Product Characteristics (SmPC) – electronic Medicines Compendium (eMC) | url = https://www.medicines.org.uk/emc/product/299 | work = www.medicines.org.uk | publisher = Datapharm Communications Limited | access-date = 24 March 2018 }}</ref> The average middle ear volume is 0.4 mL, which limits otic accumulation in overdose.<ref name="Kirtane">{{cite book | first1 = Vicky S. | last1 = Khattar | first2 = Bachi T. | last2 = Hathiram | first3 = Supriya | last3 = Rode | first4 = Hemant | last4 = Sharma | editor-first1 = Bachi T. | editor-last1 = Hathiram | editor-first2 = Vicky S. | editor-last2 = Khattar | name-list-style = vanc | chapter = Chapter 7: Intratympanic Injection | title = Atlas of operative otorhinolaryngology and head & neck surgery | date = 2013 | edition = first | publisher = Jaypee Brothers Medical Publishers, Ltd. | location = New Delhi | isbn = 978-9350904794 | page = 60 | chapter-url = https://books.google.com/books?id=0skwCwAAQBAJ | access-date = 24 March 2018 }}</ref> It is unlikely that an cerumenolytic administered into the ear would cause systemic toxicity in an overdose situation, due to the lack of systemic absorption resulting from minimal volume flow within the inner ear.<ref name="Salt 09">{{cite journal | vauthors = Salt AN, Plontke SK | title = Principles of local drug delivery to the inner ear | journal = Audiology and Neuro-Otology | volume = 14 | issue = 6 | pages = 350–60 | date = November 2009 | pmid = 19923805 | pmc = 2820328 | doi = 10.1159/000241892 }}</ref> However, again using hydrogen peroxide as an example, clinically relevant overdoses of cerumenolytics are possible if the drugs are administered by other routes (e.g. by mouth).<ref name="poison org">{{cite web|title=Hydrogen Peroxide|url=https://www.poison.org/articles/2012-jun/hydrogen-peroxide|website=www.poison.org|access-date=24 March 2018|language=en}}</ref>

==Pharmacology== The mechanism of action of cerumenolytics vary by the classification.<ref name="AAOHNSF 2017 CPG" /> Water-based cerumenolytics, including water itself, work by hydrating ear wax, fragmenting corneocytes (a type of skin cell) within the ear wax itself.<ref name="AAOHNSF 2017 CPG" /> Cerumenolytics with peroxides release oxygen upon contact with the skin, inducing effervescence (bubbling) that mechanically fragments ear wax.<ref name="IndPharmUK">{{cite web | title = Treatment of ear problems | url = http://www.independentpharmacist.co.uk/treatment-of-ear-problems | work = Independent Community Pharmacist | publisher=Communications International Group | access-date = 24 March 2018 }}</ref> Oil-based cerumenolytics provide lubrication to the ear wax, softening the surface without fragmenting the ear wax. The mechanism of action of non-water- and non-oil-based cerumenolytics is unknown.<ref name="AAOHNSF 2017 CPG" /> Using carbamide peroxide as an example, the pharmacokinetics of cerumenolytics are not well studied.<ref name="Jeske2017">{{cite book|last=Jeske|first=Arthur H.|title=Mosby's Dental Drug Reference |url=https://books.google.com/books?id=Ekq4DgAAQBAJ|edition=12th|year=2018|publisher=Elsevier |location=USA|isbn=978-0-323-48111-3|page=217}}</ref>

==Veterinary use== Cerumenolytics are used to treat cerumen impaction in cats and dogs.<ref name="Delauche 2001">{{cite book | first1 = Richard G. | last1 = Harvey | first2 = Joseph | last2 = Harari | last3 = Delauche | first3 = Agnès J. | name-list-style = vanc | title = Ear diseases of the dog and cat | date = 2001 |chapter=9, Cleaning the External Ear Canal|publisher = Manson Publishing Ltd.|location=London|isbn=978-1-84076-527-4|page=221|edition=Second|chapter-url=https://books.google.com/books?id=DmGIsH7UVfAC|access-date=24 March 2018}}</ref> The removal of cerumen is also an important step in the treatment of otitis in small animals.<ref name="Peterson 2016">{{cite journal | vauthors = Paterson S | title = Topical ear treatment – options, indications and limitations of current therapy | journal = The Journal of Small Animal Practice | volume = 57 | issue = 12 | pages = 668–678 | date = December 2016 | pmid = 27747880 | doi = 10.1111/jsap.12583 }}{{Subscription required}}</ref> Veterinary cerumenolytics possess different potencies. Diocytl sodium sulfosuccinate (DOSS), dioctyl calcium sulfosuccinate, and urea or carbamide peroxide are considered to be potent veterinary cerumenolytics.<ref name="Peterson 2016" />

== References == <references />

Category:Drugs by mechanism of action Category:Ear procedures