SUMMARY OF PRODUCT CHARACTERISTICS

1. NAME OF THE VETERINARY MEDICINAL PRODUCT

Posatex ear drops suspension for dogs

2. QUALITATIVE AND QUANTITATIVE COMPOSITION

Each ml of the ear drops suspension contains:

Active substances:

Orbifloxacin	8.5 mg
Mometasone furoate (as monohydrate)	0.9 mg
Posaconazole	0.9 mg

Excipients:

Qualitative composition of excipients and other constituents

Lauric acid

Paraffin, liquid

Plasticised hydrocarbon gel (5% polyethylene in 95% mineral oil)

White to off-white viscous suspension.

3. CLINICAL INFORMATION

3.1 Target species

Dogs.

3.2 Indications for use for each target species

Treatment of acute otitis externa and acute exacerbations of recurrent otitis externa, associated with bacteria susceptible to orbifloxacin and fungi susceptible to posaconazole, in particular Malassezia pachydermatis.

3.3 Contraindications

Do not use if the eardrum is perforated.

Do not use in cases of hypersensitivity to the active substances, to any of the excipients, to corticosteroids, to other azole antifungal agents or to other fluoroquinolones.

Do not use during the whole or part of the pregnancy.

3.4 Special warnings

Bacterial and fungal otitis is often secondary in nature. The underlying cause should be identified and treated.

3.5 Special precautions for use

Special precautions for safe use in the target species:

Heavy reliance on a single class of antibiotic may result in the induction of resistance in a bacterial population. It is prudent to reserve fluoroquinolones for the treatment of clinical conditions, which have responded poorly or are expected to respond poorly to other classes of antibiotics.

Use of the veterinary medicinal product should be based on identification and susceptibility testing of the target pathogen(s). If this is not possible, therapy should be based on epidemiological information and knowledge of susceptibility of the target pathogens at local/regional level.

Use of the product should be in accordance with official, national and regional antimicrobial policies.

An antibiotic with a lower risk of antimicrobial resistance selection (lower AMEG category) should be used for first line treatment where susceptibility testing suggests the likely efficacy of this approach.

Narrow spectrum antibiotic therapy with a lower risk of antimicrobial resistance selection should be

used for first line treatment where susceptibility testing suggests the likely efficacy of this approach

Quinolone class veterinary medicinal products have been associated with cartilage erosions in weightbearing joints and other forms of arthropathy in immature animals of various species. Therefore, do not use in animals less than 4 months of age.

Prolonged and intensive use of topical corticosteroids preparation is known to trigger local and systemic effects, including suppression of adrenal function, thinning of the epidermis and delayed healing. See section 3.10.

Before the veterinary medicinal product is applied, the external auditory canal must be examined thoroughly to ensure that the ear drum is not perforated in order to avoid the risk of transmission of the infection to the middle ear and to prevent damage to the cochlear and vestibular apparatus.

Special precautions to be taken by the person administering the veterinary medicinal product to animals:

Wash hands carefully after applying the veterinary medicinal product. Avoid skin contact. In case of accidental exposure, rinse the affected area with copious quantities of water.

Special precautions for the protection of the environment:

Not applicable.

3.6 Adverse events Dogs:

Common (1 to 10 animals / 100 animals treated):	Pinnal erythema1
Uncommon (1 to 10 animals / 1,000 animals treated):	Impaired hearing2

¹ Mild

² Usually temporary and primarily in geriatric dogs.

Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or the national competent authority via the national reporting system. See the package leaflet for respective contact details.

3.7 Use during pregnancy, lactation or lay

The safety of the veterinary medicinal product has not been established during pregnancy or lactation.

Pregnancy and lactation:

Do not use during the whole or part of the pregnancy. The use is not recommended during lactation.

Laboratory studies in puppies have shown evidence of arthropathy after systemic administration of orbifloxacin. Fluoroquinolones are known to cross the placenta and to be distributed into milk.

Fertility:

Studies to determine the effect of orbifloxacin on fertility of dogs have not been conducted.

Do not use in breeding animals.

3.8 Interaction with other medicinal products and other forms of interaction

No data available.

3.9 Administration routes and dosage

Auricular use.

One drop contains 267 mcg orbifloxacin, 27 mcg mometasone furoate and 27 mcg posaconazole.

The external ear canal should be meticulously cleaned and dried before treatment. Excess hair around the treatment area should be cut.

Shake well before use.

Dogs weighing less than 2 kg, apply 2 drops to the ear once a day. Dogs weighing 2 - 15 kg, apply 4 drops to the ear once a day.

Dogs weighing 15 kg or more, apply 8 drops to the ear once a day.

Treatment should continue for 7 consecutive days.

After application, the base of the ear may be massaged briefly and gently to allow the veterinary medicinal product to penetrate the lower part of the ear canal.

Posatex is a viscous suspension. The inherent viscosity will result in a reduced delivery volume compared to the fill volume (see section 5.4).

3.10 Symptoms of overdose (and where applicable, emergency procedures and antidotes)

Administration of the recommended dose (4 drops per ear) 5 times daily for 21 consecutive days to dogs weighing 7.6 to 11.4 kg bodyweight caused a slight decrease in serum cortisol response after adrenocorticotropic hormone (ACTH) administration in an ACTH stimulation test. Discontinuation of treatment will result in a complete return to normal adrenal response.

3.11 Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance

Not applicable.

3.12 Withdrawal periods

Not applicable.

4. PHARMACOLOGICAL INFORMATION

4.1 ATCvet code: QS02CA91

4.2 Pharmacodynamics

Orbifloxacin is a synthetic broad-spectrum bactericidal agent classified as a quinolone carboxylic acid derivative, or more specifically, a fluoroquinolone. The bactericidal action of orbifloxacin results from interference with the enzymes DNA topoisomerase II (DNA-gyrase) and DNA topoisomerase IV which are needed for the synthesis and maintenance of bacterial DNA. Such impairment disrupts replication of the bacterial cell, leading to rapid cell death. The rapidity and extent of killing are directly proportional to the drug concentration. Orbifloxacin has in vitro activity against a wide range of Gram-positive and Gram-negative organisms.

Mometasone furoate is a corticosteroid with high topical potency but little systemic effect. Like other topical corticosteroids, it has anti-inflammatory and anti-pruritic properties.

Posaconazole is a broad-spectrum triazole antifungal agent. The mechanism by which Posaconazole exerts fungicidal action involves the selective inhibition of the enzyme lanosterol 14-demethylase (CYP51) involved in ergosterol biosynthesis in yeasts and filamentous fungi. In in vitro tests, posaconazole has shown fungicidal activity against most of the approximately 7,000 strains of yeast and filamentous fungi tested. Posaconazole is 40 – 100 times more potent in vitro against Malassezia pachydermatis than clotrimazole, miconazole and nystatin.

Resistance to fluoroquinolones occurs by chromosomal mutation with three mechanisms: Decrease of the bacterial wall permeability, expression of efflux pump, or mutation of enzymes responsible for the molecule’s binding site. Cross-resistance across the fluoroquinolone class of antibiotics is common. Malassezia pachydermatis resistance to azoles, including posaconazole, has not been reported.

The in vitro activity of orbifloxacin against pathogens isolated from clinical cases of canine otitis externa in an EU field trial conducted in 2000 - 2001 was:

Minimum Inhibitory Concentrations vs. Orbifloxacin – Summary
Pathogen	N	Min	Max	MIC50	MIC90
E coli	10	0.06	0.5	0.125	0.5
Enterococci	19	0.250	16	4	8
Proteus mirabilis	9	0.5	8	1	8
Pseudomonas aeruginosa	18	1	> 16	4	8
Staphylococcus intermedius	96	0.25	2	0.5	1
Streptococcus ß-haemolyticus G	19	2	4	2	4

4.3 Pharmacokinetics

Systemic absorption of the active substances was determined in single-dose studies with [¹⁴C]-orbifloxacin, [³H]-mometasone furoate and [¹⁴C]-posaconazole contained within the Posatex formulation and placed into the ear canals of normal Beagle dogs. Most of the absorption occurred in the first few days after administration. The extent of percutaneous absorption of topically administered veterinary medicinal products is determined by many factors including the integrity of the epidermal barrier. Inflammation can increase the percutaneous absorption of veterinary medicinal products.

5. PHARMACEUTICAL PARTICULARS

5.1 Major incompatibilities

None known.

Studies with a range of proprietary ear cleaners have shown no chemical incompatibilities.

5.2 Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 2 years Shelf life after first opening the immediate packaging:

8.8 ml: 7 days

17.5 ml and 35.1 ml: 28 days 5.3 Special precautions for storage

Keep the bottle in the outer carton.

5.4 Nature and composition of immediate packaging

White HDPE bottle with a white LDPE cap, a natural or white LDPE applicator and a sheath.

Pack sizes: 8.8 ml (corresponding to 5.0 ml delivery volume), 17.5 ml (corresponding to 12.6 ml delivery volume) and 35.1 ml (corresponding to 28.6 ml delivery volume) Not all pack sizes may be marketed.

5.5 Special precautions for the disposal of unused veterinary medicinal products or waste materials derived from the use of such products

Medicines should not be disposed of via wastewater.

Use take-back schemes for the disposal of any unused veterinary medicinal product or waste materials derived thereof in accordance with local requirements and with any national collection systems applicable to the veterinary medicinal product concerned.

6. NAME OF THE MARKETING AUTHORISATION HOLDER

MSD Animal Health UK Limited

7. MARKETING AUTHORISATION NUMBER

Vm 01708/5059

8. DATE OF FIRST AUTHORISATION

23 June 2008

9. DATE OF THE LAST REVISION OF THE SUMMARY OF THE PRODUCT CHARACTERISTICS

November 2024

10. CLASSIFICATION OF VETERINARY MEDICINAL PRODUCTS

Veterinary medicinal product subject to prescription.

Find more product information by searching for the ‘Product Information Database’ on www.gov.uk.