Zycortal 25 mg/ml Prolonged-release Suspension for Injection for Dogs

Composition

Each ml contains:

Active substances:

Desoxycortone pivalate 25 mg

Excipients:

Opaque white suspension.

3

Pharmacological properties

4.1 ATCvet code :

QH02AA03

4.2 Pharmacodynamics

Desoxycortone is a corticosteroid with primarily mineralocorticoid activity, similar to aldosterone. In the kidney, desoxycortone causes sodium and chloride ion retention, and hydrogen and potassium ion excretion, creating an osmotic gradient. The osmotic gradient promotes water absorption from the renal tubules resulting in increased extracellular fluid volume, leading to blood volume expansion, improved venous return to the heart, and increased cardiac output.

4.3 Pharmacokinetics

After subcutaneous administration of desoxycortone pivalate at a dose of 11 mg/kg body weight (five times the recommended dosage), the plasma half-life (mean ± standard deviation) is approximately 17 ± 7 days, with a maximum concentration (Cmax) of 13.2 ± 5 ng/ml, and time to maximum concentration (Tmax) of 10 ± 3.5 days.

3

Target species

Dogs.

3

Indications

For use as replacement therapy for mineralocorticoid deficiency in dogs with primary hypoadrenocorticism (Addison’s disease).

3

Dosage

Subcutaneous use.

Prior to use, gently shake the vial to resuspend the veterinary medicinal product.

Use an appropriately graduated syringe to accurately administer the required dose volume. This is particularly important when injecting small volumes.

To ensure a correct dosage, body weight should be determined as accurately as possible.

The use of suitably calibrated measuring equipment is recommended.

Zycortal replaces the mineralocorticoid hormones only. Dogs with combined glucocorticoid and mineralocorticoid deficiency should also receive a glucocorticoid such as prednisolone taking into account the current scientific knowledge.

Zycortal is intended for long term administration at intervals and doses dependent upon individual response. Tailor the dose of Zycortal and the concurrently administered glucocorticoid replacement therapy to the individual dog based on clinical response and normalization of Na⁺ and K⁺ serum concentrations.

Initial dose of Zycortal:

The initial dose is 2.2 mg/kg body weight, administered by subcutaneous injection.

Interim monitoring visit:

Re-evaluate the dog and measure the serum sodium/potassium ratio (Na⁺/K⁺ ratio) approximately 10 days after the first dose (which is the time to maximum concentration (Tmax) of desoxycortone). If the dog’s clinical signs have worsened or not resolved, adjust the dose of glucocorticoid and/or investigate other causes of the clinical signs.

Second dose of Zycortal:

At approximately 25 days after the first dose, re-evaluate the dog and measure the Na⁺/K⁺ ratio.

• If the dog is both clinically normal and has a normal Na+/K+ ratio (i.e. 27 to 32) on Day 25, adjust the dose based on the Day 10 Na⁺/K⁺ ratio using the guidelines in Table 1, below.

• If the dog is clinically normal and has a Na⁺/K⁺ ratio > 32 on Day 25, either adjust the dose based on the Day 10 Na⁺/K⁺ ratio according to Table 1 or delay the dose (see Prolonging the dosing interval).

• If the dog is either not clinically normal or if the Na⁺/K⁺ ratio is abnormal on Day 25, adjust the dose of glucocorticoid or Zycortal (see Subsequent doses and long term management).

Table 1: Day 25: Administering the Second Dose of Zycortal

Prolonging the dosing interval:

If the dog is clinically normal and the Day 25 Na⁺/K⁺ ratio is > 32, it is possible to prolong the dosing interval instead of adjusting the dose as described in Table 1. Evaluate the electrolytes every 5–9 days until the Na⁺/K⁺ ratio is < 32, and then administer 2.2 mg/kg of Zycortal.

Subsequent doses and long term management:

Once the optimal dose and dosing interval have been determined, maintain the same regimen. If the dog develops abnormal clinical signs or Na⁺ or K⁺ serum concentrations, use the following guidelines for subsequent doses:

• Clinical signs of polyuria/polydipsia: Decrease the glucocorticoid dose first. If the polyuria/polydipsia persists and the Na⁺/K⁺ ratio is >32, then decrease the dose of Zycortal without changing the dosing interval.

• Clinical signs of depression, lethargy, vomiting, diarrhoea or weakness: Increase the glucocorticoid dose.

• Hyperkalaemia, hyponatremia or Na⁺/K⁺ ratio < 27: Decrease the Zycortal dosing interval by 2–3 days or increase the dose.

• Hypokalaemia, hypernatremia or Na⁺/K⁺ ratio > 32: Decrease the Zycortal dose.

Prior to a stressful situation, consider temporarily increasing the dose of glucocorticoid.

In the clinical trial, the mean final dose of desoxycortone pivalate was 1.9 mg/kg (range 1.2–2.5 mg/kg) and the mean final dosing interval was 38.7 ± 12.7 days (range 20–99 days) with the majority of dogs having a dosing interval between 20 and 46 days.

3

Contraindications

Do not use in cases of hypersensitivity to the active substance or to any of the excipients.

3

Adverse reactions

Dogs:

a The concurrent administration of glucocorticoids may contribute to these signs.

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 its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.

3

Warnings

Special precautions for safe use in the target species:

Use with caution in dogs with congestive heart disease, severe renal disease, primary hepatic failure or oedema.

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

Avoid contact with the eyes and skin. In case of accidental spillage onto the skin or eyes, wash the affected area with water. If irritation occurs, seek medical advice immediately and show the package leaflet or the label to the physician.

This veterinary medicinal product may cause pain and swelling at the injection site if accidentally self-administered.

This veterinary medicinal product may cause adverse events on male reproductive organs and, as a result, fertility.

This veterinary medicinal product may cause adverse developmental effects on unborn children and neonates.

The veterinary medicinal product should not be administered by pregnant or breast-feeding women.

In case of accidental self-injection, seek medical advice immediately and show the package leaflet or the label to the physician.

Special precautions for the protection of the environment:

Not applicable.

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

Use during pregnancy, lactation or lay

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

Use only according to the benefit-risk assessment by the responsible veterinarian.

3

Interactions

Use with caution when administering Zycortal concurrently with medicinal products which affect either serum sodium or potassium concentrations, or cellular transportation of sodium or potassium, for example: trimethoprim, amphotericin B, digoxin or insulin.

3

Overdose

When given to dogs at three to five times the recommended dose, injection site reactions characterised by erythema and oedema occurred.

As expected from the pharmacodynamic effects, escalating doses of desoxycortone are associated with a dose-related trend for increased serum sodium, and decreased blood urea nitrogen, serum potassium and urine specific gravity. Polyuria, polydipsia may be observed.

Hypertension has been observed in dogs receiving 20 mg/kg of desoxycortone pivalate.

There is no specific antidote. In case of signs of overdose, the dog should be treated symptomatically, and subsequent doses reduced.

3

Special warnings

Before starting treatment with the veterinary medicinal product, it is important that Addison’s disease has been definitively diagnosed. Any dog presenting with severe hypovolaemia, dehydration, pre-renal azotaemia and inadequate tissue perfusion (also known as “Addisonian crisis”) must be rehydrated with intravenous fluid (saline) therapy before starting treatment with the veterinary medicinal product.

3

Withdrawal period

Not applicable.

3

Incompatibilities

In the absence of compatibility studies, this veterinary medicinal product must not be mixed with other veterinary medicinal products.

3

Immediate packaging

Type I glass vial (4 ml) with a coated chlorobutyl rubber stopper and aluminium seal with a plastic flip-off cap.

One vial of 4 ml in a cardboard box.

3

Storage

Do not store above 30 °C.

Do not freeze.

3

Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 3 years.

Shelf life after first opening the immediate packaging: 4 months.

3

Disposal of unused product

5.5 Special precautions for the disposal of unused veterinary medicinal product 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.

3

Additional information

Vm 50406/5053

8 DATE OF FIRST AUTHORISATION

06 November 2015

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

October 2025

10 CLASSIFICATION OF VETERINARY MEDICINAL PRODUCT

Veterinary medicinal product subject to prescription.

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

3

Registration holder

Dechra Regulatory B.V.

3