Alizin Solution For Injection (Aglepristone) Unwanted Pregnancy In Dogs 10 ml

Alizin for dogs

Alizin is used as an effective treatment of canine misalliance, for the termination of pregnancy in bitches up to 45 days from mating.

Alizin® contains 30mg/ml aglepristone and is available in 10ml vials.

Aglepristone is a synthetic progesterone antagonist that is effective on uterine progesterone receptors. Its relative binding affinity is three times stronger than that of endogenous progesterone, thus providing effective competitive antagonism of progesterone and blocking the hormone responsible for implantation and pregnancy maintenance.

High efficacy over a flexible treatment period from 0 to 45 days post mating.
Two doses 24 hours apart (timing is essential in its success).
Give by subcutaneous injection at 1ml / 3kg, using a maximum of 5ml per injection site.

Alizin® (Aglepristone) 30 mg/mL Solution for Injection

Prescription Only Veterinary Medicine – Use Under Veterinary Guidance Only

Introduction

Alizin® is an injectable veterinary medication containing aglepristone, a synthetic steroid that acts as a progesterone antagonist. It is primarily licensed for the termination of unwanted pregnancy (misalliance) in bitches (female dogs) up to 45 days after mating. Alizin works by blocking progesterone receptors in the uterus, preventing the establishment or maintenance of pregnancy, leading to abortion or fetal resorption. While licensed for dogs, it is also used off-label under veterinary direction in cats for pregnancy termination and certain medical conditions.

Detailed Composition and Excipients

Alizin is provided as a clear, yellow, oily solution for injection.

• Active Substance: Aglepristone (30 mg per 1 mL of solution)

• Excipients:

  • Ethanol (anhydrous) (0.1 mL per 1 mL of solution)

  • Arachis Oil, refined (Peanut Oil) (up to 1 mL)

This product does not contain an antimicrobial preservative. It is supplied in glass vials (e.g. 10 mL).

Comprehensive Pharmacological Properties

Pharmacodynamics (How it Works):

• Progesterone Antagonism: Aglepristone is a synthetic steroid that competitively binds to progesterone receptors in the uterus. Its binding affinity is significantly higher than natural progesterone (approximately 3 times higher in dogs, 9 times higher in cats).

• Mechanism: By blocking progesterone receptors, aglepristone inhibits the effects of progesterone, which are essential for the implantation of embryos and the maintenance of pregnancy. This action results in abortion (expulsion of fetuses) or resorption (breakdown and absorption of fetal tissue) within approximately 7 days of administration.

• Hormonal Effects: Within 24 hours of administration, aglepristone does not significantly alter plasma concentrations of progesterone, prostaglandins, oxytocin, or cortisol. However, it does induce a release of prolactin within 12 hours.

• Anti-Glucocorticoid Effect: Aglepristone also binds to glucocorticoid receptors with an affinity similar to dexamethasone but acts as an antagonist, potentially reducing the effects of natural or administered corticosteroids.

Pharmacokinetics (How the Body Processes It):

• Absorption & Distribution: After subcutaneous injection in dogs (two doses of 10 mg/kg, 24 hours apart), the maximum plasma concentration (approx. 280 ng/mL) is reached after about 2.5 days.

• Metabolism: Aglepristone is metabolized in the liver.

• Elimination: Excretion is very slow and occurs primarily via the feces (around 90%). About 60% of the dose is excreted in the first 10 days and about 80% over 24 days. The mean residence time in the body is around 6 days.

Indications for Use

• Dogs (Licensed Use):

  • Induction of abortion in pregnant bitches up to 45 days after mating.

• Dogs (Off-Label Use):

  • Medical treatment of pyometra (uterine infection), often in combination with other medications like prostaglandins (e.g., cloprostenol) and antibiotics.

  • Induction of parturition (labor).

• Cats (Off-Label Use):

  • Termination of pregnancy (misalliance). Efficacy can vary, particularly in later gestation (e.g., studies show ~87% efficacy at day 25, potentially lower like ~67% at day 45).

  • Medical treatment of pyometra.

  • Medical treatment of benign mammary hyperplasia (fibroadenomatous hyperplasia – FAH), a condition often influenced by progesterone.

Off-label use should only occur under a veterinarian’s strict guidance and risk assessment.

Dosage and Administration

General Instructions:

• Administer by Subcutaneous Injection ONLY.

• Strict aseptic technique is required (clean the vial septum before drawing each dose, and use a sterile needle and syringe).

• To minimise local reactions, injection into the scruff of the neck is recommended.

• Lightly massage the injection site after administration.

• If the dose volume exceeds 5 mL, divide the dose and administer at two or more separate sites.

• The vial stopper can be safely punctured up to 10 times.

Dosage:

• Dogs (Pregnancy Termination):

  • 10 mg aglepristone per kg of bodyweight.

  • This is equivalent to 0.33 mL of Alizin per kg of body weight.

  • Administer TWO injections, precisely 24 hours apart.

• Cats (Pregnancy Termination – Off-Label):

  • Typically 10 mg/kg to 15 mg/kg bodyweight (0.33 mL/kg to 0.5 mL/kg).

  • Administer TWO injections, precisely 24 hours apart. The veterinarian determines the appropriate dose.

• Pyometra Treatment (Dogs & Cats – Off-Label Examples):

  • Protocols vary significantly and often involve multiple injections over several days (e.g., Dogs: 10 mg/kg on Days 1, 2, 8 ± Day 15; Cats: 15 mg/kg on Days 0, 2, 5, 8), frequently combined with antibiotics and potentially prostaglandins. Requires intensive veterinary supervision and monitoring.

• Feline Mammary Hyperplasia (Off-Label Example):

  • 10-15 mg/kg SC on Days 1, 2, and 7, followed by weekly injections until resolution.

Pyometra Treatment Information (Off-Label Use)

Alizin (aglepristone) is sometimes used as part of a medical management protocol for pyometra, particularly in breeding animals or those considered poor surgical candidates.

• Mechanism: Aglepristone helps by blocking progesterone’s effects, which can lead to cervical relaxation/opening and increased uterine contractility, facilitating the expulsion of uterine contents.

• Protocol: It is typically used alongside broad-spectrum antibiotics and sometimes prostaglandins (like cloprostenol) to enhance uterine evacuation. Protocols vary (e.g., Alizin injections on days 1, 2, 8, +/- 15).

• Suitability: It is best suited for cases of open-cervix pyometra where the animal is systemically stable. It is generally not recommended for closed-cervix pyometra or in animals that are severely ill, dehydrated, or septic, as these often require emergency ovariohysterectomy (spay surgery).

• Monitoring: Close veterinary monitoring, including ultrasound examinations to assess uterine size and contents and blood work, is crucial during treatment.

• Risks: Medical management carries risks, including treatment failure, incomplete uterine emptying, recurrence of pyometra in future heat cycles, and potential complications like sepsis or uterine rupture.

• Surgery: Ovariohysterectomy remains the definitive and most recommended treatment for pyometra.

Side Effects and Contraindications

Possible Side Effects / Adverse Reactions:

• Injection Site Reactions (Common): Pain during or shortly after injection (~17% of dogs), local inflammation (~23% of dogs). Swelling, skin thickening, local lymph node enlargement, or, rarely, ulceration may occur. These reactions are usually temporary and resolve within ~28 days. Limiting volume per site (<5 mL) and injecting into the scruff helps minimize this.

• Systemic Effects (Reported in Dog Field Trials): Anorexia (loss of appetite, ~25%), excitation/restlessness (~23%), depression (~21%), diarrhea (~13%), vomiting (~2%).

• Post-Abortion Effects (Dogs treated > Day 20): Abortion may be accompanied by signs similar to normal birth: fetal expulsion, vaginal discharge (may be brownish), reduced appetite, restlessness, mammary gland congestion/lactation.

• Uterine Infections: Reported in 3.4% of dogs in field trials after induced abortion.

• Estrus Cycle: After treatment, an early return to heat (estrus interval shortened by 1-3 months) is frequently observed.

• Blood Work Changes: Transient, reversible changes in blood cell counts and biochemistry values were observed in <5% of dogs.

• Cats (Off-Label): Similar side effects are possible. Mammary gland enlargement/lactation is expected with pregnancy termination. Haemorrhagic (bloody) vaginal discharge has been specifically reported in cats post-abortion.

• Hypersensitivity: Rare cases of allergic reactions can occur.

• Owner Monitoring: Owners should contact their veterinarian if the animal develops purulent (pus-like) or hemorrhagic (bloody) vaginal discharge, if any discharge persists for over 3 weeks, or if the animal shows signs of prolonged illness (e.g., severe lethargy, persistent vomiting, refusal to eat).

Contraindications (When NOT to Use Alizin):

• Do not use in animals with known hypersensitivity to aglepristone or any excipients (especially peanut oil).

• Do not use in dogs with impaired liver function.

• Do not use in dogs with impaired kidney function.

• Do not use in diabetic animals.

• Do not use in dogs in poor general health.

• Do not use in pregnant animals unless the intention is to terminate the pregnancy.

Special Warnings and Precautions for Use:

• Treatment Failure: Incomplete abortion or complete failure is possible (partial abortion seen in 5% of bitches in trials). Confirmation of pregnancy termination via veterinary examination (ideally ultrasound) is essential approximately 10 days after treatment and at least 30 days post-mating. Repeat treatment may be considered (between days 30-45 post-mating if failure is detected), or surgical options may be discussed.

• Risk vs. Benefit: Mating does not always result in pregnancy (up to 50% failure rate). The possibility of treating a non-pregnant animal should be considered.

• Compromised Puppy Viability: If treatment fails and pregnancy continues, the viability of the puppies may be compromised

• Underlying Conditions: Use caution in animals with chronic obstructive airway disease or cardiovascular disease (especially bacterial endocarditis).

• Off-Label Use Risks: Fatalities have been reported after off-label use in severely ill bitches with uterine infections. A definite causal link is complex, but caution is warranted.

• Drug Interactions: Potential interactions with certain antifungals (ketoconazole, itraconazole) and antibiotics (erythromycin) haven’t been thoroughly studied. As an anti-glucocorticoid, Alizin may reduce the effectiveness of corticosteroid treatments. Do not mix Alizin with other injectable products in the same syringe.

• Accidental Human Injection:

  • EXTREME CAUTION IS REQUIRED. Aglepristone can induce abortion in humans.

  • Accidental self-injection poses a significant risk, particularly to women who are pregnant, trying to become pregnant, or whose pregnancy status is unknown.

  • The oil-based formulation can cause prolonged, severe local reactions (intense pain, swelling, and potentially ischemic necrosis leading to tissue loss).

  • Wear disposable protective gloves when handling and administering the product.

  • Avoid contact with skin and eyes.

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

  • Keep out of reach of children.

Storage Information

• Store below 25°C (77°F). Some sources may state 15-25°C. Do not freeze.

• Keep the vial in the outer carton to protect it from light.

• Shelf life (unopened): As stated on the packaging (typically 3 years from manufacture).

• Shelf life after first opening the vial: Use within 28 days.

• Discard the product if any signs of particle growth or discoloration are observed.

Kilogram (kg) to Pound (lb) Conversion Table

(Approximate values; 1 kg ≈ 2.2046 lbs)[