Ilium MPA-50

Injection

Actions
Medroxyprogesterone acetate (MPA) is α6, alpha-methyl synthetic derivative of progesterone.
It has considerably stronger progestational effects than progesterone. MPA maintains effective blood levels for several months following a single injection. MPA is anti-oestrogenic in effect by blocking GnRH output and has significant glucocorticoid activity.

Its behaviour-modifying action is attributed to both an anti-androgenic effect and a direct calming activity in the limbic system.

Indications
MPA-50 is indicated for the treatment of certain behavioural problems in dogs and cats. It has also assisted with control of certain feline dermatoses.

Behavioural modification: MPA has been used to reduce aggression in male dogs and cats, reduce hyperexcitability, treat separation anxiety, and eliminate urine spraying or marking. Other responsive conditions include destructiveness, timidity, sexual perversion, subepileptic episodes and roaming in dogs, and overgrooming, claw marking of territory and bizarre psychotic behaviour in cats.

Feline dermatoses: Good results have been achieved in the treatment of feline endocrine alopecia, feline acne, “stud
tail”, psychogenic alopecia and dermatitis, miliary dermatitis and the eosinophilic granuloma complex.

Directions for use
Give by subcutaneous injection.
Dogs: 20mg/kg to effect then repeat every 4 - 6 months if necessary.
Cats: 30 - 50mg repeated every
4 - 6 months.

Presentation
Injection 20mL.

Composition
Medroxyprogesterone acetate 50mg/mL.

Adverse effects Progestogens can induce a variety of side effects and should be used with caution. Those reported include polyphagia, weight gain, polyuria/polydipsia, temperament changes (increased friendliness), alterations in pituitary-adrenal axis including adrenocortical atrophy, diabetes mellitus, cystic endometritis, pyometra, mammary enlargement and tumours, lactation, reduced spermatogenesis, cutaneous atrophy and local alopecia, elevated growth hormone levels and acromegaly.

Precautions
Loss of hair pigment may occur around the injection site. It is advisable to inject in an inconspicuous area. Injectable progestational compounds have been associated with skin fragility syndrome which involves thinning of skin such that it may be damaged rapidly by minor trauma. It is suggested that the calculated dose of MPA-50 be split into 2-3 doses and injected at separate sites in order to minimise the possibility of this occurring. Previous injection sites should be examined prior to administering follow-up doses.

Metabolism
Progestogens are weakly but extensively bound to plasma proteins, and strongly bound to transcortin. Progesterone is eliminated as various glucuronides in the urine.

Precautions
Do not use where there is uterine infection, abnormal or persistent vaginal discharge, or following recent surgery of the genital tracts. Do not use during Pro-oestrus, oestrus metoestrus, pregnancy, in sexually immature animals or bitches and queens intended for breeding. Do not use in the presence of ovarian and mammary tumours in patients with diabetes mellitus.

Storage
Store below 30ºC (room temperature). Protect from light.

Registration
All states

APVMA Number
50445

References
Marder, (1991) Clinics of N. America, Small Animal Prac. 21:2, Psychotropic drugs and behavioural therapy.
Borchet & Voith, (1985) Comp. on Cont. Educ for the Practicing Vet 7:949-957, Aggressive behaviour in dogs and cats.
Henik et al (1985) Comp. on Cont. Educ. For the Practicing Vet 7:
132-137, Progestogen therapy in cats.
Permberton, (1988) Current Veterinary Therapy VIII, p 62, Canine and feline behaviour control: Progestin therapy.
Hart, (1981) JAVMA 178: 1070, Progestin therapy for aggressive behaviour in male dogs
Hart, (1976) Canine Practice 3: 10 Aggressive behaviour.
Muller, Kirk & Scott, Small Animal Dermatology, 3rd Ed.