PHARMACOLOGICAL ACTION
Benzylpenicillin: “The penicillins impair the development of bacterial cell walls by interfering with transpeptidase enzymes responsible for the formation of the cross-links between peptidoglycan strands. During bacterial cell growth, while the peptidoglycan structure is being formed, autolysins continuously cleave the lattice to provide acceptor sites for new strands. Normal bacterial growth depends on a balance between cell wall deposition and autolysis. When penicillin interacts with penicillin-binding proteins (PBP) and inhibits the synthetic enzymes, defective cell walls are formed which lead to abnormal elongation of cells, formation of spheroplasts or osmolysis. The effect of the penicillins is generally bactericidal, although bacteriolysis may also occur”.
They have been shown to be effective in vitro against Gram-positive bacteria such as Staphylococcus aureus, Streptococci, most Trueperella pyogenes and Erysipelothrix spp. Sensitive anaerobic bacteria include mostClostridia. They are also effective in vitro against certain Gram-negative bacteria such as Pasteurella multocida, Leptospira and Actinobacillus (Haemophilus) pleuropneumoniae.
Benzathine benzylpenicillin: When given by intramuscular injection it forms a depot from which it is slowly released and hydrolysed to benzylpenicillin. Peak plasma concentrations are produced in about 24 hours and effective concentrations of benzylpenicillin are maintained for up to 4 weeks.
However, plasma concentrations are lower than those following an equivalent dose of benzylpenicillin. Due to the slow absorption from the site of injection, benzylpenicillin has been detected in the urine for up to 12 weeks after a single dose.
Procaine benzylpenicillin: It is a narrow-spectrum penicillinase-sensitive penicillin and is administered intramuscularly or subcutaneously. It forms a depot from which it is slowly released and hydrolysed to benzylpenicillin. Peak plasma concentrations are produced in 1 to 4 hours, with effective concentrations of benzylpenicillin usually being maintained for 12 to 24 hours.
INDICATIONS
Duplocillin® is recommended for the treatment and prevention of infections caused by bacteria sensitive to penicillin in both large and small animals where prolonged therapy is required. It is particularly useful for the treatment of swine erysipelas, as a post-operative prophylactic and for the control of wound infections.
CONTRAINDICATIONS
Not to be administered to animals known to be allergic to penicillin.
It should not be used if beta-lactamase producing organisms are known to be present.
Cross-reactions are common with penicillins and in some instances with cephalosporins.
Psittacine birds are sensitive to procaine.
WARNINGS
Withdrawal periods (for food producing animals)
Meat and organs : 14 days
Milk : 5 milkings
Injection site, cattle and pigs : 70 days
Injection site, sheep : 56 days
When administered to an animal known to be penicillin-sensitive anaphylactic shock may occur. Adrenaline, corticosteroids and antihistamines should be used to treat anaphylaxis.
Do not administer to animals known to be allergic to penicillin. Such allergies to penicillin have been observed but are rare.
Do not use in small herbivores (rabbits, guinea pigs, hamsters, chinchillas)
Procaine benzylpenicillin may occasionally cause transient pyrexia, vomiting, shivering, listlessness and incoordination in pigs. Additionally in pregnant sows and gilts, abortion has been reported in a few cases.
Procaine is detected in urine of horses up to 2 weeks after intramuscular (i.m.) administration.
Do not administer to animals known to be sensitive to procaine.
Do not administer intravenously.
KEEP OUT OF REACH AND SIGHT OF CHILDREN, UNINFORMED PERSONS AND ANIMALS.
DOSAGE AND DIRECTIONS FOR USE – USE ONLY AS DIRECTED
SHAKE WELL BEFORE USE.
Observe aseptic precautions
Use sterile equipment when administering Duplocillin®.
Clean the area of the injection site and swab with alcohol.
Horses and Cattle : 1 mℓ/25 kg body mass by intramuscular injection.
Pigs and Sheep : 1 mℓ/20 kg body mass by intramuscular injection.
Dogs and Cats : 1 mℓ/10 kg body mass by intramuscular or subcutaneous injection.
Dosage Interval : 72 hours.
Repeat injections should be given at a different injection site.
SIDE EFFECTS AND SPECIAL PRECAUTIONS
Hypersensitivity reactions to penicillins range from mild and transient skin reactions to fatal anaphylactoid shock.
Pharyngitis or sore throat has been reported in dogs following 4 days of penicillin therapy.
Intrathecal administration of penicillins is not recommended, because it is a potent convulsant when given by this route.
KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT
See SIDE EFFECTS.
Treatment is symptomatic and supportive.
CONDITIONS OF REGISTRATION
Promote to the Professions only.
IDENTIFICATION
Duplocillin® is a white to off-white ready-to-use aqueous suspension.
On standing the colour of the sediment and upper layer is as follows:
Sediment: white to off-white suspension.
Upper layer: < B5 according to the Ph. Eur.
PRESENTATION
100 mℓ and 250 mℓ Type II colourless glass vials or 100 mℓ, 250 mℓ and 500 mℓ PET vials, closed with halogenated butyl rubber stoppers. The vial is sealed with an aluminium cap.
Cartons containing a single 250 mℓ vial or a carton containing 12 x 100 mℓ vials.
Not all pack sizes may necessarily be marketed.
STORAGE
Store in a cool dark place between 2 °C and 8 °C in a refrigerator.
Do not freeze.
In-use stability: Duplocillin® is stable for 28 days after opening, when stored between 2 °C and 8 °C.
REGISTRATION NUMBER
83/661 (Act 101/1965)
Namibia Reg. No. V12/17.1.1.1/1182 NS2
