Creamy oblong tablet with small brown spots marked with a score line. The tablets can be divided into halves.

Tablets for oral administration containing cephalexin (as cephalexin monohydrate PhEur) in three strengths:

Rilexine 75 containing 75mg cephalexin

Rilexine 300 containing 300mg cephalexin

Rilexine 600 containing 600mg cephalexin

The active ingredient of product is Cefalexin monohydrate.

Cefalexin is a bactericidal antibiotic of the cephalosporin family which acts by inhibiting the nucleopeptide synthesis of the bacterial wall. It is obtained by hemi-synthesis from the 7- amino cephalosporanic nucleus. Cephalosporins interfere with transpepditation by acylating the enzyme making it unable to cross-link muramic acid-containing peptidoglycan strands. The inhibition of the biosynthesis of the material required to build the cell wall results in a defective cell wall which is consequently osmotically unstable. The combined action results in cell lysis and filament formation.

Cefalexin is active against a wide range of gram-positive and gram-negative aerobic bacteria: Staphylococcus spp. (including penicillin-resistant strains), Streptococcus spp., Escherichia coli, Klebsiella spp., Salmonella spp. and Pasteurella multocida. Cefalexin is not inactivated by β-lactamases produced by gram-positive bacteria and which usually affect penicillins.

Cefalexin had a time-dependent bactericidal activity on both tested bacteria species, Staphylococcus felis (gram-positive) and Pasteurella multocida (gram-negative). In vitro activity of Cefalexin towards European strains isolated in 2003-2006 in cats exhibiting cutaneous or subcutaneous infections showed that the MIC90 was 2 µg/ml for Staphylococcus spp. and Pasteurella spp. and 0.5 µg/ml for Streptococcus spp. These susceptible genera were also the bacteria the most-frequently isolated from wounds and abscesses in cats.

Resistance to Cefalexin may be due to one of the following mechanisms of resistance. Firstly, the production of various beta-lactamases (cephalosporinase), that inactivate the antibiotic, is the most prevalent mechanism among gram-negative bacteria. Secondly, a decreased affinity of the PBPs (penicillin-binding proteins) for β-lactam drugs is frequently involved for β-lactam resistant gram-positive bacteria. Lastly, efflux pumps, extruding the antibiotic from the bacterial cell, and structural changes in porins, reducing passive diffusion of the drug through the cell wall, may contribute to improve the resistant phenotype of a bacterium.

Well-known cross-resistance (involving the same resistance mechanism) exists between antibiotics belonging to the β-lactam group due to structural similarities. It occurs with βlactamases enzymes, structural changes in porins or variations in efflux pumps. Coresistance (different resistance mechanisms involved) has been described in Escherichia coli due to a plasmid harbouring various resistance genes.

After single oral administration of the recommended dosage of 15 mg of cefalexin per kg of bodyweight to Beagle dogs, plasma concentrations were observed within 30 minutes. The plasma peak was observed at 1.3 hour with a plasma concentration of 18.2 µg/ml. The bioavailability of the active was over 90 %. Cefalexin was detected until 24 hours after the administration. The first urine specimen was collected within 2 to 12 hours with peak concentrations of cefalexin measured at 430 to 2758 µg/ml within 12 hours.

After repeated oral administration of the same dosage, twice a day for 7 days, plasma peaks occurred 2 hours later with a concentration of 20 µg/ml. Over the treatment period, concentrations were maintained above 1 µg/ml. The mean elimination half-life is 2 hours. Skin levels were around 5.8 to 6.6 µg/g, 2 hours after treatment.

A single oral administration of 15 mg of Cefalexin per kg of bodyweight in cats led to a bioavailability of 56 %. The plasma peak was observed at 1.55 hour following administration with a plasma concentration above 15.1 µg/ml. The mean plasma half-life was about 1 to 2 hours. The first urine specimen was collected between 4 and 24 hours with the highest concentrations ranging between 63.7 and 393 µg/ml, occurring within 24 hours.

With the same dosage administered over 7 days, twice a day, the highest urine concentration of Cefalexin reached between 518 and 1256 µg/ml.

For the treatment of bacterial skin infections in dogs (including deep and superficial pyodermas) caused by organisms susceptible to Cefalexin.

For the treatment of cutaneous and subcutaneous infections (wounds and abscesses) in cats caused by organisms susceptible to Cefalexin.

For the treatment of urinary-tract infections in cats and dogs (including nephritis and cystitis) caused by organisms susceptible to Cefalexin.

15 mg Cephalexin per kg bodyweight twice daily (equivalent to 30 mg per kg bodyweight per day):

To achieve this dosage, administer:

One tablet of Rilexine 75 per 5 kg bodyweight or 1/2 tablet per 2.5 kg of bodyweight twice daily.

One tablet of Rilexine 300 per 20 kg bodyweight or ½ tablet per 10 kg of bodyweight twice daily.

One tablet of Rilexine 600 per 40 kg bodyweight or ½ tablet per 20 kg of bodyweight twice daily.

To ensure correct dosage, bodyweight should be determined as accurately as possible to avoid under dosing.

Due to its palatable formulation, the product is well accepted by cats and dogs but may be crushed or added to food if necessary.

In severe or acute conditions the dose may be safely doubled.

Do not use in animals known to be hypersensitive to penicillins and cephalosporins.

Do not use in rabbits, guinea pigs, hamsters and gerbils.

As with other antibiotics which are excreted mainly by the kidneys, unnecessary accumulation may occur in the body when renal function is impaired. In case of known renal insufficiency, the dose should be reduced and antimicrobials known to be nephrotoxic should not be administered concurrently.

This product should not be used to treat puppies of less than 1 kg of bodyweight or kittens under 9 weeks of age.

Use of the product deviating from the instructions given in the S.P.C. may increase the prevalence of bacteria resistant to Cefalexin and may decrease the effectiveness of treatment with other cephalosporins and penicillins, due to the potential for cross-resistance.

Use of the product should be based on susceptibility testing of the bacteria isolated from the animal. If this is not possible, therapy should be based on local epidemiological information.

Official, national and regional antimicrobial policies should be taken into account when the product is used.

As the tablets are palatable to animals there is a danger of excessive ingestion. The tablets must therefore be stored out of the reach of animals.

Local treatment of cutaneous and subcutaneous infections in cats should be considered as a complement of the antibiotic treatment.

Penicillins and cephalosporins may cause hypersensitivity (allergy) following injection, inhalation, ingestion or skin contact. Hypersensitivity to penicillin may lead to cross sensitivity to cephalosporin and vice versa. Allergic reactions to these substances may occasionally be serious.

Hypersensitivity to Cefalexin is rare, however, the product should not be administered to animals which are known to be hypersensitive to Cefalexin or penicillins (see also Contraindications).

Allergic cross-reactivity with other β-lactam may occur.

Very rare cases of soft faeces and vomiting may be observed in animals during treatment.

The product can be used in pregnant and lactating animals.

The association of first-generation cephalosporins with aminoglycoside antibiotics and some diuretics such as furosemide can enhance nephrotoxicity risks.

The bactericidal activity of cephalosporins is reduced by concomitant administration of bacteriostatic acting compounds (tetracyclines, chloramphenicol, macrolides and rifampicin).

Trials performed on animals with up to 5 times the recommended dose of 15 mg/kg demonstrated that the product is well tolerated.

Not applicable.

Crospovidone

Mannitol

Starch pregelantinised

Croscarmellose sodium

Collodial anhydrous silica

Collodial hydrated silica

Povidone K30

Microcrystalline cellulose type A

Poultry liver powder

Magnesium stearate

Microcrystalline cellulose type B

Not applicable.

Rilexine 300 and 600mg

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

Rilexine 75mg

Shelf life of the veterinary medicinal product as packaged for sale: 15 months.

Keep the blisters in the outer carton in order to protect from light.

Divided tablets should be stored in blister packs.

Any unused veterinary medicinal products or waste materials derived from such veterinary medicinal product should be disposed of in accordance with local requirements.

Rilexine 75: Cardboard Box with 30 blisters of 7 tablets.

Rilexine 300: Cardboard Box with 30 blisters of 7 tablets.

Rilexine 600: Cardboard Box with 30 blisters of 7 tablets.

Nil.