Retarpene

Retarpen is a natural antibiotic from the β-lactam penicillin subgroup. The active element of the drug is benzylpenicillin benzathine (penicillin subtype G), which has a prolonged type of therapeutic activity.

The specified medicinal component (benzylpenicillin benzathine) is extracted from mold fungi. The drug has a bactericidal effect on the cells of pathogenic bacteria. It is used in the treatment of various forms of bacterial infections. [ 1 ]

Indications Retarpene

It is used in cases of diseases caused by the action of pale treponema and streptococci: scarlet fever, erysipelas, active tonsillitis, as well as rheumatism and syphilis.

The medication can also be used to prevent the development of complications after surgery.

Release form

The release of the therapeutic element is realized in the form of a suspension for intramuscular injections (lyophilisate inside vials). The pack contains 50 such vials.

Pharmacodynamics

The principle of the antibiotic's therapeutic activity is realized by inhibiting the processes of bacterial cell membrane binding. The drug has a long-lasting effect. It demonstrates high activity against gram-negative and -positive microbes, treponema, anaerobes and spore-forming bacteria. [ 2 ]

Retarpen has no effect against penicillinase-producing staphylococci. [ 3 ]

Pharmacokinetics

After administration of benzylpenicillin benzathine, it is absorbed from the injection site at an extremely low rate, providing for the development of a prolonged effect.

Serum Cmax values are observed after 12-24 hours from the moment of administration. The long half-life term leads to the establishment of long-term and stable values of the drug in the blood: by the 14th day from the moment of administration of 2400000 IU, the serum level is 0.12 μg/ml. The protein synthesis rate is about 55%.

The medicinal substance in small volumes crosses the placenta and gets into the mother's milk. The metabolic processes of the drug are quite weak.

Excretion occurs mainly through the kidneys, unchanged; up to 33% of the administered dose is excreted over a period of 8 days.

Dosing and administration

The medication should be administered only by the intramuscular method. If two injections are required, they should be administered into different buttocks.

When treating congenital syphilis in newborns or small children, a single dose of 1.2 million IU is required (or the dose is divided into 2 injections).

For seronegative primary syphilis: intramuscular administration of the drug at a dosage of 2.4 million IU.

In case of a fresh form of secondary syphilis or a seropositive form of primary syphilis: administration of 2.4 million IU, with a repeat injection after 1 week.

For tertiary syphilis: use 2.4 million IU; therapy continues for a period of 3-5 weeks.

People with flambesia are given 1-2 injections at a dosage of 1.2 million units.

In the active form of tonsillitis, wound infections, scarlet fever or erysipelas, therapy begins with the use of benzylpenicillin, and then Retarpen is administered.

Prevention of the development of rheumatism attacks in the joint area: intramuscular administration of 2.4 million IU at 15-day intervals.

• Application for children

Retarpen is not used in pediatrics.

Use Retarpene during pregnancy

Since benzylpenicillin benzathine crosses the placenta, the drug should only be used after careful assessment of all risks and benefits.

A small amount of the drug is excreted in breast milk (these figures range from 2-15% of the drug's figure in the woman's plasma). There is no information on the occurrence of negative signs in infants, but it is necessary to take into account that sensitization or interference with intestinal flora may be observed. Breastfeeding should be discontinued if the infant develops candidiasis, diarrhea or rash.

Children on combined feeding should be transferred to infant formula for the duration of the woman's therapy. Breastfeeding may be resumed 24 hours after the therapy has been discontinued.

Contraindications

Main contraindications:

• severe intolerance to benzylpenicillin;
• hay fever;
• BA.

Side effects Retarpene

Long-term administration of the drug may provoke the appearance of superinfection. Therapy may lead to the appearance of glossitis, stomatitis, headaches, arthralgia, anemia, as well as signs of allergy, fever, exfoliative dermatitis, hypocoagulation, anaphylaxis and leukopenia.

Overdose

Movement disorders, encephalopathy, seizures, confusion and neuromuscular excitability may occur.

Symptomatic and supportive measures are taken, as well as hemodialysis procedures. The drug has no antidote.

Interactions with other drugs

Rifampicin, cycloserine with aminoglycosides, cephalosporins with vancomycin and other bactericidal antibacterial agents have a synergistic effect with respect to drugs.

Lincosamides, chloramphenicol, tetracyclines with macrolides and other bacteriostatic drugs have a powerful antagonistic effect.

Retarpen reduces the values of PTI, increases the effect of indirect anticoagulants, inhibits intestinal microflora and has little effect on the therapeutic efficacy of hormonal contraception.

Diuretics, NSAIDs, allopurinol with phenylbutazone and agents blocking tubular secretion increase penicillin values. Combination with allopurinol increases the likelihood of allergy symptoms in the form of epidermal rashes.

Storage conditions

Retarpen must be stored in a place closed to small children and sunlight. Temperature values are maximum 30°C.

Shelf life

Retarpen is allowed to be used for a 4-year period from the date of manufacture of the medicinal product.

Analogues

The analogs of the drug are Amosin, Ospen with Ampicillin, Bicillin and Ospamox.

Reviews

Retarpen receives good reviews from patients - it is a powerful antibiotic that demonstrates high efficiency when used according to indications. It is necessary to take into account that therapy can only be carried out under medical supervision.