Phenoxymethylpenicillin

Phenoxymethylpenicillin is an antibiotic in the penicillin class.

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Indications Phenoxymethylpenicillin.

It is used to eliminate infections that occur:

• in the oral cavity (such as periodontitis with actinomycosis, as well as bacterial stomatitis );
• within the respiratory system (bronchitis or pneumonia);
• in the area of the epidermis and subcutaneous layers (impetigo of a contagious nature, abscesses with phlegmon, as well as furunculosis, Breaker's erythema and migratory rash of an erythematous nature).

In addition, the drug is recommended for use in cases of tetanus with botulism, as well as lymphadenitis, gonorrhea with syphilis, anthrax, diphtheria and infectious jaundice.

The medication is used to prevent the development of relapses of rheumatoid arthritis, endocarditis of bacterial origin, Sydenham's chorea, glomerular nephritis and rheumatism, and in addition to this, to prevent the occurrence of complications of infectious genesis after surgical procedures.

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Release form

The drug is released in the form of a lyophilisate or tablets, which are taken orally.

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Pharmacodynamics

The mechanism of drug action is based on the inhibition of cell membrane binding processes.

Phenoxymethylpenicillin has a bactericidal effect on most gram-positive bacteria (such as staphylococci and streptococci), a small number of gram-negative bacteria (for example, Neisseria), and also Listeria and Treponema and Corynebacteria.

The drug does not affect the activity of streptococci, which are capable of independently producing penicillinase (this is a specific enzyme that can inactivate and break down β-lactam antibiotics).

The medication does not affect the vital activity of microbes that cause amoebiasis, rickettsia, viruses, or most gram-negative bacteria.

The active element of the drug is resistant to acid, but is destroyed upon contact with penicillinase.

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Pharmacokinetics

The drug is stable when in an acidic environment. Absorption in the small intestine is approximately 30-60%, synthesis with protein in the plasma is about 60-80%. The substance circulates in the blood for a long time, passing into the tissues at a low speed. High levels of the medicinal element are found in the kidneys, and lower levels are found in the intestinal walls, liver and epidermis. The drug reaches therapeutic levels in the blood after 0.5 hours; they persist for 3-6 hours.

The liver metabolism rate of the element is approximately 30-35%. The half-life is approximately 30-45 minutes. This period is prolonged in the elderly, newborns, and those with renal failure.

Excretion of the unchanged component is 25%, and of the metabolic products is 35%. Approximately 30% of the drug is excreted in feces.

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Dosing and administration

The tablets should be taken 60 minutes before meals, with plain water.

For teenagers over 12 years of age and adults, the following regimen is prescribed: taking 0.5-1 g of the drug 3-4 times a day (1 mg of the drug contains 1610 IU).

People with severe renal impairment should take the medicine at intervals of at least 12 hours.

The average duration of the treatment cycle is 5-7 days.

During therapy for infections caused by β-hemolytic streptococcus, the antibacterial treatment course should continue for another 3 days after the patient’s temperature has returned to normal (average duration is 1-2 weeks).

To prevent the development of attacks of Sydenham's chorea or rheumatic symptoms, it is necessary to take 0.5 g of the drug twice.

To eliminate the risk of infection after a surgical procedure, it is necessary to administer 2 g of the drug before the procedure, and then take 0.5 g of the substance at intervals of 6 hours for another 2 days.

A suspension made from soluble powder is used for children. Dosage sizes are calculated in the proportion of 20-50 mg/kg.

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Contraindications

Main contraindications:

• pathologies of infectious nature, having a severe degree of expression;
• the presence of hypersensitivity to penicillins with cephalosporins, carbapenems, and other β-lactam antibiotics;
• stomatitis or pharyngitis of aphthous nature;
• diseases affecting the digestive system, which are accompanied by vomiting and diarrhea.

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Side effects Phenoxymethylpenicillin.

The drug may cause allergic symptoms (local skin hyperemia, rhinitis, conjunctivitis, Quincke's edema and urticaria). Rarely, therapy causes the development of eosinophilia, arthralgia, anaphylaxis, fever and serum sickness.

The tablets can cause thrombocytopenia, leukopenia, or pancytopenia, as well as agranulocytosis and hemolytic anemia.

Among the digestive disorders: vesicular cheilitis (develops due to the irritating effect of the active element of the drug on the mucous membranes), glossitis with stomatitis, and in addition dyspeptic symptoms (vomiting or diarrhea syndrome, as well as nausea and discomfort in the epigastric zone) and dryness of the oral mucosa. Appetite also worsens, taste buds are impaired, and pseudomembranous enterocolitis develops (rarely).

Therapy may also lead to the development of vasculitis, pharyngitis, or tubulointerstitial nephritis.

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Overdose

Phenoxymethylpenicillin poisoning can cause vomiting, diarrhea, seizures, and nausea.

To eliminate the disorders, you need to seek help from a doctor.

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Interactions with other drugs

The drug reduces the effectiveness of oral contraceptives, as well as drugs that are metabolized with the formation of PABA. Combination with indirect anticoagulants leads to the development of the opposite effect.

The use of ethinyl estradiol significantly increases the risk of breakthrough bleeding. The use of allopurinol increases the risk of developing an allergy, manifested in the form of a rash on the epidermis.

Diuretics, phenylbutazone and NSAIDs increase blood levels of the antibiotic by weakening the excretory processes within the renal tubules.

When taken with laxatives, aminoglycosides, food, glucosamine or antacids, the rate and degree of absorption of the drug is reduced. The opposite effect is observed when combined with vitamin C.

Synergism of drug effects is recorded when the drug is combined with bactericidal antibiotics (vancomycin with cycloserine, individual cephalosporins and rifampicin).

Antagonistic effects are observed when used together with bacteriostatic antibiotics (including macrolides with lincosamides, as well as chloramphenicol with tetracyclines).

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Storage conditions

Phenoxymethylpenicillin should be kept out of reach of children and away from sunlight. Temperature values should not exceed 30°C.

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Shelf life

Phenoxymethylpenicillin can be used within 48 months from the date of manufacture of the drug.

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Analogues

Analogues of the drug are Vepikombin with Ospen, as well as Kliatsil with Megatsillin oral.

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Reviews

Phenoxymethylpenicillin receives a large number of positive reviews. It is noted that it works very well in the treatment of various infections, and is also tolerated by patients without complications (subject to compliance with the treatment regimen and all instructions prescribed by the attending physician).