Phenoxymethylpenicillin (Granules, Powder) Instructions for Use

ATC Code

J01CE02 (Phenoxymethylpenicillin)

Active Substance

Phenoxymethylpenicillin (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Penicillin antibiotic, destroyed by penicillinase

Pharmacotherapeutic Group

Antibiotic, penicillin

Pharmacological Action

An antibiotic from the group of biosynthetic penicillins. The mechanism of action is associated with the inhibition of bacterial cell wall synthesis. It acts bactericidally. It is acid-resistant.

It is active against aerobic gram-positive bacteria: Staphylococcus spp., Streptococcus spp. (including Streptococcus pneumoniae), Enterococcus spp. (some strains), Clostridium spp., Corynebacterium spp., Erysipelothrix rhusiopathiae, Listeria spp., Bacillus anthracis, Actinomyces spp.; aerobic gram-negative bacteria: Neisseria meningitidis, Neisseria gonorrhoeae; Pasteurella multocida, Streptobacillus spp.; anaerobic bacteria: Peptococcus spp., Peptostreptococcus spp., Fusobacterium spp., Clostridium spp.

It is also active against Spirullinum minus, Treponema pallidum, Borrelia spp., Leptospira interrogans.

Staphylococcus spp. (strains producing penicillinase) are resistant to phenoxymethylpenicillin.

Pharmacokinetics

Phenoxymethylpenicillin is acid-resistant and is not destroyed in the acidic environment of the stomach. Absorption in the alkaline environment of the small intestine is 30-60%. Plasma protein binding is 60-80%. C_max is reached 30-60 minutes after administration. Phenoxymethylpenicillin penetrates into the kidneys, liver, skin, lungs, mucous membrane, muscles, wall of the small intestine and into most body fluids, especially in the presence of inflammatory processes; lower concentrations are determined in bone tissue. It crosses the placental barrier and is found in small amounts in breast milk. About 30-35% is metabolized in the liver. T_1/2 is 30-60 minutes. It is excreted mainly by the kidneys unchanged (25%) and in the form of metabolites (35%); about 30% is excreted through the gastrointestinal tract.

Indications

Infectious and inflammatory diseases caused by microorganisms sensitive to phenoxymethylpenicillin, including bronchitis, pneumonia, tonsillitis, scarlet fever, otitis media, gonorrhea, syphilis, tetanus, anthrax, purulent diseases of the skin and soft tissues.

For prophylaxis: wounds of various etiologies (including bites); burns; prevention of streptococcal infections and their complications (including rheumatism /rheumatic attack, chorea minor/, polyarthritis, glomerulonephritis, endocarditis); prevention of bacterial endocarditis in patients with congenital or acquired rheumatic heart defects before and after minor surgical interventions (tonsillectomy, tooth extraction); prevention of pneumococcal pneumonia in children with sickle cell anemia; prevention of rheumatism exacerbations.

ICD codes

Dosage Regimen

Granules, Powder

Individual. For moderate infections, adults and children over 10 years – 3 million IU/day. For severe infections, the dose is increased to 6-9 million IU/day. For children under 10 years of age – 50,000-100,000 IU/kg/day. Frequency of administration – 3-6 times/day. The course of treatment is on average at least 5-7 days; when treating infections caused by β-hemolytic streptococcus – at least 7-10 days.

Adverse Reactions

Allergic reactions infrequently – urticaria, skin hyperemia, angioedema, rhinitis, conjunctivitis; rarely – fever, serum sickness, arthralgia, eosinophilia; very rarely – anaphylactic shock.

From the hematopoietic system rarely – hemolytic anemia, leukopenia, agranulocytosis, thrombocytopenia, pancytopenia.

From the digestive system infrequently – nausea, vomiting, diarrhea, glossitis, stomatitis, vesicular cheilitis, decreased appetite, dry mouth, taste disturbance; rarely – pseudomembranous colitis.

Other rarely – interstitial nephritis, vasculitis.

Contraindications

Hypersensitivity to phenoxymethylpenicillin and other beta-lactam antibiotics (penicillins, cephalosporins, carbapenems); severe course of infections (including the acute stage of severe pneumonia); gastrointestinal diseases accompanied by vomiting and diarrhea; aphthous stomatitis and pharyngitis; gastroparesis, cardia spasm or increased intestinal motility; children’s age – depending on the dosage form.

With caution

In allergic diseases (bronchial asthma, hay fever, diathesis), allergic reactions (in history).

Use in Pregnancy and Lactation

During pregnancy, it is possible to use according to indications in cases where the intended benefit to the mother outweighs the potential risk to the fetus. If it is necessary to use during lactation, the issue of stopping breastfeeding should be decided.

Pediatric Use

It can be used in children according to indications, in doses and dosage forms recommended according to age. It is necessary to strictly follow the instructions in the instructions for phenoxymethylpenicillin drugs regarding contraindications for the use of specific dosage forms of phenoxymethylpenicillin in children of different ages.

Special Precautions

If allergic reactions develop, Phenoxymethylpenicillin should be discontinued and appropriate therapy prescribed.

The use of phenoxymethylpenicillin in combination with bacteriostatic antibiotics should be avoided. Combination with other antibiotics is allowed if an additive or synergistic effect is expected.

During long-term treatment, the possibility of growth of resistant strains of bacteria and fungi should be taken into account.

In case of persistent diarrhea, the possibility of developing pseudomembranous colitis should be considered.

With prolonged use, periodic monitoring of the peripheral blood picture and indicators of liver and kidney function is recommended.

When using phenoxymethylpenicillin, false-positive results are possible in the reaction during non-enzymatic determination of glucose in urine and in the analysis for urobilinogen and the results of quantitative determination of amino acids in urine by the ninhydrin method.

Effect on ability to drive vehicles and mechanisms

During the use of phenoxymethylpenicillin, patients should exercise caution when driving vehicles and mechanisms, as well as when engaging in other potentially hazardous activities that require increased concentration and speed of psychomotor reactions.

Drug Interactions

With simultaneous use, Phenoxymethylpenicillin increases the effectiveness of indirect anticoagulants (by suppressing the intestinal microflora, it reduces the formation of vitamin K); reduces the effectiveness of oral contraceptives and drugs in the metabolism of which para-aminobenzoic acid is formed.

With simultaneous use, Phenoxymethylpenicillin increases the risk of “breakthrough” bleeding while taking ethinyl estradiol.

With simultaneous use, antacids, glucosamine, laxatives, aminoglycosides and food slow down and reduce the absorption of phenoxymethylpenicillin; ascorbic acid increases it.

With simultaneous use of bactericidal antibiotics (including cephalosporins, cycloserine, vancomycin, rifampicin), aminoglycosides, a synergistic effect is observed; with simultaneous use of bacteriostatic antibiotics (including macrolides, chloramphenicol, lincosamides, tetracyclines) – antagonism.

With simultaneous use, diuretics, allopurinol, phenylbutazone, NSAIDs and other drugs that reduce tubular secretion increase the concentration of phenoxymethylpenicillin and enhance its effect.

With simultaneous use of phenoxymethylpenicillin and allopurinol, the risk of developing allergic reactions (skin rash) increases.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.