Sumapen

Phenoxymethylpenicillin potassium.

Each capsule contains: Phenoxymethylpenicillin (as potassium salt) 250 mg or 500 mg.

Pharmacology: Pharmacodynamics Mechanism of Action: Phenoxymethylpenicillin (Penicillin V) is a natural penicillin produced by fermentation of mutant strains of Penicillium chrysogenum. It is usually bactericidal in action by interfering with the bacterial cell wall synthesis. Phenoxymethylpenicillin binds to penicillin-binding proteins on the bacterial cell wall and blocks peptidoglycan synthesis. Peptidoglycan is a heteropolymeric structure that gives the cell wall its mechanical stability. The final stage of peptidoglycan synthesis involves the completion of the cross-linking with the terminal glycine residue of the pentaglycine bridge linking to the fourth residue of the pentapeptide. The transpeptidase enzyme that performs this step is inhibited by penicillins. The bacterial cell wall is thus weakened, the bacterial cell swells and then ruptures.
Pharmacokinetics: In healthy, fasting adults, about 60 to 73% of an oral dose of phenoxymethylpenicillin is absorbed rapidly from the gastrointestinal (GI) tract.
Peak serum concentrations are reached within 30 to 60 minutes after a single oral dose of phenoxymethylpenicillin in fasting children or adults.
Single oral administration of phenoxymethylpenicillin 250 mg tablet in healthy, fasting adults results in serum drug concentrations averaging 2.1-2.8, 2.3-2.7, 0.8-0.9, and 0.1-0.2 µg/mL at 30 minutes, 1 hour, 2 hours, and 4 hours, respectively, after the dose. Single oral administration of phenoxymethylpenicillin 500 mg tablet in healthy, fasting adults results in serum drug concentrations averaging 4.7-5, 4.9-6.3, 2.3-3, and 0.04-0.1 μg/mL at 30 minutes, 1 hour, 2 hours, and 6 hours, respectively, after the dose.
Phenoxymethylpenicillin is readily distributed into ascetic, synovial, pleural, and pericardial fluids. The drug is widely distributed into body tissues with highest concentrations attained in the kidneys and lower amounts in the liver, skin, intestines, and muscle. Phenoxymethylpenicillin is also distributed into bile, tonsils, maxillary sinus secretions, and saliva in low concentrations. Minimal drug concentrations generally distribute into CSF in patients with uninflamed meninges. In general, only negligible amounts of natural penicillins are attained in avascular areas, abscesses, aqueous humor, sweat, team, or bone.
Phenoxymethylpenicillin readily crosses the placenta and is distributed into human milk. About 75% to 89% of the drug is bound to serum proteins.
The serum half-life of phenoxymethylpenicillin in adults with normal renal function is reportedly 0.5 hours. About 35% to 70% of the drug is metabolized to penicilloic acid which is microbiologically inactive. Small amounts of 6-aminopenicillanic acid (6-APA) have also been found in urine of patients receiving phenoxymethylpenicillin. In addition, the drug appears to be hydroxylated to a small extent to one or more microbiologically active metabolites.
Phenoxymethylpenicillin and its metabolites are excreted in urine mainly by tubular secretion. Small amounts of the drug are also excreted in feces and bile. After a single oral administration of phenoxymethylpenicillin in adults with normal renal function, 26% to 65% of the dose is excreted in urine as unchanged drug and metabolites within 6 to 8 hours; about 32% of the dose is excreted in feces. Renal clearance of phenoxymethylpenicillin is delayed in neonates, young infants, and patients with renal impairment. It is not known if the drug is removed by hemodialysis or peritoneal dialysis.
Microbiology: Antimicrobial Spectrum of Activity: Phenoxymethylpenicillin is bactericidal against penicillin-sensitive microorganisms during the stage of active multiplication.
It has demonstrated activity in vitro and in clinical infections against strains of the following microorganisms: (See Table 1.)

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Phenoxymethylpenicillin has also demonstrated in vitro activity against some strains of the following microorganisms; however, clinical significance is unknown: (See Table 2.)

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For the treatment of the following mild to moderately severe infections caused by susceptible organisms: Respiratory tract infections; Genitourinary tract infections; Skin and skin structure infections; Oral and dental infections including necrotizing gingivitis.
For prevention and treatment of secondary bacterial infections in measles, mumps, chickenpox, influenza, and other viral infections.
As prophylaxis in recurrent streptococcal infections including the prevention of recurrence following rheumatic fever and/or Syndenham's chorea, and to prevent bacterial endocarditis after tonsillectomy or tooth extraction in patients with history of rheumatic fever and/or congenital heart disease.
NOTE: Oral penicillin should not be used as adjunctive prophylaxis for genitourinary instrumentation or surgery, lower intestinal tract surgery, sigmoidoscopy or complications of childbirth.

Usual Dose in Adults and Children 12 years and older: (See Table 3.)

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Usual Dose in Children 6 to 12 years old (Who can swallow capsule whole): Orally, one 250 mg every 6 hours.
Or, as prescribed by a physician.
Duration of Treatment: 10 to 14 days depending on the severity of infection, clinical response and bacteriological course.

In general, phenoxymethylpenicillin has low toxicity. Clinical features of overdose may include GI symptoms such as nausea and vomiting. In patients with renal impairment, the drug may accumulate in the blood, and the dose should be adjusted accordingly.
In case of overdosage, the cardiovascular status, electrolyte balance and renal function should be monitored. Penicillins are not readily removed by dialysis.

Known hypersensitivity to penicillin and/or cephalosporin, or to any ingredient of the product.
Chronic, severe, or deep-seated infections since absorption can be unpredictable.

Serious and occasionally fatal hypersensitivity (anaphylactoid) reactions have been reported in patients on penicillin therapy. Careful inquiry should be made concerning previous hypersensitivity to penicillins, cephalosporins, or other allergens before initiating therapy with phenoxymethylpenicillin. If an allergic reaction occurs, the medicine should be discontinued and the appropriate therapy instituted. Serious anaphylactoid reactions require immediate emergency treatment with epinephrine. Oxygen, intravenous steroids, and airway management, including intubation, should also be instituted.
Use with caution in patients with a history of allergy and/or asthma.
Clostridium difficile-associated diarrhea (CDAD) and colitis have been reported with the use of nearly all antibacterial agents, including phenoxymethylpenicillin, and may range in severity from mild to life threatening. It is important to consider this diagnosis in patients who present with diarrhea following administration of antibacterial agents.
Orally administered phenoxymethylpenidllin should not be relied upon to achieve therapeutic levels in some patients with severe infections or with nausea, vomiting, gastric dilatation, esophageal achalasia, cardiospasm, or intestinal hypermotility. Occasionally patients will not absorb therapeutic amounts of oral penicillin. Parenteral administration of suitable antibiotics is recommended in these patients.
Use of an alternative or an additional method of contraception is strongly advised if an estrogen-containing contraceptive is taken concomitantly [see Interactions].
As with other antibacterial drugs, long term or repeated use may result in overgrowth of non-susceptible organisms, including fungi.
Use in Patients with Renal Impairment: Elimination is delayed in patients with renal impairment and a modest dose reduction is recommended in patients with severe renal impairment.
Use in Patients with Hepatic Impairment: Phenoxymethylpenicillin can be used safely in patients with hepatic impairment without dose adjustment.
Use in Elderly: There are no special problems relating to the use of penicillin in the elderly.

Use in Pregnancy: (Pregnancy Category B): There are no adequate or well-controlled studies in pregnant women and safe use in pregnancy has not been established. However, phenoxymethylpenicillin has been administered to pregnant women, particularly in the treatment of respiratory tract infections, without evidence of adverse effects to the fetus.
Use in Lactation: Since phenoxymethylpenicillin is distributed into human milk, use with caution when breastfeeding.

Hypersensitivity Reactions: Anaphylaxis [manifested by generalized pruritus, angioneurotic edema (which may affect the larynx), tachycardia, severe dyspnea, cyanosis, diaphoresis, stridor, dizziness, rigors, loss of consciousness, and peripheral circulatory failure], acute interstitial nephritis, agranulocytosis, allergic bronchial asthma, allergic vasculitis, angioedema, Arthus phenomenon, chills, drug fever, eosinophilia, erythema multiforme, erythema nodosum, exfoliative dermatitis, fixed drug eruptions, hemolytic anemia, hypotension, laryngospasm, leukopenia, urticarial, erythematous, or morbiliform (maculopapular or exanthematic) rash and pruritus, serum sickness-like reactions (characterized by fever, malaise, urticaria, arthralgia, myalgia, lymphadenopathy, splenomegaly), Stevens-Johnson syndrome, vesiculobullous eruptions.
Hematologic Effects: Transient neutropenia, thrombocytopenia, thrombocytopenic purpura.
Gastrointestinal Effects: Black hairy tongue, Clostridium difficile-associated diarrhea and colitis, increased capillary fragility characterized by spontaneous petechial hemorrhages with positive result on the tourniquet test, diarrhea, epigastric distress, nausea, pruritus ani, sore mouth or tongue, vomiting.
Other Adverse Effects: Hepatotoxicity, nephropathy, neuropathy.

Interactions with other Medicaments: (See Table 4.)

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Interference with Laboratory Tests: Penicillins may interfere with urinary tests for fructose, aminolevulinic acid, estrogens, 17-hydroxycorticosteroids, protein, and sugar, with serum tests for uric acid; with biological tests for serum folate; and with serum electrophoresis.
Penicillins may decrease urinary excretion of aminohippurate sodium (PAH) and phenolsulfonphthalein (PSP) by competing for renal tubular secretion with these diagnostic agents.

Store at temperatures not exceeding 30°C. Protect from light.
Powder for Suspension: After constitution, always keep container tightly closed. Store at 2-8°C (refrigerator) and use within 7 days.

Penicillins

J01CE02 - phenoxymethylpenicillin ; Belongs to the class of beta-lactamase sensitive penicillins. Used in the systemic treatment of infections.

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