Phenoxymethylpenicillin 250mg Tablets
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Phenoxymethylpenicillin 250mg Tablets BP
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains Phenoxymethylpenicillin potassium (1515 l-U/mg) BP 280.00mg
3 PHARMACEUTICAL FORM
White, flat bevelled edge tablets, engraved on one side with company logo and with breakline and A057 on the other side
4 Clinical particulars
4.1 Therapeutic indications
Phenoxymethylpenicillin and potassium phenoxymethylpenicillin are indicated in the treatment of mild to moderately severe infections associated with micro-organisms whose susceptibility to penicillin is within the range of serum levels attained with these dosage forms. The following infections will usually respond to adequate doses:
Streptococcal infections (without bacteraemia): Mild to moderate infections of the upper respiratory tract, scarlet fever and mild erysipelas.
Pneumococcal infections: Mild to moderately severe infections of the respiratory tract.
Staphylococcal infections sensitive to penicillin: Mild infections of the skin and soft tissues.
Fusospirochaetosis (Vincent’s gingivitis and pharyngitis): Mild to moderately severe infections of the oropharynx usually respond to therapy with oral penicillin.
Prophylactic use: Prophylaxis with oral penicillin has proved effective in preventing reccurrence of rheumatic fever and chorea.
Patients with a past history of rheumatic fever receiving continuous prophylaxis may harbour penicillin-resistant organisms. In these patients, the use of another prophylactic agent should be considered.
Note: severe empyema, bacteraemia, pericarditis, meningitis and arthritis should not be treated with Phenoxymethylpenicillin during the acute phase.
Consideration should be given to official guidance on the appropriate use of antibacterial agent.
4.2 Posology and method of administration
Adults: 125-500mg every 4-6 hours depending on the severity of the condition.
Prophylactic use: 125mg twice daily is recommended for long term prophylaxis of rheumatic fever.
Children:
Up to 1 year : 250 mg strength product is not suitable 1 - 5 years : 125 mg 6 hourly
6-12 years : 250 mg 6 hourly
The elderly: As for adults. Reduce dosage if renal function is markedly impaired.
Each dose should be administered half an hour before or at least three hours after a meal.
In patients with beta-haemolytic streptococcal infection, it is usual to continue treatment at the full dosage for 10 days, in order to minimise the occurrence of secondary complications such as acute nephritis and rheumatic fever.
Route of administration: oral
4.3 Contraindications
Hypersensitivity reaction to any penicillin
4.4 Special warnings and precautions for use
All degrees of hypersensitivity, including fatal anaphylaxis, have been observed with oral penicillin. These reactions are more likely to occur in individuals with a history of sensitivity to penicillins, cephalosporins and other allergens.
Enquiry should be made for such a history before therapy with a penicillin is begun. If an allergic reaction occurs, the drug should be discontinued and the patient treated with the usual agents (e.g. Adrenaline and other pressor amines, antihistamines and corticosteroids).
Oral therapy should not be relied upon in patients with severe illness, or with nausea, vomiting, gastric dilatation, cardiospasm or intestinal hypermotility.
Occasionally, patients do not absorb therapeutic amounts of orally administered penicillin.
Administer with caution in the presence of markedly impaired renal function, as safe dosage may be lower than that usually recommended.
Streptococcal infections should be treated for a minimum of 10 days, and posttherapy cultures should be performed to confirm the eradication of the organisms.
Prolonged use of antibiotics may promote the overgrowth of non-susceptible organisms, including fungi. If super-infection occurs, appropriate measures should be taken.
Patients with rare hereditary problems of galactose intolerance, the LAPP lactase deficiency or glucose-galactose malabsorption should not take this medicine.
4.5 Interaction with other medicinal products and other forms of interaction
Concomitant administration of guar gum with phenoxymethylpenicillin reduces the absorption of the latter. Concurrent use of phenoxym ethyl -penicillin with probenecid reduces the excretion of phenoxymethylpenicillin.
Concurrent use of oestrogen-containing oral contraceptives may decrease the effectiveness of oral contraceptives because of stimulation of oestrogen metabolism resulting in menstrual irregularities, intermenstrual bleeding and unplanned pregnancies.
4.6 Pregnancy and lactation
Laboratory and clinical studies have shown no evidence of teratogenicity with the use of phenoxymethylpenicillin potassium during pregnancy. However, as with other drugs, caution should be exercised when prescribing to pregnant patients. Phenoxymethylpenicillin is excreted in the milk and should be used with caution in nursing mothers as it may cause an allergic reaction in the offspring.
4.7 Effects on ability to drive and use machines
None reported
4.8 Undesirable effects
The most common reactions to oral penicillin are nausea, vomiting, epigastric distress, diarrhoea and black, hairy tongue. The hypersensitivity reactions noted are skin eruptions (ranging from maculopapular to exfoliative dermatitis); urticaria; reactions resembling serum sickness, including chills, fever, oedema, arthralgia and prostration; laryngeal oedema; and anaphylaxis. Fever and eosinophilia may frequently be the only reactions observed. Haemolytic anaemia, leucopenia, thrombocytopenia, neuropathy and nephropathy are infrequent reactions and are usually associated with high doses of parenteral penicillin.
Reporting of suspected adverse reactions:
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.
4.9 Overdose
A large oral overdose of penicillin may cause nausea, vomiting, stomach pain, diarrhoea and rarely, major motor seizures. If other symptoms are present, consider the possibility of an allergic reaction. No specific antidote is known. Symptomatic and supportive therapy is recommended. Activated charcoal with a cathartic, such as sorbitol, may hasten drug elimination. Penicillin may be removed by haemodialysis.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Phenoxymethylpenicillin has a mainly bactericidal action against many grampositive bacteria and some gram-negative cocci, and against some spirochaetes and actinomycetes.
It is considered to act through interference with the final stage of synthesis of the bacterial cell wall. The action depends upon phenoxymethylpenicillin's ability to reach and bind to certain membrane bound proteins, known as penicillin-binding proteins (PBP's), that are located beneath the cell wall. These proteins are involved in maintaining cell wall structure, in cell wall synthesis, and in cell division, and appear to possess transpeptidase and carboxypeptidase activity.
Bacterial surface enzymes called autolysins also appear to be involved in the lethal effect of penicillins particularly for gram-positive bacteria. In gramnegative bacilli, osmotic rupture of cells may occur once the cell wall is weakened. Phenoxymethylpenicillin can also produce morphological changes in vitro including the formation of long filaments or abnormally shaped cells. Bacteria that are not growing and dividing are generally not killed by phenoxymethylpenicillin.
Its action is inhibited by penicillinase and other beta-lactamases that are produced during the growth of certain micro-organisms. The sensitivity of bacteria to phenoxymethylpenicillin varies widely, even among the general that are normally susceptible, especially as the incidence of beta-lactamase-producing organisms is increasing.
5.2 Pharmacokinetic properties
Following oral administration, phenoxymethylpenicillin potassium is more resistant to the action of gastric acid and is better absorbed than benzylpenicillin. The absorption is rapid and approximately 60% of the oral dose is absorbed.
Peak serum concentrations of 3-6 microgram per ml have been attained following a dose of 250-500 mg. The effect of food on absorption appears to be slight and variable. The plasma half-life is about 30 minutes and can be increased up to 4 hours in renal failure. Approximately 80% of the drug is bound to protein. It is widely distributed at varying concentrations in body tissues and fluids. It appears in pleural, pericardial, peritoneal and synovial fluids but diffusion is only to a small extent into abscess cavities, avascular areas, the eye, the middle ear and the CSF.
It is metabolised in the liver; several metabolites have been identified including penicilloic acid. The unchanged drug and metabolites are eliminated rapidly in the urine. Minute concentrations are excreted in the bile.
5.3 Preclinical safety data
Not applicable
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Ingredient
Maize Starch BP Lactose BP
Pregelatinised Maize Starch BP Potable Water HSE Magnesium Stearate BP
6.2 Incompatibilities
None reported
6.3 Shelf life
24 Months
6.4 Special precautions for storage
Keep out of the reach of children. Protect from heat, light and moisture.
6.5 Nature and contents of container
1) Opaque plastic containers (securitainers) fitted with snap-on plastic closures in pack sizes of 9, 10, 14, 15, 20, 21, 28, 30, 50, 56, 84, 100, 250, 500 and 1000 tablets.
2) Opaque plastic containers composed of either high density polypropylene or high density polyethylene with a tamper evident or child resistant tamper evident closure composed of high density polyethylene with a packing inclusion of standard polyether foam or polyethylene-or polypropylene-made filler in pack sizes of 9, 10, 14, 15, 20, 21, 28, 30, 50, 56, 84,100, 250, 500 and 1000 tablets.
3) Blister packs of aluminium opaque PVC in pack sizes of 9, 10, 14, 15, 20, 21, 28, 30, 56, 84 and 500 tablets.
6.6 Special precautions for disposal
No special instructions for use/handling
7 MARKETING AUTHORISATION HOLDER
Crescent Pharma Limited
Units 3 and 4, Quidhampton Business Units
Polhampton lane
Overton
Hampshire
RG25 3ED
8 MARKETING AUTHORISATION NUMBER
PL 20416/0126
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
01/11/2003 / 23/01/2009
10 DATE OF REVISION OF THE TEXT
10/07/2015