Metpen 125/250 125 mg and 250mg Powder for oral solution

METPEN is used prophylactically to prevent recurrence of rheumatic fever. It is also indicated in the treatment of:

• Mild to moderate infections caused by sensitive organisms,
• Pneumococcal infections of the middle ear,
• Streptococcal otitis media and sinusitis,
• Sore throat due to Group A haemolytic streptococci,
• Streptococcal pharyngitis caused by Streptococcus pyogenes.

Method of administration

METPEN is for oral administration. For instructions on reconstitution of the medicinal product before administration, see section 6.6.

• Hypersensitivity to the phenoxymethylpenicillins, cephalosporin or to any of the excipients listed in section 6.1.
• Use in dysentery and typhus, and other infections caused by penicillin resistant microbes such as Brucella and E.coli.
• For treatment of trivial disorders.

• Penicillin should be used with caution in individuals with histories of significant allergies and/or asthma. 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. Enquiries should be made for such a history before therapy is begun.
• If any allergic reaction occurs, the medicine 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 for patients with severe illness, or with nausea, vomiting, gastric dilation, achalasia 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 the usually recommended doses.
• Streptococcal infections should be treated for a minimum of 10 days, and post therapy 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 sure infection occurs, appropriate measures should be taken.
• This medicine contains sucrose: patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrose-isomaltase insufficiency should not take this medicine.

• Aminoglycosides: Neomycin is reported to reduce the absorption of phenoxymethylpenicillin.
• Anticoagulants: Penicillins may interfere with anticoagulant control.
• Bacteriostatic antibiotics: Certain bacteriostatic antibiotics such as Chloramphenicol, Erythromycin and Tetracyclines have been reported to antagonise the bactericidal activity of penicillins and concomitant use is not recommended.
• Guar gum: Reduced absorption of phenoxymethylpenicillin.
• Methotrexate: Use of Phenoxymethylpenicillin while taking methotrexate can cause reduced excretion of methotrexate thereby increasing the risk of toxicity.
• Probenecid: Reduced excretion of phenoxymethylpenicillin by competing with it for renal tubular secretion.
• Sulfinpyrazone: Excretion of penicillins reduced by sulfinpyrazone.
• Typhoid vaccine (oral): Penicillins may inactivate oral typhoid vaccine if ingested concomitantly.

Pregnancy

There are no or a limited amount of data from the use of Phenoxymethylpenicillin in pregnant women. As a precaution measure, it is preferable to avoid the use of Phenoxymethylpenicillin during pregnancy.

Breastfeeding

Phenoxymethylpenicillin metabolites are excreted in human milk to such an extent that effects on breastfed newborns are likely.

Fertility

No data available.

None known

a) Summary of the safety profile

The most common reactions to oral penicillin are gastrointestinal effects and hypersensitivity reactions. Although hypersensitivity reactions have been reported much less frequently after oral than after parenteral therapy, it should be remembered that all forms of hypersensitivity, including fatal anaphylaxis have been observed with oral penicillin.

b) Tabulated list of adverse reactions

The table below shows all adverse drug reactions (ADRs) observed during clinical trials and postmarket spontaneous reports with Phenoxymethylpenicillin potassium.

System Organ Class Frequency Frequent Less Frequent Not known Infections and infestations Pseudomembranous colitis.

Blood and lymphatic system disorders Changes in blood counts, including thrombocytopenia, neutropenia, leucopenia, eosinophilia and haemolytic anaemia. Coagulation disorders (including prolongation of bleeding time and defective platelet function).

Gastrointestinal disorders Nausea, vomiting, abdominal pain, diarrhoea. Sore mouth and black hairy tongue (discolouration of tongue).

Hepatobiliary disorders Hepatitis and cholestatic jaundice.

Cardiac disorders Kounis syndrome.

Immune disorders Allergic reactions (typically manifest as skin reactions) (See Skin and subcutaneous disorders). Severe allergic reactions causing angioedema, laryngeal oedema and anaphylaxis. Serum sickness-like reactions characterised by fever, chills, arthralgia and oedema.

Nervous system disorders Central nervous system toxicity including convulsions (especially with high doses or in severe renal impairment); paraesthesia may occur with prolonged use, Neuropathy (usually associated with high doses of parenteral penicillin).

Renal and urinary disorders Interstitial nephritis, nephropathy (usually associated with high doses of parenteral penicillin).

Skin and subcutaneous tissue disorders Urticarial, erythematous or morbilliform rash and pruritus. Exfoliative dermatitis. Linear IgA.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicine is important. It allows continued monitoring of the benefit/risk balance of the medicine. Health care providers are requested to report any suspected adverse drug reactions to SAHPRA via the Med Safety APP (Medsafety X SAHPRA) and eReporting platform (who-umc.org) found on SAHPRA website. Suspected adverse reactions can also be reported directly to the HCR via [email protected].

Signs and symptoms

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. Hyperkalaemia may result from overdosage, particularly for patients with renal insufficiency.

Treatment

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 haemodialyses.