Trimethoprim Tablets 100mg
Product Summary
1. Trade Name of the Medicinal Product Trimethoprim Tablets 100 mg.
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains 100 mg of trimethoprim. For the full list of excipients, see section 6.1
3 PHARMACEUTICAL FORM
Tablet
White, normal biconvex tablets, engraved Berk 2H7 or 2H7 with a breakline on reverse.
The breakline is only to facilitate breaking for ease of swallowing and not to divide into equal doses. Clinical Particulars
4.1. Therapeutic Indications
Trimethoprim is indicated for the treatment of susceptible infections caused by trimethoprim -sensitive organisms including urinary tract and respiratory tract infections.
Trimethoprim is also indicated for the prevention of recurrent urinary tract infections.
4.2 Posology and method of administration
For oral administration
Acute infections:
Adults and children over 12 years of age: 200 mg twice daily Children 6years to 12 years: 100 mg twice daily
Children under 6 years of age: This dosage form is not suitable for use in children younger than 6 years; a more suitable dosage form (such as a suspension) should be used in this age group.
Elderly: Depending on kidney function, see special dosage schedule.
Treatment should continue for at least one week but not last longer than two weeks. The first dose can be doubled.
Long-term treatment and prophylactic therapy:
Adults and children over 12 years: 100 mg at night
Children under 12 years of age: This dosage form is not suitable for use in children younger than 12 years; a more suitable dosage form (such as a suspension) should be used in this age group.
Elderly: Depending on kidney function, see special dosage schedule.
Dosage advised where there is reduced kidney function:
|
Creatinine clearance ml/sec |
Plasma creatinine micromol/1 |
Dosage advised |
|
Over 0.45 |
Men<250 Women <175 |
Normal |
|
0.25-0.45 |
Men 250-600 Women 175-400 |
Normal for 3 days then half dose. |
|
Under 0.25 |
Men > 600 Women > 400 |
Half the normal dose. |
Trimethoprim is removed by dialysis. It should not, however, be administered to dialysis patients unless plasma concentrations can be estimated regularly.
4.3 Contraindications
Trimethoprim is contra-indicated in pregnancy, hypersensitivity to trimethoprim or to any of the excipients listed in section 6.1, blood dyscrasias, severe hepatic insufficiency and also in severe renal insufficiency, unless blood trimethoprim concentrations can be monitored regularly.
4.4 Special warnings and precautions for use
In patients with marked impairment of renal function, care should be taken to avoid accumulation and resulting adverse haematological effects.
Caution should be exercised in the administration of trimethoprim to patients with actual or potential folate deficiency (e.g. the elderly). Administration of a folate supplement should be considered. Although an effect on folic acid metabolism is possible, interference with haematopoiesis rarely occurs at the recommended dose. If any such change occurs, folinic acid should reverse the effect. Elderly people may be more susceptible and a lower dose may be advisable.
Regular haematological tests should be undertaken in patients receiving long term treatment and those predisposed to folate deficiency. Particular care should be exercised in the haematological monitoring of children on long term therapy. The usual caution in prescribing any drug for women of child bearing age should be exercised with trimethoprim.
Trimethoprim should be used under careful medical supervision in neonates.
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
Anti-arrhythmics: Trimethoprim increases plasma concentrations of procainamide.
Antimalarials: Increased antifolate effect when trimethoprim is given with pyrimethamine.
Cytotoxics: Increased risk of haematological toxicity when trimethoprim is given with azathioprine or mercaptopurine. Trimethoprim increases the antifolate effect of methotrexate therefore use should be avoided
Rifampicin may increase the elimination and shorten the elimination half-life of trimethoprim. With bone marrow depressants, trimethoprim may increase the potential for bone marrow aplasia.
Digoxin and phenytoin: Trimethoprim may increase the elimination half-life of phenytoin and digoxin therefore patients should be carefully controlled.
Ciclosporin may increase the nephrotoxicity of trimethoprim.
Trimethoprim may potentiate the anticoagulant effect of warfarin.
4.6 Fertility, pregnancy and lactation
Pregnancy
Trimethoprim is contra-indicated in pregnant women.
Breast-feeding
Trimethoprim is excreted in breast milk but is not contra-indicated for short term use in lactating mothers.
4.7. Effects on Ability to Drive and Use Machines
None known.
4.8 Undesirable effects
The frequencies of adverse events are ranked according to the following: very common
(> 1/10), common (> 1/100 to < 1/10), uncommon (> 1/1,000 to < 1/100), rare (> 1/10,000 to
< 1/1,000), very rare (< 1/10,000), not known (cannot be estimated from the available data).
The most frequent adverse effects at usual doses are pruritus and skin rash (in about 3 to 7% of patients) and mild, gastrointestinal disturbances including nausea, vomiting and glossitis. These effects are generally mild and quickly reversible on withdrawal of the drug.
Infections and infestations Aseptic meningitis has been reported.
Blood and lymphatic system disorders
Isolated cases of megaloblastic anaemia during prolonged therapy with trimethoprim, with higher doses than those recommended, have been reported. These effects are reversible with discontinuation of therapy and administration of calcium folinate.
Leucopenia, thrombocytopenia, agranulocyctosis, methaemoglobinaemia
Trimethoprim may affect haematopoiesis.
Immune system disorders
Rare: Anaphylactic reactions, anaphylactoid reactions have been reported.
Metabolism and nutrition disorders
Hyperkalaemia (particularly in the elderly and in HIV patients)
Nervous system disorders Rare: Headache Gastrointestinal disorders Glossitis, sore mouth
Rare: Nausea, vomiting, gastrointestinal disturbances Hepatobiliary disorders
Disturbances in liver enzyme values, cholestatic jaundice Renal and Urinary disorders
Raised serum creatinine and blood urea nitrogen levels. It is not known however, whether this represents inhibition of creatinine tubular secretion or genuine renal dysfunction
Skin and subcutaneous tissue disorders
Pruritus, skin rashes, exfoliative dermatitis, urticaria
Rare: More severe skin sensitivity or allergic reactions such as photosensitivity, angioedema, erythema multiforme, Stevens-Johnson Syndrome and toxic epidermal necrolysis
Musculoskeletal system disorders
Myalgia
General disorders and administration site conditions
Drug fever
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
Symptomatic treatment, gastric lavage and forced diuresis can be used. Depression of haematopoiesis by trimethoprim can be counteracted by intramuscular administration of calcium folinate.
Pharmacological Properties
5.1. Pharmacodynamic Properties
ATC code: J01EA01 Sulfonamides And Trimethoprim (Trimethoprim and derivatives)
Trimethoprim inhibits dihydrofolate reductase and thus prevents the synthesis of tetrahydrofolic acid from dihydrofolic acid. It therefore affects the nucleoprotein metabolism of microorganisms.
5.2. Pharmacokinetic Properties
Trimethoprim is readily absorbed from the gastro-intestinal tract and peak concentrations in the circulation occur about 3 hours after a dose is taken. About 45% is bound to plasma proteins. Tissue concentrations are reported to be higher than serum concentrations with particularly high concentrations in the kidneys and lungs. Concentrations in the CSF are about half that of those in blood. The half life is about 10-16 hours. 40-50 % of the dose is excreted unchanged in the urine within 24 hours.
5.3. Preclinical Safety Data
Preclinical information has not been included because the safety profile of trimethoprim has been established after many years of clinical use. Please refer to section 4.
Pharmaceutical Particulars
6.1. List of Excipients
The tablet contains:
Lactose Monohydrate Maize Starch Microciystalline Cellulose Sodium Starch Glycollate (Type A) Polyvidone
Colloidal Anhydrous Silica Magnesium Stearate Stearic Acid
6.2. Incompatibilities
Not applicable.
Shelf Life
6.3.
Blisters: 24 months. Containers/buckets: 36 months.
6.4. Special Precautions for Storage
No special precautions.
6.5. Nature and Contents of Container
HDPE or polypropylene containers with caps or child resistant closures in packs of 28, 100 and 500 tablets.
Polythene container with lid in a pack of 5000 tablets.
Blister strips in packs of 7, 10, 14, 20, 21, 28, 30, 56, 60, 84, 90, 100, 110, 112, 120, 150, 160 and 168 tablets.
6.6. Instructions for Use/Handling Not applicabe.
Administration Data
7 MARKETING AUTHORISATION HOLDER
TEVA UK Limited
Brampton Road, Hampden Park
Eastbourne, East Sussex, BN22 9AG
8. Marketing Authorisation Numbers
PL 0289/0196
9 Date of the first authorisation or renewal
17/10/2005
10 DATE OF REVISION OF THE TEXT
29/04/2016