Hiprex 1g Tablets
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Hiprex 1 g Tablets
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each Hiprex tablet contains methenamine hippurate 1 g.
For the full list of excipients, see 6.1.
3 PHARMACEUTICAL FORM
White, oblong tablet with breakline marked HX on one side and 3M on the other.
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
Hiprex is indicated in the prophylaxis and treatment of urinary tract infections:
As maintenance therapy after successful initial treatment of acute infections with antibiotics.
As long-term therapy in the prevention of recurrent cystitis.
To suppress urinary infection in patients with indwelling catheters and to reduce the incidence of catheter blockage.
To provide prophylaxis against the introduction of infection into the urinary tract during instrumental procedures.
Asymptomatic bacteriuria.
4.2 Posology and method of administration
Posology
Adults: 1g twice daily.
In patients with catheters the dosage may be increased to 1g three times daily.
Paediatric population :
Children under 6years: Not recommended.
Children: 6-12years: 500mg twice daily.
Older people :
No special dosage recommendations.
Method of administration
The tablets may be halved, or they can be crushed and taken with a drink of milk or fruit juice if the patient prefers.
4.3 Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
Hepatic dysfunction, renal parenchymal infection, severe dehydration, metabolic acidosis, severe renal failure (creatinine clearance or GFR<10 ml/min.) or gout. Hiprex may be used where mild (20-50 ml/min.) to moderate (10-20 ml/min.) renal insufficiency is present. (If the GFR is not available the serum creatinine concentration can be used as a guide.). Hiprex should not be administered concurrently with sulphonamides because of the possibility of crystalluria, or with alkalising agents, such as a mixture of potassium citrate.
4.4 Special warnings and precautions for use
None.
4.5
Interaction with other medicinal products and other forms of interaction
Methenamine hippurate should not be given/administered concurrently with sulphonamides because of the possibility of crytalluria, or with alkalising
agents such as potassium citrate. Concurrent use with acetazolamide should be avoided as the desired effect of hexamine will be lost.
4.6 Fertility, pregnancy and lactation
Pregnancy
There is inadequate evidence of safety of the drug in human pregnancy but it has been in wide use for many years without apparent ill consequence, animal studies having shown no hazard.
Breast-feeding
Methenamine is excreted in breast milk but the quantities will be insignificant to the infant. Mothers can therefore breast feed their infants.
4.7 Effects on ability to drive and use machines
None.
4.8 Undesirable effects
Adverse events are listed below by system organ class and frequency. Frequencies are defined as:
Very common (>1/l0)
Common (>1/100 and <1/10)
Uncommon (>1/1000 and <1/100)
Rare (> 1/10,000 and <1/1000)
Very rare (<1/10,000)
Not known (cannot be estimated from the available data).
Uncommon: rashes, pruritis, gastric irritation, irritation of the bladder All side effects are reversible on the withdrawal of the drug.
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
Vomiting and haematuria may occur. These can be treated by the use of an anti-emetic and drinking copious quantities of water respectively. Bladder symptoms can be treated by the consumption of copious quantities of water and 2-3 teaspoonfuls of bicarbonate of soda.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Pharmacotherapeutic group G04A A01
Hiprex is a urinary antibacterial agent with a wide antibacterial spectrum covering both gram-positive and gram-negative organisms. Urinary antibacterial activity can be shown within 30 minutes of administration.
The chemical structure of methenamine hippurate is such that a two-fold antibacterial action is obtained:
1. The slow release of the bactericidal formaldehyde, from the methenamine part, in the urine; acid pH is necessary for this reaction to occur. It is obtained and maintained there by the presence of hippuric acid.
2. The bacteriostatic effect of hippuric acid itself on urinary tract pathogens.
5.2 Pharmacokinetic properties
Methenamine hippurate is readily absorbed from the gastro-intestinal tract and excreted via the kidney.
Plasma concentrations of methenamine hippurate reach maximum 1-2 hours after a single dose and then decline with a half-life of about 4 hours. Methenamine recovered in the urine corresponds to about 80% of the dose given per 12 hours.
5.3 Preclinical safety data
Not applicable
PHARMACEUTICAL PARTICULARS
6
6.1 List of excipients
Magnesium Stearate Povidone
Colloidal anhydrous silica
6.2 Incompatibilities
Not applicable.
6.3 Shelf life
5 years
6.4 Special precautions for storage
Do not store above 30°C. Keep bottle tightly closed.
6.5 Nature and contents of container
Glass bottles of 60 tablets
6.6 Special precautions for disposal
No special requirements.
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
MARKETING AUTHORISATION HOLDER
Meda Pharmaceuticals Ltd Skyway House Parsonage Road Takeley
Bishop’s Stortford CM22 6PU UK
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MARKETING AUTHORISATION NUMBER(S)
PL 15142/0099
DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
13/09/2005
DATE OF REVISION OF THE TEXT
21/04/2015