BNF for Children 2011-2012

412 7.4.3 Drugs used in urological pain BNFC 2011–20127 Obstetrics, gynaecology, and urinary-tract disorders1 hour before taking desmopressin until 8 hours after.When stopping treatment with desmopressin, gradualwithdrawal should be considered.Nocturnal enuresis associated with daytime symptoms(overactive bladder) can be managed with antimuscarinicdrugs (see Urinary incontinence, p. 410) incombination with desmopressin. Treatment should beprescribed only after specialist assessment and shouldbe continued for 3 months; the course can be repeated ifnecessary.The tricyclic antidepressant imipramine (section 4.3.1)may be considered for children who have not respondedto all other treatments and have undergone specialistassessment, however, behavioural disturbances canoccur and relapse is common after withdrawal. Treatmentshould not normally exceed 3 months unless aphysical examination is made and the child is fullyreassessed; toxicity following overdosage with tricyclicsis of particular concern.7.4.3 Drugs used in urologicalpainLidocaine gel is a useful topical application in urethralpain or to relieve the discomfort of catheterisation(section 15.2).Alkalinisation of urineAlkalinisation of urine can be undertaken with potassiumcitrate. The alkalinising action may relieve thediscomfort of cystitis caused by lower urinary tractinfections.POTASSIUM CITRATECautions cardiac disease; interactions: Appendix 1(potassium salts)Renal impairment close monitoring required—highrisk of hyperkalaemia; avoid in severe impairmentSide-effects hyperkalaemia on prolonged highdosage, mild diuresisIndication and doseRelief of discomfort in mild urinary-tract infections,alkalinisation of urine for dose see preparationsbelowPotassium Citrate Mixture BP(Potassium Citrate Oral Solution)Oral solution, potassium citrate 30%, citric acidmonohydrate 5% in a suitable vehicle with a lemonflavour. Extemporaneous preparations should berecently prepared according to the following formula:potassium citrate 3 g, citric acid monohydrate 500 mg,syrup 2.5 mL, quillaia tincture 0.1 mL, lemon spirit0.05 mL, double-strength chloroform water 3 mL,water to 10 mL. Contains about 28 mmol K + /10 mL.Label: 27Dose. By mouthChild 1–6 years 5 mL 3 times daily well diluted withwaterChild 6–18 years 10 mL 3 times daily well diluted withwaterNote Proprietary brands of potassium citrate are on sale tothe public for the relief of discomfort in mild urinary-tractinfections7.4.4 Bladder instillations andurological surgeryBladder infection Various solutions are available asirrigations or washouts.Aqueous chlorhexidine (section 13.11.2) can be used inthe management of common infections of the bladderbut it is ineffective against most Pseudomonas spp.Solutions containing chlorhexidine 1 in 5000 (0.02%)are used, but they may irritate the mucosa and causeburning and haematuria (in which case they should bediscontinued); sterile sodium chloride solution 0.9%(physiological saline) is usually adequate and is preferredas a mechanical irrigant.Dissolution of blood clots Clot retention is usuallytreated by irrigation with sterile sodium chloride solution0.9% but sterile sodium citrate solution forbladder irrigation 3% may also be helpful.Maintenance of indwelling urinarycathetersThe deposition which occurs in catheterised patients isusually chiefly composed of phosphate and to minimisethis the catheter (if latex) should be changed at least asoften as every 6 weeks. If the catheter is to be left forlonger periods a silicone catheter should be usedtogether with the appropriate use of catheter maintenancesolutions. Repeated blockage usually indicatesthat the catheter needs to be changed.CATHETER PATENCY SOLUTIONSChlorhexidine 0.02%Brands include Uro-Tainer Chlorhexidine c , 100-mLsachet = £2.60Sodium chloride 0.9%Brands include OptiFlo S c , 50- and 100-mL sachets =£3.20; Uriflex S c , 100-mL sachet = £2.40; UriflexSP c , with integral drug additive port, 100-mL sachet= £2.40; Uro-Tainer Sodium Chloride c , 50- and 100-mL sachets = £3.25; Uro-Tainer M c , with integraldrug additive port, 50- and 100-mL sachets = £2.90Solution GCitric acid 3.23%, magnesium oxide 0.38%, sodiumbicarbonate 0.7%, disodium edetate 0.01%. Brandsinclude OptiFlo G c , 50- and 100-mL sachets = £3.40;Uriflex G c , 100-mL sachet = £2.40; Uro-Tainer cTwin Suby G, 2 30-mL = £4.46Solution RCitric acid 6%, gluconolactone 0.6%, magnesiumcarbonate 2.8%, disodium edetate 0.01%. Brandsinclude OptiFlo R c , 50- and 100-mL sachets = £3.40;Uriflex R c , 100-mL sachet = £2.40; Uro-Tainer cTwin Solutio R, 2 30-mL = £4.46