BNF for Children 2011-2012

454 9.1.5 G6PD deficiency BNFC 2011–20129 Nutrition and blood9.1.5 G6PD deficiencyGlucose 6-phosphate dehydrogenase (G6PD) deficiencyis highly prevalent in individuals originating from mostparts of Africa, from most parts of Asia, from Oceania,and from Southern Europe; it can also occur, rarely, inany other individuals. G6PD deficiency is more commonin males than it is in females.Individuals with G6PD deficiency are susceptible todeveloping acute haemolytic anaemia when they takea number of common drugs. They are also susceptibleto developing acute haemolytic anaemia when they eatfava beans (broad beans, Vicia faba); this is termedfavism and can be more severe in children or when thefresh fava beans are eaten raw.When prescribing drugs for children with G6PD deficiency,the following three points should be kept inmind:. G6PD deficiency is genetically heterogeneous; susceptibilityto the haemolytic risk from drugs varies;thus, a drug found to be safe in some G6PD-deficientindividuals may not be equally safe in others;. manufacturers do not routinely test drugs for theireffects in G6PD-deficient individuals;. the risk and severity of haemolysis is almost alwaysdose-related.The lists below should be read with these points in mind.Ideally, information about G6PD deficiency should beavailable before prescribing a drug listed below. However,in the absence of this information, the possibility ofhaemolysis should be considered, especially if the childbelongs to a group in which G6PD deficiency is common.A very few G6PD-deficient individuals with chronic nonspherocytichaemolytic anaemia have haemolysis evenin the absence of an exogenous trigger. These childrenmust be regarded as being at high risk of severe exacerbationof haemolysis following administration of any ofthe drugs listed below.Drugs with definite risk of haemolysis in mostG6PD-deficient individualsDapsone and other sulfones (higher doses fordermatitis herpetiformis more likely to cause problems)Methylthioninium chlorideNiridazole [not on UK market]NitrofurantoinPamaquin [not on UK market]Primaquine (30 mg weekly for 8 weeks has beenfound to be without undue harmful effects in Africanand Asian people, see section 5.4.1)Quinolones (including ciprofloxacin, moxifloxacin,nalidixic acid, norfloxacin, and ofloxacin)RasburicaseSulfonamides (including co-trimoxazole; some sulfonamides,e.g. sulfadiazine, have been tested andfound not to be haemolytic in many G6PD-deficientindividuals)Drugs with possible risk of haemolysis insome G6PD-deficient individualsAspirin (acceptable up to a dose of at least 1 g dailyin most G6PD-deficient individuals)Chloroquine (acceptable in acute malaria and malariachemoprophylaxis)Menadione, water-soluble derivatives (e.g.menadiol sodium phosphate)Probenecid [not on UK market]Quinidine (acceptable in acute malaria) [not on UKmarket]Quinine (acceptable in acute malaria)Note Naphthalene in mothballs also causes haemolysis inindividuals with G6PD-deficiency.9.1.6 Drugs used inneutropeniaRecombinant human granulocyte-colony stimulatingfactor (rhG-CSF) stimulates the production of neutrophilsand may reduce the duration of chemotherapyinducedneutropenia and thereby reduce the incidenceof associated sepsis; there is as yet no evidence that itimproves overall survival. Filgrastim (unglycosylatedrhG-CSF) and lenograstim (glycosylated rhG-CSF)have similar effects; both have been used in a varietyof clinical settings, including cytotoxic-induced neutropenia,and neutropenia following bone marrow transplantation,but they do not have any clear-cut routineindications. In congenital neutropenia filgrastim usuallyincreases the neutrophil count with an appropriateclinical response. Prolonged use may be associatedwith an increased risk of myeloid malignancy.Treatment with granulocyte-colony stimulating factorsshould only be prescribed by those experienced in theiruse.Neonatal neutropenia Filgrastim has been used totreat sepsis-induced neutropenia in preterm neonates.There is no clear evidence that granulocyte-colonystimulating factors improve survival or long-term outcomes.Cautions Granulocyte-colony stimulating factorsshould be used with caution in patients with pre-malignantor malignant myeloid conditions. Full blood counts(including differential white cell count and plateletcount) should be monitored. Treatment should be withdrawnin patients who develop signs of pulmonaryinfiltration. There have been reports of pulmonary infiltratesleading to acute respiratory distress syndrome—patients with a history of pulmonary infiltrates or pneumoniamay be at higher risk. Granulocyte-colony stimulatingfactors should be used with caution in childrenwith sickle-cell disease. Spleen size should be monitoredduring treatment as there is a risk of splenomegaly andrupture.