Etherified Starches ⊗ Blood Coagulation: a Comparative Review
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Etamsylate/Etherified Starches 1065 that etamsylate produced about a 10 to 15% reduction in men- Description. Etherified starches are starches that are composed 4. De Labarthe A, et al. Acute renal failure secondary to hydrox- strual blood loss.3 Etamsylate is now considered to be less effec- of more than 90% of amylopectin and that have been etherified yethylstarch administration in a surgical patient. Am J Med 2001; tive than other treatments for menorrhagia, and is no longer rec- to varying extents. 111: 417–18. 4 5. Boldt J. Hydroxyethylstarch as a risk factor for acute renal fail- ommended. •hetastarch (BAN, USAN): an average of 7 to 8 of the hydroxy ure: is a change of clinical practice indicated? Drug Safety 2002; 1. Chamberlain G, et al. A comparative study of ethamsylate and groups in each 10 D-glucopyranose units of starch polymer 25: 837–46. mefenamic acid in dysfunctional uterine bleeding. Br J Obstet have been converted into OCH2CH2OH groups Effects on the skin. Pruritus has been reported after infusion of Gynaecol 1991; 98: 707–11. 1 • pentastarch (BAN, USAN): an average of 4 to 5 of the hydroxy etherified starches. It appears to be associated with tissue depo- 2. Bonnar J, Sheppard BL. Treatment of menorrhagia during men- sition of the starch although the actual mechanism by which this struation: randomised controlled trial of ethamsylate, mefenamic groups in each 10 D-glucopyranose units of the starch polymer provokes pruritus is unresolved. The effect appears to be dose- acid, and tranexamic acid. BMJ 1996; 313: 579–82. have been converted to OCH2CH2OH groups 3. Coulter A, et al. Treating menorrhagia in primary care: an over- related, which may explain the differences in reported incidences Etherified starches also vary in terms of average molecular that have ranged from less than 10% to more than 60% of pa- view of drug trials and a survey of prescribing practice. Int J weight and the position of etherification within the glucopyran- Technol Assess Health Care 1995; 11: 456–71. tients being affected. The molecular weight and degree of substi- ose unit. 4. National Collaborating Centre for Women’s and Children’s tution of the etherified starch do not appear to be risk factors. The Health/NICE. Heavy menstrual bleeding (issued January 2007). Incompatibility. Hetastarch is incompatible with many com- pruritus is usually generalised, but there are reports of localised Available at: http://www.nice.org.uk/nicemedia/pdf/ pounds including a number of injectable antibacterials. pruritus affecting the trunk, extremities, anogenital area, and CG44FullGuideline.pdf (accessed 06/03/08) head and neck. It is frequently severe, persistent, and refractory References. to treatment, causing sleep disturbances and adversely affecting Neonatal intraventricular haemorrhage. Etamsylate is 1. Wohlford JG, Fowler MD. Visual compatibility of hetastarch quality of life. Attacks of pruritus may be precipitated by heat, one of several drugs that have been tried in the prevention of in- with injectable critical-care drugs. Am J Hosp Pharm 1989; 46: sweating, exercise, bathing, mechanical pressure, and mental traventricular haemorrhage in very low birth-weight infants 995–6. stress. It typically has a delayed onset of 1 to 6 weeks after expo- (p.1050). In a multicentre, placebo-controlled, double-blind 2. Wohlford JG, et al. More information on the visual compatibility sure to the etherified starch. Average durations of 9 to 15 weeks study,1 etamsylate was given in an initial dose of 12.5 mg/kg in- of hetastarch with injectable critical-care drugs. Am J Hosp Pharm 1990; 47: 297–8. have been reported, but in some cases pruritus has continued for travenously or intramuscularly within 1 hour of delivery, fol- up to 2 years. The condition is generally unresponsive to treat- lowed by the same dose intravenously every 6 hours for 4 days ment, although there have been reports of relief with topical cap- to a total dose of 200 mg/kg. Of 330 infants who had had no ev- Adverse Effects and Precautions saicin, ultraviolet therapy, or oral naltrexone. idence of haemorrhage soon after delivery, the subsequent inci- Hypersensitivity reactions including anaphylactic re- dence of haemorrhage in the 162 who received etamsylate was Marked and persistent periocular swelling developed in a patient actions have occurred after infusion of etherified after 15 daily infusions of hetastarch.2 reduced, particularly the more extensive grades when compared Abnormal accumulation of hetastarch was found in the periocular tissues. with the 168 who received placebo. Of a further 30 infants with starches. Pruritus can occur after long-term use of high evidence of periventricular haemorrhage before treatment, 21 doses of etherified starches; the onset may be delayed 1. Bork K. Pruritus precipitated by hydroxyethyl starch: a review. Br J Dermatol 2005; 152: 3–12. were given etamsylate and 9 placebo; treatment with etamsylate until weeks after the last infusion. Serum-amylase con- 2. Kiehl P, et al. Decreased activity of acid α-glucosidase in a pa- limited the extension of bleeding. There was also a reduction in centrations may appear to increase during infusion of tient with persistent periocular swelling after infusions of hy- patent ductus arteriosus in the treated infants. However, a subse- droxyethyl starch. Br J Dermatol 1998; 138: 672–77. 2 etherified starches due to formation of an enzyme-sub- quent study using the same dosage regimen, showed little bene- strate complex that is only eliminated slowly. fit on short-term follow-up. It was considered that the study size Pharmacokinetics may have been too small and the drug given too late; the initial Precautions that should be observed with plasma ex- Etherified starches consist of mixtures of molecules dose was given within 4 hours of birth whereas, in the previous panders are described under Dextran 70, p.1060, and study, treatment was started within 1 hour of birth. Follow-up3 of with a range of molecular weights and with varying de- these infants at 2 years of age found that etamsylate had not re- these should be considered when etherified starches grees of etherification. After intravenous infusion the duced the risk of death, impairment, or disability. Developmental are used. There may be some interference with blood molecules with a molecular weight of less than 50 000 outcome assessments at about 4 years of age in patients from the grouping and cross-matching of blood. are readily excreted unchanged by the kidney; larger first study4 also found that despite the original reduction in intra- molecules are metabolised and eliminated more slow- ventricular haemorrhage with etamsylate, it had not reduced cer- ◊ Reviews. ebral palsy compared with the control group. 1. Wiedermann CJ. Hydroxyethyl starch - can the safety problems ly. The rate of metabolism depends upon the size of the be ignored? Wien Klin Wochenschr 2004; 116: 583–94. molecule and the degree and position of etherification, 1. Benson JWT, et al. Multicentre trial of ethamsylate for preven- tion of periventricular haemorrhage in very low birthweight in- Effects on the blood. Use of plasma expanders causes dilution with a high molecular weight, high degree of etherifi- fants. Lancet 1986; ii: 1297–1300. of clotting factors and may also have direct effects on coagula- cation, and etherification predominantly at the C2 po- 2. The EC Ethamsylate Trial Group. The EC randomised controlled tion. Effects of etherified starches on the coagulation system sition leading to a slower rate of metabolism and hence trial of prophylactic ethamsylate for very preterm neonates: early include1,2 a decrease in clotting factor VIII and von Willebrand a longer duration of action. About 33% of a dose of mortality and morbidity. Arch Dis Child 1994; 70: F201–F205. factor that results in an acquired type I von Willebrand disease 3. Elbourne D, et al. Randomised controlled trial of prophylactic (see p.1051), a prolongation of the activated partial thromboplas- high-molecular-weight hetastarch (weight average etamsylate: follow up at 2 years of age. Arch Dis Child Fetal tin time, and a reduction in platelet volume. The extent of these molecular weight 450 000) and about 70% of a dose of Neonatal Ed 2001; 84: F183–F187. effects appears to depend on the molecular weight and the rate of medium-molecular-weight pentastarch (weight aver- 4. Schulte J, et al. Developmental outcome of the use of etamsylate degradation in vivo of the starch. Etherified starches of high mo- for prevention of periventricular haemorrhage in a randomised age molecular weight 250 000) is excreted in the urine controlled trial. Arch Dis Child Fetal Neonatal Ed 2005; 90: lecular weight that are more slowly degraded (due to a high de- in 24 hours. Etherified starches may be distributed to F31–F35. gree of substitution or a high ratio of hydroxyethylation at the C2:C6 positions) have a greater effect on blood coagulation than various tissues; a small proportion of the dose may per- Preparations medium and low molecular weight, easily degraded, etherified sist in the body for several years. starches. Coagulopathy and haemorrhage have been reported (details are given in Part 3) ◊ References. Proprietary Preparations with the use of solutions of etherified starches.1,3 Serious compli- Arg.: Impedil; Belg.: Dicynone; Braz.: Dicinone; Chile: Om-Dicynone†; cations such as intracranial bleeding and cerebral oedema have 1. Mishler JM, et al. Changes in the molecular composition of cir- Cz.: Dicynone; Fr.: Dicynone; Hung.: Dicynone; India: Alstat; Ethacid; culating hydroxyethyl starch following consecutive daily infu- Ethamcip; Ethasyl; Hemsyl; Revici-E; Indon.: Dicynone; Irl.: Dicynene; Ital.: been reported in studies of patients with ischaemic stroke and sions in man. Br J Clin Pharmacol 1979; 7: 505–9. Dicynone; Eselin; Mex.: Dicynone; Rus.: Dicynone (Дицинон); Singa- other brain injuries who have been treated with etherified starch- 2.