Andrea L Gordon

University of Adelaide, Adelaide, South Australia, Australia

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Publications (3)7.89 Total impact

  • Article: Patterns of symptom reporting during pregnancy comparing opioid maintained and control women.
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    ABSTRACT: : To characterize the range of symptoms experienced by pregnant methadone-maintained (MM) and buprenorphine-maintained (BM) women to determine whether these differ from those experienced by a control group of nonopioid exposed pregnant women. Opioid-maintained (OM) patients report high rates of symptoms related to direct opioid effects and withdrawal. Pregnancy is associated with a range of symptoms, some overlapping with opioid effects and withdrawal. : Prospective, nonrandomized, open-label comparison study undertaken in a large teaching maternity hospital in South Australia. Pregnant BM (n = 25), MM (n = 25) and nonopioid exposed controls (n = 25) were recruited and matched for age, parity, gravidity, alcohol consumption, and smoking status. Symptom report patterns, maternal withdrawal, and additional substance use were assessed. : MM women reported 10 and BM women reported 2 symptoms throughout pregnancy at rates greater than controls. Methadone-maintained women reported significantly (P < 0.05) more symptoms than BM women compared to controls throughout pregnancy. Methadone-maintained women reported 8 and BM women reported 3 symptoms in the third trimester at rates greater than controls. Methadone-maintained women reported greater opioid withdrawal than controls; this did not occur in BM women. Additional substance use was comparable between BM and MM women but greater than controls. : Patterns of symptom reports may have clinical implications for maternal and fetal health during pregnancy for OM women including optimization of opioid dosing regimens, education regarding maternal nutritional intake and preventing postnatal depression, thereby ensuring maternal health and fetal development during pregnancy and enhancing mother-infant bonding and healthy child development postnatally.
    Journal of Addiction Medicine 12/2012; 6(4):258-64. · 1.95 Impact Factor
  • Article: (R)- and (S)-methadone and buprenorphine concentration ratios in maternal and umbilical cord plasma following chronic maintenance dosing in pregnancy.
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    ABSTRACT: The aim of this study was to compare the transfer of buprenorphine and methadone between maternal and cord blood in women under chronic dosing conditions and to determine if differences exist in the transfer of the two methadone enantiomers. Maternal and cord blood samples were collected at delivery from women maintained on methadone (35, 25-140 mg day⁻¹) (median; range) or buprenorphine (6.00, 2-20 mg day⁻¹) during pregnancy. Plasma concentration ratios are presented as an indicator of foetal exposure relative to the mother. Methadone was quantified in all samples, with cord : maternal plasma methadone concentration ratios (n= 15 mother-infant pairs) being significantly higher (P < 0.0001; mean difference (MD) 0.07; 95% confidence interval (CI) 0.048, 0.092) for the active (R)-methadone enantiomer (0.41; 0.19, 0.56) (median; range) compared with (S)-methadone (0.36; 0.15, 0.53). (R)- : (S)-methadone concentration ratios were also significantly higher (P < 0.0001; MD 0.24 95% CI 0.300, 0.180) for cord (1.40; 0.95, 1.67) compared with maternal plasma (1.16; 0.81, 1.38). Half the infant buprenorphine samples were below the assay lower limit of quantification (LLOQ) (0.125 ng ml⁻¹). The latter was four-fold lower than the LLOQ for methadone (0.50 ng ml⁻¹). The cord : maternal plasma buprenorphine concentration ratio (n= 9 mother-infant pairs) was 0.35; 0.14, 0.47 and for norbuprenorphine 0.49; 0.24, 0.91. The transfer of the individual methadone enantiomers to the foetal circulation is stereoselective. Infants born to buprenorphine maintained women are not exposed to a greater proportion of the maternal dose compared with methadone and may be exposed to relatively less of the maternal dose compared with infants born to women maintained on methadone during pregnancy.
    British Journal of Clinical Pharmacology 12/2010; 70(6):895-902. · 2.96 Impact Factor
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    Article: The effects of prenatal exposure to buprenorphine or methadone on infant visual evoked potentials.
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    ABSTRACT: This study compared the neurological development of 4 month old infants exposed to buprenorphine or methadone during pregnancy to that of a control group of non-exposed infants. Participants were 30 buprenorphine-maintained women, 22 methadone-maintained women and 33 non opioid-dependent controls, and their infants. Women were enrolled during pregnancy as part of an open-label non-randomised flexible-dosing longitudinal study. Groups were matched for maternal age, parity, gravida, and tobacco and alcohol use. Infant neurological development was assessed by measuring latency of pattern reversal visual evoked potentials (VEP). One-way between groups analyses of variance (ANOVA) were conducted to test the statistical significance of differences between the mean latencies of the peak response to two different sized checkerboard patterns (48' and 69' of retinal arc). Infants prenatally exposed to methadone had significantly prolonged latencies, compared with infants in the control group and infants prenatally exposed to buprenorphine, in response to checks of 48' and 69'. VEP latencies of infants prenatally exposed to buprenorphine did not differ significantly from controls for either check size. After adjustment for covariates, prenatal exposure to methadone remained a significant predictor of VEP response to checks of 48', but not 69'. Maternal self-reported used of marijuana during pregnancy made a significant unique contribution to the variance in P1 latencies for both check sizes. Data from this controlled, non-randomised study suggest that buprenorphine may confer an advantage over methadone as a maintenance drug during pregnancy in terms of infant neural development at 4 months of age.
    Neurotoxicology and Teratology 09/2009; 32(2):280-8. · 2.98 Impact Factor