Phenobarbitone in cholestasis

Effect of Phenobarbital on Elevated Direct Bilirubin Concentrations in Neonates and Infants in the Neonatal Intensive Care Unit

OBJECTIVE

Few studies have evaluated the effect of phenobarbital (PB) on elevated direct bilirubin (DB) plasma concentrations in neonates and infants, and none have compared its effect with a control group with matched study baseline DB values. The purpose of this study was to quantify changes in elevated DB plasma concentrations (≥2 mg/dL) in neonates and infants between a PB-treated and control group.

METHODS

A retrospective, observational, matched, cohort study was performed comparing patients between a PB-treated group and a control group with similar study baseline plasma DB values ≥2 mg/dL over an 8-week period. The percent change in DB plasma concentrations from study baseline was compared for each week of the study period.

RESULTS

During the 8-year study period, 310 patients had DB plasma concentrations ≥2 mg/dL, of which 26 remained in each group after exclusions. The PB group had increased DB concentrations and the control group had decreased DB concentrations when compared with their study baseline DB concentrations each week of the study period. By study end, the mean DB concentration increased by 11.2% in the PB group and decreased by 48.5% in the control group (p = 0.02). In multiple regression analysis, only birth weight (standardized coefficient = 0.44, p = 0.02), and gastrointestinal obstruction (standardized coefficient = −0.4, p = 0.03) were associated with significant percent change in DB concentrations.

CONCLUSIONS

This study demonstrated PB does not improve cholestasis in neonates and infants.

Pharmacological interventions for treating intrahepatic cholestasis of pregnancy

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder that can develop in pregnancy. It occurs when there is a build-up of bile acids in the maternal blood. It has been linked to adverse maternal and fetal/neonatal outcomes. As the pathophysiology is poorly understood, therapies have been largely empiric. As ICP is an uncommon condition (incidence less than 2% a year), many trials have been small. Synthesis, including recent larger trials, will provide more evidence to guide clinical practice. This review is an update of a review first published in 2001 and last updated in 2013.

OBJECTIVES

To assess the effects of pharmacological interventions to treat women with intrahepatic cholestasis of pregnancy, on maternal, fetal and neonatal outcomes.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (13 December 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials, including cluster-randomised trials and trials published in abstract form only, that compared any drug with placebo or no treatment, or two drug intervention strategies, for women with a clinical diagnosis of intrahepatic cholestasis of pregnancy.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed trials for eligibility and risks of bias. We independently extracted data and checked these for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 26 trials involving 2007 women. They were mostly at unclear to high risk of bias. They assessed nine different pharmacological interventions, resulting in 14 different comparisons. We judged two placebo-controlled trials of ursodeoxycholic acid (UDCA) in 715 women to be at low risk of bias. The ten different pharmacological interventions were: agents believed to detoxify bile acids (UCDA) and S-adenosylmethionine (SAMe); agents used to bind bile acids in the intestine (activated charcoal, guar gum, cholestyramine); Chinese herbal medicines (yinchenghao decoction (YCHD), salvia, Yiganling and Danxioling pill (DXLP)), and agents aimed to reduce bile acid production (dexamethasone) Compared with placebo, UDCA probably results in a small improvement in pruritus score measured on a 100 mm visual analogue scale (VAS) (mean difference (MD) -7.64 points, 95% confidence interval (CI) -9.69 to -5.60 points; 2 trials, 715 women; GRADE moderate certainty), where a score of zero indicates no itch and a score of 100 indicates severe itching. The evidence for fetal distress and stillbirth were uncertain, due to serious limitations in study design and imprecision (risk ratio (RR) 0.70, 95% CI 0.35 to 1.40; 6 trials, 944 women; RR 0.33, 95% CI 0.08 to 1.37; 6 trials, 955 women; GRADE very low certainty). We found very few differences for the other comparisons included in this review. There is insufficient evidence to indicate if SAMe, guar gum, activated charcoal, dexamethasone, cholestyramine, Salvia, Yinchenghao decoction, Danxioling and Yiganling, or Yiganling alone or in combination are effective in treating women with intrahepatic cholestasis of pregnancy.

AUTHORS' CONCLUSIONS

When compared with placebo, UDCA administered to women with ICP probably shows a reduction in pruritus. However the size of the effect is small and for most pregnant women and clinicians, the reduction may fall below the minimum clinically worthwhile effect. The evidence was unclear for other adverse fetal outcomes, due to very low-certainty evidence. There is insufficient evidence to indicate that SAMe, guar gum, activated charcoal, dexamethasone, cholestyramine, YCHD, DXLP, Salvia, Yiganling alone or in combination are effective in treating women with cholestasis of pregnancy. There are no trials of the efficacy of topical emollients. Further high-quality trials of other interventions are needed in order to identify effective treatments for maternal itching and preventing adverse perinatal outcomes. It would also be helpful to identify those women who are mostly likely to respond to UDCA (for example, whether bile acid concentrations affect how women with ICP respond to treatment with UDCA).

Interventions for treating cholestasis in pregnancy

BACKGROUND

Obstetric cholestasis has been linked to adverse maternal and fetal/neonatal outcomes. As the pathophysiology is poorly understood, therapies have been empiric. The first version of this review, published in 2001, and including nine randomised controlled trials involving 227 women, concluded that there was insufficient evidence to recommend any of the interventions alone or in combination. This is the first update.

OBJECTIVES

To evaluate the effectiveness and safety of therapeutic and delivery interventions in women with cholestasis of pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 February 2013) and reference lists of identified studies.

SELECTION CRITERIA

Randomised controlled trials that compared two intervention strategies for women with a clinical diagnosis of obstetric cholestasis.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed trials for eligibility and risk of bias. We independently extracted data and checked these for accuracy.

MAIN RESULTS

We included 21 trials with a total of 1197 women. They were mostly at moderate to high risk of bias. They assessed 11 different interventions resulting in 15 different comparisons.Compared with placebo, ursodeoxycholic acid (UDCA) showed improvement in pruritus in five (228 women) out of seven trials. There were no significant differences in instances of fetal distress in the UDCA groups compared with placebo (average risk ratio (RR) 0.67; 95% confidence interval (CI) 0.22 to 2.02; five trials, 304 women; random-effects analysis: T² = 0.74; I² = 48%). There were significantly fewer total preterm births with UDCA (RR 0.46; 95% CI 0.28 to 0.73; two trials, 179 women). The difference for spontaneous preterm births was not significant (RR 0.99; 95% CI 0.41 to 2.36, two trials, 109 women).Two trials (48 women) reported lower (better) pruritus scores for S-adenosylmethionine (SAMe) compared with placebo, while two other trials of 34 women reported no significant differences between groups.UDCA was more effective in improving pruritus than either SAMe (four trials; 133 women) or cholestyramine (one trial; 84 women), as was combined UDCA+SAMe when compared with placebo (one trial; 16 women) and SAMe alone (two trials; 68 women). However, combined UDCA+SAMe was no more effective than UDCA alone in regard to pruritus improvement (one trial; 53 women) and two trials (80 women) reported data were insufficient to draw any conclusions from. In one trial comparing UDCA and dexamethasone (83 women), a significant improvement with UDCA was seen only in a subgroup of women with severe obstetric cholestasis (23 women).Danxiaoling significantly improved pruritus in comparison to Yiganling. No significant differences were seen in pruritus improvement with other interventions.Eight trials reported fetal or neonatal deaths, with two deaths reported overall (both in the placebo groups).Women receiving UDCA and cholestyramine experienced nausea, vomiting and diarrhoea. Guar gum caused mild abdominal distress, diarrhoea and flatulence during the first days of treatment. Women found charcoal suspension unpleasant to swallow. Dexamethasone caused nausea, dizziness and stomach pain in one woman.One trial (62 women) looked at the timing of delivery intervention. There were no stillbirths or neonatal deaths in 'early delivery' or the 'await spontaneous labour' group. There were no significant differences in the rates of caesarean section, meconium passage or admission to neonatal intensive care unit between the two groups.

AUTHORS' CONCLUSIONS

Different approaches to assessing and reporting pruritus precluded pooling of trials comparing the effects of UDCA versus placebo on pruritus, but examination of individual trials suggests that UDCA significantly improves pruritus, albeit by a small amount. Fewer instances of fetal distress/asphyxial events were seen in the UDCA groups when compared with placebo but the difference was not statistically significant. Large trials of UDCA to determine fetal benefits or risks are needed.A single trial was too small to rule in or out a clinically important effect of early term delivery on caesarean section.There is insufficient evidence to indicate that SAMe, guar gum, activated charcoal, dexamethasone, cholestyramine, Salvia, Yinchenghao decoction (YCHD), Danxioling and Yiganling, or Yiganling alone or in combination are effective in treating women with cholestasis of pregnancy.

Effects of postoperative cholestyramine and phenobarbital administration on bile flow restoration in infants with extrahepatic biliary atresia

Surgical restoration of bile flow in patients with extrahepatic biliary atresia (EHBA) results in the disappearance of clinical cholestasis in about 30% of cases. It is suggested that early postoperative administration of phenobarbital (PB) or cholestyramine (Ch) may improve this percentage. Eighty patients were randomly divided into three subgroups comprising 27 who were treated with Ch (4 g/d), 27 who were given PB (7.5 to 10 mg/kg/d) during the first 3 postoperative months and 26 untreated patients, who served as controls. Cholestasis was observed to disappear in 38 (group I) patients and to persist in 42 (group II) patients, as judged from their total blood bilirubin levels, the conjugated/total bilirubin ratio, measurements of cholesterol, bile acids and alkaline phosphatase, and of Rose Bengal fecal excretion. Neither Ch nor PB significantly improved the degree or duration of cholestasis in either group.

Successful long-term phenobarbital therapy of hyperbilirubinemia in congenital hemolytic anemia due to glucose phosphate isomerase deficiency

Long-term phenobarbital treatment (2 mg/kg body weight/day) permanently reduced hyperbilirubinemia in a patient with congenital non-spherocytic hemolytic anemia due to erythrocyte glucose phosphate isomerase deficiency. Phenobarbital treatment is recommended in patients with congenital hemolytic anemia in whom hyperbilirubinemia is not improved by splenectomy or in whom splenectomy is not indicated. Early phenobarbital treatment may prevent the development of cholelithiasis in patients with chronic hemolysis.

Efficacy and safety of long-term phenobarbital therapy of familial cholestasis

Two brothers with progressive familial intrahepatic cholestasis were followed during four years of phenobarbital therapy to assess its long-term safety and efficacy. Effects attributable to phenobarbital included sustained relief of pruritus, lowering of serum bilirubin levels, and enhanced hepatic excretion of 131I-rose bengal; serum bile acid levels were only transiently decreased. Two brief interruptions in therapy resulted in symptomatic deterioration. Phenobarbital did not retard growth nor impede the response to vitamin D therapy of concomitant rickets.