Effect of acamprosate on neonatal excitotoxic cortical lesions in in utero alcohol-exposed hamsters

The Safety of Alcohol Pharmacotherapies in Pregnancy: A Scoping Review of Human and Animal Research

BACKGROUND AND OBJECTIVE

Alcohol pharmacotherapies pose unknown teratogenic risks in pregnancy and are therefore recommended to be avoided. This limits treatment options for pregnant individuals with alcohol use disorders (AUD). The information on the safety of these medications during pregnancy is uncertain, prompting a scoping review. The objective of this review was to investigate available information on the safety of alcohol pharmacotherapies in pregnancy.

METHODS

Studies published between January 1990 and July 2023 were identified through searches in BIOSIS, Embase, PsycINFO and MEDLINE databases, using terms related to pregnancy and alcohol pharmacotherapies. The alcohol pharmacotherapies investigated were naltrexone, acamprosate, disulfiram, nalmefene, baclofen, gabapentin and topiramate. Studies were screened by two independent reviewers. Covidence software facilitated the management, screening and extraction of studies.

RESULTS

A total of 105 studies were included in the review (naltrexone: 21, acamprosate: 4, disulfiram: 3, baclofen: 3, nalmefene: 0, topiramate: 55, gabapentin: 32) with some studies investigating multiple medications. Studies investigating naltrexone's safety in pregnancy focussed on opioid use disorders, with limited evidence regarding its safety in the context of AUD. Despite concerns about higher rates of some pregnancy complications, studies generally indicate naltrexone as a safer option compared with opioid agonists or alcohol during pregnancy. Acamprosate was not clearly associated with adverse effects of exposure in pregnancy, with two pre-clinical studies suggesting potential neuroprotective properties. Disulfiram has a high risk of congenital anomalies when used in pregnancy, believed to be due to its mechanism of action. Prenatal topiramate has also been associated with an increased risk of congenital anomalies, particularly oral clefts. There were mixed results concerning the safety of prenatal gabapentin and little to no literature investigating the safety of baclofen or nalmefene during pregnancy.

CONCLUSIONS

There is insufficient research on the safety of alcohol pharmacotherapies in pregnancy. Despite this, given alcohol's teratogenic effects, naltrexone could be considered to help maintain abstinence in pregnant individuals with AUD, particularly when psychosocial treatments have failed.

The effects of acamprosate on maternal and neonatal outcomes in a mouse model of alcohol use disorders

BACKGROUND

Despite the teratogenic effects of alcohol, little is known about the safety of pharmacotherapies such as acamprosate for the treatment of alcohol use disorders in pregnancy. The aims of this study were to investigate, in a mouse model, the effects of maternally administered acamprosate on maternal and neonatal health, offspring neurodevelopment and behaviour, as well as examine whether acamprosate reduces the neurological harm associated with alcohol consumption in pregnancy.

METHODS

Dams were randomly allocated to one of four treatment groups: (i) control (water), (ii) acamprosate (1.6 g/L), (iii) alcohol (5% v/v) or (iv) acamprosate and alcohol (1.6 g/L; 5% v/v ethanol) and exposed from 2-weeks pre-pregnancy until postpartum day 7. Gestational outcomes including litter size and sex ratio were assessed, in addition to early-life markers of neurodevelopment. At 8 weeks of age, motor coordination, anxiety, locomotion, and memory of the adult offspring were also examined.

RESULTS

Exposure to acamprosate did not affect maternal and birth outcomes (mating success, gestational weight gain, litter size, sex ratio), neonatal outcomes (head and body length, postnatal weight) or neurodevelopmental markers (righting reflex and negative geotaxis). Acamprosate exposure did not affect offspring motor control, locomotion or anxiety, however the effects on short-term memory remain uncertain. Prenatal alcohol exposed offspring exhibited various alterations, such as lower postnatal weight, smaller head (p = 0.04) and body lengths (p = 0.046) at postnatal day 70 (males only), increased negative geotaxis speed (p = 0.03), an increased time spent in the inner zone of the open field (p = 0.02). Acamprosate mitigated the effects of alcohol for negative geotaxis at postnatal day 7 (p = 0.01) and female offspring weight at postnatal day 70 (p = 0.03).

CONCLUSIONS

Overall, we show that prenatal acamprosate exposure was not associated with poor maternal or neonatal health outcomes or impaired neurodevelopment and behaviour. However, acamprosate's effects on short-term memory remain uncertain. We present preliminary evidence to suggest acamprosate displayed some neuroprotective effects against damage caused by in utero alcohol exposure.

Pharmacotherapies for the Treatment of Alcohol Use Disorders During Pregnancy: Time to Reconsider?

It is generally recommended that medications only be used in pregnancy where the potential harms to both the mother and foetus are outweighed by the potential benefits. Despite the known harms associated with alcohol consumption during pregnancy, the use of medication for the treatment of pregnant women with an alcohol use disorder (AUD) appears to be rare. This is likely due to the lack of available data regarding the safety of these medications in pregnancy. We reviewed the literature and weighed up the harms associated with alcohol use and AUD during pregnancy with the potential benefits of medications for AUD in pregnancy, including acamprosate, naltrexone and disulfiram. There is little published evidence to support the safety of medications for AUD in pregnancy. However, from the research available it is likely that only disulfiram has the potential to cause serious foetal harm. While further research is required, acamprosate and naltrexone do not appear to be associated with substantial risks of congenital malformations or other serious consequences. Given the potential risks associated with alcohol consumption during pregnancy, the use of acamprosate and naltrexone should be considered for the treatment of pregnant women with AUD based on the current evidence base, although more research is warranted.

Detrimental effects of ethanol and its metabolite acetaldehyde, on first trimester human placental cell turnover and function

Fetal alcohol spectrum disorder (FASD) describes developmental issues from high maternal alcohol intake, which commonly results in fetal growth restriction and long term morbidity. We aimed to investigate the effect of alcohol and acetaldehyde, on the first trimester placenta, the period essential for normal fetal organogenesis. Normal invasion and establishment of the placenta during this time are essential for sustaining fetal viability to term. We hypothesise that alcohol (ethanol) and acetaldehyde have detrimental effects on cytotrophoblast invasion, turnover and placental function. Taurine is an important amino acid for neuronal and physiological development, and so, its uptake was assayed in cells and placental explants exposed to alcohol or acetaldehyde. First trimester villous explants and BeWo cells were treated with 0, 10, 20, 40 mM ethanol or 0, 10, 20, 40 µM acetaldehyde. The invasive capacity of SGHPL4, a first trimester extravillous cytotrophoblast cell line, was unaffected by ethanol or acetaldehyde (p>0.05; N = 6). The cells in-cycle were estimated using immunostaining for Ki67. Proliferating trophoblast cells treated with ethanol were decreased in both experiments (explants: 40% at 20 mM and 40 mM, p<0.05, N = 8–9) (cell line: 5% at 20 mM and 40 mM, p<0.05, N = 6). Acetaldehyde also reduced Ki67-positive cells in both experiments (explants at 40 µM p<0.05; N = 6) (cell line at 10 µM and 40 µM; p<0.05; N = 7). Only in the cell line at 20 µM acetaldehyde demonstrated increased apoptosis (p<0.05; N = 6). Alcohol inhibited taurine transport in BeWo cells at 10 mM and 40 mM (p<0.05; N = 6), and in placenta at 40 mM (p<0.05; N = 7). Acetaldehyde did not affect taurine transport in either model (P<0.05; N = 6). Interestingly, system A amino acid transport in placental explants was increased at 10 µM and 40 µM acetaldehyde exposure (p<0.05; N = 6). Our results demonstrate that exposure to both genotoxins may contribute to the pathogenesis of FASD by reducing placental growth. Alcohol also reduces the transport of taurine, which is vital for developmental neurogenesis.