Topiramate in pregnancy and breastfeeding

Impact of maternal topiramate ingestion on ossification of skull and appendicular bones in rat fetuses

The skull and appendicular bones are derived from different embryological sources during their development. The impact of prenatal exposure of topiramate on ossification of these bones is not adequately studied. The goal of this study was to assess the ossification patterns of the craniofacial bones and bones of the forelimbs and hindlimbs in 20-day-old rat fetuses after maternal exposure to topiramate at doses equivalent to human therapeutic doses. Three groups of Sprague-Dawley pregnant rats were used: control, topiramate 50mg/kg/day (T50) and topiramate 100mg/kg/day (T100). Topiramate was given by oral gavage from day 6 to day19 of gestation. Ossification was evaluated in the bones of 20 days fetuses after staining with Alizarin red. Results showed a significant reduction in complete ossified centers of the metacarpal, metatarsal and craniofacial bones in topiramate-exposed fetuses at both doses when compared to the control group. Also, a significant decrease in the length of ossified part of the long bones of the forelimbs and hindlimbs in topiramate-exposed fetuses at both doses was noted when compared to the control group. Crown-rump length and fetal weight were significantly decreased in topiramate treated groups compared to the control group. In all examined groups, there was a positive correlation between the crown-rump length and the lengths of humerus and femur. No abnormalities in the ossified bones and no significant changes in their ossification pattern were observed between the treated groups. In conclusion, prenatal administration of topiramate in doses equivalent to human therapeutic doses delayed ossification and development of craniofacial and appendicular bones in rat fetuses and their effects are not dose dependent at doses investigated. The implications of these findings in women who require topiramate therapy in pregnancy merit further evaluation.

[Use of antiepileptic drugs during breastfeeding : What do we tell the mother?]

BACKGROUND

Knowledge about the passage of various antiepileptic drugs into breast milk and its consequences for the infant is limited. Faced with this uncertainty, breastfeeding is often discouraged for these patients. The aim of this study was to comprehensively review the available data regarding antiepileptic drugs during breastfeeding, to compare these data with information provided by the summary of product characteristics (SmPCs), and to provide recommendations for the use of these drugs in breastfeeding women.

MATERIAL AND METHODS

We performed a systematic literature review on breastfeeding data for 23 antiepileptic drugs. A breastfeeding compatibility score was developed and validated. The estimated score based on the literature review was compared with the estimated score based on recommendations provided by the SmPCs.

RESULTS

We identified 75 articles containing exposure and safety data for 15 antiepileptic agents during breastfeeding. The comparison between the score values based on the literature review and on the SmPCs revealed a very low degree of concordance (weighted kappa: 0.08).

CONCLUSION

Phenobarbital, primidone, carbamazepine, valproate and levetiracetam are probably compatible with breastfeeding. Treatment with phenytoin, ethosuximide, clonazepam, oxcarbazepine, vigabatrin, topiramate, gabapentin, pregabalin, lamotrigine and zonisamide can be authorized during breastfeeding, provided breastfed infants are carefully monitored for side effects. Since data on the use of mesuximide, clobazam, rufinamide, felbamate, lacosamide, sultiame, perampanel and retigabine are insufficient to adequately assess the risk for breastfed infants, use in breastfeeding women is in principle not recommended and should be carefully evaluated on a case by case basis. In practice, a risk-benefit analysis should be performed for each mother under antiepileptic treatment wishing to breastfeed her child, so that individual risk factors can adequately be taken into account when counseling the patient.

Breastfeeding and migraine drugs

PURPOSE

Breastfeeding women may suffer from migraine. While we have many drugs for its treatment and prophylaxis, the majority are poorly studied in breastfeeding women. We conducted a review of the most common anti-migraine drugs (AMDs) and we determined their lactation risk.

METHODS

For each AMD, we collected all retrievable data from Hale's Medications and Mother Milk (2012), from the LactMed database (2014) of the National Library of Medicine, and from a MedLine Search of relevant studies published in the last 10 years.

RESULTS

According to our review, AMDs safe during breastfeeding are as follows: low-dose acetylsalicylic acid (ASA), ibuprofen, sumatriptan, metoprolol, propranolol, verapamil, amitriptyline, escitalopram, paroxetine, sertraline, acetaminophen, caffeine, and metoclopramide. AMDs compatible with breastfeeding but warranting caution are as follows: diclofenac, ketoprofen, naproxen, most new triptans, topiramate, valproate, venlafaxine, and cyproheptadine. Finally, high-dose ASA, atenolol, nadolol, cinnarizine, flunarizine, ergotamine, methysergide, and pizotifen are contraindicated.

CONCLUSIONS

According to our review, the majority of the revised AMDs were assessed to be compatible with breastfeeding.

Probable topiramate-induced diarrhea in a 2-month-old breast-fed child - A case report

An infant developed a severe condition of recurrent and persistent watery diarrhea at 40 days of age. The child had been partially breast-fed, and the mother used topiramate for epilepsy. Hospital examination excluded a viral or bacterial infection and failed to identify any other potential cause. After two weeks, topiramate exposure was suspected to be the cause, and breast-feeding was suspended. The diarrhea ceased within 2 days. Analysis of the breast milk showed a topiramate concentration of 15.7 μmol/L (5.3 μg/mL). There is little information on the use of topiramate in breast-feeding women. The potential effects on the children are not known. Topiramate passes into breast milk, and the concentration may equal the therapeutic plasma concentration. In this case, the infant may have ingested up to 40% of the mother's weight-adjusted dose. Diarrhea is a well-known adverse reaction to topiramate and has the potential to cause serious electrolyte disturbances in neonates and infants. The condition improved rapidly after suspension of breast-feeding. Topiramate in breast milk may reach levels that cause adverse effects in infants. Based on the adverse reaction profile of topiramate and the milk concentration, the diarrhea was assessed as a probable adverse drug reaction in the infant.

Antiepileptic drugs and breastfeeding

INTRODUCTION

This review provides a synopsis for clinicians on the use of antiepileptic drugs (AEDs) in the breastfeeding mother.

METHODS

For each AED, we collected all retrievable data from Hale's "Medications and Mother Milk" (2012), from the LactMed database (2013) of the National Library of Medicine, and from a MedLine Search of relevant studies in the past 10 years.

RESULTS

Older AEDs, such as carbamazepine, valproic acid, phenytoin, phenobarbital, primidone are considered to have a good level of safety during lactation, due to the long term clinical experience and the consequent amount of available data from the scientific literature. On the contrary, fewer data are available on the use of new AEDs. Therefore, gabapentin, lamotrigine, oxcarbazepine, vigabatrin, tiagabine, pregabalin, leviracetam and topiramate are compatible with breastfeeding with a less documented safety profile. Ethosuximide, zonisamide and the continue use of clonazepam and diazepam are contraindicated during breastfeeding.

CONCLUSIONS

Although the current available advice on the use of AEDs during breastfeeding, given by different accredited sources, present some contradictions, most AEDs can be considered safe according to our review.

Second-generation antiepileptic drugs and pregnancy: a guide for clinicians

When treating pregnant women with antiepileptic drugs (AEDs), clinicians have to balance potential fetal adverse effects against the risks of uncontrolled maternal disease. Only recently have emerging scientic data provided a rational basis for treatment decisions considering both aspects. The focus of research is currently moving from the first to the second AED generation. Lamotrigine is relatively well studied, and data on other novel AEDs, such as levetiracetam, oxcarbazepine, topiramate, zonisamide, gabapentin and pregabalin, are in progress. Safety issues appear to be favorable for lamotrigine, and preliminary results are also promising for levetiracetam and oxcarbazepine. Drugs metabolized by uridine-diphospate glucuronosyl transferase or excreted unchanged by the kidneys are particularly susceptible to increased body clearance during pregnancy. Lamotrigine is subject to both mechanisms, and therapeutic serum levels may sometimes be difficult to maintain. The authors review the recommendations and clinical research on modern AED treatment during pregnancy, highlighting current experience with second-generation drugs.

Multiple fetal anomalies in association with topiramate and oxcarbezepine treatment

We present a case of a woman who used topiramate (100 mg) and oxcarbazepine (300 mg) continuously during pregnancy. Multiple fetal anomalies including limp defects of the lower extremities, pericardiac fluid collection, cardiomegaly, cleft lip and palate, absent right kidney, and dysplastic left kidney were found by ultrasonography. Labor was induced and anomalies were confirmed by autopsy. The malformation rate after exposure to oxcarbazepine in utero as a monotherapy was calculated to be 2.4%, which is compatible with the malformation rate seen in the general population. Topiramate is teratogenic in mice, rats, and rabbits, but there are very few reports about its teratogenicity in humans.