F. J. E. Vajda

Dose-dependent risk of malformations with antiepileptic drugs: an analysis of data from the EURAP epilepsy and pregnancy registry

BACKGROUND Prenatal exposure to antiepileptic drugs is associated with a greater risk of major congenital malformations, but there is inadequate information on the comparative teratogenicity of individual antiepileptic drugs and the association with dose. We aimed to establish the risks of major congenital malformations after monotherapy exposure to four major antiepileptic drugs at different doses. METHODS The EURAP epilepsy and pregnancy registry is an observational cohort study representing a collaboration of physicians from 42 countries. We prospectively monitored pregnancies exposed to monotherapy with different doses of four common drugs: carbamazepine, lamotrigine, valproic acid, or phenobarbital. Our primary endpoint was the rate of major congenital malformations detected up to 12 months after birth. We assessed pregnancy outcomes according to dose at the time of conception irrespective of subsequent dose changes. FINDINGS After excluding pregnancies that ended in spontaneous abortions or chromosomal or genetic abnormalities, those in which the women had treatment changes in the first trimester, and those involving other diseases or treatments that could affect fetal outcome, we assessed rates of major congenital malformations in 1402 pregnancies exposed to carbamazepine, 1280 on lamotrigine, 1010 on valproic acid, and 217 on phenobarbital. An increase in malformation rates with increasing dose at the time of conception was recorded for all drugs. Multivariable analysis including ten covariates in addition to treatment with antiepileptic drugs showed that the risk of malformations was greater with a parental history of major congenital malformations (odds ratio 4·4, 95% CI 2·06-9·23). We noted the lowest rates of malformation with less than 300 mg per day lamotrigine (2·0% [17 events], 95% CI 1·19-3·24) and less than 400 mg per day carbamazepine (3·4% [5 events], 95% CI 1·11-7·71). Compared with lamotrigine monotherapy at doses less than 300 mg per day, risks of malformation were significantly higher with valproic acid and phenobarbital at all investigated doses, and with carbamazepine at doses greater than 400 mg per day. INTERPRETATION The risk of major congenital malformations is influenced not only by type of antiepileptic drug, but also by dose and other variables, which should be taken into account in the management of epilepsy in women of childbearing potential. FUNDING Eisai, GlaxoSmithKline, Janssen-Cilag, Novartis, Pfizer, Sanofi-Aventis, UCB, Netherlands Epilepsy Foundation, Stockholm County Council, and ALF.

A double-blind, placebo-controlled trial of diclofenac/misoprostol in Alzheimer’s disease

Background: Previous studies suggest a potential benefit from nonsteroidal anti-inflammatory drugs (NSAIDs) in Alzheimer’s disease (AD). Prescribing NSAIDs, however, carries the risk of significant gastrointestinal adverse events. Objectives: To study whether treatment with an NSAID prevents expected decline in AD patients and evaluate whether co-administration of the gastro-protective agent, misoprostol, with an NSAID is safe in AD. Methods: The efficacy and safety of diclofenac in combination with misoprostol (D/M) was evaluated in 41 patients with mild-moderate AD in a prospective 25-week, randomized, double-blind placebo-controlled trial. Efficacy measures comprised the Alzheimer’s Disease Assessment Scale cognitive and noncognitive subsections, Global Deterioration Scale, Clinical Global Impression of Change, Mini-Mental State Examination, Instrumental Activities of Daily Living, Physical Self-Maintenance Scale, and a caregiver-rated Global Impression of Change. Results: There were no group differences with any of the outcome measures in an intent-to-treat analysis. There were some nonsignificant trends for the placebo group to have deteriorated more than the D/M-treated patients. Withdrawal rates were 12 of 24 in the D/M group and 2 of 17 in the placebo group. There were no serious drug-related adverse events. Conclusions: This pilot study, with small treatment numbers, did not demonstrate a significant effect of NSAID treatment in AD, but the trends observed justify further investigations with a larger number of participants. D/M is safe in AD patients, but its tolerability is not optimal.

Neuroprotection and neurodegenerative disease

This paper will focus on commonalities in the aetiology and pathology in five areas of neurological disease with illustrative examples of therapy. Possibilities of multimodal and neuroprotective therapies in human disease, employing currently available drugs and showing evidence of neuroprotective potential in animal models, are discussed. By definition, neuroprotection is an effect that may result in salvage, recovery or regeneration of the nervous system, its cells, structure and function. It is thought that there are many neurochemical modulators of nervous system damage. In epilepsy, excessive glutamate-mediated neurotransmission, impaired voltage sensitive sodium and calcium channel functioning, impaired GABA-mediated inhibition and alterations in acid base balance, when set in motion, may trigger a cascade of events leading to neuronal damage and cell death. Acute and chronic nervous system damage in response to an insult may lead to acute or delayed neuronal death, apoptotic cell death, neuronal degeneration, injury and loss, and gliosis. Cell death in the CNS following injury can occur in the manner of apoptosis, necrosis or hybrid forms. In general, NMDA receptor and non-NMDA receptor mediated excitotoxic injury results in neurodegeneration along an apoptosis-necrosis continuum. The effects of neuronal injury depend on factors including the degree of brain maturity or site of the lesion. There is some evidence supporting the hypothesis that neuroprotection may be a practical and achievable target using drugs already available, at present employed only for limited indications. Using these drugs early in the disease, may save decades of development of new drugs, which would require evaluation in animal studies, and human clinical trials. New drugs would also need to be shown to be safe and acceptable, physiologically not detrimental to humans and free from idiosyncratic adverse effects.

Critical relationship between sodium valproate dose and human teratogenicity: results of the Australian register of anti-epileptic drugs in pregnancy

UNLABELLED To compare the incidence of foetal malformations (FMs) in pregnant women with epilepsy treated with different anti-epileptic drugs (AED) and doses, and the influence of seizures, family and personal history, and environmental factors. A prospective, observational, community-based cohort study. METHODS A voluntary, Australia-wide, telephone-interview-based register prospectively enrolling three groups of pregnant women: taking AEDs for epilepsy; with epilepsy not taking AEDs; taking AEDs for a non-epileptic indication. Four hundred and fifty eligible women were enrolled over 40 months. Three hundred and ninety six pregnancies had been completed, with 7 sets of twins, for a total of 403 pregnancy outcomes. RESULTS 354 (87.8%) pregnancy outcomes resulted in a healthy live birth, 26 (6.5%) had a FM, 4 (1%) a death in utero, 1 (0.2%) a premature labour with stillbirth, 14 (3.5%) a spontaneous abortion and 4 lost to follow-up. The FM rate was greater in pregnancies exposed to sodium valproate (VPA) in the first trimester (16.0%) compared with those exposed to all other AEDs (16.0% vs. 2.4%, P < 0.01) or no AEDs (16.0% vs. 3.1%, [Formula: see text] ). The mean daily dose of VPA taken in pregnancy with FMs was significantly greater than in those without (1,975 vs. 1,128 mg, P < 0.01). The incidence of FM with VPA doses >or= 1,100 mg was 30.2% vs. 3.2% with doses <1,100 mg (P <0.01). CONCLUSIONS There is a dose-effect relationship for FM and exposure to VPA during the first trimester of pregnancy, with higher doses of VPA associated with a significantly greater risk than with lower doses or with other AEDs. These results highlight the need to limit, where possible, the dose of VPA in pregnancy.

Double-blind, placebo controlled, crossover study of lamotrigine in treatment resistant partial seizures.

The results of a multicentre, randomised, double-blind, placebo controlled, crossover trial of lamotrigine as add-on therapy in patients with partial seizures poorly controlled by established antiepileptic drugs (AEDs) are presented. The study consisted of two 12 week treatment periods each followed by a four week washout period. During the lamotrigine treatment phase, patients received 150 mg or 300 mg daily dose depending on their concomitant AEDs to achieve concentrations in the range 1-3 mg/L. Forty one patients were entered at four centres and all patients entered completed the study. There was a highly significant (p < 0.001) decrease in total seizure counts on lamotrigine compared with placebo. Overall, 22% of patients experienced at least a 50% reduction in the total numbers of all seizures types on lamotrigine, compared with none on placebo. When the total numbers of partial seizures (simple and complex partial) were analysed there was also a significant (p < 0.05) reduction in seizure counts on lamotrigine compared with placebo. When total numbers of secondarily generalised seizures were compared the trend for a reduction in this seizure type did not achieve significance (0.05 < p < 0.1). Concomitant AED plasma concentrations were virtually unchanged. It is concluded that lamotrigine is an effective AED in the treatment of therapy-resistant partial seizures.

Foetal malformations and seizure control: 52 months data of the Australian Pregnancy Registry.

The Australian Pregnancy Registry, affiliated European Register of Antiepileptic drugs in Pregnancy (EURAP), recruits informed consenting women with epilepsy on treatment with antiepileptic drugs (AEDs), those untreated, and women on AEDs for other indications. Enrolment is considered prospective if it has occurred before presence or absence of major foetal malformations (FMs) are known, or retrospective, if they had occurred after the birth of infant or detection of major FM. Telephone Interviews are conducted to ascertain pregnancy outcome and collect data about seizures. To date 630 women have been enrolled, with 565 known pregnancy outcomes. Valproate (VPA) above 1100 mg/day was associated with a significantly higher incidence of FMs than other AEDs (P < 0.05). This was independent of other AED use or potentially confounding factors on multivariate analysis (OR = 7.3, P < 0.0001). Lamotrigine (LTG) monotherapy (n = 65), has so far been free of malformations. Although seizure control was not a primary outcome, we noted that more patients on LTG than on VPA required dose adjustments to control seizures. Data indicate an increased risk of FM in women taking VPA in doses >1100 mg/day compared with other AEDs. The choice of AED for pregnant women with epilepsy requires assessment of balance of risks between teratogenicity and seizure control.

Fluorouracil therapy in patients with carcinoma of the large bowel: a pharmacokinetic comparison of various rates and routes of administration.

SummaryThe pharmacokinetics of fluorouracil after oral, intravenous and rectal administration were compared in 12 patients with colorectal cancers.Oral administration of 10 to 15mg/kg gave variable plasma levels (0 to 10.5μg/ml) and bioavailability (0 to 74%; mean 28%). Bioavailability increased markedly with increases in dose, suggesting saturation of the ‘frst pass’ hepatic metabolism of the drug. Differences in bioavailability could not be related to standard liver function tests or the presence of metastatic deposits i the liver.Plasma levels were not detectable after rectal administration in the 4 patients studied and were very low (0 to 8μg/ml) during high dose (20 to 30mg/kg/24h) slow intravenous infusion in 6 patients.These findings indicate that different dose schedules and routes of administration produce markedly different plasma levels. They suggest that the rate of degradation of fluorouracil by the liver is quite variable and may become saturated with increasing dose. For these reasons monitoring of plasma levels of the drug in individual patients may be useful.

Seizure control and treatment changes in pregnancy: Observations from the EURAP epilepsy pregnancy registry

To analyze seizure control, dose adjustments, and other changes of antiepileptic drug (AED) treatment during pregnancy in a large cohort of women with epilepsy entering pregnancy on monotherapy with carbamazepine, lamotrigine, phenobarbital, or valproate.

Maternal valproate dosage and foetal malformations

Objective–  To study the possible dose dependence of the foetal malformation rate after exposure to sodium valproate in pregnancy

Double-blind, placebo-controlled, crossover study of lamotrigine in treatment-resistant generalised epilepsy.

Summary: Purpose: Lamotrigine (LTG) is recognised as effective add‐on therapy for focal epilepsies, but this is the first double‐blind, placebo‐controlled, crossover study in treatmentresistant generalised epilepsy.