Carbamazepine increases atherogenic lipoproteins: mechanism of action in male adults

Long-Term Effects of Antiseizure Medications

Most patients with epilepsy will benefit from seizure control with one of an array of chronic antiseizure medications. Knowledge of the potential long-term effects of these medications is critical to prevent adverse consequences on overall health. Antiseizure medications vary in their capacities to affect the brain and peripheral nerves, hormones, bone mineralization, cardiovascular risk, renal health, hepatic, hematological, and dermatological systems. Understanding of pathophysiology and population risk has evolved, although most of the data available are still on older generation antiseizure medications such as phenytoin, carbamazepine, and valproic acid. The enzyme-inducing properties of some antiseizure medications make their effects on cardiovascular risk and bone health detrimental. Few clear guidelines exist for monitoring long-term effects of medication therapy for epilepsy. When selecting an antiseizure medication, consideration should be given to the individual patient's risks of adverse consequences on other organ systems. During monitoring of patients on chronic therapy, screening tools such as metabolic panels and bone density measurements can help stratify risk and guide management.

Transcriptome analysis of the brain of the sea bream (Sparus aurata) after exposure to human pharmaceuticals at realistic environmental concentrations

Human pharmaceuticals such as Acetaminophen, Atenolol and Carbamazepine are pseudo persistent aquatic pollutants with yet unknown sub-lethal effects at environmentally relevant concentrations. Gilthead seabream (Sparus aurata) were exposed to Acetaminophen: 31.90 ± 11.07 μg L^-1; Atenolol: 0.95 ± 0.38 μg L^-1 and Carbamazepine: 6.95 ± 0.13 μg L^-1 in a 28 day flow through experiment to (1) determine whether exposure to low concentrations in the μg·L^-1 range of the pharmaceuticals alters the brain transcriptome and, (2) identify different expression profiles and treatment specific modes of action and pathways. Despite low exposure concentrations, 411, 7 and 612 differently expressed transcripts were identified in the individual treatments with Acetaminophen, Atenolol and Carbamazepine, respectively. Functional analyses of differentially expressed genes revealed a significant over representation of several biological processes, cellular compartment features and molecular functions for both Acetaminophen and Carbamazepine treatments. Overall, the results obtained in seabream brain suggest similar physiological responses to those observed in humans also at environmental concentrations, as well as the existence of treatment specific processes that may be useful for the development of biomarkers of contamination.

Favorable change of lipid profile after carbamazepine withdrawal

OBJECTIVE

Patients treated with carbamazepine (CBZ) have increased serum levels of total cholesterol (TC), high-density lipoproteins (HDL), and low-density lipoproteins (LDL). We aimed to investigate whether these changes of serum lipids are reversible after CBZ withdrawal.

MATERIAL AND METHODS

We used a prospective, randomized double-blinded design. A total of 160 patients who had been seizure free on anti-epileptic drug monotherapy for more than 2 years were included and randomized to withdrawal or not. The intervention was completed by 150 (80 females, 53%) patients. Serum samples from before and 4 months after completed withdrawal or no withdrawal were obtained from 130 patients (63 females, 48%). Of these, 84 were treated with CBZ, 28 with valproate, nine with phenytoin, four with phenobarbital, and five with lamotrigine. Of the patients who had been treated with CBZ, 47 were randomized to the withdrawal group, and 37 were randomized to the non-withdrawal group.

RESULTS

Among the CBZ-treated patients, a significant decrease in serum levels of TC, LDL, and apolipoprotein B (ApoB) were found in the withdrawal group compared with the non-withdrawal group. Mean differences in change were as follows: TC 0.68 mmol/l (P = 0.005, CL - 1.15 to -0.21); LDL - 0.67 mmol/l (P = 0.001, CL - 1.03 to -0.29); ApoB - 0.13 g/l (P = 0.02, CL - 0.23 to -0.03). No significant changes in HDL, apolipoprotein A, and C-reactive protein were detected.

CONCLUSION

Our results indicate that CBZ may have unfavorable effects on serum levels of TC, LDL, and ApoB. However, these changes seem to be reversible even after years of treatment.

Practical guidance and considerations for transitioning patients from oxcarbazepine or carbamazepine to eslicarbazepine acetate--Expert opinion

There is currently a lack of guidance on methodology and special considerations for transitioning patients from oxcarbazepine (OXC) or carbamazepine (CBZ) to eslicarbazepine acetate (ESL), if deemed clinically necessary. An advisory panel of epilepsy experts was convened to share their experience on the use of adjunctive ESL in clinical practice and to provide practical recommendations to help address this gap. When changing over from OXC to ESL, an OXC:ESL dose ratio of 1:1 should be employed to calculate the ESL target dose, and the changeover can take place overnight. No changes to comedication are required. Since CBZ has a different mechanism of action to ESL and is a stronger inducer of cytochrome P450 (CYP) enzymes, the transitioning of patients from CBZ to ESL requires careful consideration on a patient-by-patient basis. In general, a CBZ:ESL dose ratio of 1:1.3 should be employed to calculate the ESL target dose, and patients should be transitioned over a minimum period of 1-2weeks. Special considerations include adjustment of titration schedule and target dose in elderly patients and those with hepatic or renal impairment and potential adjustment of comedications metabolized by CYP enzymes. In summary, due to structural distinctions between ESL, OXC, and CBZ, which affect mechanism of action and tolerability, there are clinical situations in which it may be appropriate to consider transitioning patients from OXC or CBZ to ESL. Changing patients over from OXC to ESL is generally more straightforward than transitioning patients from CBZ to ESL, which requires careful consideration.

Concomitant therapy in people with epilepsy: potential drug-drug interactions and patient awareness

People with epilepsy (PWE) may use prescription and over-the-counter (OTC) drugs for the treatment of concomitant diseases. Combinations of these drugs, as well as dietary supplements, with antiepileptic drugs (AEDs) may lead to reduced control of seizures and of coexisting medical conditions and increased risk of adverse drug reactions (ADRs). The aims of this study were to obtain comprehensive lists of medications, dietary supplements, botanicals, and specific food components used by adult PWE and to evaluate the potential for interactions involving AEDs and patients' awareness of such potential interactions. We conducted a prospective, questionnaire-based study of PWE attending the Hadassah-Hebrew University Epilepsy Clinic over a period of 7months. The questionnaire interview included the listing of medications, medicinal herbs, dietary supplements, and specific food components consumed and the knowledge of potential drug-drug interactions (DDIs), and it was conducted by a pharmacist. Drug-drug interactions were analyzed via the Micromedex online database. Out of 179 patients who attended the clinic over the study period, we interviewed 73 PWE, of which 71 were included in our final analysis. The mean number of AEDs consumed per subject was 1.7 (SD: 0.8, range: 1-4). Forty (56%) subjects were also treated with other prescription and/or OTC medications, and thirty-four (48%) took dietary supplements. Drug families most prone to DDIs involving AEDs included antipsychotic agents, selective serotonin reuptake inhibitors, and statins. Two-thirds of study participants (67%) knew that DDIs may lead to ADRs, but only half (56%) were aware of the potential for reduced seizure control. Only 44% always reported treatment with AEDs to medical professionals. This study provides for the first time a comprehensive picture of prescription and OTC drugs and food supplements used by PWE. Despite a considerable potential for DDIs involving AEDs, patient awareness is limited, highlighting the importance of patient and caregiver education.

Possible Induction of Cholinesterase in Epileptic Patients Treated With Anticonvulsant Drugs: Relationship With Lipoprotein Levels

The effect of enzyme-inducing anticonvulsant drugs on the serum concentrations of lipoproteins has been widely studied. However, there is little agreement between the results with regard to the possible development of a lipoprotein profile related to an increased or decreased cardiovascular risk. It has been suggested that cholinesterase (ChE) could be induced by these drugs, something of undeniable interest as ChE appears to have a relation to the metabolism of lipoproteins. The serum activity of ChE was determined in a group of 90 adult epileptic patients (56 male and 34 female) treated with phenobarbital, phenytoin, and carbamazepine. The liver enzyme induction produced by these drugs was then evaluated by determining serum gamma-glutamyltranspherase activity and urinary excretion of D-glucaric acid. A significant increase of serum ChE (p < 0.005) was found in the group of patients compared to a control group (n = 49) with a similar distribution for age and sex. A significant correlation was found for both male and female patients between ChE and concentrations of triglycerides, phospholipids, cholesterol, low-density lipoprotein (LDL) phospholipids, LDL-cholesterol, and apolipoprotein B (p < 0.01). Similarly, in female patients, ChE had a significant correlation with the total cholesterol/high-density lipoprotein (HDL) cholesterol and LDL-cholesterol/HDL-cholesterol ratios (p < 0.01). The ChE/HDL-cholesterol relationship, which has been proposed as a marker for cardiovascular risk, presented significant correlations with the total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios in patients of both sexes (p < 0.001). In the case of epileptic patients treated with enzyme-inducing anticonvulsant drugs, there may be an association between the possible induction of ChE and the metabolism of lipoproteins containing apolipoprotein B.

Effects of epilepsy and selected antiepileptic drugs on risk of myocardial infarction, stroke, and death in patients with or without previous stroke: a nationwide cohort study

PURPOSE

Patients with epilepsy have increased morbidity and mortality. We evaluated the risk of myocardial infarction (MI), stroke, and death associated with epilepsy and examined if this risk was modified by treatment with antiepileptic drugs (AEDs).

METHODS

A cohort consisting of the Danish population was followed from January 1997 to December 2006. The risk of MI, stroke, cardiovascular death, and all-cause death associated with epilepsy was estimated by multivariable Cox proportional hazard models stratified for occurrence of previous stroke. AED use was determined at baseline, and risks associated with exposure to individual AEDs were examined in patients with epilepsy.

RESULTS

In patients without previous stroke, AED-treated epilepsy was associated with an increased risk of MI (hazard ratio [HR], 1.09; 95%CI, 1.00-1.19), stroke (HR, 2.22; 95%CI, 2.09-2.36), cardiovascular death (HR, 1.64; 95%CI, 1.57-1.72), and all-cause death (HR, 1.92; 95%CI, 1.86-1.97). Compared with carbamazepine monotherapy, valproate was associated with a decreased risk of MI (HR, 0.72; 95%CI, 0.59-0.87) and stroke (HR, 0.86; 95%CI, 0.76-0.96), oxcarbazepine and phenobarbital with increased risk of cardiovascular death (HR, 1.10; 95%CI, 1.02-1.19 and HR, 1.08; 95%CI, 1.00-1.17, respectively) and all-cause death (HR, 1.11; 95%CI, 1.05-1.18 and HR, 1.18; 95%CI, 1.12-1.25, respectively), and oxcarbazepine with increased risk of stroke (HR, 1.21; 95%CI, 1.10-1.34), in patients with epilepsy.

CONCLUSIONS

Patients with epilepsy exhibit increased risk of MI, stroke, cardiovascular death, and all-cause death. Compared with carbamazepine monotherapy, valproate may decrease, and oxcarbazepine and phenobarbital may increase, the risk of adverse cardiovascular events in these patients.

Non-alcoholic fatty liver disease (NAFLD), insulin resistance and lipid profile in antiepileptic drug treatment

PURPOSE

Patients undergoing long-term treatment with valproic acid (VPA) are prone to develop different features of the metabolic syndrome (MS). The aim of the present study was to evaluate the occurrence of non-alcoholic fatty liver disease (NAFLD), insulin resistance (IR) and a pro-atherogenic lipid profile in patients undergoing VPA, carbamazepine (CBZ) and lamotrigine (LTG) monotherapy compared to healthy controls.

METHODS

Abdominal ultrasound as well as measurement of serum fasting insulin and glucose, serum lipids and liver function parameters were performed in VPA (n=23), CBZ (n=22) and LTG (n=23) treated non-diabetic and non-obese epileptic patients compared to healthy controls (n=16).

RESULTS

Ultrasound measurement demonstrated characteristics of fatty liver disease in 60.9% of VPA, in 22.7% of CBZ, in 8.7% of LTG treated patients and in 12.5% of the healthy controls, with highest level of steatosis seen in VPA treated patients. In addition, patients on VPA monotherapy showed a higher body-mass index (BMI) when compared to LTG treated patients and controls (p<or=0.049). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and gamma-glutamyltransferase (gammaGT) were greatest in the CBZ group (p<or=0.043). Interestingly, serum fasting glucose, serum fasting insulin as well as the HOMA-IR did not differ significantly between groups.

CONCLUSION

In conclusion, VPA (and moderately CBZ) therapy is related to increased risk for ultrasonographic signs of fatty liver disease, emphasizing the importance of regular ultrasound measurements as well as monitoring of serum lipids and BMI during enzyme-modulating AED treatment.

Comorbidity, health screening, and quality of life among persons with a history of epilepsy

Previous population surveys outside the United States have found an increased prevalence of comorbid conditions in persons with epilepsy. However, the effect of comorbid conditions on health-related quality of life (HRQOL) has not been previously examined in the epilepsy literature from the United States. Results from the California Health Interview Survey (CHIS) indicate an increased prevalence of comorbid conditions in persons with a history of epilepsy compared to those without epilepsy. After controlling for demographics and comorbid conditions, persons with a history of epilepsy were significantly more likely to report poor HRQOL. Although seizure freedom should continue to be a primary clinical goal, optimal care should also include primary and secondary prevention of comorbid conditions, especially cardiovascular and pulmonary diseases. Prevention, early identification, and treatment of comorbid conditions may reduce mortality risk and improve health outcomes in persons with epilepsy.

Weight gain and metabolic issues of medicines used for bipolar disorder

Patients with bipolar disorder are at high risk of gaining weight and developing metabolic illnesses, and pharmacologic treatment for the disorder may significantly increase this risk. This paper reviews the literature on the metabolic consequences of the medications used in bipolar disorder and describes the possible strategies to prevent, monitor, and treat the common metabolic illnesses that patients with bipolar disorder may develop during treatment.

Cardiovascular risk factors and homocysteine in epilepsy

Epidemiological studies have found the risk for heart disease and stroke are increased in persons with epilepsy. Anti-epileptic drugs (AEDs) have varying effects on serum lipids and homocysteine-an independent risk factor for coronary disease. The prevalence of cardiovascular risk factors (high cholesterol, hypertension, diabetes, obesity and smoking) and homocysteine were investigated in a multiethnic epilepsy population. Data included demographics, clinical factors, lab assessments and supplementation patterns. Mean age was 45 years (71 males and 94 females)-75 were African American, 27 Latino and 60 Caucasian. Fifty-two percent of participants had two or more cardiovascular risk factors when compared with rates for the general population of 28%. The Framingham risk score (FRS) assessment was also used to compare risk levels. Twenty-nine percent of men and 1% of women had a FRS indicating >5% level of risk, only 7% had a FRS>10%. Cardiovascular screening and primary preventative recommendations based on the American Heart Association and supplementation should be suggested for the adult epilepsy population when appropriate.

Practical considerations for carbamazepine use in bipolar disorder

Carbamazepine (CBZ) has a long history of successful use in epilepsy and, therefore, has a safety profile that is well characterised. Additionally, an extended-release formulation of CBZ (CBZ-ERC; Equetro, Shire US) has recently been approved for use in bipolar disorder. The most frequent adverse events associated with CBZ are somnolence, fatigue, dizziness and headache. Rash and leukopoenia may occur in approximately 10% of patients, but are benign and transient in most cases. Rare serious adverse effects include agranulocytosis, aplastic anaemia, Stevens-Johnson syndrome and toxic epidermal necrolysis. Although changes in lipid profiles have been noted, hyperglycaemia does not occur with CBZ, and clinically significant weight gain is uncommon. Proper monitoring and careful titration of the extended-release formulation should allow for successful use of CBZ in psychiatric patients.

Effects of common anti-epileptic drug monotherapy on serum levels of homocysteine, vitamin B12, folic acid and vitamin B6

There is emerging evidence to support the unfavorable effects of some anti-epileptic drugs on the plasma homocysteine concentrations. Elevated homocysteine levels induced by anti-epileptic drug administration can theoretically increase not only the risk of vascular occlusive diseases, but also the risk of resistance to anti-epileptics and development of refractory epilepsy. To investigate the effect of common anti-epileptic drugs on the homocysteine metabolism, a total of 75 epileptic patients receiving phenytoin (n=16), carbamazepine (n=19), or valproic acid (n=22) and no anti-epileptic drug (n=18) were enrolled. Eleven age- and sex-matched healthy subjects served as the control group. Blood concentrations of homocysteine, folic acid, Vitamin B12 and pyridoxal 5'-phosphate (active circulating form of Vitamin B6) were measured. Compared to the control group, epileptic patients on anti-epileptic drug had higher blood levels of homocysteine. No difference in homocysteine concentrations was observed among epileptic patients in terms of the anti-epileptic drug used. Patients receiving phenytoin had significantly lower folic acid levels and those receiving carbamazepine had marginally lower pyridoxal 5'-phosphate levels in comparison with those using other anti-epileptic drugs. A negative correlation between homocysteine and folic acid concentrations was detected in epileptic patients on anti-epileptic drug. The duration of anti-epileptic drug use was correlated to the decrease of folic acid levels, but not with changes observed in homocysteine, Vitamin B12 and pyridoxal 5'-phosphate levels. No relationship between seizure frequency and homocysteine levels was observed in epileptic patients. Our results confirm that common anti-epileptic drugs has disadvantageous effects on homocysteine status. Because there was no significant change in homocysteine concentrations in epileptic patients who were not receiving an anti-epileptic drug, and no positive correlation between seizure frequency and homocysteine levels, we suggest that increase of homocysteine levels may be due to anti-epileptic drug use, rather than being epileptic in origin. Additionally, the underlying mechanism for homocysteine increase seems to be a decrease of cofactor molecules in patients using carbamazepine and phenytoin (pyridoxal 5'-phosphate and folic acid, respectively). However, changes observed are not related to the alteration in the levels of cofactors and remain unclear in the patients using valproic acid.

Serum thyroid hormone balance and lipid profile in patients with epilepsy

PURPOSE

Patients with epilepsy may exhibit changes in thyroid hormone balance, lipids and lipoproteins concentrations. The suggestion that lipid abnormalities are associated with subclinical thyroid dysfunction remains controversial. The aim of this study was to analyze whether thyroid dysfunction encountered in patients with epilepsy would also be associated with abnormal lipid profile.

METHODS

Eighty-eight patients with epilepsy and 30 control subjects were included in the study. A fasting blood sample for thyroid hormones, lipid profile and GGT determination was obtained.

RESULTS

The serum levels of FT3 was elevated in 10.2% of patients, FT4 was low in 28.4%, TSH was high in 4.6% and low in 2.3%. 13.6% of patients had high TC, 17.1% had high LDL-c, 60.2% had marked reduction of HDL-c levels (P<0.0001) and only 2.3% had high TG levels. Abnormalities were predominated in CBZ-treated patients. 27.3% patients with abnormal hormones had abnormal lipid profile. Significant association was identified between the serum TC, LDL-c, TG, GGT and EIAEDs and between the duration of illness and TG (r=-0.411; P=0.017), and FT4 (r=-0.412; P=0.018). HDL was higher in women than men (r=0.416; P<0.002). However, changes in HDL-c levels associated neither with duration of illness, type or serum levels of AEDs nor with age or degree of control on AEDs.

CONCLUSIONS

Our results support that (1) altered lipid metabolism might be associated but not solely influenced by thyroid hormones and (2) enzyme induction is not the main or only reason for altered thyroid function or HDL-c among patients with epilepsy. Hypothalamic/pituitary dysregulation by precisely mechanism caused by epilepsy itself or AEDs seems possible and (3) it is important to recognize that patients with epilepsy are at great risk for atherosclerosis, hence monitoring and correction of the culprit risks are mandatory.

The High Atherosclerotic Risk Among Epileptics: the Atheroprotective Role of Multivitamins

Neurologists have little concern about the high atherosclerotic risk among epileptics. Recent evidences mount that chronic epilepsy and prolonged use of antiepileptic drugs (AEDs) are associated with multiple risk factors that are critically implicated in pathobiology and dysfunction of the vessel wall through complex molecular mechanisms that promote atherogenesis. This review is concerned with three metabolic alterations, which are attributed as major risk factors for atherosclerosis among epileptics: altered metabolism of a) homocysteine (Hcy), b) lipids and lipoproteins, and c) uric acid. Most conventional AEDs reduce folic acid levels, thereby raising Hcy levels. Hyperhomosysteinemia is recently believed to induce endothelial dysfunction and promote atherosclerosis through complex oxidative and excitatory neurotoxic molecular mechanisms. However, Hcy itself is a convulsing substance with increased seizure recurrence and intractability to antiepileptic medications. AEDs can disturb lipid metabolism with resultant hypercholestrolemia and dyslipidemia, common recognized risks for atherosclerosis. Altered uric acid metabolism is common among epileptics. Uric acid has been implicated in endothelial cell damage and decreased endothelial nitric oxide bioavailability. In the presence of atherosclerotic milieu, uric acid interacts with other substrate toxicities and increased reactive oxygen species, accelerating atherosclerosis. The above information forms the rationale for future routine screening and correction of such metabolic alterations in epileptics. A convincing argument now develops that routine polyvitamin supplementation (folic acid, vitamin B12, vitamin B6, vitamin C, vitamin E, and beta-carotene) becomes increasingly important for women and men receiving AEDs at all ages. The atheroprotective effect of multivitamins is through their antioxidant and anti-inflammatory effects together with their lipid and Hcy lowering effects.

Lipoprotein(a) concentration increases during treatment with carbamazepine

PURPOSE

Treatment with carbamazepine (CBZ) is known to affect apolipoprotein B-containing lipoprotein concentrations in serum. However, little is known about the effects of anticonvulsant drugs (AEDs) on lipoprotein(a) [Lp(a)], although Lp(a) has been characterized as independent cardiovascular risk factor. We investigated prospectively the effect of CBZ on lipoprotein(a) concentration in normolipidemic healthy adults.

METHODS

Twenty male volunteers were included in the study. Lp(a) levels were determined before and 69 +/- 19 days after CBZ administration by using an enzyme-linked immunoassay.

RESULTS

CBZ (mean plasma concentration, 6.6 +/- 0.6 microg/ml) caused a significant increase in Lp(a) concentrations, with a median change of +19.5% (95% CI: +8.2, +53.3; p < 0.001). Total cholesterol, low density lipoprotein (LDL) cholesterol, and triglycerides also increased significantly.

CONCLUSIONS

Although the precise mechanism of action of CBZ on Lp(a) elevation remains uncertain, it might be related to its enzyme-inducing properties. During treatment with CBZ, special focus should be given to elevated LDL cholesterol and Lp(a) concentrations with regard to increased risk for atherosclerotic vascular diseases.