Early hormonal changes during valproate or carbamazepine treatment: a 3-month study

BACKGROUND: Long-term treatment with valproate (VPA) or carbamazepine (CBZ) may induce reproductive endocrine disorders in patients with epilepsy. METHODS: Serum concentrations of reproductive hormones were studied in 17 women and 22 men with recently diagnosed epilepsy before they started either VPA or CBZ medication, and 1 and 3 months later. RESULTS: No weight gain or clinical signs of hormonal disorders were observed during the follow-up. The mean serum levels of testosterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin (SHBG) increased, and dehydroepiandrosterone sulfate (DHEAS) decreased, in women starting VPA. Serum testosterone levels increased in half of the women on VPA. Serum concentrations of progesterone and dehydroepiandrosterone increased, and gonadotropins decreased, in men on VPA during the follow-up. Serum SHBG levels increased and DHEAS decreased during the first months of CBZ treatment in both sexes. In addition, the free-androgen index decreased in men after starting CBZ. CONCLUSIONS: Hormonal changes occur after only 1 month's use of VPA or CBZ. VPA-treatment seems to be associated with increased serum androgen levels, but the profile of hormonal changes appears to be different in women than in men. The use of CBZ, in turn, was associated with increased SHBG concentrations and thus with diminished sex steroid function in both sexes. The women with increased serum testosterone levels in the early phase of VPA medication may be at increased risk for VPA-related endocrine disorders later during treatment.     

Effects of carbamazepine and oxcarbazepine on the reproductive endocrine function in women with epilepsy

PURPOSE: The aim of the study was to compare the effects of carbamazepine (CBZ) and oxcarbazepine (OXC) on the reproductive endocrine function in women with epilepsy. OXC is a novel antiepileptic drug (AED), and the occurrence of reproductive dysfunction in women treated with OXC monotherapy for epilepsy has not been studied previously. METHODS: Thirty-five women with epilepsy were examined in the Department of Neurology at Oulu University Hospital. Sixteen patients were treated with CBZ monotherapy, and nineteen patients were treated with OXC monotherapy. The subjects were clinically examined, vaginal ultrasonography was performed, and serum sex hormone concentrations were measured. RESULTS: The women taking CBZ or OXC had lower serum testosterone (T) levels and lower free androgen indexes (FAIs) than the control subjects. CBZ medication was associated with increased concentrations of serum sex hormone-binding globulin (SHBG). The patients taking OXC had higher concentrations of dehydroepiandrosterone sulfate (DHEAS) and androstendione (A) than did the women taking CBZ. Moreover, the prevalence of polycystic ovaries (PCOs) was high in the OXC-treated women. CONCLUSIONS: CBZ and OXC have different effects on the reproductive endocrine function. Although both drugs were associated with low serum T concentrations and low FAIs, only OXC was associated with a high frequency of elevated levels of A and DHEAS and with an increased prevalence of PCOs. These findings suggest that OXC may be disadvantageous for women with epilepsy and hyperandrogenism, whereas CBZ may be beneficial for these women.     

Serum androgen levels and testicular structure during pubertal maturation in male subjects with epilepsy

Summary:  Purpose: To evaluate reproductive endocrine function in boys and young men with epilepsy taking an antiepileptic drug in a population-based, controlled study.
Methods: Seventy patients and 70 controls matched for age and pubertal stage participated in this study. Twenty-eight patients were taking carbamazepine (CBZ); five, lamotrigine (LTG); 12, oxcarbazepine (OXC); and 25, valproate (VPA) as monotherapy for epilepsy. All subjects were examined clinically, and their medical histories were obtained. Serum reproductive hormone and sex hormone–binding globulin concentrations were measured, and testicular ultrasonography was performed.
Results: Serum testosterone levels were within the normal range in young male patients with epilepsy. However, the patients taking VPA had high serum androstenedione levels at all pubertal stages. In prepuberty, their serum androstenedione values were already approximately fivefold compared with the values of the controls (8.7 n M ; SD, 4.0 vs. 1.8 n M , SD, 1.0; p < 0.0003), and they were elevated in 64% of the VPA-treated patients compared with none of the other patients, p = 0.0006. Serum sex hormone–binding globulin levels were increased, and serum dehydroepiandrosterone sulfate concentrations decreased in the pubertal patients taking CBZ. The mean testicular volumes did not differ between the patients and the controls.
Conclusions: CBZ and VPA, but not LTG and OXC, are associated with changes in serum sex-hormone levels in boys and young men with epilepsy. However, the long-term health consequences of these reproductive endocrine changes during pubertal development remain to be established.     

Antiepileptic drugs alter reproductive endocrine hormones in men with epilepsy

Disturbances of reproductive endocrine hormones are more often found in men with epilepsy than in the general population. There is an ongoing debate whether this can be attributed to chronic use of antiepileptic drugs or to the epilepsy itself. The aim of the present study was to evaluate the degree of endocrine disturbances in men with epilepsy compared with healthy controls, and to investigate whether there was a drug-specific effect of valproate (VPA) or carbamazepine (CBZ). Men with epilepsy, 20-40 years old, having used either VPA (n = 16) or CBZ (n = 19) as monotherapy for >2 years were included and compared with age-matched controls. Men with epilepsy (VPA + CBZ) had significantly lower FSH values and higher C-peptide values compared with controls. Regarding possible drug-specific effects, the VPA treated patients had significantly higher dehydroepiandrosterone (DHEAS) levels and lower FSH and LH concentrations compared with the controls, whereas there were no differences in testosterone, testosterone/sexhormone-binding globulin (SHBG) ratio or androstenedione levels. Men on VPA also had significantly lower free carnitine/total carnitine, which may have implications for sperm motility, and also higher insulin and C-peptide concentrations. The CBZ treated patients had significantly lower testosterone/SHBG ratio than the controls. Compared with the CBZ treated patients, men on VPA had significantly higher DHEAS concentrations and lower levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) as well as a lower free carnitine/total carnitine ratio. A marked age dependency was found in all three groups regarding several of the endocrine hormones. In conclusion, drug-specific endocrine effects of VPA and CBZ were found in men with epilepsy. Long-term VPA treatment leads to significant changes in DHEAS, FSH, LH, insulin, C-peptide and carnitine ratio. Long-term CBZ treatment leads to significant lower testosterone/SHBG ratio. A strict age matching were found to be of importance in the evaluation of endocrine function in men.     

Disorders of reproduction in patients with epilepsy: antiepileptic drug related mechanisms.

Epilepsy, antiepileptic drugs (AEDs), and the reproductive system have complex interactions. Fertility is lower in both men and women with epilepsy than in the general population. Moreover, reproductive endocrine disorders are more common among patients with epilepsy than among the population in general. These disorders have been attributed both to epilepsy itself and to AEDs. The use of the liver enzyme inducing AEDs phenobarbital, phenytoin and carbamazepine increases serum sex hormone binding globulin (SHBG) concentrations in both men and women with epilepsy. Over time the increase in serum SHBG levels leads to diminished bioactivity of testosterone and estradiol, which may result in diminished potency in men and menstrual disorders in some women, and, thus, to reduced fertility. Valproate (VPA) medication may have effects on serum androgen concentrations and it reduces serum follicle stimulating hormone levels in men with epilepsy. However, the clinical significance of the VPA related reproductive endocrine changes in men is unknown. On the other hand, in women the use of VPA is associated with a frequent occurrence of reproductive endocrine disorders characterized by polycystic changes in the ovaries, high serum testosterone concentrations (hyperandrogenism) and menstrual disorders. Young women with epilepsy seem to be especially vulnerable to the effects of VPA on serum androgen levels. The endocrine effects of the new AEDs have not been widely studied. However, it seems they may offer an alternative if reproductive endocrine problems emerge during treatment with the older antiepileptic drugs. On the other hand, it seems that in many cases the reproductive endocrine effects of the AEDs are reversible, if the medication is discontinued.     

Thyroid function in men taking carbamazepine, oxcarbazepine, or valproate for epilepsy

PURPOSE: Antiepileptic drugs (AEDs) may affect serum thyroid hormone concentrations. This study aimed to evaluate thyroid function in men taking carbamazepine (CBZ), oxcarbazepine (OCBZ), or valproate (VPA) for epilepsy. METHODS: Ninety men with epilepsy (40 taking CBZ, 29 taking OCBZ, and 21 taking VPA monotherapy) and 25 control subjects participated in the study. After clinical examination, a blood sample for hormone, gamma-glutamyl-transferase (GGT) and antibody (ab) assays was obtained. RESULTS: Serum thyroxine (T4) and free thyroxine (FT4) concentrations were low in men taking CBZ or OCBZ. Forty-five percent of men taking CBZ and 24% of men taking OCBZ had serum T4 and/or FT4 levels below the reference range. However, no correlations were found between T4 or FT4 and GGT concentrations in men taking CBZ or OCBZ. Thirteen percent of men taking CBZ, 17% of men taking OCBZ, and 6% of control men had increased levels of thyroid peroxidase (TPO)-ab and/or thyroglobulin (TG)-ab, but these were not associated with altered serum thyroid hormone concentrations. Serum triiodothyronine and thyrotropin levels in men taking CBZ or OCBZ were normal. In men taking VPA, the concentrations of thyroid hormones, thyrotropin, and antithyroid ab were normal. CONCLUSIONS: Serum thyroid hormone concentrations are low in CBZ- or OCBZ-treated men. However, these low levels do not seem to be due to liver enzyme induction or activation of immunologic mechanisms. Therefore, interference with hypothalamic regulation of thyroid function by CBZ and OCBZ seems possible. VPA does not have any significant effects on thyroid function.     

Thyroid function in girls with epilepsy with carbamazepine, oxcarbazepine, or valproate monotherapy and after withdrawal of medication

Summary: Purpose: Antiepileptic drugs may affect the serum thyroid hormone concentrations. The aim of this study was to evaluate thyroid function in 78 girls taking carbamazepine (CBZ), oxcarbazepine (OXC), or valproate (VPA) monotherapy for epilepsy and after withdrawal of the treatment. Methods: Forty‐one girls taking VPA, 19 taking CBZ, and 18 taking OXC for epilepsy, as well as 54 healthy age‐matched controls, aged 8 to 18 years, participated in the study. All the girls were examined clinically, and their pubertal stage was assessed. Blood samples were obtained for thyroid hormone and antibody assays. These examinations were repeated after a mean follow‐up of 5.8 years to assess thyroid function, and 64 (82%) of 78 patients and 42 (78%) of 54 controls agreed to participate in the second evaluation. Results: In the first evaluation, the mean serum thyroid hormone concentrations were lower in the girls taking CBZ [thyroxine (T₄), 70.2; SD, 10.9 nM; and free thyroxine (FT₄), 11.5; SD, 1.8 pM] or OXC (T₄, 74.9; SD, 16.4 nM; and FT₄, 11.3; SD, 1.8 pM) than in the control girls (T₄, 96.6; SD, 15.1 nM, and FT₄, 14.4; SD, 1.5 pM; p < 0.001, all comparisons). However, thyrotropin (TSH) concentrations were normal in the girls taking CBZ or OXC. Sixty‐three% of the girls taking CBZ and 67% of the girls taking OXC had serum T₄ and/or FT₄ levels below the lower limit of the reference range. The VPA‐treated girls with epilepsy had normal serum T₄ and FT₄ concentrations, but slightly increased TSH levels (3.3; SD, 1.5 mU/L; p < 0.01) compared with the control girls (2.5; SD, 1.0 mU/L). Normal serum hormone concentrations were restored in the patients who discontinued the medication. Conclusions: Both CBZ and OXC reduce serum thyroid hormone concentrations in girls with epilepsy. Conversely, VPA is associated with normal serum thyroid hormone and increased thyrotropin levels. However, our results suggest that the changes in serum thyroid hormone and thyrotropin levels are reversible after withdrawal of the medication.     

Carbamazepine, Phenytoin, Sex Hormones, and Sexual Function in Men with Epilepsy

Summary We evaluated the effects of carbamazepine (CBZ) on serum androgen levels and sexual function prospectively for 5 years in 11 men with epilepsy and in 25 patients receiving either CBZ (14 patients) or phenytoin (PHT) (11) monotherapy for >5 years. Serum sex hormone binding globulin (SHBG) levels increased and free androgen index (FAI) decreased during CBZ treatment, and these changes correlated with duration of CBZ therapy. Similarly, serum SHBG levels increased and FA1 values decreased in patients receiving PHT for >5 years. CBZ and PHT increase serum SHBG levels, leading to decreased FAI. These drugrelated hormonal changes may be the primary cause of hyposexuality common in men with epilepsy.     

Growth and lipid metabolism in girls and young women with epilepsy during pubertal maturation

Summary:  Purpose: To assess growth and the serum lipid profile in girls with epilepsy receiving monotherapy at a mean age of 12.6 years and approximately 6 years later.
Methods: A population-based cohort of 77 girls with epilepsy and 49 healthy controls participated in this follow-up study including two cross-sectional evaluations (age range, 8–18.5 years on the first evaluation, and 12.5–25.8 years on the second evaluation). Forty of the patients were initially taking valproate (VPA), 19, carbamazepine (CBZ), and 18, oxcarbazepine (OXC). Growth data were compiled, body mass index (BMI) was calculated, and serum total (TC), and high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterol and triglyceride concentrations were analyzed.
Results: Linear growth and final height did not differ between the patients and the controls. At follow-up, the mean BMI of the patients who were off medication (61%) was similar to that of the controls, whereas the patients initially treated with VPA who were still taking any medication had a higher BMI. On the first evaluation, the patients taking VPA had low serum HDL-C, and those taking CBZ or OXC had high serum TC and LDL-C concentrations. At follow-up, serum lipid levels were similar in the patients off medication and the controls.
Conclusions: Neither epilepsy nor antiepileptic therapy affects linear growth or final height, but they may have unfavorable effects on body weight and serum lipid concentrations. Lipid-profile impairment seems to be transient if the medication is discontinued. Overweight is common in patients treated with VPA during puberty if epilepsy and medication continue into adulthood.     

Menstrual Disorders in Women with Epilepsy Receiving Carbamazepine

Summary: We measured concentrations of serum sex hormones and sex hormone binding globulin (SHBG) in relation to regularity of the menstrual cycles in 8 women before carbamazepine (CBZ) treatment was initiated and after 1 and 5 years of CBZ therapy. In addition, we evaluated menstrual cycle regularity and related endocrine changes in 56 women receiving CBZ treatment for >5 years. Serum SHBG levels increased, and serum concentrations of 17β-estradiol (estradiol) and estradiol/SHBG ratio decreased during CBZ treatment. Two of the 8 patients (25%) in the prospective study group developed menstrual irregularities during the first 5 years of therapy. In the cross-sectional study group of patients treated with CBZ for >5 years, the frequency of menstrual disturbances was also 25.0% (14 of 56 patients). Concentrations of serum sex hormones and SHBG were measured in 13 women with menstrual disorders and in 11 randomly selected women with regular cycles. In most cases, menstrual disorders were associated with increased serum SHBG and decreased serum estradiol levels and low estradiol/SHBG ratio. Long-term CBZ treatment results in increased serum SHBG levels and decreased estradiol effect, which correlate with the frequency of menstrual disorders in CBZ-treated women with epilepsy.