Seizures during concomitant treatment with theophylline and ranitidine: a case report.

H2-antagonists such as cimetidine and ranitidine are metabolized by cytochrome P-450. In this way they may interfere with theophylline metabolism. Cimetidine is known to have this effect and frequently to induce a theophylline toxic effect, while data concerning ranitidine are more uncertain. In this paper, we report the case of a 67-year-old woman with non-insulin dependent diabetes. She was taking aminophylline for respiratory failure and after ranitidine infusion exhibited generalized convulsions. Theophylline values which were monitored within the therapeutic range, increased toxic levels after ranitidine therapy and epileptic episodes. The increase in theophylline levels was associated with a further reduction in the clearance rate of the bronchodilator. We think that ranitidine may combine with other clinical factors known to reduce theophylline metabolism mainly in the elderly and severely ill patients. Theophylline-induced seizures may occur when theophylline serum levels are slightly above the therapeutic range, as in our case report.

[The neuroendocrine aspects of chronic alcoholism: the effect of alcohol intake and its withdrawal]. / Aspetti neuroendocrini dell'etilismo cronico: effetto dell'assunzione di alcool e della sua sospensione.

Neuroendocrine dysfunctions, in part similar to those found in depression, are present in chronic alcoholism. The aim of this investigation was to evaluate the effects of chronic alcohol intake on cortisol secretion in basal conditions, after dexamethasone (DXT) suppression or corticotropin (ACTH) stimulation in 10 alcoholic men, during active drinking and after two weeks of alcohol withdrawal. The 24-hour, day- and night-time urinary cortisol and melatonin levels, and the effects of thyrotropin releasing hormone (TRH) on thyrotropin (TSH) and prolactin (PRL) secretions were studied in the same subjects. The data were correlated to the scores obtained by the Hamilton Rating Scale for depression and compared to those found in healthy subjects. Increased cortisol levels and the lack of DXT suppression of cortisol secretion are considered to be alcohol-dependent inasmuch as they disappear in most patients after alcohol withdrawal. The cortisol response to ACTH 1-24 infusion measured before and after alcohol withdrawal was similar in the patients we studied; moreover no significant difference was found between patients and controls. The increment of urine free cortisol levels in active alcoholics was not statistically significant. Urine cortisol levels became similar to those of the control subjects after alcohol withdrawal. The increased diurnal values of urine melatonin and the inversion of the physiological ratio between nocturnal and diurnal levels observed during alcohol intake became normal upon alcohol withdrawal. The TSH and PRL responses after the administration of 50 or 200 micrograms TRH were higher in alcoholics than in controls, while a blunted response is known to occur in depression.

Circadian secretion of melatonin and thyrotropin in hospitalized aged patients.

Alterations in periodical functions are known to occur in aging and may be regarded as markers of the aging process itself. Melatonin and Thyroid Stimulating Hormone (TSH) circadian periodicities were studied in 22 aged subjects and in 13 adult controls. The study of rhythmicity was performed by the Cosinor analysis. Elderly subjects were hospitalized because of various concomitant diseases. Circadian periodicity of both hormones was disrupted in the aged group, and the deterioration of melatonin periodicity was significantly correlated with the decay in cognitive functions, quantified by the Mini Mental State evaluation. Diabetes was also found to affect, though not significantly, melatonin, but not TSH, periodicity. Melatonin and TSH nocturnal peaks were decreased in aged people. TSH oscillation amplitudes were inversely correlated with age. No correlation was found between melatonin and TSH secretory features both in adult and in aged subjects.

Urine melatonin in alcoholic patients: a marker of alcohol abuse?

Ethanol is known to alter central neurotransmission and endocrine functions. Urine melatonin was studied in 10 male chronic alcoholic patients, before and after two weeks of controlled alcohol abstinence, and in sex and age matched healthy controls. In both groups, 24-hour urines were collected in two fractions corresponding to day- (D) (08:00-20:00) and night- (N) (20:00-08:00) time. Urine melatonin was assayed by RIA after methylene chloride extraction. Twenty-four hour urine melatonin levels were calculated adding up D and N values. In patients during alcohol intake, the 24-hour urine melatonin levels were significantly higher than in controls (p = 0.004, Student's t test). A disruption of the physiological ratio between N and D values was also observed, since the higher melatonin levels occurred in the D fraction. In drinking alcoholics, melatonin D values were significantly higher than the D values found in controls (p less than 0.01, Student's t test) and in the same patients after alcohol withdrawal (p less than 0.05). The N/D ratio approximated 1 during alcohol intake and became larger than 1 after alcohol withdrawal, as in the controls. The melatonin data were correlated with the suppressive effects of dexamethasone (DXT) on cortisol secretion evaluated both during alcohol intake and during abstinence. After alcohol withdrawal, the two (out of 10) patients, who remained unresponsive to the DXT suppression test, showed high D melatonin values and a low N/D ratio. These preliminary data indicate that in chronic alcoholism the pattern of urinary "melatonin- like immunoreactivity" is altered.

Urinary melatonin excretion throughout the ovarian cycle in menstrually related migraine.

Nocturnal urinary melatonin excretion was significantly decreased throughout an ovarian cycle in 12 migraine without aura patients compared to 8 healthy controls. Normal increases in urinary melatonin excretion during the luteal phase was less pronounced in the migraine patients. Melatonin excretion was further decreased during headache. The data indicate impaired pineal function in migraine.

Relationship between cognitive function, growth hormone and insulin-like growth factor I plasma levels in aged subjects.

Basal growth hormone (GH) and insulin-like growth factor I (IGF-I) as well as GH responses to GH-releasing hormone (GHRH) were studied in 22 subjects (7 females, 15 males), aged between 65 and 86 years. The study was aimed at investigating the possible correlations between the age-dependent GH-IGF-I axis decline and the cognitive function - assessed by the Mini Mental State Examination (MMSE). The relationship between hormonal data, cognition and age, body weight, body mass index (BMI), some nutritional indices (triceps skinfolds, TSF, mid-arm circumference, MAC), and physical activity - quantified by the physical functioning index (PFI)--were also analyzed. GH basal levels were within the normal range, while GH responses to GHRH were blunted in most cases. GH peaks after GHRH were directly correlated with GH basal values. IGF-I serum levels were found to be in the lower part of the reference range for adult subjects or below it. GH responses to GHRH, but not GH and IGF-I basal levels, were inversely correlated with subject age. GH secretion areas after GHRH were inversely correlated with BMI, but no further correlations between GH data and clinical or nutritional parameters were found. MMSE values directly correlated with MAC and PFI values. IGF-I levels were directly correlated with MMSE scores, being lowered in patients with more advanced cognitive deterioration, and with MAC values--the decrease of which is thought to reflect protein caloric malnutrition--but not with body weight, BMI, TSF and PFI. MMSE-related protein caloric malnutrition and decreased physical activity possibly take part in affecting IGF- I function in subjects with mild cognitive impairment and, reciprocally, IGF-I decrement might affect neuronal function.

Effects of pyridostigmine, corticotropin-releasing hormone and growth hormone-releasing hormone on the pituitary-adrenal axis and on growth hormone secretion in dementia.

Alterations of neuroendocrinological indices determined by the impaired regulating effects of cholinergic neurotransmission have been described in primary dementia. In this study we have evaluated the effects of acetylcholinesterase inhibition by pyridostigmine on growth hormone (GH), adrenocorticotropic hormone (ACTH) and cortisol secretion and on their responses to GH-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) in 7 patients with primary degenerative dementia and in 8 sex- and age-matched controls. Demented subjects showed higher cortisol basal levels and lower ACTH levels than controls. Pyridostigmine increased the GH response to GHRH in both groups, the effect being significantly enhanced in patients. An increase of ACTH and cortisol levels was found in both groups after pyridostigmine and CRH administration. Pyridostigmine pretreatment significantly increased the ACTH response to CRH in controls but not in patients. The obtained data may indicate that a muscarinic receptor upregulation and an impairment of somatostatinergic function are operative in the regulation of GH secretion in dementia. An underlying hyperactivity of the hypothalamic-pituitary-adrenal axis impairs the responses of ACTH and cortisol to CRH in this disorder.

Melatonin and cortisol circadian secretion during ethanol withdrawal in chronic alcoholics.

Changes in central neurotransmission and in hypothalamo-pituitary function occur in both ethanol (ETOH) intake and withdrawal. Melatonin (MLT) secretion is regulated by the noradrenergic system, which is activated upon ETOH withdrawal. Experimental evidence exist that pineal gland may have a role in ETOH intake and preference in rats. Twenty-four hour urinary excretion of MLT was found to be increased during ETOH intake in chronic alcoholics. In this study we have determined 24h plasma levels of MLT and cortisol in 8 chronic alcoholic males hospitalized for a detoxication program and in 8 healthy controls. The study was performed just after admission, on the first day of ETOH withdrawal and after 14 days of controlled abstinence. Circadian periodicity has been evaluated by the cosinor method. The initial determinations corresponded to the acute withdrawal phase. Twenty-four hour plasma MLT mean levels on acute withdrawal were higher than after 14 days abstinence and than those found in controls. Large interindividual differences prevented the detection of statistical significance. The cosinor analysis disclosed the loss of circadian periodicity in the acute withdrawal. Significant 24h periodicity was restored after 14 days abstinence. Cortisol levels were significantly higher than those found on day 14 and in healthy controls. Twenty-four hour periodicity was maintained in both alcoholics series. A delay in cortisol acrophase occurred in acute withdrawal. The effects of Corticotropin Releasing Hormone infusion on cortisol secretion were significantly enhanced in the acute withdrawal phase in comparison with those occurring when patients were retested and with healthy controls.

Sex hormones, gonadotropins and prolactin in male epileptic subjects in remission: role of the epileptic syndrome and of antiepileptic drugs.

Sex steroid peripheral pattern, pulsatile luteinizing hormone (LH) secretion, gonadotropin and prolactin responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) were studied in 35 male epileptics treated with phenobarbital (PB), carbamazepine (CBZ), or phenytoin (PHT), and in age-matched healthy males. Idiopathic generalized epilepsy (IGE) was diagnosed in 12 cases and partial epilepsy (PE) in 23 cases. Patients were seizure-free and did not show EEG abnormalities at repeated controls in the last 5 years, so that interfering effects of seizures were possibly excluded. The aim of the study was to evaluate both the role of epileptic syndromes and of anti-epileptic drugs on the endocrine function. Changes in sex hormone binding globulin, total and free testosterone, dihydrotestosterone and delta 4-androstenedione were found to be independent of the epileptic syndrome type. The LH response to LHRH was lower in PB-treated PE than in IGE subjects on the same drug regimen. An impairment of LH pulsatility with respect to controls was found in PE but not in IGE patients taking PB. Among antiepileptic drugs, PHT is associated with higher sex hormone binding globulin and estradiol and lower free testosterone and dihydrotestosterone levels. PB and CBZ, but not PHT, blunt the LH response to exogenous LHRH in PE. Prolactin responses to TRH were consistently enhanced in PE subjects treated with CBZ or PHT.

Sex hormones and pituitary function in male epileptic patients with altered or normal sexuality.

Male epileptic patients frequently complain of sexual dysfunction, particularly impotence and loss of libido. Epilepsy itself, antiepileptic drugs (AEDs), and psychosocial factors are believed to contribute to impaired sexuality. We studied luteinizing hormone (LH) pulsatile secretion, gonadotropin, and prolactin (PRL) responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) in 37 adult male epileptic patients receiving AED monotherapy who were seizure-free and had normal EEGs. Sexuality was assessed by psychological interview. Impotence was diagnosed in 8 patients (in 2 combined with loss of sexual desire). The occurrence of hyposexuality (approximately 20%) was independent of epilepsy syndrome or AED. No change in total testosterone (T) level was observed. Free T (fT) and dihydrotestosterone (DHT) levels were lower and sex hormone binding globulin (SHBG) levels were higher in epileptic subjects than in healthy controls, but a statistically significant difference was not observed between hypo- and normosexual patients. In impotent epileptic patients, estradiol (E2) levels were significantly increased as compared with those of patients with preserved sexuality and of healthy controls. The unbalanced relation between androgen and E2 levels was emphasized by decreased T/E2, fT/E2, and DHT/E2 ratios obtained in hyposexual epileptic patients. In this group, LHRH induced blunted LH peaks. No changes were noted in LH pulsatility features. These findings of higher E2 levels and of decreased LH response to LHRH administration in some epileptic patients with impaired sexuality, may suggest they have subclinical hypogonadotropic hypogonadism.

Cholinergic modulation of growth hormone-releasing hormone effects on growth hormone secretion in dementia.

An impairment of cholinergic and somatostatinergic neurotransmission have been reported in dementia. Both acetylcholine and somatostatin are involved in the regulation of growth hormone (GH) secretion. The effects of GH-releasing hormone (GHRH) 1-44 on GH release have been studied before and after the pretreatment with pyridostigmine or pirenzepine in subjects with senile dementia of the Alzheimer type, multi-infarct dementia and mixed dementia. The data have been compared with those obtained in an age-matched healthy control group. The GH response to GHRH is similar in the patients and in the controls, though the peak occurrence is significantly delayed in dementia. The cholinesterase inhibitor pyridostigmine enhances significantly the GH response to GHRH in both groups. The responses obtained in demented subjects are significantly larger than those found in the controls. Pirenzepine, a muscarinic receptor blocker, inhibits the GHRH effect on GH secretion in both groups. The findings may be interpreted in terms of an underlying impairment of the hypothalamic cholinergic neurotransmission, with an acetylcholine receptor supersensitivity that becomes apparent when the cholinergic tonus is enhanced by the inhibition of cholinesterase by pyridostigmine. No significant differences, due to the type of dementia, have been observed.