Frontotemporal dementia

Neurological Sciences - Frontotemporal dementia is a clinicopathological syndrome caused by progressive degeneration of the frontal lobes, anterior temporal lobes or both. A wide spectrum of...     

Beta-blockade antagonism of tyramine-induced rise in blood pressure

Summary The effect -adrenoceptor blockade on the pressor response to tyramine has been investigated in 6 healthy volunteers, each submitted to an i.v. tyramine pressor test before and after 7 days of propranolol 40 mg b.d. or indenolol 60 mg o.d. Tyramine was given as i.v. boluses of 1–6 mg, alternating with saline, in a randomized, single blind fashion.Prior to treatment tyramine caused a temporary, dose-dependent increase in systolic and diastolic blood pressure, whilst the heart rate remained unaffected. Both propranolol and indenolol reduced the pressor response to tyramine, as shown by a significant increase in ED₁₅, i.e. the dose of tyramine required to increase systolic blood pressure by 15%.     

Dihydroergocriptine in management of microprolactinomas

The effects of dihydroergocriptine (DHECP), a dihydrogenated ergot alkaloid with dopaminergic agonistic and alpha-adrenergic antagonistic properties, were studied in 22 women with PRL-secreting microprolactinomas and compared with those recorded in 36 previously studied patients treated with bromocriptine (BRC). After acute administration of 5 mg DHECP, orally, serum PRL decreased by 61 +/- 18% (+/- SD); only 1 patient was unresponsive. The nadir was reached at 300 min. Long term treatment with increasing DHECP doses caused a progressive PRL fall from 125 +/- 142 (+/- SD) to 81 +/- 159 micrograms/L after 1 week of a 3 mg twice daily regimen, to 64 +/- 88 micrograms/L after 1 week of 5 mg twice daily, 46 +/- 57 micrograms/L after 1 week of 10 mg twice daily, and 28 +/- 34 to 33 +/- 45 micrograms/L throughout 9 months of treatment with 10 mg DHECP 3 times daily. Seventy-seven percent of patients had normal serum PRL levels during chronic treatment. All women, including those with supranormal serum PRL levels, resumed regular menses, and 16 had ovulatory cycles; 1 woman became pregnant. Galactorrhea disappeared in all. During treatment the PRL response to TRH, initially absent in all patients, became positive in 10. In 7 patients, after DHECP treatment for 9 months, high definition computed tomographic scan no longer showed the focal lesions initially seen. After drug withdrawal, serum PRL increased again in all except 1 patient. Two patients had regular menses for 6 months, and 3 still had no adenoma imaged by high definition computed tomography. In BRC-treated patients the serum PRL changes and clinical results were very similar to those in the DHECP-treated patients, except for the persistence of normal serum PRL levels in 4 patients after drug withdrawal. On the other hand, side-effects were negligible during DHECP treatment, but remarkable during BRC. Systolic and diastolic blood pressures decreased by only 5.4 and 3.0 mm Hg, respectively, after acute 5 mg DHECP administration, but decreased by 12.8 and 14 mm Hg after acute 2.5 mg BRC administration. Orthostatic hypotension and peripheral vasomotor phenomena occurred in the long term DHECP treated patients except one, but they occurred in 9 and 3 of those treated with BRC, respectively. Gastric discomfort or mild nausea occurred in 12 DHECP-treated patients, while mild or severe nausea or vomiting were observed in 18, 11, and 2 of those taking BRC, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)     

Alpha-dihydroergocryptine and predictive factors in migraine prophylaxis

OBJECTIVE: A double-blind, crossover study was carried out to compare the efficacy of alpha-dihydroergocryptine mesylate (10 mg twice daily) vs propranolol (40 mg twice daily) in the prophylaxis of migraine without aura, and to identify possible predictors of therapeutic response by evaluating the symptomatological profile of individual migraine attacks and the autonomic cardiovascular response to noradrenergic and dopaminergic (cold pressor, bromocriptine) tests. PATIENTS AND METHODS: Forty migraineurs (10 males, 30 females) were randomized according to a two-period (3-month), two-treatment, crossover design. Efficacy was assessed using quantitative data recorded in the patient's headache diary. Data were evaluated using the Wallenstein's method. RESULTS: Both drugs showed a significant reduction in all the efficacy variables (headache attacks, days with headache, analgesic consumption) with no difference between treatments. Neither a bromocriptine test, nor a cold pressor test nor the symptomatological profile of individual migraine attacks differed between the two groups of migraine patients. Ten patients experienced at least one adverse drug reaction during the first period of the crossover design, 5 being treated with alpha-dihydroergocryptine and 5 with propranolol. CONCLUSIONS: It is concluded that alpha-dihydroergocryptine is an effective medication for migraine prophylaxis. The biochemical tests and the type of psychological profile cannot be used to predict drug response.     

Prolactin lowering effect of dihydroergokryptine in rat and in man

The prolactin lowering activity of dihydroergokryptine was investigated both in rats and in humans. The drug was administered orally at the doses of 0.2, 1 and 5 mg/Kg to intact or reserpinized male rats. Nine male adult volunteers were given 300 mg cimetidine iv 90 min after receiving 2, 3 or 4.5 mg of dihydroergokryptine and 3, 4.5 and 6.75 mg of dihydroergocristine or placebo per os in a randomized, cross-over design. Eight young adult males were injected im with 10 mg sulpiride 120 min after randomly receiving dihydroergokryptine 2.5 and 5 mg or placebo in a cross-over manner. Finally, five healthy young women were given dihydroergokryptine 2.5 and 5 mg, bromocriptine 2.5 mg and placebo in a cross-over design. Dihydroergokryptine caused a strong, long-lasting, dose-dependent fall of plasma prolactin concentrations in both rats and humans. Moreover, it inhibited the reserpine-induced rise of plasma prolactin in rats, as well as the cimetidine-or sulpiride-induced hyperprolactinemia in humans. Dihydroergokryptine proved twice as potent as dihydroergocristine and about half as potent as bromocriptine. Effective doses of both dihydrogenated ergot alkaloids were much better tolerated than bromocriptine.     

Pharmacokinetics of alpha-dihydroergocryptine in rats after intravenous and oral administration.

The pharmacokinetic properties of alpha-dihydroergocryptine methanesulphonate (alpha-DHEK, CAS 19467-62-0) were investigated in rat using a radioimmunoassay technique for nonmetabolized drug. alpha-DHEK, intravenously administered at the dose of 6 mg/kg, showed a plasma profile according to an open 3-compartment pharmacokinetic model with a long half-life (about 7.56 h). The kinetics of alpha-DHEK after oral administration (6 mg/kg) showed two peaks; the second peak at 8 h was probably due to an enterohepatic cycle. The disposition of alpha-DHEK consisted in a fast absorption and a slow elimination (t1/2el about 6.78 h). The alpha-DHEK was largely metabolized as results from the complex metabolite profile in body fluids and from very low urinary elimination of unchanged drug.     

The effects of amineptine on the mood and nocturnal sleep of depressed patients

The effect of amineptine, a new tricyclic antidepressant, was studied on the sleep of 12 depressed patients. A single blind comparative trial vs placebo was carried out and changes in depression symptoms were recorded using Hamilton Rating Scale for Depression (HRSD). The sleep was evaluated according to the Rechtschaffen and Kales criteria to determine various parameters. Amineptine treatment induced statistically significant reduction of HRSD total score after 14 days of treatment. Polysomnographic analysis revealed significant differences between depressed patients and healthy volunteers.     

Indenolol pharmacokinetics and pharmacodynamics after single and repeated daily doses

The relationship between indenolol (an investigational agent) plasma levels and the drug's effect on blood pressure and heart rate was investigated after single and repeated once daily administration at two dosage levels (60 mg and 120 mg) in two different groups of patients with first or second stage hypertension, according to the World Health Organization classification. The pharmacokinetic data were indicative of a first order absorption-elimination curve; time of maximum plasma levels was 1.5 to two hours, and elimination half-life was four hours. The drug did not accumulate in the central compartment after repeated administrations. A long-lasting decrease of both resting and isometric exercise systolic pressure values was recorded after acute indenolol administration. Diastolic pressure was affected only by repeated administrations. The lower dose (60 mg daily) of indenolol did not affect heart rate, whereas the higher dose (120 mg daily) decreased this parameter. A steady state of pressure values and heart rate was reached after 14 days of once daily treatment.     

Validation of bovine hoof slices as a model for infected human toenails: in vitro ciclopirox transungual permeation

Background Topical therapy has recently been proposed for treating onychomycosis and other nail disturbances. However, the clinical outcome may be limited by the difficulty of active ingredients effectively penetrating the nail plate. Bovine hoof membranes have been widely used to predict in vitro efficacy of drug products in nail diseases. Many studies have compared bovine hooves with human healthy nails, considering the difference between healthy and unhealthy nails to be negligible. Objectives To validate bovine hoof slices as a model for human unhealthy nails by investigating the transungual permeation/retention of ciclopirox (CPX) through bovine hoof slices and excised infected human toenails after application of a new film‐forming formulation (P‐3051). To investigate the ability of CPX to achieve fungicidal concentrations in and through infected toenails. Methods A new experimental technique based on a permeation unit allowed analysis by high‐performance liquid chromatography of the amounts of CPX permeating through and retained in the membranes. The efficacy index was evaluated as follows: amount of permeated CPX/Trichophyton rubrum minimum inhibiting concentration. Results Extrapolated CPX flux through bovine hoof slices was about 14‐fold higher than through infected human toenails, the difference being mainly due to the fourfold higher thickness of the toenails. In toenails, the CPX efficacy index for T. rubrum was positive (> 1·0) soon after P‐3051 application. Conclusions This study confirms the validity of bovine hoof slices as a model for infected human nails, and suggests a substantial equivalence between the two models. Following P‐3051 application, CPX reaches fungicidal concentrations in and through human infected toenails.