Biomedical subjects

P R Bittencourt

Publications and source records attributed to P R Bittencourt.

At least 19 recordsLinked to original sources

PubMed1994

Carbamazepine kinetics in cardiac patients before and during amiodarone.

Carbamazepine and amiodarone may often be used together, especially in countries where cardiomyopathies are common. In this study single doses of carbamazepine (400 mg) were given to patients with cardiac disease before and after one month of therapy with amiodarone, 400 mg daily. The kinetic profile of carbamazepine, its free fraction, and serum amiodarone, were measured at the two occasions. There was no statistically significant change in carbamazepine kinetics or free fraction, before and after the introduction of amiodarone. The concentrations of amiodarone after one month of therapy were low. It is suggested that the possible interaction in the hepatic metabolism was not demonstrated because amiodarone concentrations were not enough to inhibit carbamazepine metabolism.

Adult↗

PubMed1993

Carbamazepine and phenytoin in epilepsies refractory to barbiturates: efficacy, toxicity and mental function.

A group of 51 patients with chronic cryptogenic or symptomatic localized epilepsy refractory to therapy with barbiturates underwent progressive substitution with phenytoin or carbamazepine, in standardized and randomized fashion. After drug changes were completed two thirds of the patients remained seizure free during a period of 6 months. A clearer effect of phenytoin and carbamazepine was seen on secondary generalized than on partial seizures. The frequency of severe side effects decreased after the change to phenytoin and carbamazepine. The group on carbamazepine improved in immediate and late recall, and in immediate and late recognition of pictures. The group on phenytoin improved significantly in the Stroop test. Patients changed to phenytoin, but not those changed to carbamazepine, became significantly more aggressive, anxious and depressive than when on phenobarbital, as measured by subjective scales. The results indicate that patients should not be considered refractory to antiepileptic drug therapy while on barbiturates. Cognitive dysfunction and mood changes observed in epilepsy may be temporary and dependent on the presence of seizures and/or on use of barbiturates.

Adolescent↗

PubMed1992

Phenytoin and carbamazepine decreased oral bioavailability of praziquantel.

Antiepileptic drugs, especially carbamazepine and phenytoin, are potent liver enzyme inducers. Since praziquantel, the drug used to treat neurocysticercosis, undergoes extensive liver first-pass metabolism, we carried out a prospective study to verify whether there was a decrease in oral bioavailability induced by carbamazepine and phenytoin. Carbamazepine and phenytoin significantly decreased concentrations of praziquantel, due to increased clearance secondary to induction of first pass-liver metabolism. The magnitude of the decrease is surprisingly high and may be responsible for failures of treatment.

Adult↗

PubMed1992

Cognitive functions, epileptic syndromes and antiepileptic drugs.

Cognitive function of patients on monotherapy specific for their epileptic syndrome has been studied infrequently. We evaluated 7 patients with symptomatic localised epilepsies (SEL) on phenytoin aged 30 +/- 12 (mean +/- standard deviation) years, 8 with idiopathic generalised epilepsies on sodium valproate aged 18 +/- 4 years, 16 with SEL on carbamazepine aged 28 +/- 11 years, and 35 healthy controls aged 27 +/- 11 years. All subjects were of normal intelligence, educated appropriately to age, and led productive lives in the community. Two of the patients on carbamazepine and one on valproate had less than five partial, absence or myoclonic seizures monthly, the remaining were controlled. Carbamazepine serum concentrations were 12 +/- 5 micrograms/ml, phenytoin were 23 +/- 7, and valproate were 62 +/- 23 (mean +/- sd). Tests included immediate recall and recognition for pictures, Stroop test, delayed recall and recognition of pictures. Patients on phenytoin and valproate performed significantly worse than controls on immediate recall, and patients on carbamazepine performed significantly worse than controls in Stroop test (p < 0.01). The results indicate relatively minor effects of the epileptic syndromes and of phenytoin, carbamazepine and valproate on cognition of patients with controlled epilepsy leading productive lives in the community. We conclude that the cognitive deficit found in chronic epileptic patients on poly-therapeutic drug regimen must be multifactorial, and that future studies need to control for all possible variables in order to achieve meaningful results.

Adolescent↗

PubMed1992

[Immunosuppressive treatment in multiple sclerosis].

An open, retrospective, uncontrolled study was carried out to evaluate efficacy and tolerability of immunosuppressive therapy used in the period 1982-1990 in patients with clinically definite multiple sclerosis. Of 42 patients 43% were treated with one drug, and the others with more than one. Tolerability was evaluated after at least 6 months of therapy in 6 patients on prednisone, 26 on azathioprine, 17 on methyl-prednisolone and 15 on cyclophosphamide pulses. Reversible mild or moderate side-effects were noted in 54% of the patients on azathioprine, leading to change in dose or withdrawal. There were similar side-effects in 83% of the patients on prednisone, 40% of those on cyclophosphamide, and in 12% of those on methylprednisolone. Efficacy was evaluated in 15 patients with a follow-up of at least 2 years, measured by objective scales. The results indicated therapy appeared to arrest progress of disability. We conclude that this study supports the use of immunosuppression in selected cases with rapidly evolving neurological deficits.

Adolescent↗

PubMed1991

[Multiple sclerosis: objective criteria of diagnosis].

The frequency of multiple sclerosis in Brasil is assumed to be lower than in some geographically comparable regions, but internationally available objective diagnostic criteria are not generally used. We have reviewed a number of such criteria and applied those of Poser and colleagues to all patients who could be examined specifically for this study; who had been under our care between 1982-87; with clinically satisfactory history, physical exam, ancillary investigations and follow-up; with enough information to warrant immunosuppressive therapy with azathioprine, methyl-prednisolone or cyclophosphamide. There were 35 (88%) females and 5 (12%) males, with clinically definite (85%), probable (10%) disease according to Poser and cols, as well as 2 patients with chronic progressive disease. Age at time of study was 39 +/- 11 years, age at onset had been 32 +/- 10 years, and length of history was 6 +/- 7 years (mean +/- sd). Mode of onset was a disturbance of gait in 50%, of vision in 25% and dizziness in 10%. Physical exam at time of study showed motor deficits in 92.5%, sensory in 67.5%, ocular visual in 65%, spastic bladder in 35%, and vestibulo-cerebellar disturbances in 32%. Visual evoked responses were abnormal in 65% of 31 cases, auditory in 23% of 22 cases, and somatosensory in 80% of 20 cases. This study shows that international diagnostic criteria, specifically those of Poser and colleagues are applicable in Brasil, providing clear guidelines for diagnosis of multiple sclerosis. We suggest objective diagnostic criteria form the backbone of teaching about the disease, at various levels of medical education. Their wide utilization will in due time provide conditions for epidemiological, clinical and therapeutic studies which have not as yet been carried out in this country.

Adult↗

PubMed1991

Cognitive functions of epileptic patients on monotherapy with phenobarbitone and healthy controls.

Quantitative measurements have indicated that heredity, cerebral damage, psycho-social aspects, ictal and inter-ictal phenomena and antiepileptic drugs may interfere in the cognitive dysfunction of epileptic patients. In the present study objective methods included immediate and late recall and recognition of pictures, Stroop test and auditory selection. Twenty patients with symptomatic localized epilepsy aged 17-52 years (27 +/- 10, mean +/- sd) were compared to age and socially matched healthy controls. Patients were on therapeutic serum concentrations (25 +/- 12 mu/ml) of phenobarbitone and had active epilepsy with 1.94 generalized tonic-clonic, 0.85 simple partial and 6.28 complex partial seizures monthly (means). Patients performed worse than controls in all 6 tests (p less than 0.05 to p less than 0.001), indicating a generalized cognitive deficit related to seizures and/or barbiturate therapy. We suggest further studies should be carried out in populations with uniform monotherapeutic regimens and epileptic syndromes in order to isolate factors related to the cognitive dysfunction of epileptic patients.

Adolescent↗

PubMed1990

High-dose praziquantel for neurocysticercosis: serum and CSF concentrations.

Serum and CSF concentrations of praziquantel were analyzed in 8 patients with active neurocysticercosis aged 35 +/- 16 (mean +/- sd) years, in order to determine factors that may improve the therapeutic ratio. Praziquantel was given orally at 6-h intervals for 10 days at a daily dose of 100 mg/kg. Serum concentrations were determined at 1, 2 and 4 h, and CSF concentrations at 2 h after the morning dose. Peak serum concentrations occurred between 1 and 2 h after administration. There was a trend towards a drop in serum concentration from Days 1 through 5 to 10 of therapy. A fourfold increase in oral dose led to an eightfold rise in serum and CSF concentration, indicating saturation of hepatic metabolism. There were linear correlations (p less than 0.01) between serum and CSF concentrations of praziquantel, indicating free flow across the blood-brain barrier, above an apparent threshold, which may be related to occupation of plasma protein-binding sites. The results indicate that monitoring of serum concentrations may be clinically useful.

Administration, Oral↗

PubMed1990

High-dose praziquantel for neurocysticercosis: efficacy and tolerability.

Standard therapeutic regimens of praziquantel for neurocysticercosis use daily doses of 50 mg/kg for 15-21 days, with prolonged remission being achieved in 60-80% patients. In this prospective study, 100 mg/kg daily was used for 10 days in 13 patients aged 32 +/- 15 years (mean +/- SD) with severe intra-, extra-parenchymal or mixed forms of neurocysticercosis. Patients were monitored with computerized tomography and cerebrospinal fluid (CSF) examination on days 1, 5 and 10. Full blood count, sedimentation rate, blood sugar, urea, creatinine, bilirubin, liver transaminases, alkaline phosphatase, urine analysis and electrocardiogram were carried out before and after treatment. Doses of dexamethasone and of other drugs used concomitantly were controlled. There was no toxicity, clinical or detected by the methods employed in the study. After 22 +/- 5 (mean +/- SD) months follow-up, 6 patients needed ventriculoperitoneal shunting, 2 had died, 7 were improved and led useful lives and 4 were in prolonged remission. There was no correlation between serum or CSF praziquantel correlation and outcome of treatment. The proposed regimen is well tolerated, may be as efficient as previously advocated regimens, requires less hospitalization time and may be adopted routinely for therapy of neurocysticercosis.

Adolescent↗

PubMed1990

[Thymectomy and immunosuppression in myasthenia gravis: a prospective study].

Between 1982 and 1988 24 women and 6 men with myasthenia gravis were included in a prospective and standardized diagnostic and therapeutic protocol. Age varied between 10 and 74 years (34 +/- 16, mean +/- standard deviation). Three patients with the ocular form were treated with pyridostigmine. Four patients with the generalized form and advanced age received steroids and/or azathioprine. Twenty-three patients with the generalized form underwent thymectomy followed by prednisone and/or azathioprine. One patient died after complex thymectomy for invasive thymoma. Another died soon after admission in myasthenic/cholinergic crisis. Two other patients had minor complications of thymectomy. Of 19 patients followed for 1-60 (mean 24) months, 11 (58%) are in remission, one of them without any medication.

Adolescent↗

PubMed1990

Clinical, radiological and cerebrospinal fluid presentation of neurocysticercosis: a prospective study.

The wide clinical spectrum of neurocysticercosis has led to many attempts at clinical, radiological, CSF and other classifications. Based on an objective review of the relevant literature and on a prospective study of 42 patients with active neurocysticercosis, a new classification is proposed, based on clinical, tomographic, magnetic resonance and CSF evidence of viability of cysts. The first step is to define whether the disease is active or not. Inactive disease may be parenchymal calcifications or hydrocephalus. Active disease may be intraparenchymal, extraparenchymal or mixed. Statistical analysis of 42 cases with active disease shows intraparenchymal disease to occur in younger patients, perhaps more frequently in females, and to have a better prognosis than extraparenchymal of mixed disease. The latter appears to have the worst prognosis. Therapeutic implications are that only active disease warrants etiological therapy. There remain doubts about the best therapy for some infrequent subtypes of extraparenchymal and mixed disease.

Adolescent↗

PubMed1990

[Spinal cord infarction: clinical, electrophysiologic and laboratory diagnosis].

In the international, but more so in the latin-american, medical literature infarction of the spinal cord has been rarely described except in relationship with surgery of the abdominal aorta. The objective of this report is to describe the diagnostic approach including clinical, electrophysiological, imaging and cerebrospinal fluid criteria. With these methods 17 cases were diagnosed between 1982 and 1989, one related to surgery of the abdominal aorta. This series suggests that infarction of the spinal cord is a more common clinical entity than presently considered. Its rarity may be due to a high diagnostic threshold related to the perception that there is no specific therapy.

Adolescent↗

PubMed1989

Slowly progressive aphasia followed by Alzheimer's dementia: a case report.

Slowly progressive aphasia has been found in 8 published cases, 2 of whom progressed over a period of years to generalized dementia. Positron emission tomography demonstrated decreased glucose metabolism in the left perisylvian region in 2 cases. We describe a patient who had slowly progressive aphasia and developed generalized Alzheimer's dementia 7 years after presentation. There was no clinical or laboratory evidence of concomitant disease. Computerized tomography showed generalized atrophy more marked on the left perisylvian region late in the disease, when EEG showed generalized slowing more marked on the same area. Slowly progressive aphasia of old age should be considered a separate entity until further studies elucidate its relation to Alzheimer's dementia.

Aged↗

PubMed1988

[Diabetes mellitus as a prognostic factor in ischemic cerebrovascular diseases].

As part of a prospective study about 347 cases of ischemic cerebral vascular disease (DCVI) admitted to a general hospital 36 diabetic and 36 non-diabetic patients with similar sex, age and blood pressure were evaluated with the objective of assessing the effect of diabetes mellitus on prognosis in DCVI. All patients had various types of DCVI (thrombosis, thromboembolism or cardiac embolism). The diabetic patients had statistically longer admissions (p less than 0.05), more complications during admission (p less than 0.05), more infectious complications (p less than 0.01) and a greater number of deaths at the end of follow-up (p less than 0.05). After 377 +/- 429 (mean +/- standard deviation) days of follow-up, 50% of the diabetics had died while after 387 +/- 405 days 25% of the non-diabetics had died. Deaths in both groups occurred in average at the 8th month after the vascular event that led to the first admission. There were no differences with respect to the number of deaths during admission or to neurological conditions of the survivors at the end of the first admission or at the end of follow-up.

Aged↗

PubMed1988

Oxcarbazepine and spasticity: further observations.

The previously described anti-spastic effect of oxcarbazepine and 10,11-dihydro-10-hydroxycarbamazepine was found accidentally in 2 patients undergoing a double-blind comparative study for evaluation of antiepileptic effect. In this study oxcarbazepine was given orally in doses of 300-2700 mg daily to one patient with transverse myelitis and to two patients with multiple sclerosis, all of whom had clinically disabling spasticity in the form of difficulty in walking, lower limb rigidity, spastic contractions of the lower limbs and ankle clonus. Anti-spastic effect was observed at doses between 600-1200 mg daily and consisted in a substantial decrease in the above symptoms of spasticity. The anti-spastic effect appears at a dose immediately below that which produces nausea, dizziness and somnolence.

Adult↗

PubMed1987

[Loading-doses of carbamazepine and diphenylhydantoin: use in high-risk patients].

Loading-doses of phenytoin (1000 mg) and carbamazepine (600 mg) were given orally respectively to 10 and 6 patients with uncontrolled epileptic seizures secondary to acute neurological disorders or alcohol withdrawal. In the phenytoin group age varied between 12-73 years and serum concentrations at 2, 4, 6, 8, 12 and 18 hours after drug administration were 7.6, 8.8, 8.7, 8.7, 7.2 and 6.5 micrograms/ml (means). A quantitative method did not detect important side-effects. In the carbamazepine group age varied between 25-56 years and serum concentrations at the same times were 3.9, 5.3, 6.5, 7.5, 7.4 and 8.2 micrograms/ml. Side-effects were discrete. Further medication was not necessary in the 24 hours after drug administration. Although both regimens controlled the clinical situation without relevant side-effects serum concentrations were sub-therapeutic in the case of phenytoin. We suggest the ideal phenytoin oral loading-dose is 1500 mg. The carbamazepine load produced therapeutic concentrations. The stability of serum concentrations for the period of the study shows that those regimens are useful in the subacute control of epileptic seizures in the maintenance treatment of status epilepticus and in alcohol withdrawal.

Adolescent↗

PubMed1986

Simple and safe heparin regimen for acute ischaemia.

The risk/benefit ratio of acute anticoagulation in ischaemic cerebro-vascular disease is not clearly established. A simple and safe intermittent intravenous heparin regimen (20000 IU daily) was used prospectively in 50 patients of 57 +/- 14 (m +/- sd) years of age whose blood pressures ranged from normal to severe hypertension. Twenty-two patients had cardiogenic embolism and the remaining had recurrent severe transient ischaemic attacks of recent onset or progressive cerebral infarcts. Time of exposure to heparin was 6.4 +/- 4 (m +/- sd) days. Two patients had recurrences of cerebral thromboembolism and none had bleeding complications. This is a safe and efficient method of anticoagulation for patients with cerebral ischaemia when continuous infusion of heparin or close monitoring of clotting times are not used routinely.

Acute Disease↗

PubMed1986

Barbiturate-refractory epilepsy: safe schedule for therapeutic substitution.

Barbiturates are considered first line antiepileptic drugs in third world countries due to traditional and economic reasons. This prospective uncontrolled study of 52 patients aged 15 to 64 years (mean 24) demonstrates that patients who become refractory to barbiturates are mainly those with partial seizures with or without generalization or with a focal EEG abnormality (71%). Seizures tend to become refractory approximately 6 years after barbiturates were started. Progressive barbiturate withdrawal over a period of two to 8 months (mean 5) with institution of treatment with carbamazepine, phenytoin or sodium valproate allowed complete barbiturate withdrawal in 42 of the 52 patients (81%). Furthermore monthly seizure frequency in those in whom barbiturates were withdrawn decreased from 7.1 to 1.7 per patient. An improvement in mental status was observed but not measured. These results show that barbiturates should not be first-choice drugs in patients who have a chronic disease such as epilepsy, and indicate a schedule for barbiturate withdrawal which is safe and independent of hospitalization or monitoring of antiepileptic drug serum concentrations.

Adolescent↗