Comparative pharmacokinetic analysis of novel sustained-release dosage forms of pentoxifylline in healthy subjects

The pharmacokinetics and relative bioavailability of pentoxifylline, from a new sustained-release formulation (Oxopurin) and from a standard sustained-release formulation (Trental-400), were compared in 8 healthy adult male volunteers. After a single oral dose of 400 mg Oxopurin, a mean maximal plasma concentration (Cmax) of 164 +/- 62 micrograms/l was obtained after 2.2 h (tmax). After an identical dose of Trental-400, a peak plasma concentration of 123 +/- 33 micrograms/l was obtained after 2.4 h. Plasma levels of pentoxifylline were determined by a new HPLC assay which was developed as part of this study and makes possible monitoring plasma levels of pentoxifylline for 14 h after a single dose. The mean relative bioavailability of pentoxifylline from Oxopurin was 1.30 +/- 0.19 relative to that of Trental-400. As the rate and the extent of absorption of pentoxifylline was not significantly different after the administration of the two investigated formulations, it can be concluded that Oxopurin is bioequivalent to Trental-400.

Glibenclamide causing thrombocytopenia and bleeding tendency: case reports and a review of the literature

We described two patients with severe thrombocytopenia and bleeding tendency related to treatment with glibenclamide (short-acting sulfonylurea). To the best of our knowledge, thrombocytopenic purpura associated with this medication has been reported only twice previously. We suggest that platelet count should be carried out early after initiating glibenclamide treatment and every 3 months thereafter.

Atrioventricular block complicating acute streptococcal tonsillitis

A 38 year old woman presented with severe weakness, high fever, and sore throat. Physical examination showed follicular tonsillitis and bradycardia caused by a atrioventricular block. Within 24 hours a normal sinus rhythm was regained but slight transient ST-T changes compatible with myocarditis were evident. Throat culture grew Streptococcus haemolyticus group A.

Amiodarone pulmonary toxicity presenting as a solitary lung mass

Following treatment with amiodarone, a patient developed weight loss, fatigue and severe myopathy, without respiratory symptoms. A solitary lung infiltrate, impaired thyroid and liver function tests, and leukocytosis were evident. Biopsies from the lung lesion, liver, and bone marrow revealed foam cells. All these signs and symptoms subsided following cessation of amiodarone therapy. It is demonstrated that amiodarone may induce a localized lung lesion rather than diffuse pulmonary disease.

Influence of chronic diabetes on tissue and blood cells status of zinc, copper, and chromium in the rat

The influence of chronic diabetes on zinc, copper and chromium status in the urine, plasma, liver, kidney, bone, muscle, lymphocytes and erythrocytes was investigated in rats 180 days after streptozotocin injection, in comparison to age matched normal rats. The concentration and tissue content of zinc and copper were increased significantly in the liver, femur, erythrocyte and lymphocyte of the diabetic rats in addition to an increase in their urinary loss. In contrast, the concentration of zinc, copper and chromium in the kidney of the diabetic rats and the concentration of copper in the muscle and of chromium in the liver of the diabetic rats were similar to those of the normal rats. There was also a marked deficiency of zinc in the muscle and of chromium in the bone of the diabetic rats. The potential significance of altered trace metal metabolism during long term changes in endocrine status, and the possible explanation and significance of the variable concentrations of essential metals in different organs of streptozotocin induced chronic diabetic rats is discussed. The importance of erythrocyte and leukocyte zinc concentration as a mirror to their relative concentration in other tissue of animals and humans with type I diabetes is raised.

Influence of small-group education sessions on glucose homeostasis in NIDDM

In patients with non-insulin-dependent diabetes mellitus (NIDDM), the influence of knowledge about their disease on the treatment and control of the disease is not clear. We evaluated the efficacy of educational group meetings with NIDDM patients on improving their knowledge of the disease and on disease management. Fifty-one NIDDM patients were randomly assigned to either intervention or control groups. The intervention group participated in courses of three weekly lessons presented by a physician, nurse, and dietitian once every 4 mo. The intervention and control groups were also followed once every 2 mo in the clinic by the same staff. Medical treatment remained unchanged during the study. After a 12-mo follow-up of the intervention group, no significant improvement in their knowledge of diabetes could be demonstrated. However, mean fasting and postprandial blood glucose levels and HbA1c improved significantly in comparison with the control group. The same tendency was evident with the weight and lipoprotein profile. We conclude that educational group therapy can improve diabetes control in patients with NIDDM.

Pharmacokinetic analysis of sustained-release dosage forms of theophylline in humans: comparison of single and multiple dose studies

A pharmacokinetic analysis of two sustained-release dosage forms of theophylline (Theo-Dur and Theotrim) was carried out following single and multiple dose administrations of the two formulations in five healthy subjects. Despite the prolonged absorption after administration of the two sustained-release formulations, theoretical predictions of theophylline steady-state levels following multiple dosages based upon data obtained from the single dose study, correlated with the data of the multiple dose study. This study shows that the recommended dose and dosage regimen of new sustained-release formulations of theophylline can be based upon single dose studies. In the population studied, repetitive doses of 450 mg b.i.d. of Theo-Dur and Theotrim maintain steady-state concentrations of theophylline within the drug's therapeutic window.

Shigella sonnei myocarditis

A 19-year-old male was admitted to our department because of high fever, abdominal pain, and diarrhea. Electrocardiogram (ECG) on admission revealed diffuse ST-T changes which persisted for 5 days. Stool culture grew Shigella sonnei. We conclude that the infection with Shigella sonnei was the cause for these findings which were most probably due to myocarditis. To the best of our knowledge myocarditis as a complication of shigella infestation has never been reported.

Thymoma presenting as a superior vena cava syndrome remission following therapy

A 45-year-old male developed myasthenia gravis 8 years ago. He received prednisone for 3 years, and resumed complete clinical remission. Five years later, he was admitted with obstruction of the superior vena cava. Invasive thymoma was diagnosed by chest X-ray and an open lung biopsy. Radiation followed by combination chemotherapy with cyclophosphamide, vincristine, and prednisone induced a complete remission. The patient remained disease-free for more than 20 months after the first admission to our department. To the best of our knowledge, superior vena cava syndrome as the presenting symptom of thymoma has never been reported previously.

Effect of sustained-release on the pharmacokinetics of theophylline in healthy subjects

The effect of sustained-release on the pharmacokinetics of theophylline was examined by comparing two sustained-release formulations (Theo-Dur and Theotard) to an oral solution and i.v. preparation of the drug. Drug-level monitoring was performed by an HPLC assay. The absorption profiles of the three oral formulations were pharmacokinetically analyzed by using the Loo-Riegelman procedure. The absorption of theophylline after the administration of the Theo-Dur and Theotard was found to be of an apparent zero-order kinetics.

Pharmacokinetic evaluation of novel sustained-release dosage forms of valproic acid in humans

Five new sustained-release dosage forms of valproic acid (VPA) were developed. The new sustained-release formulations were administered to six healthy subjects for comparison with a standard tablet and an i.v. preparation of the drug. Three of the formulations exhibited a more prolonged and uniform absorption rate and yielded more sustained serum levels after ingestion. These three formulations maintained serum therapeutic levels of VPA for 24 h after a single oral administration of 1 g, and were bioequivalent to a marketed standard tablet of VPA. The absorption profile of the various oral formulations was analysed pharmacokinetically, using the Loo-Riegelman procedure.

Acute bilateral brachial plexus neuritis associated with hypersensitivity vasculitis. A case report and review of literature

The occurrence of brachial plexus neuritis during the acute phase of vasculitis is uncommon. We describe a patient with a long history of rhinitis and a recent onset of asthma, who developed purpuric skin lesions, abdominal pain, eosinophilia and brachial neuritis along with evidence of sacral plexus neuropathy. High dose steroids and cyclophosphamide induced a remission. He stopped all medications after 3 years and after 6 years the patient has some fixed minimal residual neurological deficit. The importance of aggressive therapy in treating extensive polyneuropathy during the acute phase of hypersensitivity vasculitis is raised. A possible cytotoxic role of eosinophils in the pathological process is suggested.

Hairy cell leukemia associated with carcinoma: report of two patients and review of the literature

The association of carcinoma and hairy cell leukemia (HCL) in two patients is recorded. One of the cases was a 58-year-old male who developed carcinoma of the kidney, while the second patient was a 48-year-old woman with carcinoma in the breast. This rare association is probably coincidental, as it is not described in most of the larger reported series of patients with HCL. It is of interest to note that the first patient had received radiation therapy thirty years before the diagnosis of HCL and carcinoma was made.

Identification of synthetic, voiced stop-consonants by hearing-impaired listeners

The identification of synthetic, voiced stop consonants changing in place of articulation was investigated in 26 normal-hearing listeners and 16 hearing-impaired listeners who reported difficulties in speech understanding, but attained high speech discrimination scores on standard test materials. Two place continua (each containing 13 stimuli changing from /ba/ to /da/ and /ga/) were employed: a continuum in which place was cued by an initial noise burst and formant transitions, and a continuum in which place was cued by formant transitions alone. All normal listeners exhibited categorical and highly consistent identification for both stimulus continua. For the hearing-impaired listeners, identification was somewhat less consistent for the burst-and-transition stimuli, and much poorer for the transition-only stimuli. Similar differences were observed when comparing the responses of 4 subjects with a unilateral hearing loss when the stimuli were presented to their normal and impaired ears, and 2 subjects with a unilateral, sudden-onset hearing loss with recovered pure-tone sensitivity.

Pharmacokinetics of valproic acid in volunteers after a single dose study

The pharmacokinetics of valproic acid (VPA) was investigated in six healthy volunteers. This was done by monitoring total and free (unbound) valproic acid levels in the serum, and the amount of one of its metabolites, VPA glucuronide, in the urine as a function of time, after a single dose administration of the parent drug. VPA half-life calculated from the urine data of the metabolite was shorter than the half-life calculated from the blood data. About 15 to 20 per cent of the administered oral dose of VPA was excreted in the urine as VPA glucuronide. The average free fraction of VPA obtained in this study, by using the EMIT technique, ranged from 1.5 to 11.5 per cent with a mean value of 4.9 per cent.

CNS involvement by non-Hodgkin's lymphoma. Response to a standard therapeutic protocol

Treatment results of 31 episodes of CNS involvement by malignant lymphoma diagnosed in 24 patients were studied. Leptomeningeal involvement occurred in 16 patients, intracerebral invasion in eight patients, and epidural cord compression in seven patients. Twelve patients with leptomeningeal involvement treated with intraventricular methotrexate sodium achieved complete CSF remission and ten patients' conditions improved neurologically. Five of the patients with epidural cord compression were ambulatory following treatment. Complete resolution of intracerebral lymphoma was documented by computed tomographic scan in four patients. The overall median survival was nine months, eight months for leptomeningeal involvement, five months for intracerebral lymphoma, and 12 months for patients with cord compression. Our results suggest that all forms of CNS lymphoma usually respond well to therapy, life span is prolonged, and is free of CNS disease until patients die of uncontrolled systemic lymphoma.