Retrospective study of salazosulfapyridine in eight patients with rheumatoid arthritis on hemodialysis.

OBJECTIVE: We examined the pharmacokinetics (PK) of salazosulfapyridine (SASP) and its metabolite, sulfapyridine (SP), as well as the influence of hemodialysis (HD), and investigated the utility of consecutive administration of SASP in rheumatoid arthritis patients undergoing HD. METHODS: The PK of salazosulfapyridine and SP in serum samples from 8 patients was determined using high-performance liquid chromatography. RESULTS: When SASP 500 mg was administered, the area under curve for serum concentration of SASP was similar to that seen with normal subjects in the Phase I study. The maximum serum concentration of SP was significantly higher than that in normal subjects, but was far from the danger level. SASP was not dialyzed, whereas on average 62% of SP was dialyzed. Following 5 consecutive days of administration of SASP, serum levels of SASP and SP on day 5 were rather higher than those on day 1, although both remained within the safe range. SASP administration from four months to three years in seven subjects resulted in four American College of Rheumatology 20 improvement criteria (57.1%), with one developing a rash. CONCLUSIONS: If SASP is initiated at a low dosage (≤ 500 mg) and increased up to 1000 mg under careful monitoring, it is safe for HD patients.

Microscopic polyangiitis presenting with liver dysfunction preceding rapidly progressive necrotizing glomerulonephritis.

The authors describe a 52-year-old woman diagnosed with microscopic polyangiitis. She presented with abnormal liver function tests accompanied by fever, headache, and fatigue. Two months later, rapidly progressive necrotizing glomerulonephritis developed together with seropositivity for perinuclear antineutrophil cytoplasmic antibody. Although liver dysfunction from microscopic polyangiitis is very rare, especially at presentation, this diagnostic possibility should be kept in mind to permit prompt consideration of steroid therapy.

[Pharmacokinetics of salazosulfapyridine in a hemodialysis patient].

The patient was a 62-year-old female. Total gastrectomy was performed due to gastric ulcer in 1969. She was diagnosed as rheumatoid arthritis (RA) in 1985 and was developed to amyloidosis in 1991. She was started on hemodialysis (HD) for chronic renal failure in 1996. In 1998, her arthralgia was aggravated, and 100 mg/day of bucillamine was administered on the day of HD. Her arthralgia persisted, and switching to salazosulfapyridine (SASP) was considered. As there were no standards and no reports for the use of SASP in HD patients, we examined the pharmacokinetics of SASP and its metabolites, and compared our patient with the results of phase one study in normal subjects in Japan. In this case, the blood concentration of SASP was similar to that in healthy controls after single administration of 500 mg of SASP on the day of non-HD, while the concentration of sulfapyridine (SP) was higher than that in healthy donors. However, the blood concentrations of SASP, SP, and N4-acetyl-SP (AcSP) at 24 hours after administration were similar to those obtained in healthy men. SASP was not dialyzed, while about half of SP and AcSP, were dialyzed. In a five-day consecutive administration study also, the blood concentrations of these compounds on Day 5 were similar to those of phase one study, suggesting no accumulation. No adverse drug reaction was observed. As this case had the past history of total gastrectomy and amyloidosis, it is possible that this result is influenced by the factors. Therefore it is necessary to examine pharmacokinetics of SASP and its metabolites beforehand when administering this agent to other HD/RA patients.

Evaluation of blood supply to the parathyroid glands in secondary hyperparathyroidism compared with histopathology.

BACKGROUND: In chronic renal failure patients, the parathyroid glands progress from diffuse hyperplasia to nodular hyperplasia, and it is important to distinguish between these as the latter form is more aggressive. This progress can be confirmed histologically, but the present study aimed to determine whether the different types of hyperplasia could be distinguished by power-Doppler ultrasonography (US). METHODS: Twenty-one consecutive renal failure patients were scheduled to undergo parathyroidectomy (PTx). Of 70 resected parathyroid glands, 63 were assessed by pre-operative power-Doppler US, classified into four groups based on the flow signal pattern and then correlated with the post-operative histopathology. RESULTS: With power-Doppler US imaging, 60.0% of glands without a signal inside the gland were diagnosed as diffuse hyperplasia or diffuse hyperplasia with early nodularity. Of glands with in-gland signals, 83.7% were nodular or had a single nodule typical of nodular hyperplasia. Even when the focus was on parathyroid glands weighing