Experience with second line drugs in frequently relapsing and steroid dependent childhood nephrotic syndrome in a large Saudi center

BACKGROUND AND OBJECTIVES

To assess the efficacy and safety of second line drugs used at our center in frequently relapsing and steroid dependant (FR/SD) childhood nephrotic syndrome.

PATIENTS AND METHODS

This was a retrospective study over a period of 3 years (July 2012 to July 2015) on the use of 4 second line drugs in FR/SD nephrotic syndrome in children treated at our center. These drugs were Levamisole, Mycophenolate Mofetil (MMF), Cyclophosphamide, and Cyclosporine. We studied the relapse rate per year, cumulative dose of steroids, success, failure, and side effects of these drugs. Statistical analyses were done with the help of a statistician using the T-test and the "N-1"Chi-Square test.

RESULTS

We reviewed the charts of 60 children. All had FR/SD nephrotic syndrome and received a 3 month protocol of prednisolone. 20 received Levamisole (33%), 12 received Cyclophosphamide (20%), 20 received MMF (25%), and 13 received Cyclosporine (22%).All the four drugs significantly reduced the relapse rate and the cumulative dose of steroids (P < .0001). Treatment success was best with Cyclosporine (69.2%), and treatment failure was the least with Cyclosporine (7.6%). However, treatment success and failure with Cyclosporine when compared to other three drugs was not statistically significant. No dangerous side effects were seen with any of the 4 drugs in the observation period.

CONCLUSION

All the second line drugs in our study were equally effective. However, we recommend that the initial treatment of FR/SD nephrotic syndrome should be chosen with the least toxic yet equally efficacious drug Levamisole.

Intravenous alfacalcidol once versus twice or thrice weekly in hemodialysis patients

Secondary hyperparathyroidism remains a serious problem in hemodialysis patients. The use of vitamin D analogs still constitutes a basis for its treatment. This study was carried out to evaluate the efficacy of intravenous administration of alfacalcidol once versus twice or thrice weekly in hemodialysis patients with secondary hyperparathyroidism. Twenty-nine end-stage renal disease patients maintained on hemodialysis for more than one year were included in this prospective study after signing the consent. These patients with secondary hyperparathyroidism had been on intravenous alfacalcidol twice or thrice per week and were followed up to 4 months (stage 1). Then they were shifted to intravenous alfacalcidol once weekly starting with the last total weekly intravenous dose for another 4 months (stage 2). The dose of alfacalcidol was adjusted according to intact parathyroid hormone, serum calcium and phosphorus levels, and calcium-phosphorus product. Intact parathyroid hormone, calcium, phosphorus, calcium-phosphorus product were measured monthly. Parathyroid ultrasound was done as a baseline and then repeated at the end of stage 1 and stage 2. The intact parathyroid hormone was reduced from 49.72 ± 2.72 pmol/L (mean ± standard error of the mean [SEM] during stage 1 to 42.13 ± 2.15 pmol/L during stage 2 (P = 0.005). Dose of alfacalcidol was reduced from 18.80 ± 1.15 µg/month (mean ± SEM) in stage 1 to 15.18 ± 1.27 µg/month in stage 2 (P = 0.008), and consequently the cost of alfacalcidol was reduced from 21.05 ± 1.25 US$/month (mean ± SEM) during stage 1 to 16.87 ± 1.40 US$/month during stage 2 (P = 0.008). Although the phosphorus level increased from 1.56 ± 0.36 mmol/L (mean ± SD) in stage 1 to 1.70 ± 0.46 mmol/ L in stage 2 (P = 0.003), and calcium-phosphorus product increased from 3.48 ± 0.82 mmol(2)/L(2) (mean ± SD) in stage 1 to 3.76 ± 1.00 mmol(2) /L(2) in stage 2 (P = 0.017), they remained in the target levels recommended by the Kidney Disease Outcomes Quality Initiative guidelines. No serious effects were observed during stage 1 and stage 2, respectively. Intravenous alfacalcidol once weekly is effective, safe and less costly in suppressing intact parathyroid hormone compared to twice or thrice weekly administration in chronic hemodialysis patients.

Cinacalcet hydrochloride therapy for secondary hyperparathyroidism in hemodialysis patients

This study compared the efficacy of a cinacalcet-based regimen with unrestricted conventional therapy (vitamin D and phosphate binders) for achieving Kidney Disease Outcome Quality Initiative (K/DOQI) targets for dialysis patients. In this multicenter, prospective study, hemodialysis patients with poorly controlled secondary hyperparathyroidism (SHPT) were randomized to receive a cinacalcet-based regimen (n=55) or a conventional therapy (n=27). Doses of cinacalcet, vitamin D sterols, and phosphate binders were adjusted during a 12-week dose-titration phase to achieve intact parathyroid hormone (iPTH) levels ≤ 31.8 pmol/L. The primary end point was the percentage of patients with values in this range during a 24-week efficacy-assessment phase. The clinical response to 36-week cinacalcet treatment was evaluated. A dual energy X-ray absorptiometry was performed before and after 36 weeks of cinacalcet therapy. Fifty-eight percent of the cinacalcet group reached the primary end point, as compared with 19% of the conventional therapy group (P=0.001). A higher percentage of patients receiving the cinacalcet-based regimen versus conventional therapy achieved the targets for calcium, phosphorus and Ca×P. Achievement of targets was greatest in patients with less severe disease (intact PTH range, 31.8 to 53 pmol/L). Cinacalcet therapy increased proximal femur bone mineral density (BMD), but did not affect the lumbar spine. Itching intensity decreased significantly. Cinacalcet based treatment facilitates achievement of the K/DOQI targets for iPTH and bone mineral metabolism compared with conventional therapy in hemodialysis patients. Suppression of iPTH with cinacalcet reverses bone loss in the proximal femur. Cinacalcet alleviated itching.

Free thyroxine, free triiodothyronine and thyroid-stimulating hormone before and after hemodialysis in Saudi patients with end-stage renal disease: is there any difference?

Patients on regular hemodialysis (HD) suffer from a chronic illness that is believed not to involve the thyroid gland. However, they may have low levels of serum thyroxine (T4) and tri-iodothyronine (T3). It was found earlier that serum total T3 and free T4 concentrations were significantly higher immediately after a HD session than before. In this single-center prospective study, we evaluated the difference between free T3 (FT3), free T4 (FT4) and thyroid-stimulating hormone (TSH) levels before and immediately after HD sessions in 40 Saudi patients with end-stage renal disease undergoing regular HD at the Prince Salman Center for Kidney Disease, Riyadh, Saudi Arabia. The study involved 23 female and 17 male patients with a mean age of 49.65 ± 16.20 years. None of the study patients had any known thyroid disease. We measured the thyroid hormones monthly for three successive months using the electrochemiluminescence technique both before and after HD sessions. At the end of our study, we found a statistically significant difference between pre-HD and post-HD levels for FT3; in the first month, it was 4.47 ± 1.01 versus 4.86 ± 1.03 pmol/L, (P = 0.004); in the second month, it was 4.48 ± 1.37 versus 4.83 ± 1.64 pmol/L, (P = 0.008); and in the third month, it was 3.84 ± 0.88 versus 4.04 ± 0.84 pmol/L, (P = 0.003). The FT4 in the first month was 15.42 ± 2.75 pmol/L versus 17.20 ± 2.85 pmol/L, P = 0.000, in the second month it was 14.86 ± 2.66 versus 16.74 ± 3.27 pmol/L, P = 0.000 and in the third month it was 14.86 ± 3.93 versus 16.70 ± 4.00 pmol/L, P = 0.000, respectively. However, the pre- and post-HD levels of TSH did not show any statistically significant difference; in the first month it was 3.17 ± 1.47 versus 3.32 ± 1.39 pmol/L, P = 0.254, in the second month it was 2.57 ± 1.36 versus 2.49 ± 1.29 pmol/L, P = 0.299 and in the third month it was 2.36 ± 1.17 versus 2.44 ± 1.22 pmol/L, P = 0.238, respectively. Thus, there was a statistically significant increase in the post-HD levels of FT3 and FT4 although the TSH levels did not show any significant change. Our study suggests that measurement of TSH alone might be more reliable in the assessment of thyroid function in patients on regular HD than FT3 and FT4.

Levamisole vs. cyclophosphamide for frequently-relapsing steroid-dependent nephrotic syndrome

A retrospective analysis comparing the first-time use of levamisole (L) or cyclophosphamide (C) as second-line therapy for children with frequently relapsing, steroid-dependent (FR/SD) nephrotic syndrome, was conducted at our center. The relapse rate and the total cumulative dose of prednisone during the year prior to L/C therapy was compared to that during the year following the institution of therapy with L or C in 51 patients, between July 1992 and June 1997. An analysis of covariance was used to adjust the outcome for differences between the 2 groups of treatment in the year prior to second-line drug initiation. In the L group the mean relapse rate was lowered by 0.28 relapses/patient/month and the mean cumulative dose of prednisone was reduced by 336 mg/m2/month versus 0.32 relapses/patient/month and 387 mg/m2/month in the C group (p = 0.395. p = 0.577). No significant difference in the effectiveness of L vs. C for therapy of FR/SD nephrotic syndrome could be identified in our patients. We conclude that L may be considered an alternative for C as a first second-line agent for these patients.