Dose-response in the treatment of hypercalcemia of malignancy by a single infusion of the bisphosphonate AHPrBP

Fifty-two patients with malignant hypercalcemia were treated with a single dose of 3-amino-1-hydroxypropylidene-1,1- bisphosphonate (AHPrBP, previously APD), a potent inhibitor of osteoclast-mediated bone resorption. In order to establish a dose-response in humans, patients were divided into four groups receiving 30 mg, 45 mg, 60 mg, or 90 mg, respectively, as a 24-hour infusion. Initial plasma calcium was similar in all groups, except in the group receiving 90 mg, of which some patients had higher initial values. All patients responded to AHPrBP with a rapid decrease of plasma calcium concentration from 3.47 +/- 0.10 mmol/L at day 0 to 2.43 +/- 0.06 at day 6 (P less than .001). Plasma calcium became normal within four to six days in 43 patients. Eight of the nine patients whose calcium did not become normal were in the low-dose (30 and 45 mg of AHPrBP) groups. Slight and asymptomatic hypocalcemia occurred in only tow of the 26 patients in the low-dose groups, but in six of the 26 patients in the high-dose groups. A follow-up study in 40 patients showed that hypercalcemia recurred within 1 month in five of ten patients in the group receiving 30 mg, in three of ten patients in the group receiving 45 mg, and in one of 20 patients in the groups receiving 60 and 90 mg, whereas mortality was almost identical in all four groups. In all groups, plasma phosphate, plasma creatinine, urinary calcium, and hydroxyproline excretion decreased significantly. In conclusion, when administered as a single-day infusion in the treatment of tumor hypercalcemia, AHPrBP leads to a dose-dependent decrease in plasma calcium. To prevent transient hypocalcemia and early relapse, the optimal dose should be adapted to the degree of severity of hypercalcemia.     

A phase I study of CNI-1493, an inhibitor of cytokine release, in combination with high-dose interleukin-2 in patients with renal cancer and melanoma.

CNI-1493, an inhibitor of proinflammatory cytokines, was studied in a Phase I trial in melanoma and renal cancer patients receiving high-dose interleukin 2 (IL-2). Objectives of the study were to define the maximum tolerated dose (MTD) and toxicity of CNI-1493, to assess its pharmacological effects, and to define its pharmacokinetics. Twenty-four patients were treated in sequential cohorts with CNI-1493 doses from 2 through 32 mg/m2 daily. Patients first received only CNI-1493 daily for 5 days. After a 9-day rest, patients received two 5-day courses of IL-2 of 600,000 IU/kg every 8 h for up to 14 doses/course plus daily CNI-1493; courses were separated by a 9-day rest period. CNI-1493 administered alone was well tolerated at doses through 32 mg/m2; MTD was not reached. The only clinical toxicity attributed to CNI-1493 was occasional injection-site phlebitis. Grade 1 creatinine increases occurred in 1 of 7 patients at 4 mg/m2, in 1 of 1 patients at 25 mg/m2, and in 3 of 6 patients at 32 mg/m2 CNI-1493 alone. In combination with high-dose IL-2, CNI-1493 at > or = 25 mg/m2 seemed to exacerbate IL-2-induced nephrotoxicity: grade 3 or 4 creatinine increases developed in 3 of 6 patients at 25 or 32 mg/m2, as compared with 1 of 16 patients at doses < or = 16 mg/m2. The MTD for CNI-1493 given with high-dose IL-2 was 16 mg/m2. The dose-limiting toxicity of IL-2 was hypotension in 63% of patients; overall tolerance to IL-2 was not improved by CNI-1493. However, relative to changes seen in a reference group receiving high-dose IL-2 alone, at doses > or = 4 mg/m2 CNI-1493 did show evidence of pharmacological activity as an inhibitor of tumor necrosis factor production.     

Randomized double-blind comparison of single high-dose ondansetron and multiple standard-dose ondansetron in chemotherapy-naive pediatric oncology patients.

This prospective, double-blind, randomized study compares the antiemetic efficacy of an equivalent dose of ondansetron administered as a single high dose or as multiple standard doses in pediatric oncology patients. Thirty-one chemotherapy-naive patients were randomized at diagnosis to receive either single high-dose ondansetron (0.6 mg/kg, maximum dose 32 mg) or multiple standard-dose ondansetron (0.15 mg/kg, maximum dose 8 mg, every 4 hr for four doses). Antiemetic efficacy was assessed by an emesis scale described as follows: 1, no nausea or emesis; 2, nauseous but able to eat; 3, nauseous and unable to eat; and 4, emesis. Sixteen patients received high-dose and 15 received standard-dose ondansetron. Patients receiving moderately or severely emetogenic chemotherapy were evenly distributed between the two treatment groups. Eighty-one percent of patients receiving high-dose and 80% receiving standard-dose ondansetron rated 1 or 2 on the emesis scale (p = 0.93). No patient experienced any clinical or laboratory toxicity. Our study suggests that single high-dose ondansetron is as efficacious as the multiple standard-dose regimen and is well tolerated. Its use will facilitate the administration of ondansetron in pediatric patients receiving chemotherapy.     

The activation of polymorphonuclear neutrophils and the complement system during immunotherapy with recombinant interleukin-2.

The toxicity due to interleukin-2 (IL-2) strongly resembles the clinical picture seen during septic shock. In septic shock activation of polymorphonuclear neutrophils (PMN) and the complement system contribute significantly to the pathophysiology of the condition. We therefore investigated whether similar events contributed to the toxicity observed with IL-2. Four patients received seven cycles of escalating dose IL-2 (18.0 to 72.0 X 10(6) IU m-2 day-1) and 16 were treated with 20 cycles of fixed dose IL-2 (12.0 or 18.0 X 10(6) IU m-2 day-1). Toxicity, as judged by hypotension (P = less than 0.005) and capillary leakage (fall in serum albumin 18.2 vs 4.0 gm l-1; P = less than 0.0005 and weight gain 4.0 vs 1.2 kg; P = less than 0.025) were worse with the esc. dose protocol. PMN became activated following IL-2 with mean peak elastase/alpha 1-antitrypsin (E alpha 1 A) and lactoferrin values of 212 (SEM = 37) and 534 (SEM = 92) ng ml-1 respectively occurring 6 h after the IL-2. Peak values for the esc. dose IL-2 group being generally higher than 500 ng ml-1. Activation of the complement cascade was evidenced by a dose dependent elevation of peak C3a values (fixed dose 9.1 (SEM = 0.6); esc. dose 25.7 (SEM = 6.33); P = less than 0.005) on day 5 of IL-2. There was a significant correlation between C3a levels and the degree of hypotention during the first 24 h after IL-2 (r = 0.91) and parameters of capillary leakage such as weight gain and fall in serum albumin (r = 0.71). These data suggest that activation of PMN initiates endothelial cell damage which subsequently leads to activation of the complement cascade. This latter system then contributes to the haemodynamic changes and capillary leakage seen in IL-2 treated patients.     

Cetuximab-induced hypomagnesaemia aggravates peripheral sensory neurotoxicity caused by oxaliplatin

Calcium and magnesium replacement is effective in reducing oxaliplatin-induced neurotoxicity. However, cetuximab treatment has been associated with severe hypomagnesaemia. Therefore, we retrospectively investigated whether cetuximab-induced hypomagnesaemia exacerbated oxaliplatin-induced neurotoxicity. Six patients with metastatic colorectal cancer who were previously treated with oxaliplatin-fluorouracil combination therapy were administered cetuximab in combination with irinotecan alone or irinotecan and fluorouracil as a second-line treatment. All patients had normal magnesium levels before receiving cetuximab. The Common Terminology Criteria for Adverse Events version 3.0 was used to evaluate the grade of neurotoxicity, hypomagnesaemia, hypocalcaemia, and hypokalemia every week. All six patients had grade 1 or higher hypomagnesaemia after starting cetuximab therapy. The serum calcium and potassium levels were within the normal range at the onset of hypomagnesaemia. Oxaliplatin-induced neurotoxicity occurred in all patients at the beginning of cetuximab therapy, with grade 1 neurotoxicity in five patients and grade 2 in one patient. After cetuximab administration, the neurotoxicity worsened in all six patients, and three progressed to grade 3. Among the three patients with grade 3 neurotoxicity, two required a dose reduction and one had to discontinue cetuximab therapy. A discontinuation or dose reduction in cetuximab therapy was associated with exacerbated oxaliplatin-induced neurotoxicity due to cetuximab-induced hypomagnesaemia in half of patients who had previously received oxaliplatin. Therefore, when administering cetuximab after oxaliplatin therapy, we suggest serially evaluating serum magnesium levels and neurotoxicity.     

Colonic ischemia complicating immunotherapy with interleukin-2 and interferon-alpha

Colonic ischemia (CI) is a rare complication of high-dose interleukin-2 (IL-2) immunotherapy. This complication occurred in three of 141 patients (2.1%) with metastatic cancer treated with high-dose IL-2 therapy; CI only developed in patients receiving interferon-alpha (IFN) with IL-2 (three of 21, 14%) compared with none of 120 in those patients receiving IL-2 alone (P equals 0.0009). Severe diarrhea (greater than or equal to 7 bowel movements/day) also was significantly more common in patients receiving IFN with IL-2 (six of 21, 29%) than in those receiving IL-2 alone (three of 120, 2.5%, P equals 0.001) and preceded the clinical diagnosis of CI in all three patients. Three of nine patients with severe diarrhea had CI. Hematochezia occurred in four patients, all of whom received IFN with IL-2; three had CI, and the other patient had nonspecific colitis. Differences in vasopressor use did not explain the increased risk of CI in patients receiving IFN; those receiving IFN with IL-2 required phenylephrine less often than patients receiving IL-2 alone (P equals 0.01). The administration of lymphokine-activated killer (LAK) cells had no significant effect on the incidence of CI, severe diarrhea, peritonitis, or vasopressor use; two of three patients with CI, however, had their ischemic episode within 24 hours after the last of three LAK cell infusions. In conclusion, CI is an unusual complication of high-dose IL-2 and IFN immunotherapy. In patients receiving such combination therapy, severe diarrhea is a risk factor for the subsequent occurrence of CI.     

Denosumab: Prevention and management of hypocalcemia,osteonecrosis of the jaw and atypical fractures

Denosumab, a bone‐modifying agent, reduces the risk of skeletal‐related events in patients with bone metastases from solid tumors and is generally well tolerated. However, hypocalcemia, osteonecrosis of the jaw (ONJ) and atypical fracture are potential and important toxicities of denosumab therapy that require attention. In pivotal phase III trials in patients with bone metastases from solid tumors, the incidence of hypocalcemia was 9.6% in denosumab‐treated patients, with most events being asymptomatic, grade 2 and resolving by week 4. Established hypocalcaemia requires additional short‐term calcium and vitamin D supplementation and, if severe, administration of intravenous calcium. ONJ was reported in 1.8% of patients receiving denosumab over 3 years in these trials. Involvement of an experienced oro‐maxillary surgeon is important if ONJ is suspected. Atypical fractures were rare in a large study of denosumab using the dose and scheduling approved for the treatment of osteoporosis. To prevent toxicities, patients should maintain calcium and vitamin D supplementation, good oral hygiene and regular dental reviews throughout treatment. This article presents case studies from our clinical practice and discusses the pathophysiology of these toxicities along with guidance on prevention, diagnosis and management.     

An antiemetic effect of methylprednisolone plus droperidol against nausea and vomiting caused by administration of high-dose adriamycin to breast carcinoma patients

An antiemetic combination of methylprednisolone and droperidol was administered to 10 patients with breast cancer showing postoperative recurrence, receiving high-dose adriamycin. Methylprednisolone was given twice intravenously at a dose of 500 mg, before and after administration of adriamycin, and droperidol was given just before administration of adriamycin. The 10 patients received a total of 20 chemotherapy courses. Complete relief of vomiting was achieved in 95% of these 20 courses, and mild nausea occurred in 40%. Side effects were drowsiness, acne and akathisia, which were minimal. It was concluded that an antiemetic combination of methylprednisolone and droperidol was very effective for prevention of high-dose adriamycin-induced nausea and vomiting.     

Therapy of renal cell carcinoma with interleukin-2 and lymphokine-activated killer cells: phase II experience with a hybrid bolus and continuous infusion interleukin-2 regimen

Forty-seven patients with metastatic or unresectable renal cell carcinoma were treated with interleukin-2 (IL-2) and lymphokine-activated killer (LAK)-cell therapy, using a hybrid IL-2 regimen. IL-2 was administered initially by intravenous bolus (10(5) U/kg [Cetus Corp, Emeryville, CA] every 8 hours for 3 days) during the priming phase, and subsequently by continuous infusion (3 x 10(6) U/m2 for 6 days); during this second treatment period, in vitro-generated LAK cells were administered. Despite selection of patients for good performance status (PS) (29, PS 0; 18, PS 1) prior nephrectomy (43 of the 47 patients), and low tumor burden, the response rate was low (two complete [CRs] and two partial responses [PRs], for an overall objective response rate of 9%). Toxicity was comparable to that experienced with the high-dose bolus regimen. These results suggest that the dose and schedule of IL-2 administration may influence the likelihood of response to IL-2 in renal cell carcinoma.     

Interleukin-2 and high-dose cisplatin in patients with metastatic melanoma: a pilot study.

In this pilot study of metastatic melanoma, interleukin-2 (IL-2) and cisplatin (CDDP) chemotherapy were combined using an alternating schedule designed to explore potential synergism between these modalities. Bolus IL-2 was given at a dose of 600,000 IU/kg intravenously (IV) every 8 hours, days 1 to 5 and 15 to 19, followed by high-dose CDDP administered by two different regimens: (A) 135 to 150 mg/m2 IV bolus over 30 minutes with the chemoprotectant WR-2721 910 mg/m2 or (B) 50 mg/m2 IV over 2 hours every day for 3 days. The trial design allowed an assessment of response to each phase of therapy. Among 27 assessable patients, there were 10 (37%) overall responses, including three (11%) complete responses (CRs) with durations of 9, 16, and 30+ months. Tumor regression was noted in seven patients (partial response [PR], four; minor response [MR], three; response rate [RR], four of 27 [15%]) after IL-2 administration and in 14 patients (PR, 12; MR, two; RR, 12 of 27 [44%]) after CDDP treatment, demonstrating noncrossresistance between the components of the regimen. Major PRs (greater than 90% reduction of tumor burden) or CRs were only seen in patients responding to IL-2. Toxicity during IL-2 therapy was typical for high-dose IL-2 protocols and was reversible. Among the first 20 patients treated with CDDP regimen A, there were eight episodes of grade IV nephrotoxicity (creatinine level greater than 5.0 mg/dL), including three of six patients treated with an initial CDDP dose of 135 mg/m2. This side effect was more frequent among patients with liver metastasis (P less than .05, Fisher's exact test). No significant nephrotoxicity was noted in seven patients treated on regimen B. Although ototoxicity was frequent, minimal bone marrow and neurologic toxicity was noted. There were no treatment-related deaths. This combination showed at least additive activity against melanoma, and the more protracted CDDP schedule was well tolerated. This regimen may serve as a model for future combined immunotherapy and chemotherapy trials in metastatic melanoma.     

Phase I evaluation of recombinant interleukin-2 in patients with advanced malignant disease

Seventeen patients with refractory malignant tumors were treated with recombinant human interleukin-2 (IL-2) administered by weekly bolus intravenous (IV) injection in a phase I dose escalation trial. Patients received 10,000 to 1,000,000 U/m2 per injection over a course of 3 to 33 weeks. Toxicity was dose related and consisted primarily of fever, chills, nausea, and vomiting. Hypotension was observed at doses of 500,000 U/m2 or higher and in one instance was sufficiently severe to require pressors. No tumor regression was seen and all patients eventually developed progressive disease. Blood levels of cortisol, ACTH, prolactin, and growth hormone as well as the acute phase reactant C-reactive protein (CRP) increased after the administration of IL-2 in most patients. Serum IL-2 levels in excess of 250 U/mL were detected five minutes after an IV injection of 1,000,000 U/m2, after which the levels declined with a half-life of approximately 25 minutes. No alteration in lymphocyte surface phenotype or enhancement in natural cell-mediated cytotoxicity against natural killer (NK)-sensitive and resistant tumor cell lines was observed when these parameters were measured weekly just before the IL-2 injections. However, a dramatic but transient decline in circulating lymphocytes and NK activity was noted within hours of receiving IL-2. This effect was independent of fever and was not abrogated by pretreatment with ibuprofen or metyrapone. The majority of patients developed serum IgG antibodies of IL-2 detectable with a sensitive enzyme-linked immunosorbent assay (ELISA) and a nitrocellulose dot blot assay. The development of anti-IL-2 antibodies was not associated with symptoms suggestive of serum sickness, reductions in serum complement levels, or deterioration in lymphocyte tumoricidal activity. This investigation provides insight into the in vivo actions of this potent biological response modifier and will assist in the design of future studies with IL-2 administered alone or in conjunction with other treatment modalities.     

Effect of corticosteroid on the antitumor activity of lymphokine-activated killer cells and interleukin 2 in mice

The adoptive transfer of lymphokine-activated killer (LAK) cells combined with low dose interleukin 2 (IL-2) mediates the regression of established pulmonary metastases in mice and has efficacy in the treatment of human cancer. Systemic administration of high dose IL-2 alone can mediate tumor regression. Cortisone acetate (CA), 25-75 mg/kg, was administered daily to mice receiving high dose IL-2 for 10 days. CA significantly reduced the toxicity induced by IL-2; 38 of 48 mice receiving CA survived compared to 0 of 30 controls (P less than 0.0001). In addition, CA administration caused a decrease in IL-2-induced 125I-labeled albumin leakage in mouse organs. However, CA abrogated the in vivo antitumor effect of high dose IL-2, and to a lesser extent the therapeutic effect of exogenous LAK cells plus lower dose IL-2. Mice treated with 100,000 units of IL-2 showed 98, 63, and 33% reductions of pulmonary metastases in Hanks' balanced salt solution, 25 mg Ca/kg, and 75 mg Ca/kg groups, respectively; treatment with LAK and 7,500 units of IL-2 resulted in reductions of 94, 77, and 57% in these same groups. CA treatment of animals did not affect LAK generation, although the absolute number of LAK precursors was greatly reduced. These results show that although CA can reduce the toxic effect(s) of IL-2, it can be detrimental to successful immunotherapy using this approach.     

High-dose metoclopramide + lorazepam versus low-dose metoclopramide + lorazepam + dehydrobenzperidol in the treatment of cisplatin-induced nausea and vomiting

In a randomized double-blind, cross-over trial of 34 patients receiving cisplatin-based chemotherapy (20-100 mg/m2), the antiemetic effect of high-dose metoclopramide (HDM) (10 mg/kg iv. loading dose + 7 hours continuous infusion) + lorazepam (L) (2.5 mg x 4 po) was compared with low-dose metoclopramide (LDM) (70 mg) + L (2.5 mg x 2 po) + dehydrobenzperidol (5 mg x 2 im). Among the 29 patients who completed the cross-over, HDM significantly reduced the number of vomiting episodes (p = 0.002) and the degree of nausea (p = 0.004). Seventeen patients preferred the HDM and 4 the LDM regimen (p = 0.01). Sedation was seen in all but 1 patient, and was graded as severe in 6 patients receiving the HDM and in 2 patients receiving the LDM regimen. No extrapyramidal adverse reactions were seen. We conclude that high-dose metoclopramide + lorazepam is a safe antiemetic regimen and significantly superior to low-dose metoclopramide + lorazepam + dehydrobenzperidol. Owing to the severe sedation which occurs in some patients, the dose of lorazepam should be individually adjusted.     

Persistent hypocalcemia induced by zoledronic acid in a patient with androgen-independent prostate cancer and extensive bone metastases

Zoledronic acid is a highly potent bisphosphonate that has been shown to reduce skeletal-related events in patients with androgen-independent prostate cancer metastatic to bone. We report a patient with androgen-independent prostate cancer and extensive bone metastases. After receiving a single dose of zoledronic acid, the patient developed hypocalcemia that persisted for approximately 60 days despite intravenous and oral calcium supplementation, likely because of excess unopposed osteoblastic activity. This case underscores the need for calcium and vitamin D monitoring and supplementation to avoid bisphosphonate-induced secondary hyperparathyroidism and highlights the possibility that extensive osteoblastic metastasis alone might lead to hypocalcemia.     

DNA damage and repair in patients receiving high-dose cyclophosphamide and radiation

DNA damage and repair were assessed by alkaline sucrose gradients in the nonstimulated circulating mononuclear cells of 7 patients receiving high-dose cyclophosphamide (HDCy) and fractionated whole-body irradiation. Measurable damage produced by HDCy appeared to be repaired in about 60 hours. Damage from a radiation dose of 2 Gy was not completely repaired within 24 hours because DNA molecular weight was found to be decreased by an average of 22%. We attempted to assess the impact of HDCy on radiation damage repair by comparing blood irradiated and incubated in vitro before therapy with in vivo incubation following HDCy administration. Two hours after a radiation dose, repair appeared increased following HDCy. These results suggest the possibility that significant interaction at the DNA level may occur when HDCy and irradiation are administered together.     

Treatment of advanced soft-tissue sarcomas using a combined strategy of high-dose ifosfamide, high-dose doxorubicin and salvage therapies

Having determined in a phase I study the maximum tolerated dose of high-dose ifosfamide combined with high-dose doxorubicin, we now report the long-term results of a phase II trial in advanced soft-tissue sarcomas. Forty-six patients with locally advanced or metastatic soft-tissue sarcomas were included, with age <60 years and all except one in good performance status (0 or 1). The chemotherapy treatment consisted of ifosfamide 10 g m(-2) (continuous infusion for 5 days), doxorubicin 30 mg m(-2) day(-1) x 3 (total dose 90 mg m(-2)), mesna and granulocyte-colony stimulating factor. Cycles were repeated every 21 days. A median of 4 (1-6) cycles per patient was administered. Twenty-two patients responded to therapy, including three complete responders and 19 partial responders for an overall response rate of 48% (95% CI: 33-63%). The response rate was not different between localised and metastatic diseases or between histological types, but was higher in grade 3 tumours. Median overall survival was 19 months. Salvage therapies (surgery and/or radiotherapy) were performed in 43% of patients and found to be the most significant predictor for favourable survival (exploratory multivariate analysis). Haematological toxicity was severe, including grade > or =3 neutropenia in 59%, thrombopenia in 39% and anaemia in 27% of cycles. Three patients experienced grade 3 neurotoxicity and one patient died of septic shock. This high-dose regimen is toxic but nonetheless feasible in multicentre settings in non elderly patients with good performance status. A high response rate was obtained. Prolonged survival was mainly a function of salvage therapies.     

Increased therapeutic index using moderate dose methotrexate and leucovorin twice weekly vs. weekly high dose methotrexate-leucovorin in patients with advanced squamous carcinoma of the head and neck: a safe new effective regimen

A new intensive methotrexate regimen for the treatment of advanced squamous carcinoma of the head and neck is presented, employing twice-weekly parenteral low-moderate doses of methotrexate and a single parenteral dose of leucovorin 24 hours following methotrexate. Toxicity and therapeutic results in 20 patients treated with this regimen favorably with results of weekly high-dose methotrexate-leucovorin in 36 patients treated immediately before initiation of the new regimen. Moderate nephrotoxicity and mild gastrointestinal/mucosal toxicity were common to both, while myelotoxicity was rarely seen with the low dose regimen and was more frequent with the high-dose regimen. Partial response was observed in 60% of patients treated on the intensive low-moderate dose schedule, and 50% of patients previously untreated with methotrexate on the weekly high-dose schedule. None of 12 patients previously failing low-moderate doses of methotrexate responded to high doses administered in this trial. The characteristics of antitumor response with low-moderate and high-dose schedules were similar except for the median dose required to attain response (50 mg/m2 vs. 3 g/m2) and the lesser toxicity of intensive lower dose therapy with leucovorin.     

Role of Postoperative Vitamin D and/or Calcium Routine Supplementation in Preventing Hypocalcemia After Thyroidectomy: A Systematic Review and Meta‐Analysis

Background.

Transient hypocalcemia is a frequent complication after total thyroidectomy. Routine postoperative administration of vitamin D and calcium can reduce the incidence of symptomatic postoperative hypocalcemia. We performed a systematic review to assess the effectiveness of this intervention. The primary aim was to evaluate the efficacy of routine postoperative oral calcium and vitamin D supplementation in preventing symptomatic post-thyroidectomy hypocalcemia. The second aim was to draw clear guidelines regarding prophylactic calcium and/or vitamin D therapy for patients after thyroidectomy.

Methods.

We identified randomized controlled trials comparing the administration of vitamin D or its metabolites to calcium or no treatment in adult patients after thyroidectomy. The search was performed in PubMed, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Google Scholar, and Web of Knowledge databases. Patients with a history of previous neck surgery, calcium supplementation, or renal impairment were excluded.

Results.

Nine studies with 2,285 patients were included: 22 in the vitamin D group, 580 in the calcium group, 792 in the vitamin D and calcium group, and 891 in the no intervention group, with symptomatic hypocalcemia incidences of 4.6%, 14%, 14%, and 20.5%, respectively. Subcomparisons demonstrated that the incidences of postoperative hypocalcemia were 10.1% versus 18.8% for calcium versus no intervention and 6.8% versus 25.9% for vitamin D and calcium versus no intervention. The studies showed a significant range of variability in patients'' characteristics.

Conclusions.

A significant decrease in postoperative hypocalcemia was identified in patients who received routine supplementation of oral calcium or vitamin D. The incidence decreased even more with the combined administration of both supplements. Based on this analysis, we recommend oral calcium for all patients following thyroidectomy, with the addition of vitamin D for high-risk individuals.     

Pharmacokinetics and toxicity of the epipodophyllotoxin derivative etoposide (VP 16-213) in patients with gestational choriocarcinoma and malignant teratoma

Summary Serum levels of etoposide obtained 5 min after administration of 100 mg/m² were between 11 and 30 g/ml. By 24 h after drug administration, serum levels had fallen to between 0.19 and 1.11 g/ml. Interpatient variation of etoposide serum concentrations obtained 5 min after drug administration was low, whereas interpatient variation 24 h later was noticeably higher. A significant correlation was observed (r=-0.698) between the WBC nadir and the mean etoposide serum concentrations, measured 24 h after drug administration, in patients receiving etoposide in combination with cyclophosphamide and actinomycin D. However, a relationship was not observed in those patients receiving etoposide alone.There was no observed difference in the efficacy or toxicity of 500 mg/m² etoposide when the dose was administered either as 100 mg/m² on each of 5 consecutive days or as 250 mg/m² on days 1 and 3. There was no significant difference between AUC values calculated from etoposide concentration versus time profiles in patients receiving the drug on days 1 and 3 and those values obtained with the 5-day schedule.Patients resistant to a conventional dose of etoposide were given a higher dose of 1 g/m²/24 h, but this schedule did not cause an increase in efficacy despite an increase in serum levels of the drug. CSF levels in two of these patients receiving high-dose etoposide were 1.28% and 2.09% of the serum concentrations.