Pamidronate treatment of hypercalcemia caused by vitamin D toxicity

The Dark Side of the Sunshine Vitamin: A Case of Acute Renal Failure and Hypercalcaemia From Vitamin D Overconsumption

Vitamin D toxicity is a rare but potentially serious condition that can lead to severe hypercalcaemia and subsequent complications, such as acute renal failure, nephrocalcinosis, congestive heart failure and coronary calcium deposition, resulting in myocardial injury. We present a case of a 76-year-old male patient who developed severe hypercalcaemia and acute kidney injury due to excessive long-term over-the-counter vitamin D supplementation. The patient was initially treated with aggressive intravenous fluids and furosemide. However, a failed effective response prompted the addition of pamidronate, resulting in the gradual improvement of hypercalcaemia and renal function. We have presented, in this case, a rare adverse effect of vitamin D toxicity and its multiorgan effect.

Hypocalcaemic tetany linked to vitamin D deficiency and hypomagnesemia in primary intestinal lymphangiectasia: a literature review

Primary intestinal lymphangiectasia (PIL) is a rare disorder in children causing protein-losing enteropathy. Vitamin D deficiency and hypomagnesemia contributed to the tetany. The literature review reflects the importance of screening for these deficiencies and regular serum magnesium monitoring in PIL cases with neuromuscular or ionic abnormalities.

Vitamin D supplementation leading to hypervitaminosis D in a breastfed infant: A case report

Breast milk alone is a poor and inadequate source of vitamin D. Many guidelines suggest supplementation of vitamin D to the newborns to prevent vitamin D deficiency. However, due to practices of outdoor breastfeeding and sunbathing, vitamin D supplementation may not be routinely required in our settings. Overzealous use of vitamin D supplementation and over-the-counter prescription may result in hypervitaminosis D.

Vitamin D: sources, physiological role, biokinetics, deficiency, therapeutic use, toxicity, and overview of analytical methods for detection of vitamin D and its metabolites

Vitamin D has a well-known role in the calcium homeostasis associated with the maintenance of healthy bones. It increases the efficiency of the intestinal absorption of dietary calcium, reduces calcium losses in urine, and mobilizes calcium stored in the skeleton. However, vitamin D receptors are present ubiquitously in the human body and indeed, vitamin D has a plethora of non-calcemic functions. In contrast to most vitamins, sufficient vitamin D can be synthesized in human skin. However, its production can be markedly decreased due to factors such as clothing, sunscreens, intentional avoidance of the direct sunlight, or the high latitude of the residence. Indeed, more than one billion people worldwide are vitamin D deficient, and the deficiency is frequently undiagnosed. The chronic deficiency is not only associated with rickets/osteomalacia/osteoporosis but it is also linked to a higher risk of hypertension, type 1 diabetes, multiple sclerosis, or cancer. Supplementation of vitamin D may be hence beneficial, but the intake of vitamin D should be under the supervision of health professionals because overdosing leads to intoxication with severe health consequences. For monitoring vitamin D, several analytical methods are employed, and their advantages and disadvantages are discussed in detail in this review.

Vitamin D Intoxication and Nephrocalcinosis in a Young Breastfed Infant

Numerous studies were performed assessing the benefits and side effects of vitamin D. Vitamin D helps in regulating the calcium and phosphate metabolism leading to a healthy mineral and bone development. Vitamin D intoxication is an uncommon event that leads to hypercalcemia which can be associated with both immediate and late morbidities that can cause severe renal complications. Here, we present a case of a 4-month-old girl with a history of decreased feed and activity due hypercalcemia and high vitamin D level, which led to nephrocalcinosis. The patient received IV fluids, IV diuretics, methylprednisolone, and bisphosphonate in order to normalize the calcium level in blood. With clear verbal and written instructions for the dosage and administration of vitamin D supplements, as well as clear warnings of the potential risks of overdose, vitamin D intoxication could be an easily avoidable condition.

Vitamin D in newborns. A randomised controlled trial comparing daily and single oral bolus vitamin D in infants

AIM

There are no published data to demonstrate the efficacy of bolus dose vitamin D in newborn infants. The study sought to evaluate this alternative approach of supplementation.

METHODS

This single centre, open randomised controlled trial was conducted from August 2013 to May 2014. It compared the efficacy and safety of daily (400 IU) versus a bolus dose (50 000 IU) of cholecalciferol in newborn infants of vitamin D deficient mothers. The primary outcome measure was the rate of 25 hydroxyvitamin D (25OHD) repletion-defined as 25OHD greater than 50 nmol/L. The secondary objective was determining safety using adjusted total serum calcium.

RESULTS

Of 70 eligible infants, 36 received a daily dose and 34 received a single high-dose cholecalciferol. Mean 25OHD in the bolus group (154 nmol/L, 95% confidence interval (CI) 131-177) was higher than the daily group (48 nmol/L, 95% CI 42-54) at 1-2 weeks of age. This was reversed at 3-4 months, (65 nmol/L, 95% CI 59-71) compared with the daily group (81 nmol/L, 95% CI 77-85). More infants in the single bolus group achieved vitamin D repletion (100 vs. 31%) at 1-2 weeks. By 3-4 months, both groups achieved similar vitamin D repletion rates (91 vs. 89%). Mean adjusted total serum calcium in the bolus group were normal at 1-2 weeks (2.73 mmol/L) and 3-4 months (2.55 mmol/L).

CONCLUSION

Single bolus dosing of 50 000 IU cholecalciferol achieves higher 25OHD repletion rates at 1-2 weeks of age compared with daily dosing, but repletion rates were similar by 3-4 months. There was no hypercalcaemia documented with single bolus dosing in this study.

Efficacy and safety of pamidronate in children with vitamin D intoxication

BACKGROUND

Bisphosphonates are used in the treatment of vitamin D intoxication (VDI) after failure of conventional therapy including prednisolone. Safety concerns restrict the use of bisphosphonates from being used as first-line therapy for VDI in children. The aim of this study was to evaluate the efficacy and safety of pamidronate in comparison with prednisolone in children with VDI.

METHODS

We reviewed the hospital records of children consecutively diagnosed with VDI at two medical centers in a 15 year period.

RESULTS

The subjects consisted of 21 children (age, 0.3-4.2 years) who were treated with prednisolone and/or bisphosphonates. Pamidronate (n = 18) or alendronate (n = 3) was used in six patients after unsuccessful prednisolone treatment, and in 15 patients from baseline. Initial serum calcium and 25-hydroxyvitamin D were 16.1 ± 1.9 mg/dL and 493 ± 219 ng/mL, respectively. The median time to reach normocalcemia in the pamidronate, alendronate and prednisolone groups was 3 days (range, 2-12 days), 4 days (range, 3-6 days) and 17 days (range, 12-26 days), respectively (P = 0.013). The pamidronate group had a fivefold shorter hospital stay than the prednisolone group. Three patients initially treated with prednisolone developed nephrocalcinosis but this did not occur in any patient treated with bisphosphonates from baseline. Apart from transient fever and moderate hypophosphatemia, no side-effect of bisphosphonate treatment was observed.

CONCLUSIONS

Pamidronate is efficient and safe for the treatment of VDI in children. Pamidronate use significantly shortens the duration of treatment, and thereby may prevent the development of nephrocalcinosis. Instead of prednisolone, pamidronate should be used together with hydration and furosemide as the first-line therapy for VDI.

Vitamin D supplementation and risk of toxicity in pediatrics: a review of current literature

CONTEXT

Although vitamin D toxicity is rare in children, increased use of vitamin D formulations, re-examination of optimal vitamin D levels, and use of higher doses lend potential for an increased incidence of vitamin D toxicity.

EVIDENCE ACQUISITION

A PubMed search was conducted through May 2013 for cases of vitamin D intoxication and vitamin D trials in pediatrics. Safety data were collected and reviewed.

EVIDENCE SYNTHESIS

A small number of pediatric studies tested vitamin D doses at or above the currently recommended upper tolerable intake. In children and adolescents, vitamin D excess was rare and usually asymptomatic. Recent cases of intoxication relate to errors in manufacturing, formulation, or prescription; involve high total intake in the range of 240,000 to 4,500,000 IU; and present with severe hypercalcemia, hypercalciuria, or nephrocalcinosis. However, mild hypercalcemia and hypervitaminosis using currently recommended doses have been reported in infants with rickets.

CONCLUSIONS

Although rare, cases of vitamin D intoxication that present with dramatic life-threatening symptoms still occur in children. Moreover, recent studies in infants raise a potential need for monitoring vitamin D levels when doses at or above the currently recommended upper range are used. Further studies are needed to clarify these findings. The Drugs and Therapeutics Committee of the Pediatric Endocrine Society suggests obtaining serum 25-hydroxyvitamin D levels in infants and children who receive long-term vitamin D supplementation at or above the upper level intake that is currently recommended.

Bisphosphonates use in children

Bisphosphonates are synthetic analogues of pyrophosphate that inhibit bone resorption by their action on osteoclasts. In recent years, bisphosphonates have been used in children for treatment of a growing number of disorders associated primarily with generalized or localized osteoporosis, genetic and acquired metabolic bone diseases, heterotopic calcifications in soft tissues, and for hypercalcemia. In this review, the authors address the role of and experience with bisphosphonate therapy in disorders of childhood.

A case of hypercalcemia and gastric necrosis from hot pack ingestion

Hot packs (instant hot compresses) are frequently used to relieve pain. We report a patient who had significant complications from ingestion of a hot pack containing calcium salts. A 35-year-old male swallowed three hot packs, and developed hematemesis, severe abdominal pain, and hypercalcemia (21.1 mg/dl). He developed diffuse gastric necrosis requiring gastrectomy and colonic interposition. Hypercalcemia was treated with intravenous fluids, pamidronate, and calcitonin. A Medline search revealed no prior report on hot pack ingestion though ingestion of calcium salts has been reported. Hot packs can potentially cause significant injury both from an exothermic reaction and hypercalcemia. Ingestions of calcium salts can result in necrosis of the stomach. Management includes aggressive treatment of hypercalcemia, supportive care and upper gastrointestinal endoscopy.

Benefit-risk assessment of vitamin D supplementation

Current intake recommendations of 200 to 600 IU vitamin D per day may be insufficient for important disease outcomes reduced by vitamin D.

INTRODUCTION

This study assessed the benefit of higher-dose and higher achieved 25-hydroxyvitamin D levels [25(OH)D] versus any associated risk.

METHODS AND RESULTS

Based on double-blind randomized control trials (RCTs), eight for falls (n = 2426) and 12 for non-vertebral fractures (n = 42,279), there was a significant dose-response relationship between higher-dose and higher achieved 25(OH)D and greater fall and fracture prevention. Optimal benefits were observed at the highest dose tested to date for 700 to 1000 IU vitamin D per day or mean 25(OH)D between 75 and 110 nmol/l (30-44 ng/ml). Prospective cohort data on cardiovascular health and colorectal cancer prevention suggested increased benefits with the highest categories of 25(OH)D evaluated (median between 75 and 110 nmol/l). In 25 RCTs, mean serum calcium levels were not related to oral vitamin D up to 100,000 IU per day or achieved 25(OH)D up to 643 nmol/l. Mean levels of 75 to 110 nmol/l were reached in most RCTs with 1,800 to 4,000 IU vitamin D per day without risk.

CONCLUSION

Our analysis suggests that mean serum 25(OH)D levels of about 75 to 110 nmol/l provide optimal benefits for all investigated endpoints without increasing health risks. These levels can be best obtained with oral doses in the range of 1,800 to 4,000 IU vitamin D per day; further work is needed, including subject and environment factors, to better define the doses that will achieve optimal blood levels in the large majority of the population.

Dihydrotachysterol intoxication treated with pamidronate: a case report

Introduction

Hypoparathyroidism is a chronic condition which requires a lifelong substitution with vitamin D analogues and careful monitoring. This is especially true for older patients and older compounds as dihydrotachysterol with longer half-life that might lead to long-lasting hypercalcemic episodes.

Case presentation

A 74-year old male patient with postsurgical hypoparathyroidism who has been successfully supplemented with dihydrotachysterol (1.7 ml/day) for over 50 years presented with neuropsychiatric disturbances, constipation, renal insufficiency and polyuria. Laboratory investigation demonstrated serum calcium 3.7 mmol/L, serum creatinine 180 micromol/L, urine calcium excretion 1.1 mmol/mmol of the creatinine, normal 25 OH vitamin D₃ and low parathormone and 1,25 di OH vitamin D₃. Careful history revealed that he has been erroneously taking 2.5 ml of dihydrotachysterol per day for at least 6 to 8 weeks that caused vitamin D intoxication and symptomatic hypercalcemia. He was treated with intravenous saline infusion, prednisolone and 60 mg of intravenous sodium pamidronate. On the fourth day after admission serum calcium dropped rapidly within the reference range. The treatment for hypoparathyroidism had to be reinstituted 10 days after dihydrotachysterol had been discontinued when the patient was switched to shorter acting calcitriol.

Conclusions

Here we reported that the immediate use of pamidronate in addition to classic treatment of dihydrotachysterol intoxication with intravenous saline, diuretics and glucocorticoids is an effective treatment choice that leads to rapid resolution of hypercalcemia.

Drugs and pharmaceuticals: management of intoxication and antidotes

The treatment of patients poisoned with drugs and pharmaceuticals can be quite challenging. Diverse exposure circumstances, varied clinical presentations, unique patient-specific factors, and inconsistent diagnostic and therapeutic infrastructure support, coupled with relatively few definitive antidotes, may complicate evaluation and management. The historical approach to poisoned patients (patient arousal, toxin elimination, and toxin identification) has given way to rigorous attention to the fundamental aspects of basic life support--airway management, oxygenation and ventilation, circulatory competence, thermoregulation, and substrate availability. Selected patients may benefit from methods to alter toxin pharmacokinetics to minimize systemic, target organ, or tissue compartment exposure (either by decreasing absorption or increasing elimination). These may include syrup of ipecac, orogastric lavage, activated single- or multi-dose charcoal, whole bowel irrigation, endoscopy and surgery, urinary alkalinization, saline diuresis, or extracorporeal methods (hemodialysis, charcoal hemoperfusion, continuous venovenous hemofiltration, and exchange transfusion). Pharmaceutical adjuncts and antidotes may be useful in toxicant-induced hyperthermias. In the context of analgesic, anti-inflammatory, anticholinergic, anticonvulsant, antihyperglycemic, antimicrobial, antineoplastic, cardiovascular, opioid, or sedative-hypnotic agents overdose, N-acetylcysteine, physostigmine, L-carnitine, dextrose, octreotide, pyridoxine, dexrazoxane, leucovorin, glucarpidase, atropine, calcium, digoxin-specific antibody fragments, glucagon, high-dose insulin euglycemia therapy, lipid emulsion, magnesium, sodium bicarbonate, naloxone, and flumazenil are specifically reviewed. In summary, patients generally benefit from aggressive support of vital functions, careful history and physical examination, specific laboratory analyses, a thoughtful consideration of the risks and benefits of decontamination and enhanced elimination, and the use of specific antidotes where warranted. Data supporting antidotes effectiveness vary considerably. Clinicians are encouraged to utilize consultation with regional poison centers or those with toxicology training to assist with diagnosis, management, and administration of antidotes, particularly in unfamiliar cases.

Reversal of hypercalcemic acute kidney injury by treatment with intravenous bisphosphonates

We present the details of three children with hypercalcemia-induced acute kidney injury (AKI). After traditional therapy with fluids, loop diuretics, steroids and calcitonin had failed to correct the hypercalcemia, they were given treatment with low doses of intravenous (i.v.) pamidronate, which resulted in normalization of serum calcium and kidney function. In one child Doppler renal ultrasound revealed dampened arterial blood flow, which resolved with normalization of serum calcium. On the basis of cumulative data and our experience, we suggest that i.v. application of bisphosphonates be moved from the second to the first line of treatment of hypercalcemic AKI.