Acquired Hemophilia A following Pfizer-BioNTech SARS CoV-2 mRNA vaccine, successfully treated with prednisolone and rituximab

INTRODUCTION

Acquired haemophilia A (AHA) is a rare bleeding disorder, characterised by the presence of autoantibodies to clotting factor VIII (FVIII). AHA can be idiopathic or occur in the context of malignancy, autoimmune disease, drugs, or pregnancy. Recently, cases of AHA following both COVID-19 infection and vaccination have been reported.

CASE REPORT

We report the case of a 95-year-old female who was immunised with the Pfizer-BioNTech SARS CoV-2 mRNA vaccine, with doses given three weeks apart. Spontaneous bruising over her extremities appeared one week after the initial dose, with hospital admission occurring three weeks after the second. Examination revealed a large haematoma on the dorsum of the right hand with resultant bleeding and widespread ecchymoses. Investigations confirmed a diagnosis of AHA.

MANAGEMENT AND OUTCOME

Initial management included high dose prednisolone, recombinant Factor VIII and tranexamic acid. There was no significant clinical improvement after three days, so intravenous rituximab 100 mg weekly for four weeks was commenced. The activated partial thromboplastin time (aPTT) normalised after two doses and Factor VIII level reached 0.68U/ml on day + 22. The patient was successfully discharged from hospital after 37 days.

DISCUSSION

Four cases of AHA following administration of COVID mRNA vaccines (Pfizer and Moderna) have been documented. AHA should be a differential in patients presenting with bleeding following COVID-19 vaccination, in the presence of a normal platelet count. Rapid recognition, prompt initiation of immunosuppressive treatment and rigorous supportive cares are required to minimise morbidity and mortality.

Immediate severe hypersensitivity reaction to etoposide phosphate: Case report and review of the literature

INTRODUCTION

Hypersensitivity reactions from intravenous (IV) etoposide have been rarely reported, with these being seen more commonly with etoposide than with etoposide phosphate. This is generally explained by the need for polysorbate 80, a known cause of hypersensitivity, as a solubiliser, in the etoposide formulation.

CASE REPORT

We report a 22-year-old male, being treated with adjuvant BEP (bleomycin/etoposide phosphate/cisplatin) for a testicular germ cell tumour. Bleomycin and cisplatin were administered without incident. Within one minute of etoposide phosphate commencement he experienced a severe hypersensitivity reaction, consisting of widespread erythematous rash, facial swelling, and nausea. Observations included unrecordable blood pressure, tachycardia, hypoxia, and loss of consciousness, confirming a diagnosis of anaphylactic shock.

MANAGEMENT AND OUTCOME

Etoposide phosphate was ceased immediately. He was successfully managed with IV hydrocortisone, IV promethazine, intramuscular adrenaline, IV fluids and oxygen. Following admission for observation, significant improvement occurred over 48 h.

DISCUSSION

Hypersensitivity reactions to etoposide were first reported in the 1980s. Following reactions to etoposide, substituting etoposide phosphate into chemotherapy regimens has commonly allowed treatment to continue without incidence. Anaphylactic reactions to etoposide phosphate were first documented in 2012, with further cases reported subsequently. Unlike etoposide, etoposide phosphate is highly soluble in aqueous solutions and doesn't require adjuvants in the formulation. Hypersensitivity reactions to etoposide phosphate are therefore likely related to the etoposide drug molecule itself. Clinicians should be aware of this rare, but potentially life-threatening, toxicity when using etoposide-based treatments and have procedures in place to urgently manage any hypersensitivity reactions that may occur.

Severe cisplatin-induced renal toxicity in a patient with xeroderma pigmentosum

INTRODUCTION

Xeroderma pigmentosum is a rare genetic disorder of DNA repair, defined by extreme sensitivity to sunlight, leading to sunburn, skin pigmentation and increased incidence of skin cancers. Cisplatin acts by interfering with DNA repair mechanisms to cause DNA damage and apoptosis. It has indications in many malignancies including bladder, head and neck and lung cancers. Acute kidney injury is a well-known complication of cisplatin.

CASE REPORT

We report a 42-year-old male with a long history of Xeroderma pigmentosum treated with adjuvant cisplatin (40 mg/m²) in combination with radiotherapy for cutaneous squamous cell carcinoma of the neck. He presented to clinic prior to his second weekly dose of cisplatin with a severe acute kidney injury and a creatine level of 813 mmol/L and eGFR of 7 mL/min. No myelosuppression was present.

MANAGEMENT AND OUTCOME

Treatment consisted of aggressive electrolyte and fluid management. Creatinine levels slowly improved with conservative management without the need for dialysis. Radiation was completed without further cisplatin.

DISCUSSION

Three cases of severe adverse effects from cisplatin administration in patients with Xeroderma pigmentosum have been reported, with all fatal. Xeroderma pigmentosum complementation group C plays an important role in the DNA repair process with the recognition and repair of damage to normal cells following cisplatin. Patients with Xeroderma pigmentosum can be carriers of defective Xeroderma pigmentosum complementation group C and if the degree of Xeroderma pigmentosum complementation group C inactivity is significant, fatalities could occur. Physicians should be aware of this rare but potentially lethal toxicity when considering systemic therapy for squamous cell carcinoma in patients diagnosed with Xeroderma pigmentosum.

Systematic review and meta-analysis of febrile neutropenia risk with TCH(P) in HER2-positive breast cancer

BACKGROUND

Docetaxel, carboplatin and trastuzumab, with or without pertuzumab (TCH(P)), has become the preferred (neo)adjuvant regimen for HER2-positive breast cancer. However, its associated febrile neutropenia (FN) risk is unclear: pivotal studies reported FN risks < 10%, but in clinical practice, a high FN rate (> 20%) was observed. This systematic review and meta-analysis determine the FN risk associated with TCH(P) and the indication for primary prophylactic granulocyte colony-stimulating factor (PP G-CSF).

METHODS

The MEDLINE, Embase, Web of Science and Cochrane databases were searched for full-text English articles reporting the FN incidence in early breast cancer patients receiving (neo)adjuvant TCH(P). The primary endpoint was the pooled crude FN incidence in patients treated without PP G-CSF using the random effects method. Secondary endpoints were the FN risk with PP G-CSF support, age-related differences in FN and differences in risk with TCH versus TCHP.

RESULTS

Seventeen studies were included in the systematic review. The pooled estimates of FN incidences were 27.6% (95% CI 18.6 to 37.1) in patients who did not receive PP G-CSF (primary meta-analysis, 9 studies, n = 889) versus 5.0% (95% CI 2.6 to 8.0) in patients administered PP G-CSF (secondary meta-analysis, 7 studies, n = 445). Two studies reported non-significant age-related differences in FN. The risk comparison between TCH and TCHP was inconclusive.

CONCLUSIONS

The crude FN risk associated with (neo)adjuvant TCH(P) is over 20%, the upper limit above which the international guidelines unanimously advise PP G-CSF administration. G-CSF prophylaxis effectively reduces FN risk and should become the standard of care with (neo)adjuvant TCH(P).

Preventing drug vial wastage and reducing expenditure associated with injectable cancer drugs: International oncology pharmacy survey

PURPOSE

Our objective was to determine what vial sharing techniques and other strategies were being used globally to reduce wastage from partially used single-use drug vials, what barriers are preventing these strategies being employed, and what savings are being achieved.

METHODS

A survey, comprising 19 questions, was distributed to the membership of the International Society of Oncology Pharmacy Practitioners and British Oncology Pharmacy Association. Questions asked included how parenteral cancer drugs are obtained and prepared, what vial sharing strategies are used, what means are employed to extend stability, how prepared products are reused and what cost savings are achieved.

RESULTS

In all, 74 responses were received from 20 countries, most from the United Kingdom. Some manufacturing is done by 60.8% of institution, with 41.9% making all products. Vial sharing strategies, for frequently used drugs, were employed in 53% of cases. Barriers preventing vial sharing being used included government legislation, USP 797 guidelines, and health insurance companies. Extension of stability was possible for 70.2% of centres. Most respondents reported reduction in cytotoxic and biological waste, and alleviation of drug shortages from vial sharing utilisation. Cost savings were achieved in 74% of cases and was significant in one third.

CONCLUSIONS

The survey has determined that drug vial wastage and expenditure can be reduced, and vial sharing facilitates this. International collaboration plus the assistance of governments and the pharmaceutical industry is vital in achieving this aim. These findings can hopefully guide oncology pharmacy in establishing appropriate strategies to reduce wastage internationally.

Retrospective analysis of mortality within 30 days of systemic anticancer therapy and comparison with a previous audit at an Australian Regional Cancer Centre

PURPOSE

To retrospectively determine the rate of death occurring within 14 and 30 days of systemic anticancer therapy (SACT), compare this against a previous audit and benchmark results against other cancer centres. Secondly, to determine if the introduction of immune checkpoint inhibitors (ICI), not available at the time of the initial audit, impacted mortality rates.

METHOD

All adult solid tumour and haematology patients receiving SACT at an Australian Regional Cancer Centre (RCC) between January 2016 and July 2020 were included.

RESULTS

Over a 55-month period, 1709 patients received SACT. Patients dying within 14 and 30 days of SACT were 3.3% and 7.0% respectively and is slightly higher than our previous study which was 1.89% and 5.6%. Mean time to death was 15.5 days. Males accounted for 63.9% of patients and the mean age was 66.8 years. 46.2% of the 119 patients dying in the 30 days post SACT started a new line of treatment during that time. Of 98 patients receiving ICI, 22.5% died within 30 days of commencement. Disease progression was the most common cause of death (79%). The most common place of death was the RCC (38.7%).

CONCLUSION

The rate of death observed in our re-audit compares favourably with our previous audit and is still at the lower end of that seen in published studies in Australia and internationally. Cases of patients dying within 30 days of SACT should be regularly reviewed to maintain awareness of this benchmark of quality assurance and provide a feedback process for clinicians.

Temozolomide-induced aplastic anaemia: Case report and review of the literature

INTRODUCTION

Temozolomide (TMZ) is an oral alkylating agent principally indicated for neurological malignancies including glioblastoma (GBM) and astrocytoma. Most common side effects are mild to moderate, and include fatigue, nausea, vomiting, thrombocytopenia and neutropenia. Severe or prolonged myelosuppression, causing delayed treatment or discontinuation, is uncommon. Major haematological adverse effects such as myelodysplastic syndrome or aplastic anaemia (AA) have rarely been reported.

CASE REPORT

We report a 68-year old female with GBM treated at a tertiary hospital with short-course radiotherapy and concurrent temozolomide following craniotomy. On treatment completion she was transferred to our hospital for rehabilitation. She was thrombocytopenic on admission. Platelets continued falling with significant pancytopenia developing over the next two weeks. Blood parameters and a markedly hypocellular bone marrow confirmed the diagnosis of very severe AA, probably due to TMZ.

MANAGEMENT AND OUTCOME

Treatment consisted of repeated platelet transfusions, intravenous antibiotics, antiviral and antifungal prophylaxis, and G-CSF 300 mcg daily. Platelet and neutrophil counts had returned to normal at 38 days following the completion of TMZ treatment.

DISCUSSION

Whilst most cases of AA are idiopathic, a careful drug, occupational exposure and family history should be obtained, as acquired AA may result from viruses, chemical exposure, radiation and medications. Temozolomide-induced AA is well documented, though only 12 cases have been described in detail. Other potential causes were eliminated in our patient. Physicians should be aware of this rare and potentially fatal toxicity when prescribing. Frequent blood tests should be performed, during and following TMZ treatment, to enable early detection.

Elevated beta human chorionic gonadotropin in a non-pregnant female diagnosed with anal squamous cell carcinoma

INTRODUCTION

Elevated serum beta human chorionic gonadotrophin (β-hCG) in a female normally indicates pregnancy or possibly, gestational trophoblastic disease or ovarian germ cell tumours. Expression of β-hCG has been demonstrated in cervical and endometrial carcinoma and other non-germ cell tumours of the ovary, vulva, breast, prostate, lung, colon, oral/facial tissue and stomach.

CASE REPORT

We report a 43-year-old premenopausal woman with p16 positive squamous cell anal cancer. Pre-treatment urinary screening was positive for β-hCG (218 IU/L), which was confirmed on serum and expressed in the tumour. Pelvic ultrasound ruled out pregnancy. Cervical cytology detected human papilloma virus p16 infection and a potential squamous intraepithelial lesion. Management and outcome: She received definitive chemoradiation (Mitomycin/5-fluorouracil) for six weeks. β-hCG, taken four weeks post completion, had returned to normal levels (<2 IU/L).

DISCUSSION

Cases of elevated serum β-hCG are documented in different cancers including breast, gastric, lung, ovarian and renal cell. In our case, the elevated β-hCG is probably ectopic excretion by the squamous cell carcinoma tumour in the anus. While this has never been reported previously in the anus, it is likely due to the documented risk of development of precancerous as well as cancerous anal and cervical lesions through human papilloma virus infection. Raised levels of β-hCG have been reported in cervical cancers. Other possible causes of β-hCG elevation were excluded. Following treatment, her β-hCG level returned to normal strengthening the hypothesis that β-hCG elevation was due to the anal carcinoma. In conclusion, unexplained ectopic secretion of β-hCG may be the first sign of a primary malignancy.

Optic neuritis induced by 5-fluorouracil chemotherapy: Case report and review of the literature

Introduction

For over 50 years, 5-Fluorouracil has played a critical role in the treatment of numerous malignancies, including colorectal cancer. Ocular side effects are uncommon and include blurred vision, conjunctivitis, excessive lacrimation and keratitis.

Case report

We report a 57-year-old male with metastatic colorectal cancer who had received extensive chemotherapy with 5-Fluorouracil-based regimens for over 12 months. Following his seventh cycle of cetuximab/FOLFIRI, he developed acute onset global headache, nausea and loss of vision in the right eye. After detailed investigations, including ophthalmologic and neurologic consultations, a diagnosis of optic neuritis was made.

Management and outcome

Chemotherapy was ceased immediately, and intravenous methylprednisolone (1 g) daily for five days was commenced. His headache resolved and vision started to improve within 24 h. Three weeks after completion of corticosteroids, constriction of the right visual field had fully resolved.

Discussion

Atypical optic neuritis is an inflammatory optic neuropathy that can be caused by ischaemia, mechanical compression, nutritional deficiency, toxins and drugs. Drug-induced optic neuritis, while rare, is associated with cytotoxic medications including methotrexate, cisplatin, carboplatin, vincristine and paclitaxel. There have only been five previous case reports implicating 5-Fluorouracil in the development of optic neuropathy. The likelihood of the adverse drug reaction due to 5-Fluorouracil was assessed using the Naranjo algorithm. A score of +7 indicates probable causality. Clinicians should be alert to this potential ocular toxicity in order to initiate prompt cessation of treatment and early ophthalmology referral to prevent visual loss and damage to ocular structures.

Pembrolizumab-induced thrombotic thrombocytopenic purpura

INTRODUCTION

Pembrolizumab is a humanised monoclonal antibody targeting the receptor programmed cell death protein-1 (PD-1), with anti-tumour activity demonstrated for many malignancies. Such immune checkpoint inhibitors are associated with many immune-related adverse events including rash, colitis, hepatitis, pneumonitis, endocrinopathy and, rarely, haematological adverse events, including immune-related thrombocytopenia.

CASE REPORT

We report a 60-year-old female with metastatic non-small cell lung cancer treated with pembrolizumab every three weeks. Following her fifth cycle, she presented to our hospital with community-acquired pneumonia. Thrombocytopenia developed the next day and, after detailed investigations, thrombotic thrombocytopenic purpura was diagnosed.

MANAGEMENT AND OUTCOME

Pembrolizumab was immediately ceased and plasma exchange commenced along with IV methylprednisolone 250 mg daily for three days followed by oral prednisolone. After five days of plasma exchange, platelet counts normalised and haemolytic anaemia resolved.

DISCUSSION

Acquired thrombotic thrombocytopenic purpura is an autoimmune disorder caused by an inhibitory autoantibody against ADAMTS-13. While most cases of acquired thrombotic thrombocytopenic purpura are idiopathic, certain conditions (e.g. bacterial infection, autoimmune disorders, malignancies) and medications are associated with thrombotic thrombocytopenic purpura. Other potential causes were eliminated in our patient. As acquired thrombotic thrombocytopenic purpura is an autoimmune disorder, pembrolizumab, given its unique mechanism of action and association with immune-related adverse events, is believed to be implicated in the development of thrombotic thrombocytopenic purpura. This case is one of only two linking anti-PD-1 therapy to thrombotic thrombocytopenic purpura development (the other occurring in a patient on nivolumab plus ipilimumab). Thrombotic thrombocytopenic purpura is life-threatening and clinicians are advised to be aware of its possible occurrence in immune checkpoint inhibitor-treated patients.

[A Survey to Compare the Specifications and Stability of Anticancer Drugs in Japan, the United States, Canada, and Australia]

Recently, expensive anticancer drugs such as molecularly targeted drugs have been reportedly ineffective. The use of drug vial optimization(DVO)has been proposed to overcome this problem. The specifications and stability of anticancer drugs in Japan were compared to those in other countries that used DVO, based on the results of the survey reported at the 2016 International Society of Oncology Pharmacy Practitioners meeting that compared the international specifications and stability of anticancer drugs. Our survey investigated expensive and frequently used anticancer drugs: 14 anticancer monoclonal anti- bodies(MABs)and 26 cytotoxic agents. About 29%(4/14)of the MABs and 54%(14/26)of the cytotoxic agents mar- keted in other countries were sold in larger vials than those marketed in Japan. About 67%(2/3)of theMABs and 38%(8/ 21)of the cytotoxic agents marketed in other countries had stability data of reconstitution obtained across longer test periods than those in Japan. About 29%(4/14)of theMABs and 50%(13/26)of the cytotoxic agents marketed in other countries had stability data of final dilution obtained across longer test periods than those in Japan. The stability data obtained in Japan were comparable to those obtained in 3 other countries that used DVO. However, some differences were noted in the specifications of anticancer drugs between Japan and other countries.

Systemic anticancer therapy in the last 30 days of life: Retrospective audit from an Australian Regional Cancer Centre

Background

Cessation of chemotherapy at an appropriate time is an important component of good quality palliative care. Published studies looking at administration of chemotherapy at the end of life vary widely.

Objective

To retrospectively determine the rate of death occurring within 14 and 30 days of chemotherapy and use this to benchmark against other cancer centres as a quality of care measure.

Method

All adult patients who received systemic anticancer therapy for solid tumours and haematological malignancies at an Australian Regional Cancer Centre between 2011 and 2015 were included.

Results

Over a five-year period, 1215 patients received systemic anticancer therapy. Of these, 23 (1.89%) died within 14 days following systemic anticancer therapy and 68 (5.60%) within 30 days. All patients who died had been treated with palliative intent. Mean time to death was 17.7 days. The majority were female (61.8%) and the mean age was 62.3 years. The most common cause of death was disease progression (80.9%). Nearly half died at the Regional Cancer Centre, including 30.9% who lived in rural or remote localities.

Conclusion

The rate of death observed in this study is at the lower end of the range seen in published studies for both the last 14 and 30 days post-systemic anticancer therapy. It is important to routinely collect data to enable benchmarking against other institutions, determine factors potentially associated with higher risks of mortality at the end of life and improve clinical decision making.

Opportunities to significantly reduce expenditure associated with cancer drugs

Aim: To identify cancer drugs amenable to strategies for reducing expenditure and avoiding drug wastage. Methods: Information was sourced from product information in 20 countries on parenteral cytotoxic agents, and cancer and noncancer monoclonal antibodies. Data were collected on vial sizes, overage, stability and presentation forms. Results: Vial size availability varied significantly between countries, with often only single vial sizes for numerous medications. Overage was poorly reported. Stability data were inconsistent and variable between countries, with most drugs only having a 24 h expiry. Three cancer-indicated monoclonal antibodies, thought suitable for prefilled syringe administration, were only available as vials. Conclusion: Many expensive cancer drugs are suitable for global cost-reduction strategies. Collaboration is vital to affecting change and reducing expenditure.

History of opioid allergy: what significance?

Objective. To assess how health professionals would manage a patient’s pain when the patient is labelled as allergic to opioid analgesics.

Methods. A clinical case scenario, describing a patient obviously requiring opioid pain management but reporting a morphine allergy, was designed and pretested. This was distributed to medical (students, interns/residents, registrars, consultants) and nursing staff of Toowoomba Health Service District. All staff had some experience in pain management, though this varied widely. Respondents were asked to review the history and briefly comment on how the patient’s pain should be managed.

Results. Overall response rate was 46%. Doctors returned 47% (39/83) of scenarios, with 53% requesting further information on the nature of the allergy before using opioids. Nurses response rate was 45.2% (42/93), with only 21.4% requesting more information. Eighty three per cent (15/18) of doctors and 60% (20/33) of nurses, who didn’t query the nature of the morphine allergy, recommended opioid medication. No one specifically suggested using structurally dissimilar opioids to morphine if an allergy really existed.

Conclusion. Many health care staff either missed or ignored the allergy or assumed it was really an adverse effect and not significant, potentially placing the patient at risk of serious consequences, including anaphylaxis. Despite the low incidence of true opioid allergy, health professionals must fully investigate purported allergies to determine their validity. Patients should never be administered medications until their likelihood of experiencing a true allergy is determined.

Inappropriate labelling of patients as opioid allergic

Objectives. To investigate the incidence of patients being inappropriately labelled as allergic to opioid medications and to assess the effect that this label may have had on the subsequent prescribing of opioids.

Methods. A study was conducted on patients admitted to Toowoomba Hospital over a three month period as to their perceived opioid allergy status. In addition to medication history interview, pharmacists recorded data on any claimed drug allergy attributed to opioid medications. Events were classified depending on the probability of the event being an allergic or immunological drug reaction. Medical records and medication charts of identified patients were checked to determine if allergy status had any effect on opioid prescribing.

Results. Thirty patients reported an opioid allergy. Morphine and codeine were most commonly implicated, with nausea and vomiting the most likely adverse events. Six patients were classified as high probability of allergic reaction, although anaphylaxis wasn’t reported. Most allergy documentation was incomplete, with the nature of reaction seldom recorded. Despite a ‘supposed’ opioid allergy, 70% of patients were prescribed subsequent opioids. Of the six patients in the high probability group, four were prescribed opioids. Three received alternate opioids without incident, while nurses refused to administer the same previously implicated drug to the fourth patient.

Conclusion. Opioid prescribing did not appear to be influenced by a reported allergy. Ignoring ‘real’ allergies, however rare, may put patients at risk of severe consequences. Staff must be educated regarding the importance of recording accurately and thoroughly the specifics of patients’ medication allergies and its importance in future safe prescribing.

Cancer treatment in the extreme elderly: case study of a 100-year-old lymphoma patient

Limited data are available on the treatment of older adults with cancer. Comorbidities may preclude the administration of effective therapies, particularly in the extreme elderly. Comprehensive geriatric assessment can identify specific weaknesses of the patient and predict unexpected toxicities, thus enabling an optimized treatment strategy in this population. We report a case of the successful management of a 99-year-old female lymphoma patient with a strong wish for active treatment to improve quality of life and prolong survival past her 100th birthday. This case demonstrates that cancer treatment in the extreme elderly is possible and highlights the need for a formalized treatment plan based on geriatric assessment, frank discussion with patients and families, and defined goals of therapy.

The role of octreotide in symptom management in oncology and palliative care

Objective. To provide an overview of the role of octreotide for managing symptoms in oncology and palliative care.

Data Sources. A search of MEDLINE and IDIS databases from 1985 to 1999 and CANCERLIT from 1993 to 1999 was conducted using the terms octreotide, cancer and palliative care. The reference lists from selected articles were also reviewed. Clinical trial databases on the Internet were searched. Oncology and palliative care textbooks were also used to obtain additional references.

Data Extraction. The retrieved literature was reviewed to discuss the pharmacology, pharmacokinetics, adverse effects, indications and principally, the clinical use of octreotide for controlling a number of symptoms encountered in the oncology and palliative care population.

Data Synthesis. The unique inhibitory activity of octreotide lends itself to many possible indications, including diarrhoea from a number of causes, bowel obstruction, nausea and vomiting, bleeding, death rattle, gastrointestinal fistulae, pain and hypercalcaemia. However, convincing pieces of evidence from large prospective clinical trials are required to realise its full potential in oncology and palliative care. Completed studies and clinical experience suggest that octreotide has a role in the treatment of a number of difficult-to-manage conditions, particularly bowel obstruction and diarrhoea due to disease or treatment-related causes. Proposed benefits of octreotide must be weighed against the possible adverse effects and cost effectiveness of treatment.

The incidence of extravasation of vinca alkaloids supplied in syringes or mini-bags

Study objective. The aim of this retrospective study was to determine the incidence of vinca alkaloid extravasation following administration via syringes or mini-bags.

Methods. An electronic survey was sent to pharmacy departments at hospitals throughout Australia. The survey was designed to collect data on the administration methods of vinca alkaloids (vincristine, vinblastine, vinorelbine) and the corresponding documented incidence of extravasation. The questionnaire requested the following information: how the drugs were prepared for administration (syringe or mini-bag); volume of each product; number of items supplied; and the number of cases of extravasation reported for each product.

Results. Questionnaires were sent to 228 hospital pharmacy departments in Australia. Sixty-eight questionnaires were received (29.8%), including responses from most major cancer centres. Data represented a range of 3 to 120 months (mean: 38 months) of clinical experience. The reported incidence of vincristine extravasation from syringes was 0.03% (11/37 084) and 0.041% (3/7255) with mini-bags. One case of vinblastine extravasation was reported with syringes 0.013% (1/7913), none from mini-bags (0/1421). Vinorelbine data were difficult to interpret as cases may represent phlebitis rather than extravasation. The reported incidence from vinorelbine syringes was 0.029% (2/6914) and 0.146% (8/5475) with mini-bags. Excluding vinorelbine data, the reported vinca alkaloid extravasation episodes from syringes (0.027%) and mini-bags (0.035%) were found to be similar and infrequent.

Conclusion. The data suggest that vinca alkaloids can be given safely as low volume, short infusions via mini-bags. Policies and practices that ensure the same careful monitoring of infusional therapy as is recommended with administration by syringe may further reduce the incidence of untoward effects. Mini-bags should be used for the administration of vinca alkaloids and this practice will prevent the inadvertent intrathecal administration of vinca alkaloids via syringes.

Syndrome of inappropriate antidiuretic hormone secretion induced by a single dose of oral cyclophosphamide

OBJECTIVE

To report a case of syndrome of inappropriate antidiuretic hormone secretion (SIADH) induced by a single oral dose of cyclophosphamide.

CASE SUMMARY

A 69-year-old woman was treated with oral CTD (cyclophosphamide/thalidomide/dexamethasone) chemotherapy for multiple myeloma. Two days after the first dose (including cyclophosphamide 500 mg), the patient developed vomiting, drowsiness, and headache. Medication history included sertraline, started in 2005. On admission, laboratory values were serum sodium 113 mEq/L, serum osmolality 240 mOsm/kg, urinary osmolality 701 mOsm/kg, urinary sodium 91 mEq/L, and serum creatinine 0.71 mg/dL. Thyroid and adrenal function were normal. SIADH was diagnosed. Cyclophosphamide and sertraline were stopped and fluid restriction was commenced. The patient was discharged on day 9 following chemotherapy with serum sodium 132 mEq/L. Sertraline was restarted. Four days later she developed vomiting with serum sodium 119 mEq/L. Fluid restriction, which the woman had not performed, was reinstituted and she was discharged on day 17. Two further cycles of chemotherapy were subsequently given without cyclophosphamide and serum sodium remained within normal limits.

DISCUSSION

Cyclophosphamide-induced severe hyponatremia and SIADH have been documented in patients receiving treatment for a wide range of malignant and autoimmune disorders. All cases have involved intravenous therapy, with doses ranging from single pulse doses of 500 mg to 3000 mg/m(2). Selective serotonin reuptake inhibitors are a common cause of SIADH. Because sertraline was instituted in 2005 and reinstituted without incident, it was eliminated as a contributing factor. Malignancy, tumor lysis syndrome, other medications, hydration to prevent hemorrhagic cystitis, and renal impairment were also ruled out. The Naranjo probability scale indicated a probable association between SIADH and cyclophosphamide administration.

CONCLUSIONS

To our knowledge, our report represents the first case of SIADH due to a single oral dose of cyclophosphamide. Clinicians should be aware of this rare adverse event, as it can have life-threatening consequences.

Phenytoin and fluorouracil interaction

OBJECTIVE

To report a probable drug interaction between phenytoin and fluorouracil.

CASE REPORT

A 66-year-old white man started adjuvant chemotherapy for colon cancer with weekly bolus injections of fluorouracil and leucovorin calcium. He had been taking phenytoin 300 mg/d for epilepsy for more than four years. Eleven weeks later, the patient was reported to be unsteady on his feet and had fallen several times. The serum phenytoin concentration at that time was 36 microg/mL. The phenytoin dosage was decreased and the symptoms resolved. Phenytoin concentrations were monitored and the dosages were adjusted accordingly throughout the remaining 15 weeks of treatment with fluorouracil. After completion of chemotherapy, the phenytoin dose was gradually increased to the original dose with no signs of toxicity.

DISCUSSION

Phenytoin is principally metabolized by CYP2C9. Inhibition of that isoenzyme by fluorouracil, and possible interference with its synthesis, appears to be the most likely cause of this interaction. The reduction in saturating substrate concentration of phenytoin was reduced as a result of this interaction, thus causing decreased clearance and increased serum concentrations. No previous interaction between phenytoin and fluorouracil has been reported. Both phenytoin and warfarin are metabolized by CYP269 and therefore exhibit the same spectrum of interactions when that isoenzyme is inhibited. Interactions have been reported with concurrent administration of warfarin and fluorouracil.

CONCLUSIONS

The nature and extent of this phenytoin-fluorouracil interaction should be elucidated by in vitro investigations and a prospective study. Until then, clinicians should be aware of this potentially serious drug interaction and monitor patients closely for phenytoin toxicity.

Preventing medication errors in cancer chemotherapy referred to rural and remote hospitals

Patients from rural areas receiving simple chemotherapy regimens in regional or metropolitan centres are often sent back to their local hospital for treatment. As these centres commonly have health professionals with limited experience in the use of antineoplastic agents, it is particularly important to provide information that is accurate, thorough and has no potential for misinterpretation. The minimum information necessary has been identified in a previous study and includes patient details, diagnosis, chemotherapy protocol, dosages and method of confirmation, interval between cycles, supportive care and contact details for the prescriber. Staff at a number of small rural and remote hospitals were contacted to determine further useful information. Suggestions included: availability of premixed cytotoxics, methods of administration and possible adverse effects. A standardised computer format for providing oncological information was developed. Specific patient information is entered into the chosen protocol for each individual referred. This initiative has proven popular with participating hospitals and resulted in fewer inquiries and problems.

A Guide to Enteral Drug Administration in Palliative Care

Enternal feeding is indicated in patients unable to ingest sufficient nutrients but whose gastrointestinal function is adequate for digestion and absorption. Indications in palliative care include patients with radical esophageal surgery, upper gastrointestinal tract obstruction, anorexia, and dysphagia. As the oral route is the preferred method of palliative drug delivery, the enternal feeding tube can become an important tool for drug administration. A number of questions must be asked before a drug is considered for enteral administration. Firstly, is the drug in a suitable dosage form for administration? If not, can a different dosage form (or drug) be substituted or can the physical form of the original product be altered? Secondly, is the drug compatible with the enteral feed? Finally, are there any complicating factors that may affect drug absorption or clearance? This review attempts to answer these questions, provide easily understood guidelines for the successful enteral administration of medications, and discuss clinical implications for palliative care.