Reduction by granulocyte colony-stimulating factor of fever and neutropenia induced by chemotherapy in patients with small-cell lung cancer

BACKGROUND

Neutropenia and infection are major dose-limiting side effects of chemotherapy. Previous studies have suggested that recombinant methionyl granulocyte colony-stimulating factor (G-CSF) can reduce chemotherapy-related neutropenia in patients with cancer. We conducted a randomized clinical trial to test this hypothesis and the clinical implications.

METHODS

Patients with small-cell lung cancer were enrolled in a multicenter, randomized, double-blind, placebo-controlled trial of recombinant methionyl G-CSF to study the incidence of infection as manifested by fever with neutropenia (absolute neutrophil count, less than 1.0 x 10(9) per liter, with a temperature greater than or equal to 38.2 degrees C) resulting from up to six cycles of chemotherapy with cyclophosphamide, doxorubicin, and etoposide. The patients were randomly assigned to receive either placebo or G-CSF, with treatment beginning on day 4 and continuing through day 17 of a 21-day cycle.

RESULTS

The safety of the study treatment could be evaluated in 207 of the 211 patients assigned to either drug, and its efficacy in 199. At least one episode of fever with neutropenia occurred in 77 percent of the placebo group, as compared with 40 percent of the G-CSF group (P less than 0.001). Over all cycles of chemotherapy, the median duration of grade IV neutropenia (absolute neutrophil count, less than 0.5 x 10(9) per liter) was six days with placebo as compared with one day with G-CSF. During cycles of blinded treatment, the number of days of treatment with intravenous antibiotics, the number of days of hospitalization, and the incidence of confirmed infections were reduced by approximately 50 percent when G-CSF was given, as compared with placebo. Mild-to-moderate medullary bone pain occurred in 20 percent of the patients receiving G-CSF.

CONCLUSIONS

The use of G-CSF as an adjunct to chemotherapy in patients with small-cell cancer of the lung was well tolerated and led to reductions in the incidence of fever with neutropenia and culture-confirmed infections; in the incidence, duration, and severity of grade IV neutropenia; and in the total number of days of treatment with intravenous antibiotics and days of hospitalization.

Male pseudohermaphroditism secondary to 17 beta-hydroxysteroid dehydrogenase deficiency: gender role change with puberty

A 31-yr-old male pseudohermaphrodite is reported with 17 beta-hydroxysteroid dehydrogenase deficiency. Laboratory data revealed a plasma testosterone of 228 ng/100 ml, a plasma androstenedione of 620 ng/100 ml, and an abnormal androstenedione to testosterone ratio. Plasma estradiol was 4.6 ng/100 ml and plasma estrone was 22 ng/100 ml. This subject was born in a hospital, incontrovertibly declared to be a female, and unambiguously raised as a girl by his parents for the first 17 yr of his life. At age 14 yr, he was able to change to a male gender role with ease. As an adult, he is a well adjusted, happily married man with a successful professional career. Surgical correction of bilateral cryptorchidism and hypospadias was carried out at age 14 yr. At age 30 yr, he developed a teratocarcinoma-seminoma of the right testis with retroperitoneal node metastases. After orchiectomy and retroperitoneal node dissection, he was placed on chemotherapy and is presently free of metastases.

Venom immunotherapy in hymenoptera sting allergy. Comparison of rush and conventional hyposensitization and observations during long-term treatment

42 patients with confirmed hypersensitivity to honey bee (HBV) and/or yellow jacket (YJV) were treated with the respective venoms (7 with HBV, 5 with VJV and 30 with both venoms). Treatment tolerance, skin tests (ST), specific IgE- and specific IgG-antibodies were monitored before, after 3, 6, 12, 24 and 36 months. 21 patients had a rush and 21 a conventional treatment schedule. Maintenance dose was 100 micrograms. Adverse effects occurred as large local (8 patients), slight systemic (12 patients) and moderate to severe systemic reactions (4 patients). Of 24 re-exposed patients 17 had no reaction at all, six a markedly decreased and one an unchanged reaction. After 3 years of treatment ST became negative in nine of 31 patients on HBV and in seven of 26 patients on YJV. RAST became negative in three of 30 patients on HBV and 17 of 29 patients on YJV treatment. Both ST and RAST became negative in five HBV- and 10 YJV-treated patients. Loss of venom hypersensitivity according to diagnostic tests may correspond to actual desensitization and enable discontinuation of immunotherapy.

The impact of therapy with filgrastim (recombinant granulocyte colony-stimulating factor) on the health care costs associated with cancer chemotherapy

The objective of the study was to estimate the net impact on health resource utilisation of using recombinant granulocyte colony-stimulating factor (filgrastim) following myelosuppressive chemotherapy. Cost minimisation of the study medication in a randomised, double-blind, placebo-controlled clinical trial was conducted in teaching institutions and affiliated community hospitals participating in a clinical trial. 68 patients with small cell lung cancer undergoing cyclophosphamide, doxorubicin and etoposide chemotherapy were randomised to blinded placebo or filgrastim study medication at three or 14 clinical trials sites. The patients received daily subcutaneous injections of filgrastim or placebo, initiated 24 h after chemotherapy and continued until the neutrophil count exceeded 10,000 x 10(6)/l after the time of the expected nadir. Differences in total charges, costs and Medicare payments between treatment groups were the main outcomes measured. Compared to placebo patients, filgrastim-treated patients had significantly fewer and less resource-intensive hospitalisations. After accounting for filgrastim purchase and administration, the charge model predicts overall savings from filgrastim use in a clinical setting in which the risk of febrile neutropenia is high for patients not receiving filgrastim. The Medicare and cost models predict only a partial recapture of the cost of filgrastim therapy. The health care resources impact of filgrastim was sensitive to the risk of hospitalisation with febrile neutropenia, and to the perspective chosen for measuring resource utilisation (charges, costs or Medicare payments). The adjunctive use of filgrastim following myelosuppressive chemotherapy leads to partial or complete recapture of the cost of purchasing and administering the product.

Impact on quality of life of adding cetuximab to irinotecan in patients who have failed prior oxaliplatin-based therapy: The EPIC trial

4003

Background: EPIC, a multinational phase III clinical trial examined the impact of cetuximab on survival in pretreated EGFR- expressing metastatic colorectal (MCRC) patients (pts). Pts were randomized to either cetuximab 400 mg/m2 followed by 250 mg/m2 weekly and irinotecan 350 mg/m2 q 3 weeks or irinotecan alone. The primary endpoint was overall survival (OS) with quality of life being one of the secondary endpoints. Methods: Health Related Quality of life (HRQoL) of pts in this trial was assessed through the EORTC QLQ-C30 questionnaire, version 3.0. Pts completed the questionnaire pretreatment, every second cycle, and at first follow-up visit. HRQoL was compared between treatment arms using a Wei-Lachin test. Results: Baseline demographics were balanced between the arms. Cetuximab plus irinotecan (n=648) was superior to irinotecan alone (n=650) in progression-free survival (HR 0.69, p<.0001) and response rate (16.4 vs 4.2%, p<.0001). OS was comparable between the arms, but may have been influenced by subsequent therapy: 46% of subjects in the irinotecan alone arm received cetuximab, 89% of them in combination with irinotecan. Baseline HRQoL scores did not significantly differ between treatment arms for 11 of the 15 scales. For 4 scales (Social Functioning, Fatigue, Dyspnea, and Appetite Loss), there were statistically significant differences in baseline scores, in favor of the cetuximab plus irinotecan arm. Non- compliance rates (missing questionnaires) were similar between the arms. A statistically significant difference was noted for pts in the cetuximab plus irinotecan arm in HRQoL on 10 of the 15 scales as compared to patients in the irinotecan arm, with the scores of the cetuximab plus irinotecan arm consistently higher, as noted by the scales of Global Health Status (p=.047), pain (p< .0001), and nausea (p<.0001). Conclusions: In addition to statistically significant improvements in PFS and RR in patients receiving cetuximab plus irinotecan compared with irinotecan alone, HRQoL was better preserved on the combination arm with less deterioration in symptom scores (pain, nausea, insomnia), as well as global health status scores.

No significant financial relationships to disclose.

The efficacy of recombinant human granulocyte colony-stimulating factor and recombinant human granulocyte macrophage colony-stimulating factor in permitting the administration of higher doses of cyclophosphamide in a doxorubicin-cyclophosphamide combination. An NSABP pilot study in patients with metastatic or high-risk primary breast cancer. National Surgical Adjuvant Breast and Bowel Project

Colony-stimulating factors (CSFs) shorten the duration of myelosuppression following chemotherapy and, thus, allow the administration of higher doses. This study evaluates the efficacy of granulocyte macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) in allowing administration of high-dose cyclophosphamide in combination with doxorubicin. Ninety women with metastatic, locally advanced, or high-risk (> or = 10 positive nodes) breast cancer and no prior anthracycline treatment were given doxorubicin (60 mg/m2) with progressively increased doses of cyclophosphamide (1,200 mg/m2, 1,800 mg/m2, and 2,400 mg/m2). The first 60 patients received GM-CSF; the remaining 30, G-CSF. The maximum tolerated dose was not reached with 2,400 mg/m2 of cyclophosphamide. When compared to GM-CSF, G-CSF significantly reduced the duration of granulocytopenia (P < .001). No differences in duration of thrombocytopenia were noted. The results were not sufficiently consistent to indicate a trend toward reduction in rates of febrile neutropenia with one CSF versus the other. However, patients who received G-CSF were hospitalized less frequently than those receiving GM-CSF. With CSFs, high-dose cyclophosphamide in combination with doxorubicin can be safely administered on an outpatient basis. A shorter duration of granulocytopenia resulted from the use of G-CSF than from GM-CSF.

Phase I study of vorinostat, a histone deacetylase (HDAC) inhibitor, in combination with carboplatin (Cb) and paclitaxel (P) for patients with advanced solid malignancies (NCI #6922)

2077

Background: Vorinostat (SAHA) induces differentiation & growth arrest in a variety of human carcinoma cell lines by inhibiting HDAC. It also enhances the efficacy of chemotherapy. We are conducting a phase I study to evaluate the combination of vorinostat, Cb & P for patients with advanced solid malignancies. Methods: Patients with advanced solid malignancies who were candidates for combination therapy with Cb & P were eligible. Vorinostat was given orally on d 1–14 of each 21-d-cycle, except in cycle 1 when begun on d -4 to facilitate PK studies. Cb & P were given on d 1 of each cycle. Plasma concentrations of vorinostat, & its 2 major metabolites were quantitated with a novel LC-MS/MS assay. Results: Dose level 4 has been determined as the recommended phase II dose (RP2D) for the combination, since the RP2D of single agent vorinostat is 400 mg on this schedule. Observed toxicities included nausea, vomiting, neutropenia & thrombocytopenia, none of which were dose-limiting. Of 9 patients evaluable for response, 4 had PR (1 head & neck cancer, 3 non-small cell lung cancer), & 2 had stable disease. Vorinostat was rapidly absorbed & AUC increased with dose. Vorinostat PK parameters included Tmax 0.5–2 h, t1/2 1.6 ± 0.5 h, & CL/F 5.8 ± 1.7 l/min. Cb & P did not alter vorinostat PK. 4-Anilino-4-oxobutanoic acid was the major, & long-lived, vorinostat metabolite, with Cmax 1.5–7 fold > vorinostat Cmax & t ½ ∼6h. Vorinostat glucuronide Cmax was 1–5 fold > vorinostat Cmax & glucuronide t ½ ∼2h. The RP2D cohort is being expanded to 12 patients to obtain additional clinical & PK data. Conclusions: Vorinostat can be safely administered in combination with Cb & P at their recommended doses. Vorinostat PK are not altered by Cb & P. Promising anti-cancer activity has been noted in patients with advanced NSCLC. Support: U01CA099168–01, U01CA62505, NIH/NCCR/GCRC grant 5M01RR 00056.

[Table: see text]

No significant financial relationships to disclose.

Omeprazole-induced hepatotoxicity? A case report

CASE REPORT

We observed a serious symptomatic hepatocellular liver injury in an 85-year-old man treated with omeprazole for many years. Peak values for AST, ALT and AP were 1542 U/l (normal range 14-50), 1236 U/l (11-60) and 154 U/l (30-125) respectively. Abdominal CT scan was normal and viral serologic testing was negative. Omeprazole was discontinued and liver enzymes normalized in 12 days. The patient was known to suffer from ischemic heart disease and had had a myocardial infarction 6 months previously. He was reexposed to omeprazole and the level of liver enzymes rose again and normalized after stopping omeprazole. Despite the improvement of his liver function, the patient died 5 days later due to chronic congestive heart failure.

DISCUSSION

Five cases of omeprazole-induced liver injury have been reported to the Swiss Drug Regulatory Agency since 1990, among them two of cholestatic hepatitis and one of hepatic failure. The WHO Data Base has collected 13,630 ADRs related to omeprazole, with more than 80 cases of hepatitis, 60 of jaundice and about 40 of cholestatic hepatitis. In contrast, only one case of severe symptomatic hepatotoxicity is described in the literature. Clinical studies reported minimal increase of liver enzymes only, in 1-5% of cases.

CONCLUSION

This case with reexposure, together with those reported internationally, suggests that hepatitis is a possible but obviously rare complication of omeprazole treatment.

Is preoperative computed tomography necessary in the management of patients treated for carcinoma of the prostate by 125iodine interstitial implantation and bilateral pelvic lymphadenectomy?

We have evaluated the impact of preoperative pelvic computed tomography (PCT) on the management of 145 patients with adenocarcinoma of the prostate. Our preoperative interpretations were correct in 47 (76%) of the 62 cases with PCT. Twenty-six percent of the 62 patients had microscopically positive lymph nodes, and, of this subgroup, only 50% remain disease-free, at risk for 1 to 7 1/2 years. In contrast, 93% of the subgroup with microscopically negative lymph nodes are free of disease. Of the 83 patients who did not have PCT preoperatively, 18 patients (22%) had microscopically positive lymph nodes and 33% are disease-free; 65 patients (78%) had microscopically negative lymph nodes, and 90% are disease-free, followed for 1 1/2 to 9 years. Thus, there is no significant difference in percent nodal positivity, or disease-free survivals, when comparing the PCT and non-PCT groups, subdivided according to nodal status. We believe that preoperative PCT is an important screening tool, and will provide correct pathological correlations in the majority of cases. However, on the basis of the information derived from this study, the preoperative clinical assessment patients fared no differently from the preoperative PCT patients, thus suggesting that PCT may not be indicated routinely, but should be reserved for questionable situations.

Minocycline-induced pericardial effusion

OBJECTIVE

To describe a reversible hypersensitivity reaction characterized by pericardial effusion and acute mixed liver injury in a woman treated with minocycline.

CASE SUMMARY

A 39-year-old white woman developed dyspnea and chest pain with pericardial effusion on echocardiography approximately 20 days after starting minocycline treatment. Additional manifestations consisted of eosinophilia and liver injury. No lung, skin, or joint involvement was noted; antinuclear antibody testing was negative.

DISCUSSION

Minocycline has been associated with rare but severe hypersensitivity reactions and autoimmune disorders, generally involving the lungs, skin, or joints. We observed a patient with an unusual minocycline-induced reaction with pericardial effusion and acute mixed liver injury. The number of spontaneously reported cases in national and international databases indicates that minocycline-induced pericardial effusion is very rare as a main clinical manifestation.

CONCLUSIONS

Clinicians should be aware of the possibility of pericardial effusion without lung, skin, or joint involvement as an adverse effect of minocycline.

Use of granulocyte-macrophage colony-stimulating factor in patients with malignancy and bone marrow failure

Recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) was administered to 10 patients with refractory malignancies, 2 patients who had myelodysplastic syndromes with severe neutropenia and to a patient who had delayed marrow recovery after 3 cycles of therapy for acute leukemia. A marked neutropenia and monocytopenia was observed within 5 min after an i.v. injection of GM-CSF. This persisted for 1-2 h and seemed related to activation of an adhesive glycoprotein (MO1) on the surface of these cells. With continued daily i.v. administration of GM-CSF, all patients with refractory malignancies developed a striking leukocytosis. Total leukocyte counts reached 75,000/microliters within 2 weeks of treatment. This was due to an increase in band and segmented neutrophils, eosinophils and monocytes. Accelerated myelopoiesis required the continuous presence of GM-CSF; with pump failure for 24 h or discontinuation after 14 days, leukocyte counts returned to normal levels in 24-48 h. GM-CSF also increased myelopoiesis in the patients with myelodysplastic syndromes or following anti-leukemic treatment. These observations suggest that this growth factor should prove a useful adjunct in the treatment of patients with malignancies and bone marrow failure.

A phase Ib trial of IPI-504 (retaspimycin hydrochloride), a novel Hsp90 inhibitor, in combination with docetaxel

3547

Background: IPI-504 is a water-soluble heat shock protein 90 (Hsp90) inhibitor. IPI-504 causes the degradation of a variety of mutated or amplified oncoproteins, including epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). The combination of IPI-504 and docetaxel demonstrates additive efficacy in murine xenograft models. This Phase 1b trial was undertaken to identify the maximum tolerated dose (MTD) of IPI-504 in combination with docetaxel. Methods: Eligible patients (pts) had advanced solid tumors that were either refractory to available therapies or for which docetaxel alone was an appropriate therapy. Intravenous (IV) 75 mg/m2 docetaxel was given once every three weeks (q 3- weekly). IPI-504 was administered IV q 3-weekly, with 3 pts per cohort and inter-cohort dose escalation. All pts were evaluated for safety, pharmacokinetics (PK), and tumor response. Results: 16 pts have been enrolled at 3 dose levels of IPI-504 (7 at 300 mg/m2, 6 at 450 mg/m2, and 3 at 550 mg/m2). 6 pts had non-small cell lung cancer (NSCLC). Median age was 59 yrs (range 33–77). Median number of cycles received was 3 (1–11), with 5 pts currently on study. There have been 4 dose-limiting toxicities (DLTs): 1 at 300 mg/m2 (Grade 3 febrile neutropenia); 1 at 450 mg/m2 (Grade 3 fatigue); and 2 at 550 mg/m2 (Grade 1 asymptomatic sinus bradycardia requiring hospitalization for observation, and Grade 3 elevated AST with Grade 3 acute respiratory distress syndrome). All DLTs resolved on trial. No PK interactions between docetaxel and IPI-504 have been observed. The regimen of IPI-504 450 mg/m2 with docetaxel 75 mg/m2 has been identified as the recommended phase 2 dose on a q 3-weekly schedule. Conclusions: In this Phase 1b trial, the MTD of IPI-504 plus docetaxel q 3-weekly was identified. Toxicities were reversible and similar to those seen with docetaxel or IPI-504 alone in this patient population. Given the activity of single-agent IPI-504 against NSCLC and the standard use of docetaxel in that disease, an expanded evaluation of this regimen in pts with previously treated NSCLC is on-going. The combination of IPI-504 and docetaxel on a weekly schedule is also being explored.

[Table: see text]

[Fluoroquinolones as etiology of tendinopathy]

Tendinopathies as a result of fluoroquinolone therapy represent a new clinical entity. We report on tendinitis and tendon rupture in six fluoroquinolone treated patients of our outpatient and dialysis service between 1995 and 1997. The most important risk factors for tendinopathies were renal failure in all cases, glucocorticosteroid therapy in five patients, secondary hyperparathyroidism in three patients, advanced age in two patients, and diabetes mellitus in another patient. Latency periods of 2 to 60 days between onset of fluoroquinolone therapy and emergence of symptoms suggest significant involvement of these agents and are compatible with previously published case reports. Therefore, care should be used in prescribing fluoroquinolones to older renal transplant or hemodialysis patients with additional risk factors for tendinopathies. These drugs should be stopped when symptoms of tendinitis occur, particularly to prevent tendon rupture. The incidence of fluoroquinolone induced tendinopathies in patients without renal diseases is unknown.

Effect of recombinant human granulocyte-macrophage colony-stimulating factor on myelopoiesis in patients with refractory metastatic carcinoma

The effect of human recombinant GM-colony-stimulating factor (CSF) was evaluated in ten patients with refractory metastatic carcinoma. Initially they received an intravenous (IV) bolus injection of 5 or 25 micrograms/m2 for assessment of acute responses. Six days later, continuous IV infusions of 100 or 500 micrograms/m2 were initiated for a 14-day treatment course. All patients developed profound leukopenia within five to 30 minutes of the bolus injection. This appeared to result from increased expression of an adhesion-promoting glycoprotein (GP) on neutrophils and monocytes as judged by increased reactivity to the Mo1 monoclonal antibody (MoAb). Leukocyte counts returned to normal levels within two hours as cells were released from marrow stores. With the continuous infusion, leukocyte counts increased by 24 hours; peak values of 22,960 and 75.900/microL were achieved after ten to 14 days of treatment with the two dose levels of GM-CSF. This leukocytosis was due to an increase in virtually all cell types. At the high dose level, there was a striking increase in neutrophils (49,400/microL) and eosinophils (20,905/microL) with a sixfold increase in monocytes and two- to threefold increase in lymphocytes. Leukocyte counts declined promptly after cessation of the infusion but remained above baseline for as long as 2 weeks in some patients. These results suggest that GM-CSF may be useful as an adjuvant therapy by stimulating myelopoiesis in cancer patients.

[Liver injury caused by coumarin anticoagulants: experience of the IKS (Intercanton Monitoring Station) and the SANZ (Swiss Center for Drug Monitoring)]

Drug-induced liver diseases are potentially avoidable. Hepatotoxic drugs can mimic virtually any form of liver disease. Among all voluntary adverse drug reaction reports to central registries, 4-7% refer to drug-induced liver diseases. We analyze all cases of coumarin-induced hepatic injuries reported on a voluntary basis to the Swiss Drug Monitoring Centre (SANZ) and the Pharmacovigilance Centre (IKS) from 1981 to 1995. During this period the SANZ collected 9720 reports, 674 of which (6.9%) referred to the liver and the biliary tract. In only 11 reports an oral anticoagulant was involved. In 8 cases we assumed at least a possible causal relationship. 2 more cases were reported directly to the IKS. Among these 10 cases 7 were related to phenprocoumon and 3 to acenocoumarol. In 4 cases elevated concentrations of liver enzymes were measured 2-7 days after the beginning of therapy. In the remaining 6 cases the clinical picture was so severe that the patients had to be hospitalized. These 10 cases are discussed and compared with the cases published in the literature. According to our data, hepatic disorders induced by coumarin-anti-coagulants are rare. If hepatitis is diagnosed in a patient treated with oral anticoagulants, the differential diagnosis of a coumarin-induced hepatic injury has to be considered. Crossreactions between the coumarin derivatives phenprocoumon and acenocoumarol are possible.

Analysis of Bovine Lactoferrin in Infant Formula and Adult Nutritional Products by Optical Biosensor Immunoassay: Collaborative Study, Final Action 2021.07

BACKGROUND

Bovine lactoferrin is increasingly being used as an ingredient in infant formula manufacture to enhance nutritional efficacy through the provision of growth, immunoprotective, and antimicrobial factors to the neonate.

OBJECTIVE

To evaluate method reproducibility of AOAC First Action Official Method 2021.07 for compliance with the performance requirements described in Standard Method Performance Requirement (SMPR®) 2020.005.

METHODS

Eight laboratories participated in the analysis of blind-duplicate samples of seven nutritional products. Samples were diluted in buffer, and an optical biosensor immunoassay was used in a direct-assay format to quantitate bovine lactoferrin by its interaction with an immobilized anti-lactoferrin antibody. Quantitation was accomplished by the external standard technique with interpolation from a four-parameter calibration regression.

RESULTS

After outliers were removed, precision as reproducibility was found to be within limits set in SMPR 2020.005 (≤ 9%) for six out of seven samples and all had acceptable Horwitz Ratio (HorRatR) values ranging from 1.0 to 2.1. Additionally, comparison with an alternative independent Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) First Action method (heparin cleanup LC-UV), showed negligible difference between results.

CONCLUSION

The method described is suitable for the quantification of intact, undenatured bovine lactoferrin in powdered infant formulas. The SPIFAN Expert Review Panel evaluated the method and accompanying validation data from this multi-laboratory testing (MLT) study in July 2023 and recommended Official Method 2021.07 for adoption as a Final Action Official MethodSM.

HIGHLIGHTS

A multi-laboratory validation study of an automated optical biosensor immunoassay for the determination of intact, undenatured bovine lactoferrin is described.

[Retrospective study of drug-induced agranulocytosis in hospitalized patients in Geneva and comparison with cases reported to IOCM]

In a retrospective study, 19 cases classified as idiosyncratic drug-induced agranulocytosis were found among 162 files of patients hospitalized in internal medicine clinics of the university hospital where this diagnosis had been coded. This would give an estimated incidence of 2.6 cases per million inhabitants per year for the Geneva area. In most cases several drugs were implicated in causation of the episodes. Suspected drugs were those commonly reported in the literature, but also some drugs which might already have been taken to treat infectious complications of agranulocytosis. A comparison of the Geneva cases with those notified to the Swiss Intercantonal Office for the Control of Medicines reveals a similar profile of involved drugs.