Severe persistent cerebellar dysfunction complicating cytosine arabinoside therapy

Drug-induced cerebellar ataxia: a systematic review

BACKGROUND AND OBJECTIVES

Cerebellar ataxia can be induced by a large number of drugs. We here conducted a systemic review of the drugs that can lead to cerebellar ataxia as an adverse drug reaction (ADR).

METHODS

We performed a systematic literature search in Pubmed (1966 to January 2014) and EMBASE (1988 to January 2014) to identify all of the drugs that can have ataxia as an ADR and to assess the frequency of drug-induced ataxia for individual drugs. Furthermore, we collected reports of drug-induced ataxia over the past 20 years in the Netherlands by querying a national register of ADRs.

RESULTS

Drug-induced ataxia was reported in association with 93 individual drugs (57 from the literature, 36 from the Dutch registry). The most common groups were antiepileptic drugs, benzodiazepines, and antineoplastics. For some, the number needed to harm was below 10. Ataxia was commonly reversible, but persistent symptoms were described with lithium and certain antineoplastics.

CONCLUSIONS

It is important to be aware of the possibility that ataxia might be drug-induced, and for some drugs the relative frequency of this particular ADR is high. In most patients, symptoms occur within days or weeks after the introduction of a new drug or an increase in dose. In general, ataxia tends to disappear after discontinuation of the drug, but chronic ataxia has been described for some drugs.

Flushing out of cerebrospinal fluid as a therapy for acute cerebellar dysfunction caused by high dose of cytosine arabinoside: a case report

High dose of cytosine arabinoside is usually used in treatment of acute myelogenous leukemia. Here we report 1 case of a child who developed neurologic toxicity and rapidly improved after flushing out of cerebral spinal fluid, suggesting it could be treatment in the acute phase of toxicity. Efficacy of this treatment could be explained by reducing cytosine arabinoside metabolites in central nervous system.

Long-term neuropsychologic sequelae of childhood leukemia: comparison of two CNS prophylactic regimens

To compare the late neuropsychologic toxicities of CNS prophylaxis in childhood acute lymphoblastic leukemia (ALL), a transversal assessment was performed in two groups of ALL patients and two control groups. The ALL patients had received one of the following CNS prophylaxes: cranial irradiation, 24 Gy and i.t. MTX 10 mg/m2, 6 doses (RT group, n = 25) or i.t. Ara-C 30 mg/m2 and i.t. MTX 10 mg/m2, 10 doses (ChT group, n = 29). The two control groups were: Siblings (Sb, n = 24) and Solid Tumors (ST, n = 22). Intelligence Quotient (IQ), memory, learning, attention and frontal tasks were studied. Comparative analyses between ChT and RT showed no differences in any of the tests. When RT was compared with ST or Sb, RT showed a 10-point lower mean IQ (p greater than 0.05). The results of ChT versus ST or versus Sb were worse in the ChT group. In many tests the differences were statistically significant. Analyses of the 54 ALL patients compared with the 46 controls showed significant differences in all tests except verbal memory and verbal learning. Neuropsychological sequelae of CNS prophylaxis are discussed, and in particular, the role of cranial radiotherapy and i.t. Ara-C. We conclude that prophylactic CNS therapy may cause cognitive dysfunctions.

The toxicity of cytarabine

The principal toxicity of standard induction regimens for acute non-lymphocytic leukemia (ANLL) [including cytarabine (ARA-C) 100 mg/m2 for 7 days plus an anthracycline] is myelotoxicity, leading to death in at least 25% of cases during induction in non-selected patients. The complete remission rate is less than 35% in patients over 65 years of age, due in part to an age-related increase of myelotoxicity. The other important adverse effect of standard-dose cytarabine is gastrointestinal toxicity, especially oral mucositis, diarrhoea, intestinal ulceration, ileus and subsequent Gram-negative septicaemia. Idiosyncratic reactions like exanthema, fever and elevation of hepatic enzymes are relatively frequent, but do not represent therapeutic problems. Intermittent high-dose cytarabine (3 g/m2 in 8 to 12 doses) is extremely myelosuppressive. Similarly, the gastrointestinal toxicity is formidable and dose-limiting. Severe, and sometimes irreversible, cerebellar/cerebral toxicity in 5 to 15% of courses of treatment limits the peak dose of cytarabine. The pathogenesis, prophylactic and therapeutic measures are unknown. These major toxicities are age-related and prohibitive to the use of high-dose cytarabine therapy in patients older than 55 to 60 years. Subacute noncardiogenic pulmonary oedema occurs in some patients, with an incidence of about 20%, and seems to have an intriguing coincidence with precedent streptococcal septicaemia; high-dose systemic steroids may be beneficial. Corneal toxicity is very frequent in high-dose cytarabine therapy but is always reversible. It is largely preventable with prophylactic steroid or 2-deoxycytidine eyedrops. Fever, exanthema and hepatic toxicity have an incidence similar to that in standard dosage. The maximum tolerable cumulated dose of cytarabine is significantly lower when the agent is administered as a continuous infusion, due to myelosuppression and gastrointestinal toxicity. Conversely, continuous infusion may be less neurotoxic. The antileukaemic effect of continuous infusion high-dose cytarabine is less well established. The only significant toxicity of low-dose cytarabine is myelosuppression. Given the generally poor condition of leukaemia patients, low-dose cytarabine therapy is well tolerated, although occasional cases of diarrhoea, reversible cerebellar symptoms, peritoneal and pericardial reactions, and ocular toxicity have been reported. Continuous infusion may be more toxic than the usual intermittent dosage. It is concluded that the toxicity of the standard induction regimen for ANLL is acceptable in patients younger than 60 to 65 years with no concurrent disease. Low dose cytarabine is tolerable for virtually all ANLL patients, but the overall therapeutic efficacy still needs to be defined and compared to standard therapy in the relevant age groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Cerebellar toxicity during cytarabine therapy associated with renal insufficiency

Acute cerebellar toxicity with ataxia and dysarthria is a well-known side effect during high-dose cytarabine therapy. Dose, age, previous neurological disorders, hepatic dysfunction, and renal insufficiency have been inconsistently reported as risk factors. The present paper presents a patient with renal insufficiency who developed severe cerebellar toxicity following treatment with a dose of cytarabine (8 g/m2 over 5 days) not generally expected to be associated with neurotoxicity. Together with a review of the literature, the present case gives evidence of renal insufficiency as a major risk factor in the development of cerebellar toxicity during cytarabine therapy. Reduced doses of cytarabine should be considered in patients with renal impairment.