Crizotinib-Associated Renal Cysts: A Case Series

Crizotinib is an anaplastic lymphoma kinase (ALK) inhibitor, used as a targeted chemotherapeutic agent in ALK-positive cases of nonsmall cell lung carcinoma. Although uncommon, it may be associated with the formation of new renal cysts, which may be simple or complex, or the enlargement of preexisting simple renal cysts or their transformation into complex cysts. These cysts usually regress partially or completely but may rarely enlarge over time or get complicated by infection or abscess formation. Such cases may even require dose reduction or withholding crizotinib. Although documented in clinical literature, this entity is not well known among radiologists. Knowledge of this entity helps in preventing erroneous diagnosis of the new kidney “lesion” as metastasis or disease progression and avoids an unnecessary biopsy. We describe a series of four cases which developed complex renal cysts during treatment with crizotinib to demonstrate this point.

Pregabalin-induced sexual disinhibition

IntroductionSexual side effects have rarely been reported secondary to treatment with Pregabalin, a structural analogue of the inhibitory neurotransmitter gamma amino butyric acid (GABA).MethodWe present the case of AB, a 27-year-old single man with a diagnosis of recurrent depressive disorder who was prescribed pregabalin to alleviate the significant anxiety symptoms he was experiencing.ResultsA significant amelioration in anxiety symptoms was attained; however, he developed the adverse effects of acute sexual disinhibition and increased libido. These adverse effects were temporally related to treatment with pregabalin and reduced with dose reduction of this agent.ConclusionsTo date, limited published data are available relating such a reaction to pregabalin. A greater clinical recognition of this association between pregabalin and sexual disinhibition, would allow clinicians to intervene at an earlier stage of this adverse effect and potentially as in this case, management may only require dose reduction rather than treatment discontinuation.

Neoral conversion from Sandimmune in maintenance renal transplant patients: an individualized approach.

When converting maintenance renal allograft recipients from Sandimmune (cyclosporin A [CsA]) to Neoral (CsA-microemulsion [CsA-ME]), a dose conversion ratio of 1:1 may not be optimal, in part because of the variability in absorption of the CsA formulation of cyclosporine. After conversion using a 1:1 dose ratio, an individualized approach to the management of dosing was applied. In this article, close monitoring, which began at the time of conversion, and rapid response to potentially meaningful changes in cyclosporine trough levels early in the postconversion course were used to maintain patients' cyclosporine troughs at preconversion levels. The results of cyclosporine dose changes after converting stable, maintenance renal transplant patients from CsA (once daily and twice daily) to CsA-ME (twice daily) during 52 wk of follow-up are reported. Most patients (87.2%) required CsA-ME dose reduction to maintain preconversion trough levels, and 64% of the patients attained their CsA-ME maintenance dose by study week 4. Logistic regression analysis identified one significant predictor concerning the week 52 CsA-ME dose: patients converted from CsA doses > or = 4.0 mg/kg per d were more likely to require dose reduction (P < 0.0001). Although firm guidelines for dose modification after conversion from CsA to CsA-ME cannot be provided because of the individual nature of cyclosporine absorption, an individualized approach to patient management is recommended. Patients with higher CsA doses before conversion are particularly likely to require dose reduction early in the postconversion course. With CsA-ME, good absorbers of cyclosporine remain good absorbers, or become better absorbers, whereas poor absorbers become good absorbers.