To the Editor,
As nephrologists we are used to having to be extremely careful with the medications given to advanced kidney failure patients. However, our patients tend to have multiple disorders, meaning that we must obtain second opinions from other specialists. There are different types of consultations, and often very complex patients have a reduced visit time. Drugs are prescribed, sometimes correctly, but on other occasions without considering the degree of the renal function. It is our responsibility to supervise the dose of these drugs that are added to their usual medication, to prevent any surprises from occurring, such as the ones that we are to describe.
Seventy-eight year old male, diagnosed with end-stage kidney failure, undergoing regular haemodialysis. He arrived at the emergency department because of motor discoordination. Neurologically, he presented with ataxia, motor aphasia and visual hallucinations. Five days before, he presented pain in his left side, and erythematous and vesicular lesions in the same area. We prescribed acyclovir at a dosage of 400mg, and subsequent dosages of 200mg every 24 hours. The patient incorrectly ingested 400mg every 8 hours. After receiving a haemodialysis session, he improved rapidly and was discharged the following day. Alcohol poisoning was first suspected in the emergency department, but was dismissed given that ethanol levels were zero.
Seventy-five year old male undergoing regular haemodialysis for diabetic nephropathy, but who needed daily haemodialysis due to intense cramps, especially during the sessions. Suffering from polyneuritis, a specialist visit was arranged and he was prescribed treatment with baclofen (muscle relaxant). Two days after starting the treatment, he arrived at the emergency department presenting with intense tremors. We observed greatly intense fixed miotic and myoclonic pupils, which initially ceased with clonazepam. He then underwent dialysis and his pupils improved. He was discharged in 24 hours. The first diagnostic suspicion at the emergency department was uraemic myoclonus.
With these two cases, which are repeatedly referred to in the literature1-6 and reported in our journal Nefrología,3,4 we aim to remind readers of how easily our patients become intoxicated and how difficult it is to reach a diagnosis in the emergency department. Unnecessary examinations are required (cranial computerised tomography, etc.) if data on medication prescribed de novo to the patient is not considered or is missing. It is not ridiculous that the first case was considered to be alcohol poisoning and the second case the symptoms were thought to be secondary to uraemia. With respect to the second case, severe poisoning has been reported with low doses of baclofen 6 and it is even considered a contraindication for these patients. Although clinical symptoms vary greatly, myoclonus twitching/convulsions and mental confusion is reported. In our hospital, patients are constantly reviewed every 2 days by the dialysis staff. Furthermore, the diagnostic and therapeutic value of this treatment is considered, as occurred in both of these cases. Improvement was especially spectacular and sustained in the second case, once the drug was supposedly withdrawn by the end of the session.
