TY - JOUR T1 - N-of-1 trial of salbutamol in hyperkalaemic periodic paralysis JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 1352 LP - 1353 DO - 10.1136/jnnp-2021-326347 VL - 92 IS - 12 AU - Bas C Stunnenberg AU - Esther C Merkus AU - Joost Raaphorst AU - Christiaan GJ Saris AU - Hans Groenewoud AU - Jeffrey Statland AU - Robyn Weijma AU - Bas van Vlijmen AU - Robert Griggs AU - Baziel G M van Engelen AU - Gert Jan van der Wilt Y1 - 2021/12/01 UR - http://jnnp.bmj.com/content/92/12/1352.abstract N2 - Hyperkalemic periodic paralysis (HyperPP) is a rare neurological channelopathy caused by gain-of-function mutations in the skeletal muscle sodium channel gene (SCN4A) that disrupts sarcolemmal membrane excitability. Clinically, HyperPP is characterised by episodic muscle weakness attacks with associated rise in serum potassium and a degree of myotonia. Attacks are triggered by exercise, stress, potassium-rich food and a fasting state.Therapy of periodic paralysis typically consists of avoiding triggers and the use of prophylactic carbonic anhydrase inhibitors. Although these drugs have shown their efficacy in randomised controlled trials (RCTs), many patients oppose a daily drug intake and side effects are frequently experienced.1 Alternatively, salbutamol has been used as an attack treatment in HyperPP, presumably because catecholamines stimulate the cellular uptake of potassium.2 Still, only a few patients with HyperPP are being treated with salbutamol and the large heterogeneity in individual treatment responses makes it difficult to predict who will benefit from the treatment. We report the results from an N-of-1 trial that compared salbutamol aerosol versus placebo treatment to test whether salbutamol aerosol treatment alone, without prophylactic treatment, reduces weakness attack characteristics to a clinically meaningful degree in a single patient with HyperPP.A randomised, placebo-controlled, double-blind, single patient, multiple cross-over trial (ie, N-of-1 trial) with two (block-randomised) treatment sets: each consisting of a 2-week treatment period of salbutamol and placebo aerosol treatment. The patient (see online supplemental file 1) preferred attack treatment over daily prophylactic treatment with acetazolamide (for baseline data see online supplemental file 2, online supplemental efigure 1). We performed an N-of-1 trial because we had no experience with salbutamol treatment in HyperPP and trial evidence on the abortive effect of salbutamol in an out-of-hospital setting was lacking.Supplementary data [jnnp-2021-326347supp001.pdf] The patient was instructed to use blinded study inhalators (online supplemental efigure 2) according to the instructions from … ER -