Suspension of this drug should be freshly prepared and not stored beyond 24 hours. The average daily adult dose of the resin is 15 g to 60 g. This is best provided by administering 15 g (approximately 4 level teaspoons) of Kayexalate one to four times daily. One gram of Kayexalate contains 4.1 mEq of sodium; one level teaspoon contains approximately 3.5 g of Kayexalate and 15 mEq of sodium (A heaping teaspoon may contain as much as 10 g to 12 g of Kayexalate). Since the in vivo efficiency of sodium-potassium exchange resins is approximately 33 percent, about one third of the resin’s actual sodium content is being delivered to the body.

Parasagittal slices of cerebellum (250 mm) were prepared from male Wistar rat. Individual slices were viewed on a Zeiss FS Axioskop microscope with a 406water immersion objective and Nomarski differential interference optics, at a total magnification of 6406. Slices were maintained at 30–32uC and continuously perfused (1– 5 ml min21 ) with a CSF, which was bubbled with 95% O2 and 5% CO2. Whole-cell patch-clamp recordings were made from visualized Purkinje cells using an EPC 8 amplifier (Heka, Digitimer, Welwyn Garden City, UK) controlled via a Digidata 1322a interface (Axon Instruments INC, Foster City CA, USA) using Clampex (v 9, Axon Instruments). Patch-pipettes (thickwalled borosilicate glass, Harvard Apparatus, Edenbridge, UK) were fire-polished, and had resistances of 1.5–4 MV when filled with an intracellular solution containing (mM): 135 K gluconate, 7 NaCl, 10 HEPES, 0.5 EGTA, 2 Na2-ATP 0.3 Na2-GTP and 10 mM Na phosphocreatine (adjusted to pH 7.2 with KOH and osmolarity adjusted to 300 mOSM with sucrose). Aliquots of intracellular solution were stored frozen at 220uC and thawed on the day of recording.