Provided are immediate or prolonged administration of certain potassium ATP (KATP) channel openers, optionally in combination with growth hormone, to a subject to achieve novel pharmacodynamic, pharmacokinetic, therapeutic, physiological, metabolic and compositional outcomes in the treatment of diseases or conditions involving KATP channels. Also provided are pharmaceutical formulations, methods of administration and dosing of KATP channel openers that achieve these outcomes and reduce the incidence of adverse effects in treated individuals. Further provided are methods of co-administering KATP channel openers with other drugs (e.g., in combination with growth hormone) to treat diseases of humans and animals (e.g., Prader-Willi Syndrome (PWS), Smith-Magenis syndrome (SMS), and the like.