High dosage of marijuana may lead to hypokalemia in the brain which may be linked to either the inhibition of adenylate cyclase by cannabinoids; an active ingredient in marijuana that affects potassium channel function to bring inhibition of synaptic transmission [21] or Tachycardia i.e. heart rate more than 100 beats per minute which is one of the main peripheral effect of marijuana intake [18]. This evidence concerns the gene KCNA3 and Hypokalemia.