<prompt> Drug having narrow therapeutic range is:LithiumSeralineRoboxetineDothiepin  <response>: Therapeutic range is bounded by the dose which produces a minimal therapeutic effect and the dose which produces maximal acceptable adverse effect Lithium is an unsafe drug with a narrow therapeutic range- 0.6 - 1.2 mmolL. Ref: KD Tripathi Pharmacology 7th edition page no;56 