code: function queryRxNormApproximate(medname, maxEntries, callback) {
      // maxEntries is optional
      if (!callback) {
          callback = maxEntries;
          maxEntries = 5;
      }
  
      query("http://rxnav.nlm.nih.gov/REST/approximateTerm.json", {
          term: medname,
          maxEntries: maxEntries
      }, callback);
  }
docs: find a medication by approximate name