Request for Over the Counter Medication - Tylenol PM - with dosage range as needed with pre-condition for use

{
  "resourceType" : "MedicationRequest",
  "id" : "medrx0310",
  "contained" : [{
    "resourceType" : "Medication",
    "id" : "med0309",
    "code" : {
      "coding" : [{
        "system" : "http://hl7.org/fhir/sid/ndc",
        "code" : "50580-608-02",
        "display" : "Tylenol PM Extra Strength, 1 BOTTLE in 1 CARTON (50580-608-02) > 100 TABLET, FILM COATED in 1 BOTTLE (package)"
      }],
      "text" : "Tylenol PM"
    }
  }],
  "identifier" : [{
    "use" : "official",
    "system" : "http://www.bmc.nl/portal/prescriptions",
    "value" : "12345689"
  }],
  "status" : "active",
  "intent" : "order",
  "medication" : {
    "reference" : {
      "reference" : "#med0309"
    }
  },
  "subject" : {
    "reference" : "Patient/pat1",
    "display" : "Donald Duck"
  },
  "encounter" : {
    "reference" : "Encounter/f001",
    "display" : "encounter who leads to this prescription"
  },
  "authoredOn" : "2015-01-15",
  "requester" : {
    "reference" : "Practitioner/f007",
    "display" : "Patrick Pump"
  },
  "dosageInstruction" : [{
    "sequence" : 1,
    "text" : "Take 1-2 tablets once daily at bedtime as needed for restless legs",
    "additionalInstruction" : [{
      "text" : "Take at bedtime"
    }],
    "timing" : {
      "repeat" : {
        "frequency" : 1,
        "period" : 1,
        "periodUnit" : "d"
      }
    },
    "asNeededFor" : [{
      "coding" : [{
        "system" : "http://snomed.info/sct",
        "code" : "32914008",
        "display" : "Restless Legs"
      }]
    }],
    "route" : {
      "coding" : [{
        "system" : "http://snomed.info/sct",
        "code" : "26643006",
        "display" : "Oral Route"
      }]
    },
    "doseAndRate" : [{
      "type" : {
        "coding" : [{
          "system" : "http://terminology.hl7.org/CodeSystem/dose-rate-type",
          "code" : "ordered",
          "display" : "Ordered"
        }]
      },
      "doseRange" : {
        "low" : {
          "value" : 1,
          "unit" : "TAB",
          "system" : "http://terminology.hl7.org/CodeSystem/v3-orderableDrugForm",
          "code" : "TAB"
        },
        "high" : {
          "value" : 2,
          "unit" : "TAB",
          "system" : "http://terminology.hl7.org/CodeSystem/v3-orderableDrugForm",
          "code" : "TAB"
        }
      }
    }]
  }]
}