# Update prescription item

Partially updates an existing Prescription Item. Only provided fields will be updated.

Endpoint: PATCH /site/{siteId}/ahds/v1/prescription-item/{prescriptionItemId}
Version: 1.0
Security: bearer

## Path parameters:

  - `siteId` (number, required)
    Site identifier

  - `prescriptionItemId` (string, required)
    Prescription Item unique identifier (UUID)

## Request fields (application/json):

  - `extensions` (object)
    Vendor- or practice-specific extensions.

  - `instructions` (string)
    Free-text administration or usage instructions for this prescription item.

  - `isActive` (boolean)
    Whether the prescription item is active and usable.

  - `prescriptionId` (string)
    Identifier of the parent prescription.
    Example: "123e4567-e89b-12d3-a456-426614174000"

  - `productId` (string)
    Identifier of the prescribed product.
    Example: "123e4567-e89b-12d3-a456-426614174000"

  - `quantityPrescribed` (number)
    Total quantity prescribed for this item.

  - `quantityRemaining` (number)
    Remaining quantity that can still be dispensed.

  - `serialNumber` (string,null)
    Serial number associated with this prescription item, if applicable.

  - `startDate` (string)
    Date when the prescription item becomes valid.
    Example: "2025-01-01"

## Response 200 fields (application/json):

  - `createdAt` (string, required)
    Timestamp when the prescription item was created.
    Example: "2025-01-01T00:00:00.000Z"

  - `extensions` (object, required)
    Vendor- or practice-specific extensions.

  - `instructions` (string, required)
    Free-text administration or usage instructions for this prescription item.

  - `isActive` (boolean, required)
    Whether the prescription item is active and usable.

  - `prescriptionId` (string, required)
    Identifier of the parent prescription.
    Example: "123e4567-e89b-12d3-a456-426614174000"

  - `prescriptionItemId` (string, required)
    Canonical identifier for this prescription item.
    Example: "123e4567-e89b-12d3-a456-426614174000"

  - `productId` (string, required)
    Identifier of the prescribed product.
    Example: "123e4567-e89b-12d3-a456-426614174000"

  - `quantityPrescribed` (number, required)
    Total quantity prescribed for this item.

  - `quantityRemaining` (number, required)
    Remaining quantity that can still be dispensed.

  - `serialNumber` (string,null, required)
    Serial number associated with this prescription item, if applicable.

  - `startDate` (string, required)
    Date when the prescription item becomes valid.
    Example: "2025-01-01T00:00:00Z"

  - `updatedAt` (string, required)
    Timestamp when the prescription item was last modified.
    Example: "2025-01-01T00:00:00.000Z"


## Response 400 fields

## Response 401 fields

## Response 404 fields