To increase the quantity of a prescribed medication of an invoice line item, it is important to use the correct method.

1. Open the applicable invoice.
2. Find the line item that has the prescribed medication.
3. Select the source record button of the line item.
   
   ezyVet shows the Medication Prescription dialog box.
4. Change the Qty value of the prescribed medication to the applicable quantity.
   
5. If necessary, change the Dispense value to the applicable quantity.
   
6. If necessary, select Update previous invoice line.
   
   Note: If you select Update previous invoice line, ezyVet changes the Quantity value of the related invoice line item. If you do not select Update previous invoice line, ezyVet makes a line item in the related invoice.
7. Select Update + Dispense.
   
   ezyVet closes the Medication Prescription dialog box and shows the initial invoice.

The invoice line item shows the changed quantity of the prescribed medication: