://module2 The WHO method page 8/9
WHO Ladder Step 3 <<previous next>>
If pain persists or increases, patients move up from step 2 to step 3. The opioid drugs used in this stage will be more potent drugs such as morphine, fentanyl and methadone. Morphine is the most commonly used first line in this step, and the only one we will consider here. We will cover this class of drugs in more depth in Module 3.
To calculate a suitable starting dose, patients should have an oral morphine preparation prescribed as needed, usually oral morphine solution, 10mg as needed. The total opiate used in 24 hours will give an indication of the best starting dose. So if a patient uses a total of 60mg of morphine, they can be started on either 10mg every four hours, or preferably, 30mg twice daily of a modified release preparation.
The PRN (as needed) dose of oral morphine should be increased such that the PRN dose is 50% to 100% of the calculated regular four hourly dose. Examples are given in the table below.
| Drug | Dosage | Frequency | Total in 24h | PRN dose (4 hourly) |
| Morphine sulphate | 20mg | 4 hourly | 120 mg | 10-20mg |
| Morphine Sulphate | 40 mg | 4 hourly | 240mg | 20-40mg |
| Morphine sulphate MR (eg Zomorph) | 60mg | 12 hourly | 120mg | 10-20mg |
| Morphine sulphate Sustained Release (eg MXL) | 200mg | 24 hourly | 200mg | 15-30mg |
So a patient on Step 3 may be on a drug regime like this:
Morphine sulphate modified release 30mg twice a day
Diclofenac 50mg three times a day
Lansoprazole 15mg once a day
+ / - any adjuvants as needed.