If severe, uncontrolled side-effects (intractable nausea, confusion, hallucinations) persist several days after starting a narcotic, despite appropriate measures to prevent nausea, etc., an alternate strong narcotic analgesic may be indicated. In the case of severe nausea, however, first ensure that appropriate anti-nausea treatment has been tried vigorously, e.g. two anti-nausea preparations rather than just one, given 1/2-1 hour before narcotic analgesic and/or possibly a short course of steroid (dexamethasone).

6.1 To Switch from One Strong Narcotic Analgesic to Another

1. Calculate equianalgesic dose (refer to Indications for Parenteral Narcotic)
2. Use half this calculated dose initially and titrate up or down depending on pain control, adjusting dose after two doses if necessary

Note: Exact equianalgesic doses of narcotic analgesics are not accurately known for patients on long-term treatment for chronic pain, hence above recommendation to use half equianalgesic dose and adjust as required; this method works well in practice.

For example: Morphine solution 20 mg po q4h causes marked confusion, somnolence and nausea despite appropriate anti-nausea medication, all side-effects persisting five to seven days after morphine solution started; examination shows no other reason for side-effects (e.g., cerebral metastases, hypercalcemia, uremia); try alternate strong narcotic analgesic such as hydromorphone (Dilaudid); equianalgesic dose would be 4 mg po q4h but use half this dose to start (2 mg po q4h) and titrate up or down over next four to eight hours (or longer as required).

**Poor pain control alone is not an indication to switch narcotic analgesic; it is an indication to increase dose of drug you are using.