Protocols - Hemorio

METHADONE Intravenous (*) Oral path
Oral path 1:1 or up to 1:2
Intravenously 2:1 or up to 1:1
(*) continuous IV (PCA): The preparation existent in Brazil is not ideal for
continuous IV. In addition, methadone accumulates on the tissues and needs
to be very well monitored in order for not to present any undesirable side
effects.
- If the subject has a very intense pain, consider start morphine until reaching a
decrease of the SAE and then convert for methadone, because it takes time to
make effect and morphine has a fast effect;
- E.g., oral Methadone dose on the 24h = 40 mg. The SC dose is 20mg, on the
24h;
- Converting Methadone IV to VO - 1:1 or sometimes 1:2
- Converting Methadone VO to IV - 2:1 or sometimes 1:1
Morphine Methadone
30 – 80 mg 4:1 30mg = 6mg
81 – 300 mg 7:1 300 = 35mg
over 300 mg 12:1 400 = 35 mg
- Example: Passing from IV to VO: If 30mg/day IV 1:1 = 10 mg Methadone VO
every 7h + 5mg every 4h of rescue. In some cases, as in a Cancer with bone
metastasis, in advanced cases, the dose may have to be higher, the
conversion being 1:2.
- It must be started carefully in the elderly, impaired subjects, or who present
some clearance change, or who are intolerant to low doses of other opioids
- No conversion is effective for all the subjects, just a frequent and careful
observation can personalize the dose for every subject.
ADVERSE EFFECTS:
CONSTIPATION: All subjects in a chronic use of opioid present constipation and must use some type of
anticonstipation. The following recommendations must make part of the prescription: (1) Stimulate the
hydric ingestion, (2) make use of fibers and non constipant food.
At the most mild constipations, the diet, hydration and administration of Tamarine®, Laxarine®, Agiolax®,
and magnesium Hydroxide are enough, which can be done up to 3 times a day.
In most severe cases, use cathartic as bisacodil, Senna, casantrol at night or osmotic laxatives, actulone,
15-20ml from once up to 3 times / day; or sodium sulphate or magnesium, in the morning.
Avoid mineral Oil because it causes a disarbsorptive syndrome. After 3 days not evacuating, prescribe on
the 4 th day a glycerin suppository or a glycerinate clysters.
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