C H A P T E R 2 6
Opioids, opioid antagonists and antimigraine agents
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BOX 26.1
Drug therapy across the lifespan
Opioids
CHILDREN
The safety and effectiveness of many of these drugs have
not been established in children. If an opioid is used,
the dose should be calculated very carefully, and the
child should be monitored closely for the adverse effects
associated with opioid use.
Opioids that have an established paediatric dose
include codeine, fentanyl (but not transdermal fentanyl),
hydrocodone, pethidine and morphine. Oxycodone and
dextropropoxyphene are not recommended for children.
Methadone is not recommended as an analgesic in
children. If a child older than 16 years of age requires an
opioid agonist-antagonist, buprenorphine-naloxone is the
preparation of choice. Naloxone is the drug of choice for
reversal of opioid effects and opioid overdose in children.
ADULTS
Adults being treated for acute pain should be reassured
that the risk of addiction to an opioid during treatment
is remote.They should be encouraged to ask for pain
medication before the pain is acute, to get better
coverage for their pain. Many institutions allow people
to self-regulate intravenous drips to control their pain
postoperatively.
PREGNANCY AND BREASTFEEDING
The opioids are contraindicated or should only be used
with caution during pregnancy because of the potential for
adverse effects on the fetus.These drugs enter breast milk
and can cause opioid effects in the baby, so caution should
be used during breastfeeding. Morphine and pethidine
are often used for analgesia for labour.The mother should
be monitored closely for adverse reactions, and, if the
drug is used over a prolonged labour, the newborn infant
should be monitored for opioid effects such as respiratory
depression. Naloxone should be readily available for the
baby if the mother has received an opioid in the hours
immediately prior to the birth.
OLDER ADULTS
Elderly people should be specifically asked whether they
require pain medication. Because many older people can
recall a time when nurses were able to spend more time
with people, they may tend to believe that the nurse will
meet their needs.
Older people are more likely to experience the adverse
effects associated with these drugs, including central
nervous system, gastrointestinal and cardiovascular
effects.
Because older people often have renal or hepatic
impairment, they are also more likely to have toxic
levels of the drug related to changes in metabolism
and excretion.The older person should have safety
measures in effect—side rails, call light, assistance to
ambulate—when receiving one of these drugs in the
hospital setting.
TABLE 26.1
DRUGS IN FOCUS Opioids
Drug name
Dosage/route
Usual indications
Opioid agonists
alfentanil (Rapifen)
Spontaneous ventilation: 7 mcg/kg by slow IV
injection
Controlled ventilation: 20-50 mcg/kg by slow
IV injection
Analgesic supplement and anaesthetic
induction agent in inpatient surgery
codeine (generic)
Adult: 15–60 mg PO, IM, IV or SC q 4–6 hours;
10–20 mg PO q 4–6 hours for cough
Paediatric: 0.5 mg/kg PO, IM or SC q
4–6 hours; 2.5–10 mg PO q 4–6 hours for
cough
Relief of mild to moderate pain; relief
of coughing induced by mechanical or
chemical irritation of the respiratory tract
dextropropoxyphene
(Doloxene)
100 mg PO q 4 hours as needed
Relief of mild to moderate pain in adults
Special considerations:
limit use in
suicidal or addiction-prone people
fentanyl (Actiq, Duragesic,
Sublimaze)
Adult: 0.05–0.1 mg IM, 30–60 minutes
before surgery; 0.002 mg/kg IV or IM during
surgery; 0.05–0.1 mg postoperatively;
5 mcg/kg transmucosally; for transdermal
patch, calculate the previous day’s opioids
need and use table to convert to patch
strength; ionic delivery system, 40 mcg over
10 minutes
Paediatric (>2 years): 2–3 mcg/kg IM or IV;
base transmucosal dose on weight and do
not exceed 400 mcg
For analgesia before, during and
after surgery; transdermal patch for
management of chronic pain; control of
breakthrough pain
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