SUBSTANCE ABUSE-OPIOID DEPENDENCE Flashcards
How long does withdrawal symptoms last for untreated heroin dependence?
within 8 hours with peak symptoms at 36-72hours
subside significantly after 5 days
What two drugs are used for substitution therapy in opioid dependence?
Methadone and buprenorphine
Started with short stabilisation period followed by either withdrawal regime or maintenance regime.
What are the benefits of the maintenance regime of subsitiution therapy?
Enables patient to achieve stability, reduce drugs use and crime and improve health.
How long does complete withdrawal take in hospital setting and community setting?
4 weeks in inpatient or residential setting
12 weeks-community setting
What should happen if the patient resumes illicit drug use or cannot tolerate withdrawal?
Withdrawal regime should be stopped
and maintenance therapy resumed
Why must patients not miss 3 or more doses?
Due to risk of over dose as a result go loss of tolerance. Consider reducing dose in these patients
What must occur if patient misses 5 or more days of treatment?
an assessment of illicit drugs use is recommended before restarting substitution therapy, important in patients taking buprenorphine due to the risk of withdrawal.
What are benefits of buprenorphine over methadone?
It is less sedation than methadone so more suitable for patients undergoing skilled tasks
Safer than methadone when taken with other sedating drugs
Dose reduction may be easier because withdrawal symptoms are milder
lower risk of overdose, can be given on alternate days in higher doses and requires shorter drug free period before induction with naltrexone for prevention of relapse.
Who are at an increased risk of precipitated withdrawal?
Patients dependent on high dose of opioids
Can occur in any patient if buprenorphine is administered when other opioid agonist drugs are in circulation.
How soon does preciptated withdrawal of buprenorphine occurs?
1-3 hours of first dose and peaks at 6 hours
Treatment if symptoms are severe;
lofexidine a non opioid adjunctive
What can reduce the risk of precipitated withdrawal?
First dose of buprenorphine cane be give when the patient is exhibiting signs of withdrawal or 6-12 hours after the last use of heroin or short acting opioid.
or 24-48 hours after the last dose of methadone.
METHADONE;
What is it
What are benefits over buprenorphine?
Long acting opioid
More sedation so can be beneficial in patients with long history of opioid misuse, those who typically abuse a variety of sedative drugs and alcohol, and those who experience increased anxiety during withdrawal of opioids
METHADONE;
When can it be initiated?
At least 8 hours after the last heroin dose provided there is objective evidence of withdrawal symptoms
How does the long half of methadone affect the plasma concentrations?
plasma concentrations progressively rise during treatment even if the patient stays on the same dose
How long does it take for the plasma concentration of methadone to reach steady state?
3-10 days
therefore titration to the optimal dose in maintenance may take several weeks.
Can opioid subsititution therapy be used in pregnancy?
Yes as it Is safer than using illicit drugs
Methadone is licensed on pregnancy not buprenorphine
Avoid withdrawal regimen during first trimester due to risk of spontaneous micarriage
Avoid in third trimester as well as it is not recommended as it is associated with fatal distress, stillbirth and risk of neonatal mortality.
Why may a dose increase of methadone be needed during third trimester pregnancy?
increased metabolism during third trimester.
What are signs of neonatal withdrawal from opioids?
Usually develops 24-72 hours after delivery but symptoms may be delayed for up to 14 days
high pitched cry
rapid breathing
hungry but ineffective suckling
excessive wakefulness
severe but rare; hypertonicity and convulsions.
LOFEXIDINE;
What are benefits?
alleviate some of the physical symptoms of opioid withdrawal by attenuating the increase in adrenergic neurotransmission that occurs during opioid withdrawal.
Can be given instead of substitution therapy in patients with mild or uncertain dependance.
