substance dependance Flashcards
what are Methadone hydrochloride and buprenorphine used for
substitution therapy in opioid dependence
what happens if a patient misses 3 days or more of their regular prescribed dose of opioid maintenance therapy
they are at risk of overdose because of loss of tolerance. Consider reducing the dose in these patients
what happens if a patient misses 5 or more days of treatment of their opioid maintenance therapy
an assessment of illicit drug use is also recommended before restarting substitution therapy
why might buprenorphine be more suitable for employed patients or those undertaking other skilled tasks such as driving
because it is less sedating than methadone.
- buprenorphine also has less drug interactions than methadone and is safer to use with other medications that may cause sedation
which opioid dependence medication has milder withdrawal symptoms and a lower risk of overdose
methadone
how do you reduce the risk of precipitated withdrawal in patients taking buprenorphine
the first dose of buprenorphine should be given when:
- the patient is exhibiting signs of withdrawal
OR - 6–12 hours after the last use of heroin (or other short-acting opioid)
OR - 24–48 hours after the last dose of methadone hydrochloride.
what can you give to patients where there is a risk of dose diversion (giving their medication to someone else) during opioid maintenance therapy
- buprenorphine with naloxone for parenteral administration
- buprenorphine prolonged-release injection (also good if there’s an issue with adherence to daily supervised consumption)
which patients may prefer methadone to buprenorphine during opioid maintenance therapy
Patients with:
- a long history of opioid misuse
- those who typically abuse a variety of sedative drugs and alcohol
- those who experience increased anxiety during withdrawal of opioids
why might titrating a patient to their optimal dose of methadone take several weeks
because methadone has a long half-life, so plasma concentrations progressively rise during initial treatment even if the patient remains on the same daily dose
- this can explain why a dose tolerated on the first day may not be tolerated on the 3rd day (methadone build up and cumulative toxicity develops)
which drug can be used for Opioid substitution therapy is recommended during pregnancy
methadone
note buprenorphine may be used but it is not licensed in pregnancy
if a pregnant woman chooses a opioid withdrawal regimen, when is the best time to do this
Withdrawal of methadone hydrochloride or buprenorphine should be undertaken gradually during the second trimester
why should an opioid withdrawal regimen be avoided during the first trimester and 3rd trimester of pregnancy
- because there is an increased risk of spontaneous miscarriage during the first trimester
- in the 3rd trimester, maternal withdrawal is associated with fetal distress, stillbirth, and the risk of neonatal mortality
why may the dose of methadone need to be increased or changed to twice-daily consumption during the 3rd trimester of pregnancy
because drug metabolism can be increased in the third trimester. increasing dose or changing to twice daily consumption (can do both) prevents withdrawal symptoms from developing
what should you monitor a baby for if the mother has been prescribed high doses of opioid substitute during pregnancy
- respiratory depression
- signs of neonatal withdrawal such as: high-pitched cry, rapid breathing, hungry but ineffective suckling, and excessive wakefulness; severe, but rare symptoms include hypertonicity (muscle tightness) and convulsions
note symptoms of neonatal withdrawal usually develop 24–72 hours after delivery but symptoms may be delayed for up to 14 days, so monitoring may be required for several weeks
what doses of methadone/ buprenorphine should be given during pregnancy
dose should be kept as low as possible for breast-feeding mothers
