drugs in opioid dependence Flashcards
buprenorphine MOA
opioid receptor partial agonist
has opioid agonist and antagonist properties
buprenorphine injection can be given as adjunct in the treatment of opioid dependence under expert supervision. they are available as monthly or weekly formulations. what type of parenteral administration?
SC
Sixmo is a SC implant of buprenorphine. when can it be used.
Adjunct in the treatment of opioid dependence [in clinically stable patients who require no more than 8 mg per day of sublingual buprenorphine] (under expert supervision)
Sixmo is buprenorphine SC implant, which can be used as adjunct in the treatment of opioid dependence [in clinically stable patients who require no more than ……. per day of sublingual buprenorphine] (under expert supervision)
8mg
If you are on Sixmo, 4 implants are left in place for how many months?
6
If you are to be on Sixmo, discontinue SL buprenorphine …. hours before insertion
12-24
why are all opioids contraindicated in head injury or raised intracranial pressure
opioid analgesics interfere with pupillary responses vital for neurological assessment
Sixmo contraindications (2)
magnetic resonance imaging (MRI); history of keloid or hypertrophic scar formation
these antibiotics increases exposure to buprenorphine. monitor and adjust dose
clarith, erythromycin
the effects of buprenorphine are only partially reversed by
naloxone
buprenorphine’s partial agonist nature and high receptor affinity make it only partially reversible by naloxone, as naloxone cannot fully displace buprenorphine from the opioid receptors.
what is recommended as pre treatment screening before commencing therapy for opioid dependence
Documentation of viral hepatitis status
buprenorphine monitoring + for SC implant Sixmo
baseline liver function test is recommended before commencing therapy, and regular liver function tests should be performed throughout treatment.
For subcutaneous implant, monitor for signs of infection and problems with wound healing 1 week after insertion and regularly thereafter.
how to take oral lyophilisates of buprenorphine
placed on the tongue and allowed to dissolve. Patients should be advised not to swallow for 2 minutes and not to consume food or drink for at least 5 minutes after administration.
specific contraindication for methadone
phaeochromocytoma
methadone prolongs
QT interval
severe interactions with methadone - drugs that prolong QT interval
avoid using two or more drugs that are associated with this
e.g. amiodarone, antipsychotics, citalopram
also drugs that cause hypokalaemia
e.g. theophylline, loop and thiazide diuretics, anti fungals, CCs, b2 agonists,
methadone - other RF that predispose to QT prolongation
increasing age
female
cardiac disease
some metabolic disturbances e.g. hypokalaemia
avoid methadone with this class of antidepressants due to increased risk of CNS excitation or depression
MAOIs
isocarboxazid, tranylcpromine, phenelzine
methadone is a serotingeric drug so interacts with others - increased risk of serotonin syndrome
e.g. anti depressants, triptans, drugs for ADHD etc
methadone is affected by drugs like phenytoin , carbamazepine, phenobarbital, St Johns wart etc aka enzyme…
inducers
they decrease the exposure to methadone
what is lofexidine and when is it indicated
alpha2-adrenergic agonist
Management of symptoms of opioid withdrawal.
what time to take lofexidine and why
take part of the dose at bedtime to offset insomnia associated with opioid withdrawal.
Methadone is used in opioid dependence. What are 2 other indications?
Severe pain
Cough in palliative care (linctus)
True or false. methadone oral solution is used in the treatment of cough in palliative care
false - linctus, not oral solution
What drug is used as adjunct to prevent relapse in formerly opioid dependent patients
naltrexone
MOA naltrexone and how does it work to prevent relapse in formerly opioid dependent pt
opioid receptor antagonist
naltrexone blocks the effect of opioids and prevents opioid intoxication and physiologic dependence on opioid users
what drug is used in opioid overdose
naloxone
MOA naloxone
It is an opioid antagonist. This means that it attaches to opioid receptors and reverses and blocks the effects of other opioids.
lofexidine how to withdraw
Treatment should be withdrawn gradually over 2–4 days (or longer) to reduce the risk of rebound hypertension and associated symptoms.
