Addiction - Opiates Flashcards
What are some factors which are responsible for the addictiveness of heroin?
Rapid onset of action, short half-life, availability
What is the relevance of heroin having a short half-life?
Reaches peak plasma levels very quickly, but they also drop very quickly which causes cravings
What are the two main constituents of opium?
Codeine and morphine
How is diamorphine produced from morphine? What is this known as?
Addition of 2 acetyl rings to form heroin
How can heroin be taken?
IV, smoking, suppository, insufflation, ingestion
What are the quickest ways of getting heroin into the bloodstream and achieving a quick high?
Smoking or IV
Describe the metabolism of diacetylmorphine?
Goes to 6-mono-acetyl morphine and then to morphine
How long does 6-mono-acetyl morphine last in the system? If this is detected in a drugs test then the patient has definitely taken what?
6 hours / heroin
If morphine is shown up in a drugs test, what could the patient have taken?
Codeine or heroin since these are both metabolised to morphine
If a blood test shows up 6-mono-acetyl morphine and codeine, what is the significance of this?
The codeine was probably a contaminant
What does taking heroin do to you?
Euphoria, analgesia, respiratory depression, constipation
What are some signs of heroin use?
Reduced conscious level, hypotension/bradycardia, pupillary constriction
The body sensation of euphoria when taking heroin is more to do with what?
Release of histamine
Why do people who take heroin often have very bad dentition?
They receive so much analgesia that they don’t notice when things are wrong / they have reduced saliva production and increased gastric acid production
Withdrawal symptoms from heroin usually occur within how long of stopping it? What causes these symptoms?
6-8 hours / overactivity of adrenaline and the sympathetic nervous system
What are some infectious complications of IV drug use?
Local e.g. cellulitis, abscess, thrombophlebitis, necrotising fasciitis/ distant e.g. infective endocarditis / systemic e.g. Hep B/C, HIV
What are the two main complications of IV use of drugs?
Infections and VTE
What are some VTE related complications of IV drug use?
DVT, PE, ischaemia limb
Almost all drug related deaths occur after the consumption of what? Give an example.
Multiple substances, especially pregabalin/gabapentin as these increase the effects of opioids and increase people’s tolerance to them
What drug is used to reverse the effects of an overdose?
Naloxone
What are some psychiatric complications of heroin use? What are some psychiatric features which are NOT seen in heroin use?
Depression and anxiety / psychosis and delirium
Is opiate withdrawal dangerous?
No, it is just unpleasant
What is opiate substitution therapy?
The act of replacing a short acting opiate with a long acting opiate
Give some examples of long acting opiates that can be used for opiate substitution therapy?
Buprenorphine or methadone
How are long-acting opiates taken in opiate substitution therapy?
Once daily under supervision (initially)
What are the pros of opiate substitution therapy?
Reduces mortality and risk of blood borne virus, also reduces criminality and allows people back to education/work
What are the cons of opiate substitution therapy?
Daily visits to the chemist (initially), stigma, side effects
Describe the action of methadone and how it is taken?
Long acting full opioid agonist - liquid formulation
Describe the action of bupranorphine and how it is taken?
Long acting partial opioid agonist - tablet formulation
Can the transition from heroin to long acting opiates cause withdrawal?
Yes
What is opiate detoxification and how is this achieved?
Complete abstinence from all opiates - gradually reduce dose until patient is completely drug free
What is the big risk of opiate detoxification?
The risk of death from overdose is rapidly increased in the first 4 weeks following detoxification
What % of patients who have undergone opiate detoxification will relapse in a year? What is the significance of this?
70% / their tolerance will have decreased but they take the same dose so they overdose and die
Overall, which method of treatment for opiate addiction works best?
Opiate substitution tehrapy
What is the main psychological treatment for opiate addiction? What does it do?
Contingency management, rewards positive behaviours
For who being treated for opiate addiction may behavioural couples therapy be useful?
People in close contact with a non drug abusing partner
What are the roles of CBT and psychodynamic therapies in drug misuse?
Not indicated for the treatment of drug misuse, but is indicated for any co-morbid anxiety/depression
