Management of opiate misuse

Question 1

What contributes to the addictiveness of heroin?

Answer 1

Rapidity of onset of action

Short half-life

Availability

Question 2

how many stages to heroin production?

Answer 2

3

Opium
Morphine
Diamorphine

Question 3

Opium stage?

Answer 3

Mixture of alkaloids (especially codeine and morphine)

Question 4

Morphine stage?

Answer 4

Morphine is extracted though codeine contaminants often remain

Question 5

Diamorphine stage?

Answer 5

Addition of 2 acetyl rings to produce diacetylmorphine (diamorphine).

Question 6

How is heroin taken?

Answer 6

(In order of popularity)

• Intravenous
• Smoking
• Suppository
• Insufflation (blowing into a body cavity)
• Ingestion

Question 7

Metabolic pathway of morphine?

Answer 7

diacetylmorphine to 6-mono-acetylmorphine to morphine

Question 8

Effects of heroin (and other opiates)?

Answer 8

euphoria
analgesia
reduced conscious level
constipation
tolerance develops due to repeated use
constricted pupils

If substance, such as heroin, has been injected, there may be evidence of needle mark abscesses or vein collapse at injection sites.

Question 9

Time frame for withdrawal symptoms for heroin?

Answer 9

typically occurs within 6-8 hours

Question 10

Withdrawal symptoms of heroin?

Answer 10

Dysphoria and cravings
Diarrhoea, nausea and vomiting
Joint pains
Yawning
Tachycardia and hypotension
Agitation
Anxiety
Dilated pupils
“Goose bump skin”

Question 11

complications of IV use?

Answer 11

Infections
Local: cellulitis, abscess, thrombophlebitis, necrotising fasciitis
Distant: eg. infective endocarditis,
Systemic: Hep B, HIV, Hep C

Thrombotic/embolic
DVT, PTE, ischaemic limb

Question 12

other consequences of heroin use?

Answer 12

Social – unemployment, neglect of family/children, alternative interests, criminality, risk of violence, prostitution.
Psychiatric – depression, anxiety.

Question 13

Heroin use can cause delirium or psychosis. true/false?

Answer 13

false

Does NOT cause psychosis or delirium.

Question 14

What is opiate substitution therapy?

Answer 14

Replacement of short acting opiate with a long acting opiate

Buprenorphine or methadone

Long acting depot (buvidol)

Once daily dosing and taken under supervision (initially)

Question 15

Pros of OST?

Answer 15

Reduced mortality rate of less than 1/3 compared to those without therapy.
Reduces HIV infection by ~50%
There is evidence that OST is effective in preventing HCV (hep C) infections

Question 16

Social benefits to treatment?

Answer 16

Reduces criminality
Promotes pro-social activities
Promotes family life
Promotes employment

Question 17

Cons of OST?

Answer 17

Daily visits to chemist (initially)
Stigma (methadone > buprenorphine)
Side effects
Ongoing cost but savings elsewhere (Criminal justice, health)

Question 18

specific drugs used in OST?

Answer 18

Methadone
- long acting full agonist
- Tablet or liquid- but liquid used.

Buprenorphine
- long acting partial agonist
- Tablet or depot
- Different preparations have different dissolution rates (espranor vs sublingual buprenorphine)

Question 19

partial agonist vs full agonist?

Answer 19

Partial agonist opioids activate the opioid receptors in the brain, but to a much lesser degree than a full agonist. Buprenorphine is an example of a partial agonist.

Question 20

What determines the long acting opiate treatment for a patient?

Answer 20

The choice of opiate substitute is dependent on patient factors e.g. overdose risk (buprenorphine may have lower risk of overdose).

Question 21

If both buprenorphine and methadone are suitable. Methadone should be prescribed as first choice. true/false?

Answer 21

True

Question 22

Stages of opioid replacement?

Answer 22

1) Induction
2) Optimisation
3) Maintenance
4) Reduction

Question 23

During acute opioid withdrawal, what drugs could help manage the patients symptoms?

Answer 23

Loperamide (for diarrhoea)
Anti-emetics (for nausea)
Benzodiazepines (can be used for agitation)