Substance dependence/Wernicke's encephalopathy

Question 1

Nicotine - Substance dependence

Answer 1

NRT, Bupropion & Varenicline - effective for smoking cessation
Some PT benefit from combo therapy
Combo of NRT + Varenicline/Bupropion NOT recommended

Choices:
- Nicotine patches slow release over 16 hrs (remove at night), 24 hr patches will exp. strong craving on waking
- IR preps used to beat cravings (Gum, Lozenges, Sublingual tabs, Inhalator, Nasal spray, Oral spray)

AEs: Throat irritation (inhaler), increased saliva, Minor skin irritation (patches), Coughing, nasal irritation, sneezing, watery eyes
- Oral spray - Paraesthesia (burning hands/feet)
- Patches - Abnormal dreams
- Lozenges/Spray - Rash/Hot flushes
- Patches/Spray - Sweating/Myalgia

Question 2

Opioid - Substance dependence

Answer 2

Need work for MDT and medicine to overcome this.

Methadone, Buprenorphine.
- Start with short period of stabilisation then withdrawal or maintenance

Review regular and monitor toxicity signs

Complete withdrawal usually takes 4 week inpatient and community up to 12 weeks.

3 or more missed doses at risk of overdose due to tolerance loss.
Try reducing dose in PTs overtime.
if they miss 5 or more doses then asses for illicit drug use b4 starting substitution therapy. (esp. with buprenorphine PTs)

Buprenorphine:
Preferred by some Pts - less sedating than methadone.
Better for employed PTs
- Less interaction than methadone with other meds so safer.
- Milder withdrawal symptoms and dose reductions easier than methadone.
- Lower risk of overdose
MAX 32mg/day - sublingual
EXAM Q - know how long each patch brand can be used for for pain relief.

Methadone
Long acting opioid agonist.
Usually OD. Suitable for PTs who abused many drugs in the past

PREGNANCY and opioid withdrawal
Acute withdrawal should be avoided in pregnancy - can lead to foetal death.
- withdrawal during 1st trimester can cause spontaneous miscarriage.
- Buprenorphine not licensed in pregnancy

Question 3

Adjunctive therapies/ Symptomatic treatment

Answer 3

Loperamide - Diarrhoea,

Mebeverine - Stomach cramps,

NSAIDs - Muscular pain/Headaches

Metoclopramide/Prochlorperazine - NV

Benzos/Zopiclone - Insomnia

Lofexidine - Alleviate physical symptoms of opioid withdrawal

Naloxone - Accidental overdose

Naltrexone - Prevent relapse

Question 4

Alcohol - Substance dependence

Answer 4

Abrupt withdrawal for people who been drinking long term may cause alcohol withdrawal symptoms. - can lead to seizures, delirium tremens & death

Long acting benzos (Diazepam, Chlordiazepoxide) - Reduce effect of alcohol withdrawal symptoms

Carbamazepine - ALT treatment for acute alcohol withdrawal.

Clomethiazole - ALT to carbamazepine and benzos

Delirium tremens
Medical emergency - Symptoms:
- Agitation
- Confusion
- Paranoia
- Visual/Auditory hallucinations

Treatment -
1stline - Lorazepam
Adjunctive - Haloperidol or Parenteral lorazepam

Question 5

Wernicke’s encephalopathy

Answer 5

Caused by Vit B1 (thiamine) deficiency.

• Leads to confusion, Loss of mental activity, Death

Pt at high risk: Malnourished, Risk of malnourishment, Decompensated liver disease.

Treatment:
Parenteral thiamine followed by Oral thiamine