drug dependency

see also:

• Addiction medicine - drug and alcohol - main index and links
• ethanol/alcohol dependence
• opiate and opioid dependence
• acute pain Mx in drug dependent patients
• pain, analgesia and analgesics
• marijuana / cannabis / THC
• volatile substance abuse
• ecstasy
• amphetamines and related psychostimulant substances
• cocaine
• gamma hydroxybutyrate (GHB)
• hallucinogens
• Medical Practitioners Board of Victoria - article on the Drugs, Poisons & Controlled Substances Act 1981
• Lancet 2007: Comparative harm of substance misuse

• drug dependent doctors
  • RACGP article on impaired doctors

• use, usually by self-admin., of any drug in a manner that deviates from the approved medical or social patterns within a given culture;

• encompasses recreational & compulsive use excl. society factor;

• a behavioural syndrome where the use of a drug is given a much higher priority than other behaviours that once had a higher value → degrees of dependence.
• may not be a concern if drug low toxicity & inexpensive (eg. caffeine) → no medical or social problem;
• often but not necessarily associated with:
  • tolerance:
    • rpt doses → decr. potency → need to incr. dose for effect;
  • physical dependence:
    • altered physiol. state (neuroadaptation) produced by rpt admin. which requires continued admin. to prevent withdrawal or abstinence syndrome for that drug.
• defining criteria (Am.Psych.Ass.1987) :
  • 1. taking drug more often or incr. dose than intended;
  • 2. unsuccessful efforts to stop or decr. drug use;
  • 3. large amt time spent acquiring/using/recovering from drug;
  • 4. frequent intoxication or withdrawal symptoms
  • 5. abandonment of social or occupation activities due to drug use;
  • 6. continued use despite adverse psych. or physical effects;
  • 7. marked tolerance;
  • 8. frequent use of drug to relieve withdrawal symptoms;

• severe degree of drug dependence that is an extreme on a continuum of involvement in drug use;

• The intrinsic tendency of a drug to induce re-self-administration of that drug;
• In decreasing order: opioids/cocaine; nicotine; caffeine; ethanol; phenoth. (nil);
• mechanism of primary reinforcement:
  • ? involve dopaminergic neurons in ventral tegmental area → limbic/pallidum/frontal;

• the ability of one drug to suppress the manifestations of physical dependance produced by another, & to maintain the physically dependent state.
• May be partial, complete, symmetric or assymetric;
• eg. most sedative-hypnotics (ethanol & benzodiazepines)
  • ? all share some capacity to influence Cl channels regulated by GABA;

• provides for up to 14 days of detention and treatment (currently St Vincent's Hospital) of people with severe substance dependence
• must be a matter of urgency to save life or prevent serious damage to health
• similar to Mental Health Act as there must be no less restrictive means available to treat the patient
• patient must lack capacity to make own decisions at time of detention
• seek expert Drug & Alcohol advice
• Magistrate's Court makes the treatment and detention orders
• Addiction Medicine Specialists, Psychiatrists & Custodial Medical Officers are currently allowed to make recommendations for detention