All analysis of drug use essentially revolves around the same model of addiction that is probably taught to you in medical school. However, this doesn’t particularly help in a long case exam. As for as opiates go you need to;
1) Review the amount of use
2) Detect and diagnose dependence,
a. Tolerance
b. Withdrawal,
c. Unsuccessful attempts at cutting down or controlling use
d. A lot of time spent attempting to obtain, using or recovering from their use
e. Neglecting important social, occupational or recreational activities
f. Use continued despite knowledge of the physicalorpsycholical problems it is likely to cause or exacerbate
3) Assess harms – physical (e.g. infective), mental or social (financial, forensic)
4) Assess social factors contributing to drug use e.g. precipitants, barriers, support structures, expectations
5) Determine patients expectation of treatment and motivation to change
6) Give harm-minisation advice e.g. clean needles
7) Manage pharmacologically or non-pharmacologically
8) Prevent relapse e.g. follow-up inc narcotics anonymous
The basics of methadone prescribing (although you are unlikely to be asked) are that in general a initial daily dose of 10-40mg is prescribed. If the patient is opiate tolerant you can use 25-40mg. Care is needed when starting a dose greater than 30mg because of the risk of overdose. Additional doses of 5-20mg can be given depending on the severity of the withdrawal symptoms. When stabilising a patient attend daily for the first few days to titrate their dose. Where doses need to be increased during the first seven days, the increment should be no more than 5 – 10mg on one day. In any event, a total weekly increase should not exceed 30mg above the starting days dose. Steady state plasma levels should be reached 5 days after the last dose increase. Aim for a total of no more than 60-120mg per day. After a period of stabilisation in which the patient should be encouraged to abstain completely from heroin, the daily dose can be reduced by 5-10mg every week or fortnight until a stable dose is reached.
Buprenorphine is useful if the patient is more highly motivated or less opiate dependent or if there are access issues to medication as the dose can be 2nd daily