A Textbook of Clinical Pharmacology and Therapeutics

Withdrawal symptoms can be treated acutely by substitu-
tion with a longer-acting opioid agonist (e.g. methadoneby
mouth) or a partial agonist (e.g. buprenorphine, administered
sublingually). The dose can be tapered over one to two
weeks. Alternatively, withdrawal symptoms are alleviated by
lofexidine(anα 2 -antagonist with less marked hypotensive
effects than clonidine) and an antidiarrhoeal agent, such as
loperamide, administered over 48–72 hours.

MANAGEMENT OF OPIOID ADDICTS

Opioid addicts should be managed by specialized addiction
clinics when possible. A highly simplified outline of manage-
ment is summarized in the Key points below. Morbidity of
opioid dependence is related more to the use of infected need-
les, injection of unsterile material, adulterants and cost (e.g.
theft, prostitution) than to the acute toxicity of opioids per se.

Opioid addicts rarely present to hospital asking for treat-

ment of their addiction, but more commonly present to phys-

icians during routine medical or surgical treatment for a

condition which may or may not be related to their addiction.

Some patients will deny drug abuse and clinical examination

should always include a search for signs of needle-tracking

and withdrawal. Acute abstinence in a casualty/general hos-

pital setting is uncomfortable for the patient, but most unlikely

to be dangerous. Physicians are not allowed to prescribe diamor-

phineorcocaineto addicts for treatment of their addiction or

abstinence unless they hold a special licence. It is reasonable to

treat a genuine opioid withdrawal syndrome with a low dose

of opioid (e.g. sublingual buprenorphine). If a patient says

that they are being treated for addiction it is always wise to

confirm this by telephoning their usual prescriber and/or the

supplying pharmacist. If the patient is admitted to hospital,

expert advice must be obtained. Knowledge of local policies

towards drug addicts is essential for anyone working in the

Accident and Emergency Department or who comes into con-

tact with drug addicts. Newborn children of addicted mothers

may be born with an abstinence syndrome or, less commonly,

with features of drug overdose. Assisted ventilation is pre-

ferred to naloxoneif apnoeic at birth in this situation.

436 DRUGS AND ALCOHOL ABUSE

Key points

Management of opioid addicts in hospital

• Attempt to confirm addiction by telephoning
  prescriber. Confirm dosing regimen.


• Obtain urine screen for a full drug misuse screen.


• Look for evidence of needle marks.


• Look for signs of opioid withdrawal.


• Contact psychiatric liaison team.


• In the Accident and Emergency Department, it is rarely
  appropriate to prescribe methadone. If clear
  withdrawal signs are evident, treat symptomatcially
  (e.g. with antidiarrhoeal agent); discuss with psychiatric
  liaison team regarding dose titration.


• For in-patients, methadone may be appropriate –
  consult with psychiatric liaison regarding dose titration.


• Analgesia – address needs as for other patients, but
  note the effects of tolerance.


• On discharge, contact the patient’s usual prescriber, or
  if this is a new presentation make arrangements
  through psychiatric team.

An orally available long-acting opioid antagonist, such as nal-
trexone, is sometimes used as an adjunct to maintain abstinence
once opioid-free. (If given prematurely naltrexoneprecipitates
withdrawal.) Few opioid addicts choose to remain on long-
term antagonist therapy, in contrast to long-term methadone.

Table 53.4:Symptoms of the opioid abstinence syndrome

Early Intermediate Late

Yawning Mydriasis Involuntary muscle spasm

Lacrimation Piloerection Fever

Rhinorrhoea Flushing Nausea and vomiting

Perspiration Tachycardia Abdominal cramps

Twitching Diarrhoea

Tremor

Restlessness

Key points

Management of opioid dependence

• Refer to specialized addiction clinic.


• Conduct assessment (to include two urine samples
  positive for opioids).


• Give maintenance treatment (e.g. full agonists such as
  methadone, or partial agonists such as buprenorphine).


• Give antagonist treatment (e.g. naltrexone).


• Provide detoxification regimens (e.g. lofexidine plus
  loperamide).


• Give counselling/social support.


• Repeat urine testing to confirm use of methadone and
  not other drugs.


• Contract system.


• Avoid prescriptions of other opioids/sedatives.


• Special ‘drug-free’ centres – concentrate on
  psychological and social support through the acute and
  chronic abstinence phases, and are successful in some
  patients.

There are legal requirements for the prescription of controlled

drugs (Misuse of Drugs Regulations, 1985) distinguished in the

British National Formulary by the symbol CD (e.g. diamorphine,

morphine, injectable dihydrocodeine,dipipanone,fentanyl,

buprenorphine, dexamfetamine, methylphenidate, Ritalin®,

barbiturates,temazepam). Among the requirements are that the

prescription must be written by hand by the prescriber, in ink,

with the dose and quantity of dose units stated in both figures

and words (see British National Formulary). Diamorphine,dipi-

panoneandcocainemay only be prescribed to an addict for their

addiction by doctors with a special licence. Doctors are expected

to continue to report the treatment demands of all drug misusers

by returning the local drug misuse database reporting forms,