GGC Medicines


Adult Therapeutics Handbook

Management of Problematic Drug Users in Hospital

Management of Problematic Drug Users in Hospital

This guideline is an abbreviated version of the full guideline - Management of Problematic Drug Users in Glasgow and Clyde Acute Hospitals located on NHSGGC StaffNet / Clinical Guideline Directory and search for 'Management of Adult Problematic Drug Users in GGC' (link only active if accessing via NHS computer). Whilst this guideline focuses on opiate (heroin) and benzodiazepine use, as these substances are most associated with problematic drug use in NHSGGC, it is only intended as a guide and is not comprehensive. The full guideline on NHSGGC StaffNet will provide more guidance as well as covering:

  • Pain management following injury / surgical procedure.
  • Buprenorphine substitute prescription.
  • New psychoactive substances (e.g. synthetics cannabinoids, novel benzodiazepines, synthetic cathinones, stimulants, hallucinogens, cocaine) and serotonin toxicity management.
  • For patients with complex needs (e.g. maternity addiction) or challenging behaviours, seek advice from specialists (see Appendix 6 for contact details). 

Assessment / monitoring

  • Establish history of drug misuse:
    • Drugs used, as well as the frequency and amount used
    • Route of use e.g. IV, smoked, ingested
    • Whether usage is increasing / decreasing
    • Recent use
    • Previous use
    • Treatment - previous or current
    • Tetanus immunisation status

If appropriate, undertake clinical examination and look for signs of withdrawal (see Table 1). Assess whether patient's clinical state is compatible with their declared opioid use. Exclude other illnesses which may cause symptoms similar to opioid withdrawal.

  • Urine drug screening (if available) may be requested, however, this does not replace full clinical assessment. Positive urinalysis indicates a drug has been taken but does not indicate when. Some of the new types of drugs on the street, including novel benzodiazepines, cannot be tested for using standard urine tests. 
  • ECG - this should be done for all patients prescribed methadone to assess for prolonged QT interval (in men the upper limit of normal is 0.44 seconds and in women 0.46 seconds). See below for further details.

QT interval

Prolongation of the QT interval can be associated with ventricular arrhythmias and death. Consider and exclude other causes, apart from methadone e.g. genetic, adverse drug effects (e.g. anti-psychotics), endocrine and metabolic disturbances. 

If during hospital admission, corrected QT interval (QTc) is prolonged on repeated ECG and all other reversible causes are excluded, a risk assessment of altering methadone dose or switching to buprenorphine should be discussed with the Alcohol and Drug Recovery Service medical staff (see Appendix 6 for contact details). Consideration should be given that the risk of relapse to heroin outweighs cardiac risk in most patients. For more information refer to Drug Misuse and Dependence: UK Guidelines on Clinical Management (often also referred to as the 'Orange Book'). 

Blood Borne Virus (especially Hepatitis C and HIV)

Opportunistic screening for blood borne viruses should be offered at any healthcare contact. The HIV Failsafe team will ensure follow up, however, it is the duty of the testing clinician to inform the patient of the hepatitis screening results, unless other systems are in place.  For treatment or support advice for staff, the HIV Failsafe team can be contacted (see Appendix 6 for contact details). 

General management

  • If patient is a polydrug user not on treatment, presenting with withdrawal and requiring overnight admission, then crisis management regimens described under the 'Treatment Options' section below may be appropriate.
  • Do not feel pressurised to prescribe. Only prescribe when assessment, examination and investigations have been completed and indicate that prescription is appropriate.

Treatment options

Crisis management prescribing for opiate misusers

(See flow diagram above for when to use crisis management.)

  • Dihydrocodeine oral up to 60mg four times daily (unlicensed use). Please discuss with acute addiction liaison nurses (see Appendix 6 for contact details). Dihydrocodeine can be given for the first 24-48 hours if use of methadone is either inappropriate or there is a delay in initiating methadone because:
    • Awaiting further assessment
    • Awaiting methadone dose confirmation
    • It is a short-term admission
  • Dihydrocodeine dose can be reduced or maintained during short admissions depending on the clinical condition of the patient.
  • If required, incremental reductions can be daily or every other day
  • Liquid preparations are preferred to enable supervised administration
  • In pregnancy avoid use of dihydrocodeine. Urgent advice must be sought from local senior addiction medical staff and maternity specialists (SNIPS), see Appendix 6 for contact details..
  • Do not supply on discharge.

Take home naloxone (Prenoxad®) guidance

The Take Home Naoxone programme within NHSGGC allows individuals at risk of opiate overdose to access Overdose Awareness Training and be issued with a supply of Take Home Naloxone. An individual does not need to be in structured treatment to be able to access Take Home Naloxone. For further details see guideline on NHSGGC StaffNet / Clinical Guideline Directory and search for 'Naloxone' (link only active if accessing via NHS computer). To access training and supply for the patient in hospital, contact the acute addiction nurses, see Appendix 6 for contact details.  

Enhanced Drug Treatment Services (EDTS)

These patients will be receiving injectable diamorphine treatment and opiate replacement therapy (ORT) in the form of methadone. These are prescribed and dispensed in the EDTS premises only. Diamorphine treatment must not, under any circumstances, be continued whilst a patient is in hospital. See Appendix 6  for contact details of EDTS. 

Cautions with methadone or benzodiazepines

  • If patient is receiving opiate analgesia or other sedating medications, seek advice from addictions specialists (see Appendix 6 for contact details). If patient has severe pain then morphine IV/SC is the regimen of choice, avoid IM analgesics and do not use pethidine.
  • Interactions with other prescribed drugs, check if it will alter the effects of methadone or benzodiazepines e.g. rifampicin used in the treatment of tuberculosis reduces methadone plasma concentration by 30-65%.
  • If oral doses cannot be given, then greatly reduced parenteral doses may be required. Seek advice from addictions specialists (see Appendix 6 for contact details) as dose conversion can vary on a case by case basis.  
  • Respiratory disease present or suppressed respiratory drive. Observe respiratory rate closely.
  • In liver disease / hepatitis
  • Head injury as GCS will not be sensitive enough to assess opiate intoxication.
  • Co-existent alcohol dependence
  • Overdose / decreased tolerance
  • If patient is pregnant, always contact specialists for advice (see Appendix 6 for contact details).
  • In renal impairment, reduce dose of methadone by 50% if eGFR <10ml/minute/1.73m2 and titrate according to response. 

Please discuss above cautions with the acute addiction liaison nurses (see Appendix 6 for contact details).

Methadone prescribing

  • Methadone has a long half-life (14-72 hours, mean about 24 hours). It is frequently lethal when given to patients who have lost their tolerance to opiates or opiate naive patients. Note: extra caution should be exercised when re-introducing methadone following a period of abstinence e.g. post intubation following ITU admission. 
  • For patients not on a methadone programme and likely to be in hospital for >7 days, do not initiate treatment without seeking advice from the acute addiction liaison nurse service (see Appendix 6 for contact details). If methadone is advised then table 2 outlines management for the first 3 days. 
  • If patient is newly commenced on methadone, seek specialist advice (see Appendix 6 for contact details) with regards to titration to therapeutic dose before prescribing increased dose. 
  • If any signs of intoxication e.g. drowsiness, slurred speech or respiratory depression, then may need to administer IV naloxone. Further doses of methadone should be withheld and specialist advice should be sought (see Appendix 6 for contact details). Caution is required in pregnancy, however in life-threatening situation, use the lowest possible dose of naloxone. 

Methadone discharge procedure

  • Do not give a supply of methadone home.
  • Inform community dispenser of the last dose of methadone, providing time and date given in hospital. Prior to discharge, phone GP and community pharmacy or community addiction team prescriber to inform of discharge and dosage of methadone prescribed. Detail this information in the immediate discharge letter (IDL).
  • For patients on weekend pass / short period (<3 days) it is the responsibility of the discharging hospital to continue methadone prescribing during this period, and also advise the community prescriber / dispenser of this arrangement. So prior to leaving hospital, advise the patient to return to the ward for daily dispensing of their substitute prescription and inform the community team and dispenser of this arrangement.
  • For all other patients ensure arrangements are made to continue substitute prescription. This is particularly important for weekend discharges. If acute addiction liaison nurses are involved , they may be able to make appropriate arrangements.
  • If patient requires to be discharged on opiate analgesia, the dose should be the lowest effective dose as per the WHO pain guidelines. Remember the patient's GP can facilitate pick up of their analgesia with their methadone prescription. 

Crisis management prescribing for benzodiazepine users

Benzodiazepine withdrawal can cause potentially life-threatening seizures. Other symptoms of acute benzodiazepine withdrawal include: anxiety, tremor, insomnia, nausea and vomiting. Street bought benzodiazepines are of varying strength and patients should be treated based on their symptoms.

Small doses of diazepam (5-10mg) should be prescribed in the "once only" section of the prescription kardex and patients reassessed at regular intervals. If they are not drowsy or intoxicated then this may be repeated 6 hourly. Seek advice from acute addiction liaison nurse service (see Appendix 6 for contact details)

Benzodiazepine prescribing

Detoxification or a maintenance regimen for short-term admissions for problematic benzodiazepine use and seizures should be discussed with the acute addiction liaison nurse service (see Appendix 6 for contact details)It is recognised that the doses of diazepam used in treating these patients is well in excess of those normally prescribed and patients should have their physical observations closely monitored. Table 3 gives an example of how diazepam could be prescribed.

Diazepam detox should be agreed on an individual basis according to level of use and length of hospitalisation. If required, incremental reductions can be daily or every other day. In pregnancy always consult NHSGGC SNIPs (see Appendix 6 for contact details). 

  • For those using opiates plus benzodiazepines and/or alcohol, for whom no through care is possible, a combination of treatments outlined here can be prescribed. Please also refer to the Glasgow Modified Alcohol Withdrawal Scale (GMAWs). Further guidance in crisis management prescribing for opiate users is outlined in the full guideline on NHSGGC StaffNet / Clinical Guideline Directory and search for 'Management of Adult Problematic Drug Users in GGC' (link only active if accessing via NHS computer)
  • If sedation or intoxication is produced the dose can be withheld until clinical condition is satisfactory, then proceed with reduced dosage.
  • Do not assume if a patient becomes unusually drowsy that they have had illicit drugs. There may be an underlying medical reason that requires further investigation and patient should be closely monitored.
  • On discharge continuation of a hospital initiated benzodiazepine is not recommended.

 

Guideline reviewed and content updated October 2020