Download Substance misuse - Devon Partnership NHS Trust

Prescribing Guideline
Pharmacological Management of
Substance Misuse
PG20
These prescribing guidelines outline the management of substance misuse experienced by adults. It is
recognised that because of the potential and increased risk for drug misuse and diversion in these
settings, it may sometimes be necessary and appropriate to prescribe an alternative medication(s) to
those recommended in this document.
Document Control
Version
Date Issued
1.0
2006
2.0
October 2013
3.0
October 2014
4.0
December 2016
Target Audience/staff groups
Ratifying group
Date Ratified
Implementation date
Review date
Author Name / Job Title / Email
Dr Mary Rowlands; Consultant Psychiatrist [email protected]
Roz Gittins; Lead Clinical Pharmacist (Specialist Services) [email protected]
Chris Sullivan, Lead Clinical Pharmacist
Health care professionals working in Devon Partnership NHS Trust.
Drug and Therapeutics Committee
November 2016
December 2016
October 2020
Document History
Version
Start date
1.0
1.1
Oct 2011
1.2
1.4
2.0
2.0
Apr 2013
Oct 2013
2.1
2.1
Aug 2014
Dec14
3.0
3.1
Oct 16
4.0
End date
Author
History
2006
MR
MR
New Guideline
Revision of prescribing guidelines for alcohol and substance misuse
(Ratified by Trust Addiction Services Governance Group 2010) to
meet trust Prescribing guidelines format and inclusion of recent
NICE guidance.
Re-formatting of document alongside community policy.
Comments from Drug Service and DTC received and incorporated.
Document signed off following ratification at October DTC
Review date extended from Oct15 to Dec 15 to allow for scheduled
DTC review
Update of version 2 to incorporate inpatient prescribing.
Link to approximate equivalent dose converter updated (from UKMi
to NICE CKS)
Document ratified at DTC and signed off.
Minor amendments following consultation with Shrublands
Removal of lofexedine section – detoxes no longer performed
within community or inpatient settings
Ratified at DTC and signed off
Oct 2013
Apr2014
RG
RG
KS
KS
Dec14
RG
RG
Dec14
KS
Nov 2016
CS
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 1 of 12
Pharmacological Management of Substance Misuse
Clinicians using this prescribing guideline must also refer to Trust Policy for the Clinical
Management of Substance Misuse (P09).
The aim of these guidelines is to promote evidenced based, cost effective prescribing and support adherence to:
 NICE CG 52 Drug Misuse: Opioid Detoxification (Mar 2010).
 NICE CG 120 Psychosis with co-existing Substance Misuses (Mar 2011).
 NICE TAG 114 Methadone and Buprenorphine (Jan 2007).
 NICE TAG 115 Naltrexone (Jan 2007).
 British Association for Psychopharmacology Updated Guidelines: evidence-based guidelines for
pharmacological management of substance misuse, harmful use, addiction and co-morbidity (2012).
 Department of Health Drug Misuse and dependence: UK guidelines & clinical management (Sept 2007).
These guidelines are NOT intended to replace prescribing information contained in the BNF or Summary of
Product Characteristics. Psychological therapies and psychosocial interventions are integral to the successful
treatment and must be used or offered alongside drug treatment, but are beyond the scope of these guidelines.
Management of Poly-Drug Use
In poly-drug use, stabilisation of the primary drug of choice may enable the person to cease other drugs
without intervention. Otherwise treat as follows: StimulantsAlcoholBenzodiazepinesOpiates
(e.g. if an opiate substitute is prescribed this should be held on the current dose whilst the
benzodiazepine is reduced first). Stimulant/cannabis misuse does not require substitute prescribing:
psychosocial support and symptomatic treatment should be provided. Substitute prescribing must be
initiated in collaboration with specialist drug services.
Management of Opioid Misuse
Methadone (Maintenance/detoxification)
Oral mixture 1mg/ml OR Oral mixture 1mg/ml sugar free
If tablets prescribed this is off-label use and they have the greatest potential for injecting or diversion.
Buprenorphine (Maintenance/detoxification)
Sublingual tablets 400micrograms, 2mg, 8mg
 If tablets are crushed or if 200microgram strength (Temgesic®) prescribed this is off-label use.
 Inactivated if swallowed so therapeutic levels only achieved sublingually.
 Longer-term use may result in prolonged mild withdrawal symptoms on discontinuation.
 Alternate day dosing is off-label but may improve adherence (e.g. every 2 days give twice the
daily dose, up to 32mg/dose).
Lofexidine (Detoxification)
Tablets 200micrograms
Naltrexone (Maintaining abstinence)
Tablets 50mg
Once maintenance dose is achieved after repeated dosing, alternate day or three day a week (e.g.
Mon 100mg, Wed 100mg, Fri 150mg) dosing is off-label but may improve adherence. Dose may be
given BD with meals if for example nausea is a problematic side-effect.
Management of Side-Effects / Symptoms in Opiate Misuse
Avoid unnecessary pharmacological treatment: only treat if severe or “when required” (PRN):
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 2 of 12
the
Side-effect
Sedation
Withdrawal
symptoms
occur before
next dose
Headache
Nausea or
Vomiting
Constipation
Weight gain
Sleep
difficulties
Lowered
sex drive
Dental
problems
Anxiety
Depression
Abdominal
Cramps
Diarrhoea
Muscle/Joint
Pain
Potential Causes and Management Options
 Opiate dose too high: lower the dose.
 Concomitant drug/alcohol use: review other medications being taken.
 Opiate dose too low: increase the dose.
 Changes in concomitant drug use: review other medications being taken.
 Check adherence.
 Withdrawal symptoms may include yawning, coughing, sneezing, runny nose/eyes, raised blood
pressure/pulse, dilated pupils, cool/clammy skin, diarrhoea, nausea, fine muscle tremor,
restlessness, irritability, anxiety, insomnia, depression, drug cravings and abdominal cramps.
 Common in buprenorphine initiation, particularly if dose is too high: usually mild and transient.
 Other causes of headache e.g. dehydration should be excluded.
 Consider use of paracetamol (oral) 500mg-1g up to QDS PRN.
 Common in opiate initiation and withdrawal, usually mild and transient.
 Avoid rapid dose changes and consider dose-reduction if persistent during initiation.
 Consider use of prochlorperazine (buccal) 3-6mg up to BD PRN.
 Very common in opiate use: encourage adequate dietary fibre, fluids and regular exercise.
 Particular issue at high doses of opiates and for women.
 Due to fluid retention and increased eating.
 Lower dose, reduce fat and salt in diet, ensure regular exercise regime.
 Dose too low and causing withdrawal at night.
 Dose too late at night causing stimulation at time of peak effects.
 Due to other drugs (particularly alcohol and stimulants in the evening, such as coffee, nicotine,
amphetamines).
 Review maintenance dose and exclude other causes such as use of other medications.
 Advise on sleep hygiene and avoid hypnotic medication but as a last resort a time-limited
course may be indicated. Refer to Trust Prescribing Guideline (PG02) for the Pharmacological
Management of Insomnia.
 More common with high doses of opiates so review and consider lowering dose.
 Exclude other psychological factors (e.g. anxiety, poor relationship with partner).
 All opioids reduce saliva flow, exacerbated by poor diet/dental hygiene.
 Encourage teeth hygiene, dental floss, use of sugar free gum, regular dental checks and reduce
intake of sugary drinks and sweet food.
 Management of substance misuse may unmask pre-existing anxiety which will need assessing
in its own right. Refer to Trust Prescribing guideline (PG11) for the Pharmacological
Management of Anxiety Spectrum Disorders.
 Management of substance misuse may unmask pre-existing depression which will need
assessing in its own right. Monitor for severe persistent symptoms and suicidal ideation. Refer
to Trust Prescribing guideline (PG03) for the Pharmacological Management of Unipolar
Depression.
 Common during opiate withdrawal.
 Other causes of abdominal cramps should be excluded.
 Consider use of hyoscine butylbromide (Buscopan®) (oral) 10-20mg QDS PRN.
 Common during opiate withdrawal.
 Other causes of diarrhoea e.g. gastrointestinal infection should be excluded.
 Consider use of loperamide (oral) 4mg STAT then 2mg PRN after each loose stool, maximum
dose 16mg/day.
 Common during opiate withdrawal.
 Other causes of pain e.g. physical trauma should be excluded.
 Consider use of paracetamol (oral) 500mg-1g up to QDS PRN.
Opioid withdrawal is almost never a life threatening condition, whereas opioid toxicity is.
Stabilisation / Maintenance of Opioid Misuse
Both oral formulations of methadone and buprenorphine, using flexible dosing regimens are
recommended options. The decision about which to use must take into account the person’s
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 3 of 12
preferences, history of opioid misuse, their commitment to a particular long-term management strategy,
and relative risks and benefits of each treatment. If both drugs are equally suitable, methadone
should be prescribed as the first choice due to relative cost and evidence base.
Estimates of the degree of dependence and tolerance are unreliable, and should never be the basis for
starting doses due to the risk of overdose. Assessments should be based on the history of quantity,
frequency and route of administration. Refer to Appendix 1, as a guide, for information on opioid dose
equivalents, however titration against withdrawal and monitoring for intoxication is the safest way to
achieve dose stabilisation. Concomitant medication, illicit drug and alcohol use must be taken into
account. The Clinical Opiate Withdrawal Scale (COWS) (see Appendix 2) and / or clinical judgement of
either drug withdrawal or side-effects including intoxication will be used prior to each dose change. The
dose should be titrated to a level at which the individual is comfortable and is no longer using illicit
substitutes: exceptionally high doses are rarely needed unless clinically indicated to retain the person in
treatment and careful monitoring is required due to increased risk of opiate intoxication. If the individual
continues to use illicit opiates consider stabilisation in an in-patient setting.
START LOW AND GO SLOW BUT AIM HIGH ENOUGH TO STOP ILLICIT USE
Methadone
- Initial dose of 10-30mg/day (10mg-20mg/day if tolerance low or uncertain: experienced clinicians may use a
maximum first dose of 40mg/day for confirmed heavy dependence with significant tolerance).
 Deaths have occurred following doses as low as 20mg.
 Steady state reached after 3-10days so for safety reasons dose titrated for 2-4weeks: if dose increase
indicated during first 7 days, titrate dose upwards in increments of 5-10mg/day. The total weekly dose
increase should not be >30mg above the initial dose. For optimisation of treatment after 7 days increase dose
by 10mg every 4-7 days, usually up to a total daily dose of 60mg-120mg/day.
 Individuals prescribed methadone ≥100mg/day and/or with other risks of QT prolongation (e.g. concomitant
medication, cardiac disease and electrolyte abnormalities) should have a baseline ECG performed and
repeated 7 days after titration, with referral to a cardiologist if abnormalities are identified. If ECG is ‘normal’
but the risk of QT prolongation remains high, consider repeating at 6-12 monthly intervals. See Trust
Guidance for QTc Interval Prolongation: Risk Factors and Medication.
Buprenorphine
 To reduce the risk of precipitated withdrawal, ensure adequate time lapse between initiation and previous
dose of opiate, (e.g. 6-12 hours after the last heroin dose) and administer first dose when starting to
experience opioid withdrawal symptoms.
 Precipitated withdrawal is a transient effect commencing 30-90minutes, usually peaking within 3hours and
then subsiding (in contrast to under replacement symptoms which characteristically begin later). Less severe
symptoms may continue for the first 2-3 days due to the slow binding of buprenorphine.
 Buprenorphine will provide a blockade effect against other opioids at doses of ≥12mg/day.
 Steady state reached after 3-7days so dose can be rapidly titrated over 3 days, e.g.:
Day 1
4-8mg
Day 2
Increase by 2-8mg if withdrawal present.
Day 3
Increase by 2-4mg if withdrawal present and 16mg has not been reached.
Day 4
Usual range used to achieve abstinence is 12-16mg/day, with some needing up to 32mg/day. If
onwards doses ≥16mg/day required, ≥7 days should lapse before dose change and minimum increments
of 2mg/day every week.
Methadone and buprenorphine are metabolised by cytochrome P450 enzyme system (CYP3A4 &
CYP2D6) so there is a risk of interactions with other medication. Baseline LFTs should be ascertained
prior to initiating treatment with buprenorphine, but if clinically well, do not delay starting if informed
consent is provided (see P09, Trust Policy for the Clinical Management of Substance Misuse). If LFTs
are normal, monitor regularly (e.g. 6 monthly).
Caution required with all opiates if there is hepatic impairment, history of alcoholic liver cirrhosis, or
hepatitis: medication should be reviewed (usually reduced or stopped); LFTs monitored and referred to
hepatology if there are clinical signs of hepatic impairment. Hepatitis C may induce CYP enzymes,
increasing first pass liver metabolism so requiring higher doses. Individuals with a recent history of
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 4 of 12
hepatic impairment, HCV antibody positive or alcohol misuse should have their LFTs rechecked at 12
weeks, then frequency to be determined by prescriber dependent on previous results (usually 3
monthly during treatment). In renal impairment dose changes are usually only required in end-stage
renal disease.
Transfer from Methadone to Buprenorphine:
Do NOT transfer to buprenorphine until the methadone dose is ≤30mg/day. Methadone should be
discontinued for at least 24-48 hours and wait for signs of withdrawal to occur prior to starting
buprenorphine e.g.:
Last methadone dose
20-30mg
10-20mg
< 10mg
Buprenorphine Day 1
4mg
4mg
2mg
Buprenorphine Day 2
6-8mg
4-6mg
2-6mg
Transfer from Buprenorphine to Methadone:
Start methadone up to a maximum of 40mg/day, 24 hours after the last buprenorphine dose OR start
48 hours later if the 48 hour buprenorphine dosing schedule was being used. Residual buprenorphine
may take up to a week to wash out, during which time it may block the full effects of methadone so
titrate methadone dose gradually over at least 7 days.
Buprenorphine dose
<8mg
8-16mg
≥16mg
First methadone dose
<20mg
20-30mg
30-40mg
Emergency Management of Opiate Intoxication
Risk of overdose with opiates is increased during dose titration, in opiate naivety and with concomitant
alcohol/poly-drug use (especially sedatives). A doctor must be contacted immediately if any degree of
intoxication is observed. If severe symptoms of intoxication/severe drowsiness are observed:
 Call 999 immediately and request an ambulance in addition to calling a doctor (if available).
 Monitor and record respiratory rate every 10minutes and initiate CPR if appropriate.
 If naloxone is administered it will induce opiate withdrawal symptoms so the individual may be
uncooperative, agitated and aggressive. Their capacity to accept treatment will depend on their
level of alertness. Staff must give appropriate information to the ambulance about drug dependence
and other medication, especially opiates. For inpatient management see Clinical Protocol for the
use of naloxone in opiate overdose. Service users may be provided with naloxone for
administration in cases of overdose under CP30 The Supply and Use of Naloxone to reduce drug
related deaths associated with opioid overdose.
 The individual should be observed overnight in hospital to avoid a recurrence of opiate intoxication,
as naloxone is shorter-acting than opiates. The high affinity of buprenorphine for opiate receptors
results in the need to use very high doses of naloxone to reverse it (perhaps 10-30 times more than
required for heroin), so resuscitation in intensive care may be needed.
Mild intoxication: “Spaced out”, glazed response, pinpoint pupils: observe closely and record
respiratory rate and level of sedation every 10minutes.
Moderate intoxication: Nodding with efforts to hold up head: observe closely and record respiratory
rate and level of sedation every 10minutes.
Severe intoxication: Respiratory depression (<12 breaths/min with no signs of distress, may be unable
to talk), sedated, bradycardia (slow heart rate<60 beats/min), hypothermia, hypotension, cyanosis.
Therapeutic Plasma Level Monitoring / Drug Testing
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 5 of 12
 There is no case for routine assays of plasma levels, but monitoring may be considered for:
- Assessment of compliance.
- Monitoring the effect of drug interactions.
- Investigation of withdrawal symptoms despite high dose e.g. to identify fast-metabolisers.
- Following a change in physical state e.g. pregnancy.
- Considering splitting the dose i.e. for individuals who quickly reach peak plasma level
concentrations from a single dose/where levels drop quickly causing withdrawal before the next
dose e.g. a small takeaway evening dose can supplement the main supervised dose.
 Methadone has a linear but wide dose-plasma concentration relationship and does not plateau at
high doses. In non-responders trough methadone levels of 400g/L for (R, S)-methadone or 250g/L
for (R isomer)-methadone may be used as target values.
 Buprenorphine does not have a linear dose-plasma concentration relationship and plateaus at
higher doses. Buprenorphine should test positive with drugs testing 20-37 hours post dose.
Tolerance to Treatment and Missed Doses
Tolerance varies between and within individuals, over time. Particular caution is required after periods
of detoxification and release from prison. Missed doses can lead to loss of tolerance and prescribers
should be kept informed of missed doses and must be informed after 3 consecutive missed doses for
re-titration. The doses used for re-titration must take into account any potential loss of tolerance and
ongoing illicit drug use when prescribed medication was not being taken.
Management of Pain Control
Consider use of non-pharmacological strategies and non-opioids e.g. paracetamol/NSAIDs/local
anaesthesia. Before minor or intermediate elective surgery discuss with the anaesthetist. If opioid
analgesia is indicated:
 For individuals taking full agonist opioids (e.g. methadone), opioid analgesia may be offered in
addition to the usual opioid treatment dose but doses should be titrated according to response and
respiratory function monitored.
 For individuals taking partial agonist opioids (e.g. buprenorphine), specialist advice should be
sought. If the buprenorphine is continued, high doses of full agonist opioids will be required initially,
with careful monitoring and anticipated dose reduction in the subsequent 36 to 72 hours.
 For individuals taking opioid antagonists (e.g. naltrexone), the opioid will be ineffective. Discontinue
naltrexone 48-72hours before any procedure and for major elective surgery discontinue naltrexone
72hours beforehand.
Relapse Prevention and Supporting Abstinence
Naloxone Challenge Test can be considered prior to initiation of naltrexone, as opiate withdrawal
can still occur despite a negative opiate urinalysis. Initiation of naltrexone without this test may be the
preferred option if risk of relapse is high. The withdrawal effects that this challenge can provoke are
less acute and shorter lived than those caused by oral naltrexone: if the person is opioid dependent
withdrawal symptoms usually appear within 5 minutes and may last for up to 48 hours.
Following negative urine test for opiates and in the absence of opioid withdrawal symptoms (COWS score <5,
see Appendix 2) administer 400micrograms naloxone i/m or s/c. Observe the person following administration,
and if they do not experience any withdrawal symptoms after a few hours, naltrexone can be given.
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 6 of 12
Naltrexone is a non-addictive, long acting competitive, opiate antagonist licensed for relapse
prevention following detoxification. Naltrexone should only be administered under adequate supervision
to people who are highly motivated to remain in an abstinence programme. They must be fully informed
that opioid containing medication must not be taken with naltrexone and that an attempt to overcome
the blockade can result in acute opioid overdose. It should be reviewed every 3 months and
discontinuation should be considered if there is evidence of ongoing opiate misuse. It should be
continued for at least 12 months and at the persons’ request up to a maximum of 24 months.
Renal function should be taken at baseline and monitored every 3 months. LFTs must be taken at baseline
and then repeated once a month for the first 4-6 months of treatment, then 3 monthly thereafter.
Individuals with abnormalities should be tested every 2 weeks for the first 6 weeks then monthly thereafter.
Naltrexone should not usually be started if AST is greater than two times the upper limit of normal and
discontinued if greater than 3 times the upper limit. Individuals with minor LFT abnormalities have been
treated with naltrexone without worsening of hepatic function. When venepuncture is difficult starting
treatment without LFTs or in the presence of abnormalities may be considered but informed consent must
be obtained (see Appendix 1 of Trust Policy for the Clinical Management of Substance Misuse (P09)).
Relapse prevention with naltrexone is increasingly effective the more quickly it can be introduced.
Treatment with naltrexone should not be initiated until the individual has been opioid free for a sufficient
period of time. The person should be monitored for 60minutes after the first naltrexone dose and if
withdrawal symptoms develop they should be treated symptomatically. Monitoring should include
COWS scoring (see Appendix 2), blood pressure and pulse.
Drug
Heroin / other short
acting opiate
Methadone
Buprenorphine
400micrograms
≥1week
Buprenorphine ≤2mg
for < 2weeks
Buprenorphine >2mg
Buprenorphine >4mg
Naltrexone initiation
7 days minimum washout period before initiating naltrexone. Day 1=25mg/day, Day
2+=50mg/day.
14 days minimum washout period before initiating naltrexone. Day 1=25mg/day, Day
2+=50mg/day.
1 day minimum washout period before initiating naltrexone. It may be considered
Day 1=12.5mg/day, Day 2-8=25mg/day, Day 9+= clinically appropriate to
50mg/day.
initiate naltrexone sooner
due to a high risk of
4-6 days minimum washout period before initiating
relapse and the person is
naltrexone. Day 1=25mg/day, Day 2+=50mg/day.
prepared to tolerate mild
5 days minimum washout period before initiating
withdrawal symptoms.
naltrexone. Day 1=25mg/day, Day 2+=50mg/day.
Transition to naltrexone will precipitate withdrawal likely to be sufficient to require a
lofexidine detoxification.
Management of Benzodiazepine Misuse
In early/mild dependence and if the benzodiazepine is being prescribed, minimal interventions such as
advisory letters, provision of information, for both the individual and the prescriber should prompt review
of their ongoing use. Illicit benzodiazepine use increases high risk behaviours and benzodiazepines
should not be prescribed routinely in the treatment of substance misuse. Opiates including substitutes,
alcohol and other sedative drugs combined with benzodiazepines will greatly increase the risk of
respiratory depression and suppression of the gag reflex, a major factor in drug-related death.
Where dependence is established, benzodiazepines should be gradually discontinued. There is no
evidence that long-term maintenance prescribing of benzodiazepines reduces the risk of harm and their
use for the management of benzodiazepine withdrawal and dependency is an off-license indication.
Presence of physical dependence and the likely dependence syndrome must be determined prior to
prescribing (usually dependent on daily therapeutic doses, without a break for > 3 months).
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 7 of 12
CIWA-B (see Appendix 3) can be used to assess and monitor withdrawal symptoms. If withdrawal
symptoms occur, do not reduce the dose further until symptoms improve. In situations where the
individual experiences intolerable/severe withdrawal symptoms, it may be necessary to increase the
dose to alleviate symptoms before further reduction can be considered. Refer to Trust Prescribing
Guideline (PG02) for the Pharmacological Management of Insomnia for additional guidance on
benzodiazepine withdrawal and approximate equivalent doses (usually administered in four divided
doses) may be found here:
 ≥20mg/day diazepam the recommended maximum rate of dose reduction is 5mg/fortnight.
 <20mg/day diazepam the recommended maximum rate of dose reduction is 2mg/fortnight.
 >30mg/day diazepam, gradually reduce to a dose of 30mg/day over a 6 week period or at a rate of
10mg/month (whichever is shorter) and then review.
Diazepam
Tablets 2mg, 5mg
Oral solution (1mg/ml) may be used if there is a high risk of diversion. Tablets may also be crushed but
this is off-license use.
Oxazepam
Tablets 10mg, 15mg
Consider as an alternative to diazepam for individuals with severe hepatic impairment.
Carbamazepine
Modified release tablets 200mg
May be considered instead of benzodiazepines to control withdrawal symptoms from high doses of
benzodiazepines. Some individuals may not tolerate side effects (i.e. nausea, dizziness, diplopia), of
the rapid dose increase necessary for detoxification. Carbamazepine is an enzyme inducer which may
reduce the effect of other medication (e.g. when used with methadone, carbamazepine may decrease
its’ effect but on cessation of carbamazepine, methadone plasma levels may rise, risking overdose).
If a prescription for a benzodiazepine is to be issued, there must be a clear treatment plan, discussed
and agreed between the prescriber and the individual, outlining the goals and time frame of the
benzodiazepine withdrawal. Prescribing should be reviewed at least every three months, and more
frequently during initial stages of treatment withdrawal. Where daytime drowsiness or intoxication are
problematic, individuals may take the total daily dose in divided doses. In established hepatic
impairment the decision to treat in these situations should be made with input from hepatology. A lower
dose of diazepam or use of oxazepam (not hepatically metabolised) may be required.
Following cessation of longer-term high dose benzodiazepine use (>50mg/day diazepam equivalence),
abrupt withdrawal can cause seizures which can present weeks later. There is no need to match high
self-reported illicit doses and equivalent doses ≥30mg/day of diazepam are rarely necessary. Doses of
diazepam >30mg daily must only be prescribed after discussion with and agreement by a
Consultant Psychiatrist for Substance Misuse and inpatient stabilisation may be indicated.
During benzodiazepine withdrawal:
 Depression may be a direct result of the withdrawal process or part of the underlying cause. An
appropriate assessment of the depressive symptoms should occur. Refer to Trust Prescribing
Guidelines for Unipolar Depression (PG03).
 Anxiety spectrum disorders should not routinely be managed with benzodiazepines. Refer to Trust
Prescribing Guidelines for Anxiety Spectrum Disorders (PG11).
 Insomnia should not be managed with benzodiazepines. Promethazine may be useful short-term,
alongside sleep hygiene measures. Refer to Trust Prescribing Guidelines for Insomnia (PG02).
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 8 of 12
Management of Substance Misuse in Pregnancy and Breastfeeding
Women of childbearing age should be offered a pregnancy test, and advised to avoid
pregnancy/breast-feeding whilst misusing substances. See Trust Prescribing Guideline (PG18) on the
Pharmacological Management of Mental Health Conditions during Pregnancy and Breastfeeding. Click
here to access.
User-friendly Resources for Information about Managing Substance Misuse
These web-based links are recommended sources for user-friendly information about treatment for the
management of substance misuse:






Choice and Medication website: http://www.choiceandmedication.org.uk/devon
Includes printable summaries for medication used for substance misuse and an information leaflet
for comparison of methadone vs. buprenorphine:
http://www.choiceandmedication.org/devon/pdf/handyfactsheetmethadonevsbuprenorphine.pdf
Patient.co.uk website: www.patient.co.uk
Includes printable information for medication used for heroin replacement.
Links to Manufacturer Patient Information Leaflet: http://www.medicines.org.uk/
Methadone Alliance: (020 7837 4379) www.m-alliance.org.uk
Provides advocacy, training and helpline support for individuals accessing drug treatment services.
Exchange supplies: http://www.exchangesupplies.org/shopdisp_P301.php
Provides link to the methadone handbook: a complete guide to methadone and methadone
treatment.
Naltrexone cards are available from the Medicines Optimisation Team upon request.
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 9 of 12
Appendix 1
APPROXIMATE Equivalents
These equivalences are to aid estimates of illicit drug use. They should never be used, instead of
titrating the substitute dose against symptoms of intoxication and withdrawal. It is difficult to
convert the reported use of street drugs, particularly as individuals may exaggerate without necessarily
intending to manipulate the prescriber because of their addictive perception and anxiety, which may
vary considerably depending on their available funds and the purity of what is available. City prices tend
to be cheaper than in rural localities.
Amphetamine:
Street amphetamine sulphate averages 5% purity. Dexamphetamine is approximately twice as potent
as amphetamine sulphate so actual equivalent, e.g. 4g of street amphetamine sulphate = ~actual dose
of amphetamine sulphate = ~100mg dexamphetamine.
Benzodiazepines:
Refer to Trust Prescribing Guideline (PG02) for the Pharmacological Management of Insomnia for
guidance of approximate equivalent doses.
Opiates: UG
Drug
Codeine phosphate 15mg tablet
Dextromoramide (Palfium®) 5mg tablet
Dihydrocodeine (DF118) 30mg tablet
Dipipanone (Diconal®) 10mg tablet
Diamorphine 10mg tablet/ freeze-dried
ampoule
Morphine 10mg ampoule
Pentazocine (Fortral®) 25mg tablet
Pethidine 50mg tablet
Buprenorphine dose
0.8-2mg
2-4mg
4-6mg
6-8mg
8-12mg
12-16mg
16-24mg
24-32mg
Methadone dose
5-10mg
15-20mg
30mg
45mg
60mg
?
?
?
Methadone dose equivalent
1mg
5-10mg
0-5mg
0-5mg
10 mg
10mg
2mg
5mg
Dose of illicit ‘street’ heroin
0.1g (½ x £10 bag)
0.25g (1 x £10 bag)
0.5g (2 x £10 bags)
0.75-1g (4-5 x £10 bags)
1-1.5g (5-7 x £10 bags)
1.5-2g (7-10 x £10 bags or 1/16 oz; a “teenth” or  1.8g)
2-3g (10-15 x £10 bags; 1½ “teenths” or  2.7g)
3-4g (15-20 x £10 bags or ⅛ oz; an “eighth” or  3.5g)
A £10 bag of heroin typically contains 0.2g heroin, but may contain as little as 0.1g or as much as 0.3g.
If bought in larger quantities the cost is less, e.g. 0.5g = £20, 1g = £40, 1/16oz (=1.8g) = £60.
Reduce approximated heroin dose by 1/3 if smoked rather than injected intravenously.
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 10 of 12
Appendix 2
Clinical Opiate Withdrawal Scale (COWS) and Monitoring Form
Symptom
Resting Pulse Rate: Measured
after the resting for 60secs
Sweating: After 30mins not due
to room temperature/activity
Anxiety or Irritability:
0
1
0
1
0
1
Restlessness:
Observation
during assessment
0
1
Pupil Size: Taking into account
room lighting
0
1
Runny nose and tearing: Not
accounted for by allergies/cold
symptoms
Yawning: Observation during
assessment
GI upset: Over the past 30mins
0
1
Tremor:
Observation
outstretched hands
Gooseflesh skin:
of
Myalgia or Arthralgia: Taking
into
account
any
pain
experienced prior to opiate
withdrawal.
0
1
0
1
2
0
1
0
3
0
1
Score
pulse rate ≤80
2
pulse rate 81 –100
4
no report of chills/ flushing
2
subjective report of chills/flushing
4
none
2
person reports increasing irritability 4
or anxiousness
able to sit still
3
reports difficulty sitting still but able
to do so
5
pupils less then /normal sized
2
pupils larger than normal for room 5
light (>3mm)
Not present
2
Nasal stuffiness or unusually moist 4
eyes
no yawning
2
yawning once/twice
4
no GI symptoms
3
stomach cramps
5
nausea/loose stool
no tremor
2
tremor can be felt but not observed 4
skin is smooth
5
piloerection of skin can be felt
Not present
2
Mild diffuse discomfort
4
pulse rate 101-120
pulse rate >120
flushed/observable facial moistness
sweat streaming off face
person obviously irritable/ anxious
person so irritable/ anxious that
assessment difficult
frequent
shifting
or
arm/leg
movements
unable to sit still at all
pupils moderately dilated
pupils dilated so that only the rim of
the Iris is visible
Nose running or frank tears
Nose constantly running or tears
streaming
yawning three or more times
yawning several times/ minute
vomiting or diarrhoea
multiple episodes of vomiting or
diarrhoea
slight visible tremor
gross tremor or muscle twitching
prominent piloerection
Reports severe diffuse aching of
joints/ muscles
Person rubs joints/muscles and
unable to sit still due to discomfort
Add up the score from all 11 items to provide a maximum score of 48. Use of this scale is at the
prescriber's direction to confirm severity of withdrawal: the trend should be downwards.
Name: _________________________ Date of Birth: ____________ NHS Number: ____________
Date
Time
Resting Pulse Rate (0-4)
Sweating (0-4)
Anxiety or Irritability (0-4)
Restlessness (0-5)
Pupil Size (0-5)
Runny nose or tearing (0-4)
Yawning (0-4)
GI upset (0-5)
Tremor (0-4)
Gooseflesh skin (0-5)
Myalgia or Arthralgia (0-4)
Total Score
Score:
5-12 = mild withdrawal
13-24 = moderate withdrawal
>24 = severe withdrawal
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 11 of 12
Appendix 3
CIWA-B: Benzodiazepine Withdrawal Schedule Rating Scale and Monitoring Form
For each of the following items please circle the numbers which best describe the severity:
(0=least severe, 4=most severe)
1. Observe behaviour for restlessness and agitation.
0
1
2
(no symptoms, normal activity)
(restless, unable to sit still)
3
4
(frequent pacing)
2. Do feel you have difficulties concentrating?
0
1
(no difficulty)
3
4
(unable to concentrate)
3
4
(unable to eat)
3
4
(constantly)
3
4
(severe headache)
3
4
(very much so)
2
(some difficulties)
THIS FORM IS INCLUDED IN THIS
3. Do you have any loss of appetite?
DOCUMENT FOR INFORMATION
0
1
2
ONLY
(no loss)
(no appetite)
FOR A COPY OF THIS FORM,
4. Do you feel your heart racing (palpitations)?
PLEASE DOWNLOAD PG20b
0
1
2
FROM
THE MEDICINES
(not at all)
(occasionally)
OPTIMISATION PAGES OF THE
DEVON PARTNERSHIP TRUST
5. Does your head feel full or achy?
INTRANET
0
1
2
(not at all)
CLICK HERE TO ACCESS
6. Do you feel anxious, nervous or jittery?
0
1
(not at all)
2
Add up the score from all 6 questions to provide a maximum score of 24.
Name: _________________________ Date of Birth: ____________ NHS Number: ____________
Date
Day 1 (Week 1)
Day 2 (Week 1)
Day 3 (Week 1)
Day 7 (Week 1)
Week 2
Week 3
Week 4
Week 5
Week 6
Week 7
Week 8
08:00
10:00
12:00
14:00
Time
16:00
18;00
20:00
22:00
This scale is at the prescriber's discretion to confirm severity of withdrawal. It can be used as a
once-only score. Otherwise the aim is to reduce score initially over the first 3 days and review
clinical need for further scoring to check that the trend is downwards.
PG20 – Pharmacological Management of Substance Misuse
Approved by Drugs and Therapeutics Committee: November 2016
Review date: October 2020
Page 12 of 12