Prescribing in Substance Misuse Aide-memoire
CONTENTS
Page
Principles of Good Prescribing
Introduction
Aims of Prescribing
Care Coordination
Care Plan
Ongoing care and monitoring
2
3
3
4
5
5
Safety and Good Practice
Appointments and Review Procedures
Driving
6
6
6
Pharmacy liaison
Wording a prescription correctly
Supervised Consumption Policy
Managing “on top” use
Holiday Prescription Guidelines
Recording cancelled prescriptions
Discontinuation of a prescription
7
7
8
9
9
10
10
Methadone Prescribing
Buprenorphine (Subutex & Suboxone) Prescribing
Choosing between methadone and buprenorphine
Benzodiazepine Prescribing
Lofexidine Prescribing
Naltrexone Prescribing
Prescribing In Pregnancy and Breastfeeding
12
13
14
15
17
19
20
V. 1.2 June 2009
Page 1
Principles of Good Prescribing (Summary)

Prescribing should take place within a framework. Address co-existing
physical, emotional, social and legal problems at the same time.

Prescribe with a firm harm reduction approach.

Before prescribing, assess the patient fully, screen to confirm substance use
and agree a care plan.

Regularly monitor and review during treatment including screening.

See patients usually on a three monthly basis.

Inform patients about driving regulations and the need to contact the DVLA.

Pharmacy liaison is very important as the pharmacist is usually the only health
care professional who will have daily contact with the patient.

Ensure prescriptions are written correctly to achieve continuity of treatment.

Discontinuation of a prescription is a serious intervention and should ideally
be a multi-disciplinary decision.

Continued illicit drug/or alcohol use will lead to a review of the prescription.

Decisions to work outside the prescribing policy should be a multi-disciplinary
decision but must ultimately be supported by the prescriber. Document all
decisions.

On top use should not be ignored. It can be dealt with through psychological
therapy, pharmacological therapy or a mixture of both.
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Page 2
Introduction
Prescribing is a component of a treatment package rather than being a
treatment on its own. Community prescribing may comprise:

Stabilisation or maintenance on substitute opioids.

Withdrawal from opioids with non-opioid medication e.g. lofexidine.

Stabilisation and withdrawal from sedatives, benzodiazepines and
alcohol.

Relapse prevention prescribing with acamprosate or disulfiram.

Symptomatic and maintenance prescribing for stimulant users.
Cornwall Drug Services operate with a firm harm reduction approach in
line with Department of Health and NTA guidelines.
Aims of Prescribing

Prescribe substitute medication to stabilise patient’s withdrawal
symptoms.

Reduce or eliminate the use of illicit/non-prescribed drugs.

Reduce the dangers associated with drug misuse e.g. reducing
injecting and sharing of injecting paraphernalia.

Reduce criminal activity associated with drug misuse.

Reduce the risk of prescribed drugs being diverted.

Improve the patients’ overall functioning from a personal, social, family
and community perspective.

In the case of alcohol and benzodiazepines, achieve safe detoxification
minimising adverse events.

Engage and retain drug users in their treatment programme.
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Page 3
Care Co-ordination
Care co-ordinator’s responsibilities:

To co-ordinate the monitoring of the patient for signs of over-sedation
during titration and treatment. This will be supplemented by the
pharmacist, who will withhold doses in accordance with an agreed protocol
if the patient presents to the pharmacy intoxicated

To request the prescription via a letter or written request (handwritten is
acceptable) with start date, pharmacy and details of the prescription. All
such details must also be recorded in the case file.

To ensure that appointments are booked with the prescriber and to keep
the prescriber informed of patient’s presentation.
Action
Completed?
4-way information-sharing agreement in place?
Patient registered with a GP?
Dispensing pharmacy identified and contacted?
Tier 3 comprehensive assessment performed?
Patient’s general health status assessed?
Objective proof of dependent substance misuse?
Assessment undertaken and toxicological screening
documented?
Treatment programme agreed with care co-ordinator?
Written care plan agreed and signed by patient?
Patient clear on service policy on missed appointments etc?
Patient’s literacy confirmed?
Patient medication choice fully informed and side effects
explained?
Patient’s own GP informed of prescribing plan?
Patient’s own GP informed of final dose after titration?
Patient registered with National Drug Treatment Monitoring
System?
V. 1.2 June 2009
Page 4
The Care Plan
The care plan forms the basis for treatment and sets out the expectations of
both the service user and the service. It should include other appropriate
agencies and carers. Agreed treatment goals are central to care planning.
Treatment goals
Engagement with service
Harm reduction
Health promotion
Stabilisation of drug use
Maintenance on medication
Detoxification
Abstinence
Treatment outcome measures
Attending appointments
Modified injecting behaviour
Reduced drug use
Hepatitis B /C /HIV testing
Hepatitis A&B vaccination
Safer sex
Increased knowledge of drug use/ harm reduction
Aware of overdose prevention and management
Engagement with GP re health problems
Improved social relationships
Improved housing
Reduced debt
Increased daily activity
Reported cessation of problem drug use.
Negative toxicology
Cessation of substitute prescribing
Cessation of drug use
Drug free after 1,3,6 months
Completing relapse prevention intervention
Where supplementary prescribing by a non-medical prescriber is intended, a
clinical management plan must be in place. This can be incorporated within
the care plan to reduce duplication.
Ongoing care and monitoring
Provide the following information to the patient with the written care plan:



Information on the drug prescribed, its effects and side effects
Warnings about overdose and how to manage others who overdose.
Information regarding help and advice regarding blood borne virus
screening, safer injecting and sexual practices.
Those who are Hepatitis B or C positive should be provided with information
about alcohol usage.
V. 1.2 June 2009
Page 5
Safety and Good Practice

Monitor during treatment with regular random urine screening and/or
oral fluid tests. This should be at least two screens per year but will be
more for patients who are not stable or in early treatment.

Appropriate dispensing arrangements should be in place. Send
prescriptions to pharmacies and only give directly to patients in
exceptional circumstances. Pharmacies may collect prescriptions.

Advise the patient on safe storage of their prescription especially if
children live at or visit the same premises.

Review ineffective prescriptions with the multi-disciplinary team and, if
necessary, stop them.

Keep records of the prescription including date issued, dates to start,
drugs prescribed, dosage and prescription numbers.

Only the patient should collect the medication from the pharmacy. If a
third party needs to collect the prescription the care co-ordinator or the
prescriber must authorize this in writing (e.g. by fax to the pharmacy)
Appointments and Review Procedures
The patient will usually be seen by the prescriber three monthly. This may be
less frequent for stable patients with the agreement of the multi-disciplinary
team, while for patients with complex needs it will need to be more frequent.
The care co-ordinator should see patients at least three monthly if a patient
is completely stable on their prescription. After initiation of prescribing, the
patient should be seen at least weekly for the first fortnight and after this
typically every 2-4 weeks depending on the agreed care plan.
If the patient misses two consecutive appointments (without good reason) it is
a strong indicator for stopping the prescription, or putting it ‘on hold’. Consult
the multi-disciplinary team before reaching a decision.
Continued illicit drug use will lead to a review of the prescription and/or the
psychological approach adopted.
Driving - (See the CD-rom for patient and prescriber information)
V. 1.2 June 2009
Page 6
Pharmacy liaison



The prescriber or care co-ordinator should help the patient find a
pharmacy as pharmacies are not obliged to supervise the consumption of
controlled drugs and those that do may have reached capacity.
Liaise regarding start dates and other relevant details
Communicate in good time to allow the Pharmacist an adequate period to
secure stocks.
Prescription regulations
The doctor who signs the prescription carries ultimate responsibility for
prescribing. Prescriptions must be:

Signed by the prescriber with his/her usual signature.

Dated, but a computer generated date is acceptable. Post-dating of
prescriptions may be necessary but a prescription for a controlled drug
must be dispensed within 28 days of the date it is signed or the
commencement date if the prescriber specifies one.
The prescription for CD schedules 2 and 3 should also state:




The form and where appropriate the strength of the preparation.
The total quantity or the number of dose units, in words and figures.
The dose.
Instructions to cover when the pharmacy is closed e.g. Sundays and
Bank Holidays.
Missed Collections of Instalments
Where instalments to be dispensed are for more than one day, prescribers
are advised to include the phrase:
‘if a collection is missed the remainder of the instalment [i.e. the instalment
less the amount prescribed for the day(s) missed] may be supplied’
This will allow the pharmacist to dispense the remaining day(s) doses to a
patient who fails to collect on the designated day but attends the following
day. Without this phrase the whole instalment would be forfeited.
However should a patient fail to pick-up the instalments for more than 2
consecutive days then the prescription should be suspended and the care-coordinator contacted.
Missed doses can lead to loss of tolerance and prescribers should be kept
informed of missed doses. Patients who repeatedly miss doses should have
their treatment reviewed. If on less than daily dosing the first step would be to
revert to daily dispensing.
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Page 7
Supervised Consumption Policy (Summary)

Supervised consumption should occur for a minimum of three months
at the start of treatment unless there are exceptional circumstances.

Restart supervised consumption if a patient resumes a prescription
after a break, receives a significant increase in their dose or transfers
to daily collection from less frequent pick-up arrangements.

Certain patient groups should remain in supervised consumption during
their treatment programme.

Supervised consumption is only available for methadone mixture and
buprenorphine tablets.
In certain circumstances e.g. women near term or with infants younger than 3
months, those with verified employment or in full time education special
arrangements may be made to allow take home doses before three months
have elapsed. As this is outside policy discuss at a multi-disciplinary team
meeting and note the decision to prescribe in the patient’s records.
After three months review the need for supervision and the collection interval
with the care co-ordinator. Before offering a patient take home doses, ensure:
a)
Patients must demonstrate consistent negative screens for illicit drugs
(at least three consecutive negative screens - excluding cannabis),
b)
Regular attendance at pharmacy and appointments,
c)
Achievement of care plan goals.
d)
No criminal activity,
e)
No other users in household,
f)
No evidence of injecting and / or high-risk poly drug use through selfreporting, physical examination and/or testing.
Exclusion criteria: Continue supervised consumption if:

Patients demonstrate continued drug misuse outside their care plan.

Patients have a significant unstable psychiatric illness.

There is concern that the prescribed drug is being diverted or used
inappropriately.

There are child protection issues.
V. 1.2 June 2009
Page 8
During the initial titration of a methadone or buprenorphine prescription it is
vital that post contact arrangements are in place to assess the patient. This
will allow the assessor to determine:

Whether the dose is adequate using an appropriate withdrawal
symptoms assessment tool.

Whether the dose is too high.
Managing “on top” use

Try to ascertain whether use is indeed in addition to the prescription.
Sometimes the prescription is traded for street drugs. Reconsider daily
supervised consumption.

Clarify the treatment aims and dosing strategy with the patient. Those
who are clearly motivated to cease on top use or who report heroin use
to manage withdrawal symptoms may benefit from higher dose
regimes. Weigh potential benefit of higher doses against additional risk.

Refer clients on 100mg methadone but still unstable, or using on top, to
secondary care for review and probable subsequent treatment.

Alcohol misuse contributes to overdose risk and enhances the
respiratory depressant effects of heroin. In the face of alcohol misuse
weigh risks versus benefits and only continue prescribing together with
interventions targeted at alcohol.

Benzodiazepine use is linked to poorer treatment outcomes and
overdose risk. Benzodiazepines and allied hypnotics should be
prescribed with caution including, when necessary, daily dispensing.
Treatment will usually be short-term.
Holiday Prescription Guidelines (Summary)

The patient should give at least 7 days notice if a holiday prescription is
required for UK travel and 14 days for international travel.

A bulk prescription should not usually exceed two weeks’ supply
because safe prescribing demands regular contact with patients. Large
volume prescribing should be subject to a risk assessment. Establish
safe storage in transit and at the destination.

In UK, where possible continue current arrangements by using a
suitable pharmacy at the holiday location. Contact the local DAAT
(www.addaction.org.uk/?page_id=1691) to find a pharmacy.

Export licences are required for some quantities of certain drugs.
V. 1.2 June 2009
Page 9

Some countries prohibit importation of certain drugs. The patient
should check with the appropriate consulate (contact details at
http://www.drugs.gov.uk/publication-search/drug-licences/embassy-list)

Give a letter of authority detailing the medication the patient is carrying.
If a patient leaves the country for more than the period covered by their prescription,
they need reassessment and drug screening on their return, prior to the initiation of a
new prescription.
Recording cancelled prescriptions
When a prescription already issued to a pharmacy needs to be changed:

The care co-ordinator phones the pharmacy with details of the
prescription to be cancelled. It should be made clear whether the new
prescription supplements an existing prescription, or replaces it (e.g. if
a patient is receiving 8mg buprenorphine, and a new prescription is
issued for 4mg, is that an increase to 12mg or a reduction to 4mg?)

The cancellation of any prescription and any replacement is recorded
in the client’s prescription record
The care co-ordinator is responsible for informing the prescriber about any
prescriptions that are suspended or cancelled. This includes when patients
are admitted to hospital.
Discontinuation of prescription
When there is a disagreement between a patient and the team over
prescribing issues, aim to negotiate a new treatment agreement whenever
possible. If agreement cannot be reached, a unilateral decision to reduce or
stop a prescription may result. Reasons for this might be:

Compromised safety, either of the patient or others. This risk can
usually be addressed by a return to supervised consumption.

On top use of alcohol or illicit drugs at a level which, when combined
with a regular prescription, puts them at risk of dangerous side effects.
The discontinuation of substitute prescribing is a serious matter. The following
steps should be undertaken:

The care co-ordinator will discuss the team view with the patient. It may
be appropriate to do this together with the prescriber. If the patient
does not attend appointments, this may have to be done by phone or
by letter.
V. 1.2 June 2009
Page 10

If a patient does not attend two consecutive appointments, they are
informed by letter that if they do not attend a third appointment they
may be discharged from the service.
All decisions to end prescribing should be communicated to the service user’s
GP where they are not the prescriber and the dispensing pharmacy.
V. 1.2 June 2009
Page 11
Methadone Prescribing Policy (Summary)

Methadone maintenance is most effective at a daily dose of 60-120mg.

Prescribe methadone as the standard 1mg/1ml dose. Sugar free formulations
and tablets have a greater potential for injection, and are more expensive.

Start substitute prescribing with methadone at 20-30mg a day depending on
initial assessment and tolerance and titrate the dose in 10mg increments (not
exceeding 30mg in a week) until withdrawal symptoms are controlled; start
low and go slow. Steady state plasma levels are reached about 5 days
following the last dose increase.

Deaths have occurred following doses as low as 20mg.

Prescribe supervised consumption for a minimum of 12 weeks.

Methadone has a clinically significant interaction with benzodiazepines and
alcohol. Reassess patients who continue to misuse these drugs.

Discuss decisions to prescribe over 100mg daily in patients who are still
unstable with a Consultant in case a move to secondary care is indicated.

The higher the dose the more important it is that the patient is tightly interval
dispensed. For example a patient on 100mg or more should never pick-up
once a week, and equally patients should never, or very rarely, have more
than 1000mg in their possession at any one time (e.g. for a holiday
prescription).

Methadone use may be a risk factor for developing torsades de pointes / QT
prolongation. Monitoring (ECG) is recommended in doses above 100mg daily
or where there are other risk factors for QT prolongation including:







heart disease
liver disease
electrolyte imbalances
pimozide
erythromycin
clarithromycin
quinidine






amiodarone
chloroquine
mefloquine
clozapine
lithium
risperidone

Methadone maintenance therapy has the most cumulated evidence as safe to
use in pregnancy and breast-feeding.

Injectable methadone should only be initiated by a Consultant.
V. 1.2 June 2009
Page 12
Buprenorphine (Subutex & Suboxone) Prescribing Policy

Buprenorphine is a “safer” alternative to methadone due to its partial
agonist properties and appears to have an easier withdrawal phase.

Buprenorphine will provide a blockade effect against other opioids at
doses of 12mg or above.

Unlike methadone, buprenorphine as Subutex is easily soluble,
allowing it to be dissolved and injected. Suboxone cannot be so easily
misused in this way because it contains naloxone.

Suboxone and Subutex are the same price and assumed to be the
same efficacy. Suboxone is therefore recommended for all new clients,
and transfer of clients from Subutex to Suboxone should be
considered, especially if there is evidence of misuse of the former.

Wait at least 6-8 hours after the last heroin dose or 24-48 hours after
the last dose of methadone before initiating buprenorphine. Do not
transfer patients from methadone doses above 30mg to buprenorphine
without specialist advice.

Introduce buprenorphine by titration, commonly 4mg (day 1), 8mg (day
2) and 12mg (day 3 onwards) to reduce the risk of precipitating
withdrawal and allow monitoring of withdrawal symptoms against dose.

Sublingual dissolution can take several minutes, and if not fully
supervised during this time, client can leave the pharmacy with a
partially dissolved tablet under their tongue which can be diverted.

Buprenorphine is not contra-indicated in pregnancy. Discuss pregnant
patients with a specialist in the field of substance misuse.

Contra-indicated in acute respiratory depression, children under 16,
severe hepatic insufficiency, Acute alcoholism or delirium tremens and
breast-feeding

Caution in Respiratory Depression, Liver Disorders, Renal
insufficiency, Pregnancy, patients transferring from methadone
treatment at doses of greater than 30mg
Draft v. 1.1 June 2009
Page 13
Choosing between methadone and buprenorphine
Methadone is cheaper than buprenorphine. Where there is no patient
preference or convincing clinical reason to favour buprenorphine, methadone
should be first line treatment for opioid maintenance therapy.
Buprenorphine is the clear drug of choice for patients under the age of 18,
although it should be noted that the licence is for patients of 16 years plus.
The Royal College of General Practice suggests that you should take into
consideration:

Patient’s preference.

Previous treatment history.

Whether a sedating (methadone) or less sedating opiate
(buprenorphine) would be advantageous. Prefer methadone if there is
a risk of psychological decompensation.

Buprenorphine is more appropriate for detoxification as withdrawal
appears to be easier than for methadone if used for < 4-6 months.

Naltrexone can be started sooner if buprenorphine is used (3-7 days).

Buprenorphine is less affected by interactions with anticonvulsants,
rifampicin and ribavirin.

Buprenorphine is safer in overdose.

The blockade effects of buprenorphine may be better suited to patients
who wish to cease using heroin completely.

Buprenorphine should not be continued if patients continue to use illicit
opiates on a regular basis (risk of precipitated withdrawal).

Buprenorphine is contra-indicated in acute respiratory depression,
children under 16, severe hepatic insufficiency, Acute alcoholism or
delirium tremens and breast-feeding

Buprenorphine should be used with caution in Respiratory Depression
(particularly when used in combination with benzodiazepines), Liver
Disorders, and Renal insufficiency. Patients in methadone treatment at
doses of greater than 30mg: Transferring to buprenorphine is likely to
be associated with precipitated withdrawal Pregnancy
Draft v. 1.1 June 2009
Page 14
Benzodiazepine Prescribing Policy

There is little or no evidence that long-term benzodiazepines prescribing reduces
harm, and increasing evidence that prescribing more than 30mg diazepam may
actually cause harm. Discuss with a Consultant in Substance Misuse or GPwSI
before exceeding 30mg.

Benzodiazepines are indicated for short-term use only. They are not licensed as
substitutes for long-term dependency but benzodiazepine withdrawal states can
be treated (though the BNF specifies alcohol withdrawal only).

Assess the patient fully and confirm use with urine or saliva testing on at least
two occasions before issuing a prescription.

Adequate methadone reduces illicit benzodiazepine use. Consider increasing
doses of methadone and buprenorphine rather than introducing benzodiazepines.

Insomnia and anxiety in opiate users are most likely to be explained by their
street-drug use, and can be used as a reason to promote motivation for change.

Arrangements to prevent diversion should be in place – supervised consumption
and interval dispensing should be the same frequency as any substitute
medication being prescribed. Diazepam can be prescribed on blue MDA forms,
but on a separate prescription to methadone or buprenorphine. Other
benzodiazepines must be on green FP10 forms with a covering instalment
dispensing form.

Diazepam is the drug of choice. Its long half-life helps reduce withdrawal
symptoms. In severe liver dysfunction, lorazepam may be safer, but seek expert
advice.
Withdrawal symptoms: The incidence of convulsions is about 1–2%. Clients on
higher doses (>50mg/day) appear to be able to reduce quickly with little risk of fits.
Clients presenting with a history of excessive intake (>100mg diazepam daily) can
be started on 40% of their reported dose with no serious ill-effect. Some authorities
maintain that there is no indication for prescribing more than 60mg diazepam daily,
regardless of the client’s stated intake. Consider hospital admission. In any of these
scenarios, do not prescribe without expert advice.
Detoxification - (see CD-rom for examples of reducing regimes)



Keep any opiate substitute unchanged while reducing benzodiazepines.
Try to avoid increases in dose once reduction has commenced
Agree any change to the original plan with the client.
DoH guidelines require review of any benzodiazepine prescription at least every
three months.
Draft v. 1.1 June 2009
Page 15
Many clients have a very negative view of their ability to withdraw from
benzodiazepines. This can legitimately be challenged, as up to 40% of clients can
stop usage without undue difficulty.
Risks of Benzodiazepine Usage
Pregnancy & lactation – see special section
Liver disease impairs the metabolism of most benzodiazepines, lorazepam or
oxazepam appearing safest in these circumstances.
Contra-indications to benzodiazepine use are:





Conditions causing respiratory depression, including COPD and sleep apnoea
Severe renal impairment
Malnutrition and hypoproteinaemia (benzodiazepines bind to plasma proteins)
Severe muscular impairment, e.g. myasthenia gravis or motor neurone disease
Porphyria.
Drug interactions – the list of interactions is extensive. Check BNF appendix 1.
“Z drugs” (zopiclone, zolpidem and zaleplon) are equally potent and as liable to
dependency and illicit use as benzodiazepines. They confer no proven advantage.
Draft v. 1.1 June 2009
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Lofexidine Prescribing (Summary)

Lofexidine is useful as a detoxification regime for adult patients using up to
50mg methadone or <1g of heroin a day, short drug histories and nonpolydrug users who want abstinence as a goal of treatment.

Lofexidine can cause hypotension. Monitor blood pressure before and during
treatment and discontinue lofexidine gradually over 2 – 4 days to avoid
rebound hypertension.

Supplementary “when required” doses may be given.

Caution is advised in pregnancy and breast-feeding.

Offer the patient “The Detox Handbook” or the “Britlofex (lofexidine) - Home
detoxification programme. A users’ guide.” (Available from Britannia Pharm.)
Patients who may be excluded from a lofexidine treatment programme:

Patients with severe heart disease, recent myocardial infarction,
cerebrovascular disease or chronic renal failure.

Patients who use other CNS depressants excessively, chaotically, in binges or
in other dangerous ways.

Patients with blood pressure below 80/40 at baseline. If blood pressure is
between 90/50 and 80/40 discuss with the consultants.

Patients with marked bradycardia (less than 55 bpm).

Patients with congenital long QTc or the simultaneous use of 2 drugs that
prolong the QTc interval, unless ECG monitoring is being performed and the
lowest effective dose of lofexidine is being used (maximum lofexidine dose is
0.4 mg four times a day).

Patients on methadone doses above 80mg daily. If the patient is on doses of
methadone greater than 50mg or using more than 1 gram of heroin a day then
the case should be discussed with the Consultant.

Patients who are pregnant or breast-feeding.

Patients currently being prescribed tricyclic antidepressants or who have
taken them within the last 2 weeks, or other drugs such as anti-hypertensives
which are active at the alpha–2 adrenergic receptors.

Patients suffering from an underlying psychosis or severe health problem or
suicidality requiring admission to hospital.

Patients under the age of 16 years.
Draft v. 1.1 June 2009
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Dose Regimes
Initially, one tablet (0.2mg) twice daily increased by increments of one to two
tablets (0.2-0.4mg) a day up to a maximum of twelve tablets (2.4mg) a day in
response to withdrawal symptoms. Duration of treatment of 7-10 days is
recommended but longer treatment may be warranted.
The daily dose should be given in 2-4 doses with one dose at bedtime to
offset insomnia and peak dose should coincide with the expected onset of
severe withdrawal symptoms.
Draft v. 1.1 June 2009
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Naltrexone Prescribing (Summary)

Potential candidates for naltrexone treatment include:
o Patients who want to achieve abstinence as a treatment goal.
o Patients who have been clean but recently relapsed.
o Patients currently abstinent but afraid of relapse because of stress

Naltrexone is a useful adjunct to treatment if patients are motivated. Treatment
should be supervised and supported by psychosocial therapy to achieve best
results.

Liver function tests should be carried out both before and during treatment.

Do not prescribe in patients with acute hepatitis or liver failure.

Caution in patients with impaired hepatic or renal function, pregnancy and breastfeeding. The safe use of naltrexone in children has not been established.

Patients must be opiate-free for at least 7-10 days before treatment. The
patient should not manifest withdrawal signs or report withdrawal symptoms.
Typical wash-out periods are:
Heroin
Methadone
Buprenorphine (>2mg, >2weeks)
Buprenorphine (<2mg, <2 weeks)

Up to 7 days
Up to 10 days.
Up to 7 days.
Up to 3 days.
Warn patients to avoid opioid containing medication while on naltrexone and that
an attempt to overcome the block can result in acute opioid intoxication.
Initiation of Treatment
 Screen for opioid use with a naloxone challenge test.
 Verify self-reporting of abstinence from opioids with urine analysis.
 Where a naloxone challenge test cannot be performed the patient should give
informed consent for naltrexone treatment confirming they have been opiate free
for the required number of days.
 Initiate treatment at a dose of naltrexone 25mg. Observe the patient for 30-60
minutes for withdrawal symptoms. Lofexidine should also be available for
withdrawal symptoms on the first day of naltrexone dosing. If no withdrawal signs
occur continue on 50mg a day thereafter.
Maintenance
 50mg per day is appropriate for many patients. However, a flexible regimen
(100mg Monday, 100mg Wednesday, 150mg Friday) is possible to improve
compliance
 No standard duration of treatment can be recommended. Plan an initial period
of three months but prolonged administration may be necessary.
 Prescribe on FP10 (green) prescription forms, not in instalments.
Draft v. 1.1 June 2009
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Prescribing In Pregnancy and Breast-Feeding (Summary)
The treatment of pregnant substance misusers should be co-ordinated by or
have input from a specialist working in the field of substance misuse.
Monitor more frequently (every 6 weeks; key worker review every 1-2 weeks).
Pregnant women should be offered a course of hepatitis B vaccination if not
immune. Screen for HIV, hepatitis B and C. All babies should be routinely
immunised against hepatitis B regardless of the mother’s hepatitis B status.
Prescribing In Pregnancy
Drug
Methadone
Maintenance
Treatment (MMT)
Methadone
Reduction
Buprenorphine
Benzodiazepines
Alcohol
Lofexidine
Naltrexone
Stimulants
Draft v. 1.1 June 2009
Comments
MMT has the most robust evidence base and results in improved
maternal and foetal health. Maintain pregnant patients on methadone
on the same dose. In the third trimester an increase may be needed
due to increased blood volume in pregnancy, increased liver
metabolism and increased glomerular filtration rate. This should be
judged on withdrawal signs with small incremental increases if
necessary. Split dosing may be required in the third trimester.
Stability is more important than reduction but some women strongly
prefer to detoxify. Avoid detoxification in the first trimester (due to risk
of miscarriage) and in the second trimester reduce at a rate of no
more than 2.5-5mg methadone weekly, fortnightly or monthly or
1mg/day. Detox with caution in the third trimester (risk of foetal stress
and premature labour) only after informed consent has been obtained
regarding the lack of clear guidance.
The evidence is less robust than for methadone and therefore
buprenorphine is not a first line treatment in pregnancy. It may be
appropriate to continue buprenorphine in patients established on
treatment but this necessitates informed consent from the client and a
wish not to transfer to methadone. Its partial agonist action may
interfere with opioid analgesia in labour.
First-trimester exposure may be associated with an increased risk of
oral clefts in newborns, although the magnitude of this risk is
uncertain. Third-trimester use is associated with floppy baby
syndrome. Benzodiazepines are best avoided in pregnancy and
antenatal detoxification carried out using a controlled reduction
schedule (see CD-rom). Discuss with a GPwSI or consultant working
in the field of substance misuse.
Patients with symptomatic withdrawal should be offered
benzodiazepine withdrawal, ideally as an inpatient. Discuss with a
GPwSI or consultant working in the field of substance misuse.
Medication to sustain abstinence i.e. acamprosate and disulfiram
should not be given in pregnancy or breast-feeding. Moderate
drinking has not been shown to harm the foetus.
Manufacturers recommend caution. Assess risk-benefit before
prescribing.
Manufacturers recommend caution. Animal studies do not suggest a
teratogenic effect. Assess risk-benefit before prescribing.
Recommend abstinence from stimulants during pregnancy. If streetuse continues, seek specialist advice.
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Prescribing in Breastfeeding
Drug
Methadone and
buprenorphine
Benzodiazepines
Alcohol
Lofexidine
Naltrexone
Stimulants e.g.
cocaine and
amphetamines
Draft v. 1.1 June 2009
Comments
These enter breast milk but encourage breastfeeding because of the
usual advantages it confers and the reduction in severity of any
withdrawals the baby is experiencing.
Only continue after discussion with a GPwSI or consultant working
in the field of substance misuse. Any infant exposed to
benzodiazepines in breast milk should be monitored for CNS
depression and apnoea.
Occasional light drinking has not been shown to harm the breastfeeding baby. Moderate to heavy drinking is inadvisable as it can
interfere with the mother’s “let down” reflex and/or cause drowsiness
in the infant resulting in the baby taking in less milk.
No data available.
Give to breastfeeding women only when the potential benefits
outweigh the possible risks.
Encourage mothers to stop stimulant use, but if use continues and
the mother wishes to feed then encourage her since the more
vulnerable babies have more to gain from it. Warn mothers about
the dangers of continued use including possible delay in cognitive
development, risk of seizure or stroke, cerebral palsy, mental
retardation, vision and hearing impairment, urinary tract
abnormalities and autism.
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