Download Venlafaxine – SCG High Dose

GREATER MANCHESTER INTERFACE
PRESCRIBING GROUP
On behalf of the
GREATER MANCHESTER MEDICINES MANAGEMENT
GROUP
SHARED CARE GUIDELINE for High Dose Venlafaxine i.e.
300mg or > in severe depression
Reference Number
Scope:
GMW Mental Health NHS FT,
Bolton Primary Care Trust
Salford Primary Care Trust,
Trafford Primary care trust
Issue date July 2008
Classification
SHARED CARE GUIDELINE
Replaces
Author(s)/Originator(s)
GMW Mental Health NHS FT
To be read in conjunction with the
following documents
Authorised by
To be read in conjunction with SPC, NICE
GUIDANCE for Depression,
Authorised by Greater Manchester West
Mental Health NHS Foundation Trust MMG
July 2010
Review Date
Approved by Interface Prescribing
Committee
1. Introduction
In line with NICE Guidance venlafaxine should be reserved for the
treatment of depression in patients who have not responded to adequate
trials of two antidepressants. These would normally be an SSRI followed
by another SSRI or mirtazapine; alternatives include moclobemide,
reboxetine, and lofepramine.
Other tricyclics and venlafaxine may be considered, especially for more
severe depression see SPC for more information on adverse effects and
prescribing details.
This shared care protocol covers situations where venlafaxine is
prescribed for severe depression at doses greater than or equal to
300mg . Maximum dose 375mg daily. Venlafaxine at this dose is classed
as amber by the Greater Manchester RAG Group. The initiation of doses
of 300mg or above should only be undertaken with the advice or
supervision of a specialist in Mental Health Services or a GP with Special
Interest, with continuing supervision and monitoring of the patient.
2. Scope
Support of the use of this drug comes from NICE GUIDANCE
www.nice.org.uk Depression: management of depression in primary and
secondary care Clinical guideline 23(amended). SPC venlafaxine(Efexor)
and BNF.
3. Clinical condition being treated
Licensed Indications: There are two preparations available; tablets
37.5mg, 75mg and capsules 75mg, 150mg known as XL
XL licensed for major depressive disorder including depression with
anxiety. It is also indicated for the prevention of relapses of the initial
episode of depression or the prevention of the recurrence of new
episodes. Moderate to severe Generalised Anxiety Disorder(GAD),
moderate to severe generalised social anxiety disorder/social phobia.
Tablets are licensed for the treatment of depressive disorder including
depression accompanied by anxiety. Following an initial response the
tablets are indicated for relapse prevention.
Usual Dose for depression 75mg-225mg daily. Severely depressed
patients or hospitalised patients max 375mg daily.
Efexor XL i.e. slow release is licensed up to 225mg daily (pack sizes for
75mg, 150mg 14caps and 28caps)
Efexor tablets are licensed up to 375mg daily. (pack sizes for
37.5mg,75mg 28tabs and 56tabs)
4. Product information and treatment regimen to be used
UPDATED VENLAFAXINE PRESCRIBING AND MONITORING ADVICE
Patients should have an adequate trial of 225mg of venlafaxine for at least
4 weeks before increasing the dose beyond 225mg.Initiation and treatment
up to 225mg is classified as GREEN by the RAG.
Patients with increased risk factors for suicide should be carefully
evaluated for the presence or worsening of suicide related behaviour and
a limited amount of tablets should be provided to reduce the risk from
overdose. A maximum of two weeks supply should be considered in these
patients at initiation of treatment, during any dosage adjustment and until
improvement occurs.
The initiation of or titration to doses of 300mg or above should only be
undertaken with the advice or supervision of a specialist within Mental
Health Services or a GP with Special Interest .The prescription of
venlafaxine 300mg-375mg is classed as AMBER with shared care
arrangements being in place with the continuing supervision and
monitoring of the patient.
Venlafaxine should be used with caution in patients with established
cardiac disease that may increase the risk of ventricular arrythmias e.g.
recent MI.
Venlafaxine is contra-indicated in patients with an identified high risk of
a serious cardiac ventricular arrhythmia (e.g. those with a significant left
ventricular dysfunction, NYHA Class 111/1V) Venlafaxine remains contraindicated in uncontrolled hypertension.
The contra-indication for patients with an electrolyte imbalance and the
requirement for a baseline ECG have been removed from product
information.
Venlafaxine is not licensed for use and is not recommended in children
and adolescents under the age of 18 with Major depressive disorder.
Venlafaxine is contra-indicated in patients prescribed monoamineoxidase
inhibitors.
Regular measurement of blood pressure is recommended for patients
receiving venlafaxine. Dose related increases of BP have been reported
commonly in patients on doses of > 200mg daily of venlafaxine. For
patients who experience a sustained increase in blood pressure while
receiving venlafaxine either dose reduction or discontinuation should be
considered. However the patient’s overall physical health and mental
health need to be taken into consideration and in particular whether the
patient has had one episode or recurrent episodes of depression and the
length of treatment course (see NICE Guidelines).For example patients
with one severe episode but no symptoms of depression for a prolonged
period may be considered for a dose reduction whereas a patient with
multiple episodes who has failed a venlafaxine reduction in the past may
be considered for antihypertensive therapy depending on their physical
health and the size of the blood pressure increase. In all cases a
risk/benefit discussion needs to take place with the patient, GP and
Specialist to decide the safest option with regards to both Mental and
Physical health. In patients where there has been a history of nonresponse to treatment, treatment with antihypertensive therapy could be
considered.
5. Regimen Management
PROCEDURE FOR INITIATING SHARED CARE
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High dose may be initiated by the secondary care mental health
specialist or the GP under supervision of a secondary care mental
health specialist.
There should be an agreed care plan for monitoring the patient’s
mental health ,physical health and side effects of drug treatment.
The GP should receive a copy of the care plan, venlafaxine SCP and
completed referral form.(Appendix1) noting any recent BP readings.
The GP should notify the psychiatrist ASAP and within 10days if they
agree or not by signing the referral form.
The psychiatrist will ensure patient has adequate supplies of
venlafaxine until shared care has been agreed.
RESPONSIBILITIES OF THE PSYCHIATRIST
1. To establish the diagnosis and determine a management strategy and
care plan in conjunction with the GP, other healthcare professionals and
appropriate support agencies.
2. To initiate or recommend increasing the dose of venlafaxine to 300mg or
greater.
3. To provide advice and agree an action plan if the GP reports poor
response to treatment, signs of relapse, side effects or compliance
problems.
4. To provide prescriptions until SCP has been agreed
5. To notify the GP of any relevant test results or changes to the care plan
or prescription.
6. To discharge the patient to primary care when appropriate following
agreement with the patient’s GP
RESPONSIBILITIES OF THE GENERAL PRACTITIONER
1. To refer patients with treatment-resistant depression. The GP may
consider a trial of venlafaxine 75mg-225mg daily before referral or seeking
advice.
2. To only prescribe 300mg-375mg daily after discussion and agreement with
mental health services.
3. To prescribe 1-2weeks of medication at a time to patients at risk of
overdosing.
4. To monitor BP at baseline and regularly especially at the beginning of
treatment and after dose increases. If patients are prescribed more than
225mg daily 3monthly BP may be an appropriate frequency.
5. To notify mental health services of any relevant test results or changes to
their drug treatment.
6. GP should seek advice from the psychiatrist or other agency where
appropriate:
a) deterioration in mental state or poor response
b) difficult to manage side effects
c) if patient has hypertension or develops heart disease
d) if compliance is a problem
e) advice on drug interactions when prescribing concomitant drugs
7. Once a decision to stop venlafaxine is made it should be withdrawn very
gradually over at least 6-8weeks to avoid discontinuation symptoms if
patient has taken it for 6-8months.After less than 8weeks withdraw over 12 weeks. If a patient has been on long-term maintenance treatment reduce
by 25% every 4-6weeks.
6. Summary of side-effects and interactions
SIDE EFFECTS
The most commonly observed adverse events associated with the use of
venlafaxine in clinical trials, and which occurred more frequently than
those which were associated with placebo were: nausea, insomnia, dry
mouth, somnolence, dizziness, constipation, sweating, nervousness,
asthenia and abnormal ejaculation/orgasm.
The occurrence of most of these adverse events was dose-related, and
the majority of them decreased in intensity and frequency over time. They
generally did not lead to cessation of treatment.
Adverse events observed with venlafaxine, from both spontaneous and
clinical trials reports, are classified in body systems and listed below as
very common (>1/10); common (<1/10 and >1/100); uncommon (<1/100
and >1/1000); rare (<1/1000); very rare (<1/10,000):
Blood and lymphatic system disorders - Uncommon: ecchymosis, mucous
membrane bleeding; Rare: prolonged bleeding time, haemorrhage,
thrombocytopenia; Very rare: blood dyscrasias (including agranulocytosis,
aplastic anaemia, neutropenia and pancytopenia).
Cardiovascular and vascular disorders Common: hypertension,
palpitation, vasodilatation; Uncommon: hypotension/postural hypotension,
syncope, arrhythmias (including tachycardia); Very rare: Torsade de
Pointes, QT prolongation, ventricular tachycardia, ventricular fibrillation.
Gastrointestinal disorders - Very common: constipation, nausea Common:
anorexia, appetite decreased, diarrhoea, dyspepsia, vomiting; Uncommon:
bruxism; Rare: gastrointestinal bleeding; Very rare: pancreatitis.
General disorders - Very common: asthenia, headache; Common:
abdominal pain, chills, pyrexia; Rare: anaphylaxis
Metabolic and nutritional disorders - Common: serum cholesterol
increased (particularly with prolonged administration and possibly with
higher doses weight gain or loss; Uncommon: hyponatraemia including
SIADH; Rare: hepatitis; Very rare: prolactin increased.
Musculo-skeletal disorders - Common: arthralgia, myalgia; Uncommon:
muscle spasm; Very rare: rhabdomyolysis.
Neurological disorders - Very common: dizziness, dry mouth, insomnia,
nervousness, somnolence; Common: abnormal dreams, agitation, anxiety,
confusion, hypertonia, paraesthesia, tremor; Uncommon: apathy,
hallucinations, myoclonus; Rare: ataxia and disorders of balance and coordination, speech disorders including dysarthria, mania or hypomania,
neuroleptic malignant syndrome-like effects, seizures
serotonergic syndrome; Very rare: delirium, extrapyramidal disorders
including dyskinesia and dystonia, tardive dyskinesia, psychomotor
restlessness/akathisia.
Renal and urinary disorders - Common: urinary frequency; Uncommon:
urinary retention.
Reproductive and breast disorders - Very common: anorgasmia, erectile
dysfunction, abnormal ejaculation/orgasm; Common: decreased libido,
impotence, menstrual cycle disorders; Uncommon: menorrhagia; Rare:
galactorrhoea.
Respiratory system disorders - Common: dyspnoea, yawning; Very rare:
pulmonary eosinophilia.
Skin and subcutaneous tissue disorders -Very common: sweating
(including night sweats); Common: pruritus, rash; Uncommon:
angioedema, maculopapular eruptions, urticaria, photosensitivity
reactions, alopecia; Rare: erythema multiforme, Stevens Johnson
syndrome.
Special senses - Common: abnormal vision/ accommodation, mydriasis,
tinnitus; Uncommon: altered taste sensation.
INTERACTIONS
Potent CYP3A4 inhibitors e.g. ketoconazole ,erythromycin or drug
combinations that inhibit both CYP3A4 and CYP2D6 should only be coadministered with venlafaxine when strictly indicated because of the
possibility of clinically important interactions in patients with a ‘poor
metaboliser’ phenotype. Specialist supervision is recommended for use of
concomitant SSRIs.
7. Special considerations
TOXICITY IN OVERDOSAGE
Venlafaxine is involved in a higher rate of deaths from overdosage than
the SSRIs but lower than the tricyclic antidepressants. Monitor high risk
patients frequently and limit quantities - see section 4 for details.
Overdoses of greater to or equal to 2g have been fatal although the
majority of overdoses are non-fatal even at higher doses.
DISCONTINUATION REACTIONS
Venlafaxine is associated with a greater frequency of
withdrawal/discontinuation reactions than other antidepressants. The dose
should be tapered gradually over a period of weeks according to the
patient’s need. See under GP Responsibilities for guidance. The 37.5mg
tablet can be broken in half to aid the slow reduction.
8. Back-up care available to GP from Hospital, including emergency
contact procedures and help line numbers
9. Statement of agreement
Shared care is an agreement between the GP and the Consultant. This
form is a request by the consultant to share the suggested care pathway of
your patient. If you are unable to agree to the sharing of care and initiating
the suggested medication, please make this known to the consultant within
14 days, ideally stating the nature of your concern.
10. Written information provided to the patient
11. Supporting References
SPC Efexor and EfexorXL
NICE Guidance Depression ; management of depression in primary and
secondary care Clinical guideline 23(amended) April 2007
Wyeth Drug information
Antidepressant Discontinuation Syndromes Drug Safety 2001:24(3)183197
APPENDIX 1
REFFERAL FORM FROM CONSULTANT
PSYCHIATRIST TO GP
SHARED CARE PROTOCOL for VENLAFAXINE DOSES of 300mg or
GREATER(HIGH DOSE) IN SEVERE DEPRESSION.
From (Name of Consultant Psychiatrist)______________________________
To (Name of GP)______________________________________________
Name of GP practice or stamp______________________________________
Name of Patient_________________________________________________
Date of Birth________________________ Hospital ID Number
Diagnosis______________________________________________________
Medication prescribed by Consultant Psychiatrist_______________________
______________________________________________________________
__________ Recent BP reading ___________ Date____________
Name of Care co-ordinator/CPN_________________
Tel No____________
I would be grateful if we could adopt the shared care protocol for the above
patient prescribed ‘high dose’ venlafaxine. I accept my responsibilities as
outlined in the enclosed guideline.
Signed Consultant Psychiatrist_________________
Date__________________
FOR the GP
I confirm I have received a copy of the patients Care Plan and SCP
YES/NO
I agree to share the care of the above patient prescribed ‘high dose’
venlafaxine. I accept my responsibilities as outlined in the enclosed guideline.
YES/NO
Signed GP____________________________ Date________________