Download Monitoring antipsychotics1

Monitoring antipsychotics1
The Maudsley Prescribing Guidelines contain comprehensive guidance on monitoring patients taking antipsychotics.
All the tests which should be conducted at baseline are listed below.
Parameter/test
Suggested frequency
Action to be taken if results
outside reference range
Drugs with special
precautions
Drugs for which monitoring
is not required
Urea and electrolytes
(including creatinine or
estimated GFR)
Baseline and yearly
Investigate all
abnormalities detected
Amisulpride and sulpiride
renally excreted – consider
reducing dose if GFR reduced
None
Full blood count (FBC)
Baseline and yearly
Stop suspect drug if
neutrophils fall below
1.5 x 109/l. Refer to specialist
medical care if neutrophils
below 0.5 x 109/l. Note high
frequency of benign ethnic
neutropenia in certain
ethnic groups
Clozapine – FBC weekly for
18 weeks, then fortnightly up
to one year, then monthly
None
Blood lipids
(cholesterol; triglycerides)
Fasting sample, if possible
Baseline, at three months,
then yearly
Offer lifestyle advice.
Consider changing
antipsychotic and/or
statin therapy
Clozapine, olanzapine,
quetiapine, phenothiazines –
three monthly for first year,
then yearly
Some antipsychotics
(e.g. aripiprazole) not clearly
associated with dyslipidaemia
but prevalence is high in this
patient group so all patients
should be monitored
Weight
(including waist size and BMI,
if possible)
Baseline, frequently for
three months, then yearly
Offer lifestyle advice.
Consider changing
antipsychotic and/or dietary/
pharmacological intervention
Clozapine, olanzapine –
three monthly for first year,
then yearly
Aripiprazole and ziprasidone
not clearly associated with
weight gain but monitoring
recommended nonetheless
– obesity prevalence high
in this patient group
Plasma glucose
(fasting sample, if possible)
Baseline, at 4-6 months,
then yearly
Offer lifestyle advice.
Obtain fasting sample or
non-fasting and HbA1C.
Refer to GP or specialist
Clozapine, olanzapine –
test at baseline, one month,
then 4-6 monthly
Some antipsychotics not
clearly associated with IFG
but prevalence is high in this
patient group so all patients
should be monitored
ECG
Baseline and after dose
increases (ECG changes rare
in practice) on admission to
hospital and before discharge
if drug regimen changed
Refer to cardiologist if
abnormality detected
Haloperidol, pimozide,
sertindole* – ECG mandatory.
Ziprasidone*, zotepine* –
ECG mandatory in some
situations
Risk of sudden cardiac
death increased with most
antipsychotics. Ideally all
patients should be offered
an ECG at least yearly.
Blood pressure
Baseline; frequently during
dose titration
If severe hypotension or
hypertension (clozapine)
observed, slow rate
of titration
Clozapine, chlorpromazine
and quetiapine most likely
to be associated with
postural hypotension
Amisulpride, aripiprazole,
trifluoperazine, sulpiride
Prolactin
Baseline, then at six months,
then yearly
Switch drugs if
hyperprolactinaemia
confirmed and symptomatic
Liver function tests
(LFTs)
Baseline, then yearly
Stop suspect drug if
LFTs indicate hepatitis
(transaminases x 3 normal)
or functional damage
(PT/albumin change)
Clozapine and chlorpromazine
associated with hepatic failure
Amisulpride, sulpiride
Creatinine phosphokinase
(CPK)
Baseline, then if
NMS suspected
Refer to the Maudsley
Guidelines for further details
NMS more likely with
first-generation antipsychotics
None
Aripiprazole, clozapine,
quetiapine, olanzapine
(<20mg), ziprasidone* usually
do not elevate prolactin,
but worth measuring if
symptoms arise
Other tests: Patients on clozapine may benefit from an EEG as this may help determine the need for an anticonvulsant (although interpretation is obviously complex).
Those on quetiapine should have thyroid function tests yearly although the risk of abnormality is very small.
Key: BMI – body mass index; ECG – electrocardiograph; EEG – electroencephalogram; GFR – glomerular filtration rate; IFG – impaired fasting glucose.
*These drugs are not commercially available in the UK.
References:
1. Maudsley Prescribing Guidelines, 11th edition. Taylor D, Paton C & Kapur S.
Informa Healthcare, London 2012.
The Maudsley Prescribing Guidelines table has been reproduced with permission.
Supported by
reach4resource.co.uk