MHMM High Dose Antipsychotic Screening, Education & Advice Dosage Ready Reckoner
Percentage of BNF
maximum adult
daily
dose
Percentage
of BNF
maximum
adult daily dosage
Commonly used
antipsychotics
ORAL
5
10
15
20
25
30
400
10
100
1.5
45
50
55
60
67
600
800
15
20
500
70
75
80
85
150 (17%)
300
450
600
5 (17%)
10
15
20
2 (12.5%)
90
95
100
5
20 (12.5%)
Zuclopenthixol
1200
30
1000
900
30
5
10
15
20
200
400
600
800
9
12
8
12
4
400 (17%)
Trifluoperazine (*)
1000
(83%)
750
3
Paliperidone
Risperidone
Sulpiride
DEPOT
3
250
2.5
(12.5%)
100
(12.5%)
Quetiapine
Flupentixol
Fluphenazine
Haloperidol
Olanzapine
Paliperidone
Pipotiazine
Risperidone
Zuclopentixol
40
Total daily dose mg/day (*) No max dose stated in BNF or SPC; 50mg used by convention
Amisulpride
Aripiprazole
Chlorpromazine
Clozapine
Haloperdiol
Olanzapine
33
6 (37.5%)
800
10
1200
2400
25
50
16
1600
40
100
50
150
Equivalent dose mg/week
20
40
100
200
12.5
25
25
37.5
400
12.5
100 (17%)
200
18.75
50
101
150
50
75
12.5
37.5
75
25
37.5
25
37.5
12.5
18.75
300
400
50
25
500 (83%)
600
MHMM High Dose Antipsychotic Screening, Education & Advice Dosage Ready Reckoner
Percentage of BNF
maximum adult
daily
dose
Percentage
of BNF
maximum
adult daily dosage
Less Common
antipsychotics
ORAL
5
10
Pericyazine
Perphenazine
Pimozide
Promazine
20
25
30
33
40
45
50
55
60
67
70
75
80
85
90
95
100
Total daily dose mg/day
Beneperidol
Flupentixol
Levomepromazine
15
3 (17%)
100
250
75
0.5
0.75
1
6
9
12
100
500
150
4 (17%)
2
150
(18.5%)
6
8
300
(37.5%)
10
18
750
12
4
1.5
200
1000
300
16
24
12
400
20
800
To calculate a total daily prescribed antipsychotic doe as a percentage of the BNF maximum: determine the
percentage of BNF maximum dosage for each antipsychotic that is prescribed, and then sum the percentages
e.g. for a patient prescribed olanzapine 15mg a day and chlorpromazine 50mg bd prn, the respective
percentages would be 75% and 10%, giving a total antipsychotic prescribed of 85% of the BNF maximum
e.g. for a patient prescribed risperidone 50mg every 2/52 and risperidone 2mg od, the respective percentages
would be 100% and 12.5%, giving a total antipsychotic prescribed of 112.5% of the BNF maxmimum, this is an
example of HIGH DOSE ANTIPSYCHOTIC prescribing.