SwitchAntipsychotics

Switching Antipsychotics

To see the consequences of a switch between antipsychotics click in the crosstable below: the switch is made "from" (vertical) "to" (horizontal).
During switching: don't reduce anticholinergics and adding oxazepam might be useful.

↓ from	to →	Am	Ar	Ch	Cp	Hp	Ol	Pi	Qu	Rd	Sd	Sr	Zi	RA	Df	Di	Dh	Do	Dp	Dr	Dz	Mz
Am	Amisulpride	—	AmAr	AmCh	AmCp	AmHp	AmOl	AmPi	AmQu	AmRd	AmSd	AmSr	AmZi	AmRA	AmDf	AmDi	AmDh	AmDo	AmDp	AmDr	AmDz	AmMz
Ar	Aripiprazole	ArAm	—	ArCh	ArCp	ArHp	ArOl	ArPi	ArQu	ArRd	ArSd	ArSr	ArZi	ArRA	ArDf	ArDi	ArDh	ArDo	ArDp	ArDr	ArDz	ArMz
Ch	Chlorpromazine	ChAm	ChAr	—	ChCp	ChHp	ChOl	ChPi	ChQu	ChRd	ChSd	ChSr	ChZi	ChRA	ChDf	ChDi	ChDh	ChDo	ChDp	ChDr	ChDz	ChMz
Cp	Clozapine	CpAm	CpAr	CpCh	—	CpHp	CpOl	CpPi	CpQu	CpRd	CpSd	CpSr	CpZi	CpRA	CpDf	CpDi	CpDh	CpDo	CpDp	CpDr	CpDz	CpMz
Hp	Haloperidol	HpAm	HpAr	HpCh	HpCp	—	HpOl	HpPi	HpQu	HpRd	HpSd	HpSr	HpZi	HpRA	HpDf	HpDi	HpDh	HpDo	HpDp	HpDr	HpDz	HpMz
Ol	Olanzapine	OlAm	OlAr	OlCh	OlCp	OlHp	—	OlPi	OlQu	OlRd	OlSd	OlSr	OlZi	OlRA	OlDf	OlDi	OlDh	OlDo	OlDp	OlDr	OlDz	OlMz
Pi	Pimozide	PiAm	PiAr	PiCh	PiCp	PiHp	PiOl	—	PiQu	PiRd	PiSd	PiSr	PiZi	PiRA	PiDf	PiDi	PiDh	PiDo	PiDp	PiDr	PiDz	PiMz
Qu	Quetiapine	QuAm	QuAr	QuCh	QuCp	QuHp	QuOl	QuPi	—	QuRd	QuSd	QuSr	QuZi	QuRA	QuDf	QuDi	QuDh	QuDo	QuDp	QuDr	QuDz	QuMz
Rd	Risperidone	RdAm	RdAr	RdCh	RdCp	RdHp	RdOl	RdPi	RdQu	—	RdSd	RdSr	RdZi	RdRA	RdDf	RdDi	RdDh	RdDo	RdDp	RdDr	RdDz	RdMz
Sd	Sertindole	SdAm	SdAr	SdCh	SdCp	SdHp	SdOl	SdPi	SdQu	SdRd	—	SdSr	SdZi	SdRA	SdDf	SdDi	SdDh	SdDo	SdDp	SdDr	SdDz	SdMz
Sr	Sulpiride	SrAm	SrAr	SrCh	SrCp	SrHp	SrOl	SrPi	SrQu	SrRd	SrSd	—	SrZi	SrRA	SrDf	SrDi	SrDh	SrDo	SrDp	SrDr	SrDz	SrMz
Zi	Ziprasidone	ZiAm	ZiAr	ZiCh	ZiCp	ZiHp	ZiOl	ZiPi	ZiQu	ZiRd	ZiSd	ZiSr	—	ZiRA	ZiDf	ZiDi	ZiDh	ZiDo	ZiDp	ZiDr	ZiDz	ZiMz
RA	Rest AP	RAAm	RAAr	RACh	RACp	RAHp	RAOl	RAPi	RAQu	RARd	RASd	RASr	RAZi	—	RADf	RADi	RADh	RADo	RADp	RADr	RADz	RAMz
Df	Fluphenazine_LA	DfAm	DfAr	DfCh	DfCp	DfHp	DfOl	DfPi	DfQu	DfRd	DfSd	DfSr	DfZi	DfRA	—	DfDi	DfDh	DfDo	DfDp	DfDr	DfDz	DfMz
Di	Flupenthixol_LA	DiAm	DiAr	DiCh	DiCp	DiHp	DiOl	DiPi	DiQu	DiRd	DiSd	DiSr	DiZi	DiRA	DiDf	—	DiDh	DiDo	DiDp	DiDr	DiDz	DiMz
Dh	Haloperidol_LA	DhAm	DhAr	DhCh	DhCp	DhHp	DhOl	DhPi	DhQu	DhRd	DhSd	DhSr	DhZi	DhRA	DhDf	DhDi	—	DhDo	DhDp	DhDr	DhDz	DhMz
Do	Olanzapine_LA	DoAm	DoAr	DoCh	DoCp	DoHp	DoOl	DoPi	DoQu	DoRd	DoSd	DoSr	DoZi	DoRA	DoDf	DoDi	DoDh	—	DoDp	DoDr	DoDz	DoMz
Dp	Paliperidone_LA	DpAm	DpAr	DpCh	DpCp	DpHp	DpOl	DpPi	DpQu	DpRd	DpSd	DpSr	DpZi	DpRA	DpDf	DpDi	DpDh	DpDo	—	DpDr	DpDz	DpMz
Dr	Risperidone_LA	DrAm	DrAr	DrCh	DrCp	DrHp	DrOl	DrPi	DrQu	DrRd	DrSd	DrSr	DrZi	DrRA	DrDf	DrDi	DrDh	DrDo	DrDp	—	DrDz	DrMz
Dz	Zuclopenthixol_LA	DzAm	DzAr	DzCh	DzCp	DzHp	DzOl	DzPi	DzQu	DzRd	DzSd	DzSr	DzZi	DzRA	DzDf	DzDi	DzDh	DzDo	DzDp	DzDr	—	DzMz
Mz	Zuclopenthixol MA	MzAm	MzAr	MzCh	MzCp	MzHp	MzOl	MzPi	MzQu	MzRd	MzSd	MzSr	MzZi	MzRA	MzDf	MzDi	MzDh	MzDo	MzDp	MzDr	MzDz	—

LA = long acting, MA = medium acting
Rest AP = Chlorprothixene, Flupentixol, Loxapine, Paliperidone, Pericyazine, Perphenazine,Promazine, Trifluoperazine, Zuclopentixol.

General consideration

1. The goal of this switching table is to offer a guide for physician and pharmacist in switching antipsychotics. The table should be clear, easy to use and contain the most important information. Therefore, the table only contains the most common or special antipsychotics. There is also a group ‘rest AP’, containing antipsychotics with the same switching advice.

2. It should be noted that the table only contains a general advice.

3. Because of the risk of acute withdrawal symptoms (e.g. cholinergic rebound) and the risk of relapse, all antipsychotics are gradually tapered.

4. The standard tapering period is approximately two weeks. The two drugs are cross-tapered, reducing and increasing the dose with approximately 25% every 2-3 days.

5. To keep the content simple, dosages are given as percentages as much as possible. Dosages should be rounded to whole or half tablets.

6. All antipsychotics are categorized in short, medium and long, based on their half-life. Depot preparations are categorized as long. It takes approximately 3-5 times the half-life for a drug to reach steady state plasma levels or to be completely eliminated. Switching two antipsychotics with approximately the same half-life are not expected to generate obvious problems. Also switching from a drug with a long half-life to a shorter half-life is in general not expected to give problems, because the new drug will reach steady state plasma levels more quickly.

7. Switching from a drug with a short half life to a drug with a long half life is possibly more problematic. Plasma levels of the first drug decrease rapidly, while the second drug takes longer to reach a steady state plasma level. To overcome possible withdrawal/ relapse, the second drug should be started in a higher dose (approx. 50% of target dose) for about 4 days. Subsequently increase with 25% every 3-4 days.

8. Warnings and advice are limited to the switch only. Specific drug properties can be found via the links on the right.

9. Cytochrome P450 drug interactions between different antipsychotics are checked with the Flockart interaction table. No inductors or inhibitors were found.

10. Nearly all antipsychotics increase the risk of QT time prolongation with or without Torsade de Pointes (TDP). Under the heading ‘more information’ there is a recommendation, advising ECG monitoring. The SPC of sertindole contains the warning ECG monitoring required. No distinction has been made between drugs with and without TDP.