Priapism in Antipsychotic Drug Use: A Rare but Important Side Effect

Table 1

The relative affinities for selected receptors of some antipsychotic drugs.

Rec	Chlorpromazine	Haloperidone	Amisulpride	Sulpiride	Clozapine	Risperidone	Olanzapine	Quetiapine
D1	+	++	—	—	++	+	++	+
D2	+++	++++	+++	+++	+	+++	++	+
D3	+++	+++	+++	+++	+	+++	++	+
D4	++	+++	—	—	++	+++	++	++
5HT1A	—	—	—	—	+	+	—	+
5HT2A	+++	++	—	—	++	++++	+++	++
5HT2C	++	—	—	—	++	++	++	—
α1	++++	+++	—	—	+++	++++	++	+++
H1	++++	++	—	—	+++	++	+++	++
M1	++	—	—	—	+++	—	+++	+

Notes: Rec: receptor; D1–D4: dopamine receptors 1–4; 5-HT1A–2C: serotonine receptors 1A–2C; α1: alpha-1 adrenergic receptor; H1 = histamine receptor 1; M1: muscarine receptor 1. Adapted from Abi-Dargham & Laurelle 2005 [4]; Roth et al. 2004 [5]; Miyamoto et al 2005 [6].