Urinary retention caused after fluoxetine-risperidone combination.
A case of urinary retention emerging after fluoxetine (20 mg/day) addition to low risperidone doses (2 mg/day) is presented. Severe extrapyramidal side-effects (EPS) also occurred after fluoxetine-risperidone combination. Several possibilities, based on the pharmacodynamic and pharmacokinetic properties of risperidone and fluoxetine, which merit consideration in an attempt to explain our patient's side-effects, are discussed. Extrapyramidal side-effects can be due to an increase of the plasma concentration of risperidone and/or the intrinsic propensity of fluoxetine to produce EPS. Urinary retention may be the consequence of a central serotoninergic mechanism in, or without, combination central D2 blockade.
Bozikas
V
V
A' Psychiatric Clinic, Aristotle University of Thessaloniki, Greece.
Petrikis
P
P
Karavatos
A
A
D018687:Antidepressive Agents, Second-Generation / Q000009:adverse effects*; D014150:Antipsychotic Agents / Q000009:adverse effects*; D001480:Basal Ganglia Diseases / Q000139:chemically induced / Q000523:psychology; D003702:Delusions / Q000150:complications / Q000188:drug therapy; D004338:Drug Combinations; D005473:Fluoxetine / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018967:Risperidone / Q000009:adverse effects*; D016055:Urinary Retention / Q000139:chemically induced*
D018687:Antidepressive Agents, Second-Generation; D014150:Antipsychotic Agents; D004338:Drug Combinations; D005473:Fluoxetine; D018967:Risperidone