Table 2. Main drugs and respective dosages used in treating antipsychotic-induced sexual dysfunction.

Drug	Dose	Mechanism of action for sexual dysfunction	Side effects31	Potential psychiatric drug interactions31
Bromocriptine	2.5 mg 2-3 x/d	Dopaminergic agonist13,14,32-35	Constipation (3-14%), nausea (50%), vomiting, dizziness (17%), fatigue (7%), headache (19%), hypotension, peripheral vasoconstriction, cerebral ischemia, seizures (rare), stroke (rare), confusion, dyskinesia, hallucinations, psychosis, pleuropulmonary changes (long-term use), postpartum myocardial infarction (rare)	May induce or exacerbate psychosis in psychiatric patients, but this occurs primarily in those with a psychotic diathesis and who are not currently receiving neuroleptic medication. Factors to be considered: dose of bromocriptine, duration of treatment, and the clinical state of the patient
Cabergoline	0.5 mg twice a week	Dopaminergic agonist15,36	Dizziness, fatigue, headache, constipation, nausea, somnolence, depression, orthostatic hypotension (1-10%), pleural effusion (rare), pulmonary fibrosis (rare), abdominal pain (4-5%), vertigo (4-5%)	May decrease therapeutic effect of antipsychotics
Cyproheptadine	4 mg 4 x/d	Serotonergic antagonist (5-HT2)16	Central nervous system depression, dry mouth, drowsiness, increased appetite, weight gain, nausea, vomiting, diarrhea, abdominal discomfort, thickening of bronchial secretions, hepatitis	Decreased fluoxetine efficacy, prolonged and intensified anticholinergic effects when used with MAOI, reduced paroxetine efficacy
Amantadine	100-300 mg/d	Increases dopamine release and reduces dopamine and noradrenaline reuptake into synaptic terminals18,19,27	Dizziness, insomnia (most common), agitation, anxiety, confusion, depression, dream abnormality, fatigue, hallucinations, headache, irritability, nervousness, nausea (most common), anorexia, constipation, diarrhea, dry mouth, orthostatic hypotension, peripheral edema, neuroleptic malignant syndrome, exacerbation of mental problems, suicide attempts	Bupropion: increased risk of adverse effects; zotepine: decreased pharmacological effect of amantadine, may decrease therapeutic effect of antipsychotics
Shakuyaku-kanzo-to (TJ-68)	2.5 g three times daily	The mechanism is unknown: either a direct inhibitory effect on prolactin release from the pituitary or an indirect action via a reduction in estradiol, or both24,28	Nausea, pseudo-hyperaldosteronism,37 myoglobinuria (rare); long term effect: may decrease serum testosterone levels,38 use is not recommended for pregnant women or for people with liver and kidney disorders37	No psychiatric drug interactions known Thiazide diuretics: increased potassium loss; digitalis: more sensitivity to digitalis due to hypokalemia
Sildenafil	50 mg/week	Phosphodiesterase inhibitor20-23	Flushing (4-10%), dizziness (2%), headache (11-16%), diarrhea (4%), dyspepsia (4-8%), abnormal vision, nasal congestion, skin rash (2%), myocardial infarction (rare), priapism (rare)	No psychiatric drug interactions known Nitrates: severe hypotensive effect; clarithromycin, erythromycin: increased risk of sildenafil effects
Imipramine	25-50 mg/d	Unknown17	Blurred vision, drowsiness, dizziness, weakness, fatigue, headache, dry mouth, constipation, bloating, urinary retention, weight gain, agranulocytosis (rare), arrhythmia, atrioventricular conduction changes, heart block, palpitations, jaundice and hepatic dysfunction (rare), orthostatic hypotension, syncope, hypertension, psychotic reactions (rare), seizures (rare)	Antipsychotic: increased risk of cardiotoxicity; barbiturates: possible decreased TCA serum concentrations and possible additive adverse effects; carbamazepine: decreased imipramine effectiveness; citalopram: increased in the bio-availability and half-life of desipramine; fenfluramine: increased risk of imipramine (sedation); phenothiazine: increased levels and toxicity with either agent; fluvoxamine: increased imipramine levels and signs of toxicity; MAOI: neurotoxicity, seizures or serotonin syndrome; paroxetine: imipramine toxicity; phenytoin: increased risk of phenytoin toxicity; sertraline: modest elevations in imipramine serum levels; St John's wort: increased risk of serotonin syndrome; tobacco: decreased imipramine concentrations; ziprasidone: increased risk of cardiotoxicity; zolmitriptan: increased risk of cardiotoxicity
Selegiline	15 mg/d	Selective monoamine oxidase B inhibitor30	Abdominal pain, nausea, dizziness, lightheadedness, confusion, hallucinations	TCA: neurotoxicity, seizures, or serotonin syndrome; bupropion: increased bupropion toxicity; carbamazepine: hypertensive urgency, hyperpyrexia, and seizures; citalopram: central nervous system (CNS) toxicity or serotonin syndrome; buspirone, phenelzine, phentermine, amphetamine, and amphetamine-like: hypertensive crisis; antipsychotic: increased risk of cardiotoxicity; fluoxetine, fluvoxamine, sibutramine, sertraline, and paroxetine: CNS toxicity or serotonin syndrome; reboxetine and nefazodone: hyperthermia, rigidity, myoclonus, seizures, fluctuations of vital signs, or mental status changes; phenobarbital: CNS sedation; St John's wort: increased risk of serotonin syndrome and/or increased risk of hypertensive crisis; triptans: serotonin syndrome; tramadol: nausea, vomiting, cardiovascular collapse, respiratory depression, seizures

MAOI = monoaminooxidase inhibitor; TCA = tryciclic antidepressant.