Dizziness ziprasidone

Quetiapine (Seroquel). Another atypical antipsychotic, quetiapine has also been approved by the FDA for the treatment of acute mania. It is usually administered twice daily at doses of 150-750mg/day. Like its counterparts, quetiapine is a well-tolerated medication. Its common side effects are drowsiness, dizziness, and headache. It causes less weight gain than olanzapine or clozapine but more than ziprasidone or aripiprazole. Quetiapine also does not cause agranulocytosis nor does it increase the risk of seizures. It can occasionally cause mild changes in liver function tests, but these usually return to normal even if the patient continues taking quetiapine. 

The most common side effects are headache, dyspepsia, nausea, constipation, abdominal pain, somnolence, and EPS. Ratings of parkinsonism and akathisia with ziprasidone, 120 mg/day, did not differ from those with placebo. Although dizziness has been reported, rates of orthostatic hypotension have not differed from rates associated with placebo in controlled clinical trials. 

Published and unpublished studies from 1995 to 2004, in which intramuscular ziprasidone was assessed, have been reviewed (9). The most common adverse events in the 921 patients were nausea, headache, dizziness, anxiety, somnolence, insomnia, and injection-site pain 1.1 to 6.1% withdrew because of treatment-related adverse events. 

Ketoconazole caused a modest increase in the mean AUC (33%) and the mean Cmax (34%) of ziprasidone. This effect was not considered clinically relevant and suggests that other inhibitors of CYP3A4 are unlikely to affect the pharmacokinetics of ziprasidone significantly. Most of the reported adverse events were mild. The adverse events that were most commonly reported in subjects who took the drugs concomitantly were dizziness, weakness, and somnolence. There were no treatment-related laboratory abnormalities or abnormal vital signs during the study and at the 6-day follow-up evaluation. 

A study of intramuscular ziprasidone versus intramuscular haloperidol for managing agitation in a Chinese population was conducted [14 ]. There were fewer adverse events with ziprasidone particularly extrapyramidal symptoms and the most common adverse events with ziprasidone were dizziness and somnolence. Most subjects had no clinically significant changes in ECG five ziprasidone and three haloperidol patients had a QTcF>450ms. 

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