From the Guidelines
Hydroxyzine can cause Extrapyramidal Symptoms (ETD) at doses typically exceeding 100-200 mg daily. While hydroxyzine is primarily an antihistamine used for anxiety, allergies, and as a sedative, it has weak dopamine D2 receptor antagonism at higher concentrations, which can potentially trigger ETD such as dystonia, akathisia, or parkinsonism 1. The risk increases with advanced age, pre-existing movement disorders, concurrent use of other dopaminergic antagonists (like antipsychotics or metoclopramide), or in patients with hepatic impairment where drug metabolism may be reduced. Some key points to consider:
- If ETD occurs while taking hydroxyzine, the medication should be discontinued and symptoms typically resolve within hours to days.
- For patients requiring antihistamine therapy who have experienced ETD with hydroxyzine, alternative second-generation antihistamines with less central nervous system penetration (like cetirizine or loratadine) may be safer options.
- Healthcare providers should use the lowest effective dose of hydroxyzine, particularly in vulnerable populations, and monitor for early signs of movement disorders. It's essential to note that the provided evidence does not directly address the dose of hydroxyzine that can cause ETD, but based on the general understanding of antihistamines and their potential to cause extrapyramidal symptoms, the recommended dose range is typically not to exceed 100-200 mg daily to minimize this risk.
From the Research
Dose of Hydroxyzine and Extrapyramidal Symptoms (ETD)
- The provided studies do not directly address the dose of hydroxyzine that can cause Extrapyramidal Symptoms (ETD) 2, 3, 4, 5, 6.
- However, it is known that hydroxyzine can have anticholinergic effects, and high doses of anticholinergic medications can increase the risk of extrapyramidal symptoms 5.
- One study mentions that hydroxyzine may produce abnormal ventricular repolarization when given in substantial doses or to susceptible individuals, and that concurrent use of certain medications such as phenothiazines, tricyclic antidepressants, or antiparkinson drugs may augment this effect 5.
- The doses of hydroxyzine used in the provided studies range from 25 mg to 50 mg, and these doses were not reported to cause extrapyramidal symptoms 3, 4, 6.
- It is worth noting that the risk of extrapyramidal symptoms may be higher with higher doses of hydroxyzine, but the exact dose at which this risk increases is not specified in the provided studies.
Side Effects of Hydroxyzine
- The most common side effects of hydroxyzine reported in the studies include sleepiness, weight gain, dry mouth, loss of concentration, and insomnia 3, 4, 6.
- These side effects were generally reported to be mild and transient, and did not lead to discontinuation of treatment in most cases.