Antihistamines are a class of drugs used for treating allergic reactions such as itchiness and skin conditions. These drugs work to control the production of histamines, and hence the name. You need to know that histamines are natural substances your body produces upon sensing an onset of allergens. Allergies are often triggered when you are exposed to a pollutant or an allergen; these include dust, mites, pollen or pet dander. Hydroxyzine is a commonly used antihistamine drug. But, can it cause an inexplicable increase in body weight? It becomes essential to know more on this.

Antihistamines are widely used for treating rashes, swelling of skin caused by conditions such as dermatitis, etc. Hydroxyzine is a popular anti-allergy drug. It has the approval of the food and drug administration (FDA) for treating skin conditions and also to relieve restlessness. The drug is also taken prior to surgeries for its sedative properties. This med is available in multiple dosage strengths namely, 10 mg, 25 mg as well as 50 mg. In terms of physical form, it is made available as tablets and capsules. The duration of your dosage plan and strength of dosage depend on serval factors such as severity of your allergic condition, age, gender, body weight as well as presence of prior ailments.

What are the side effects of hydroxyzine?

This med is known to trigger a few unintended side effects and discomforts. Hence, you are advised to take it under the guidance and supervision of a qualified medical professional. Minor side effects this drug may trigger are drowsiness, migraines, weariness, weird thoughts or dreams, shakes or tremors, difficulties to pass stools, being in a confused state of mind and inability to stay focused. The good thing however is, most of these side effects may go away once your body is used to the active chemicals of this med. But, if one or more of these discomforts is known to persist for a few days, you are advised to talk to your treating physician without much delay.

In some one-off cases, this drug is also known to trigger a few serious side effects and very adverse discomforts. Users are likely to experience fainting or palpitations due to the elongation of QT time intervals. If you are noticing severe episodes of sleepiness or dizziness, it is highly recommended to refrain from driving or working on heavy machinery. It is also recommended to keep away from adventurous sports like swimming or other athletic activities.


In those who already have blood pressure related ailments, a severe drop in blood pressure has been observed. However, hydroxyzine did not cause this severe side effect during clinical trials. But, a sizable number of users complained of symptoms related to hypotension i.e., low blood pressure. The signs of hypotension are acute level of dizziness, being drowsy, problems with staying focused, etc. In some one-off instances, some users have reported a significant drop in blood pressure. This condition can often be detected through other signs like slowing down of breathing cycles, passing out accompanied by blurring of eyesight. Another unmistakable sign of a very low blood pressure is your skin may turn clammy and cold. Upon observing these symptoms, you are advised to seek clinical support on an emergency mode.

Does intake of hydroxyzine cause increase in body weight?

Users often tend to think that this drug may increase their weight. But, there are no substantive evidences to prove this assumption. The answer is hydroxyzine is not known to increase your body weight. Also, people who used this drug seldom observed such changes in body weight. But if you are worried about this fact, you are advised to talk to your caregiving team as well as your pharmacist. They can help you keep your body weight under control through a few safer approaches. Another good thing about hydroxyzine is it is not habit forming. Hence, users are unlikely to become addictive to this antihistamine med.

Safety precautions associated with the intake of hydroxyzine

Always remember that you must never take alcohol or other intoxicants along with hydroxyzine. Those who combined these two witnessed severe episodes of drowsiness, eyesight related problems, loss of coordination and passing out. Also, intake of hydroxyzine does not go well with a few antiarrhythmic-meds such as sotalol or amiodarone, citalopram (or other forms of antidepressant drugs), a few forms of antibiotic drugs (such as levofloxacin), etc. Apart from these, intake of monoamine oxidase inhibiting drugs (MOA inhibiting meds) such as selegiline can lead to a very low level of blood pressure as well as respiratory conditions such as wheezing, gasping as well as shallow breathing cycles.

It is a safe practice to tell your treating doctor about all the drugs you are currently consuming. As an extended precaution, inform about the treatment plans you are presently pursuing. It is a good thing to make a list of all the drugs you are taking; while preparing this list, include over the counter meds, prescription drugs, herbal drugs, vitamins, proteins and other dietary aids. Once having shared the list with your caregiving team, never make changes to it without telling your treating doctor.

The aforesaid side effects and precautions do not constitute a complete list. In some remote cases, users have experienced a few side effects which are not listed here. Upon encountering such unknown or unlisted discomforts, you are advised to talk to your caregiving team without any delay. Users who are residents of the US are advised to call 911 the helpline of FDA. Those who live in Canada may call Health Canada or rush to a poison control unit.

In sum, histamine is a form of protein that your body makes. This substance helps fight external threats such as invasion of allergens and pollutants. Active chemicals of hydroxyzine bind themselves to receptors of histamine. This action brings about needful relief from allergies such as itchiness, atopic dermatitis, etc. Histamines are also known to keep your brain active and alert. Intake of hydroxyzine can stop histamine production and thus makes your brain to feel sedated. This is one of the reasons for using this antihistamine as a sedative agent. This drug is generally not known to trigger an increase in body weight. However, those who are pursuing weight management goals are advised to consult with their caregiver to take needful safety precautions.

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