Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes Hydroxyzine. If you are concerned about side effects, discuss the risks and benefits of Hydroxyzine with your doctor.

The following side effects have been reported by at least 1% of people taking Hydroxyzine. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• Constipation
• drowsiness
• Dry Mouth, nose, or throat
• flushing
• headache
• itching

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blurred vision or any change in vision
• confusion
• difficult or painful urination
• dizziness
• slow, fast, or pounding heartbeat
• hallucinations (seeing or hearing things that aren’t there)
• problems with coordination
• skin rash
• symptoms of irregular heart beat (e.g., chest pain, dizziness, rapid, pounding heartbeat, shortness of breath)
• symptoms of too much medication (e.g., nausea, vomiting, slurred speech, excitement, restlessness, nervousness, irritability, or tremors)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• signs of an allergic reaction (e.g., rash, itching, or Hives)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with Fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Hydroxyzine.

Hydroxyzine is available as 10 mg, 25 mg, and 50 mg capsules.

Do not take Hydroxyzine if you:

• are allergic to hydroxyzine or any ingredients of the medication
• are in early pregnancy
• have had an allergic reaction to Aminophylline or cetirizine
• have Asthma and have had a breathing problem relating to histamine or Allergies
• have a history of irregular heartbeat, other heart problems, or a family history of sudden cardiac death
• have untreated low levels of potassium or magnesium,
• have porphyria

There may be an interaction between hydroxyzine and any of the following:

• aclidinium
• alcohol
• Alfuzosin
• Amiodarone
• amphetamines (e.g., Dextroamphetamine, lisdexamphetamine)
• antihistamines (e.g,. cetirizine, doxylamine, Diphenhydramine, Loratadine)
• anti-psychotics (e.g., chlorpromazine, Clozapine, Haloperidol, olanzepine, Quetiapine, Risperidone)
• atropine
• azelastine
• barbiturates (e.g., butalbital, pentobarbital Phenobarbital)
• belladonna
• benzodiazepines (e.g., Alprazolam, Diazepam, Lorazepam)
• Benztropine
• brimonidine
• Buprenorphine
• Buspirone
• chloral hydrate
• chloroquine
• Darifenacin
• Degarelix
• Disopyramide
• dofetilide
• Domperidone
• Donepezil
• dronabinol
• Dronedarone
• efavirenz
• Flavoxate
• Flecainide
• Galantamine
• general anesthetics (medications used to put people to sleep before surgery)
• Glucagon
• glycopyrrolate
• ipratropium
• kava kava
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• magnesium sulfate
• Methadone
• metyrosine
• mifepristone
• Minocycline
• Mirabegron
• Mirtazapine
• muscle relaxants (e.g., Baclofen, Cyclobenzaprine, methocarbamol, orphenadrine)
• Nabilone
• narcotic pain relievers (e.g., Codeine, Fentanyl, Morphine, Oxycodone)
• Oxybutynin
• Perampanel
• pimozide
• potassium chloride
• Pramipexole
• pramlitinide
• procainamide
• protein kinase inhbitors (e.g., Lapatinib, Pazopanib, Sunitinib)
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, Ofloxacin, sparfloxacin)
• rilpivirine
• Rivastigmine
• Ropinirole
• Rotigotine
• Rufinamide
• saquinavir
• scopolamine
• seizure medications (e.g., Carbamazepine, Clobazam, Levetiracetam, phenobarbital, Phenytoin, primidone, Topiramate, Valproic acid, zonisamide)
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin antagonists (anti-emetic medications; e.g., Granisetron, Ondansetron,)
• Solifenacin
• sotalol
• Tapentadol
• Tetrabenazine
• thiazide diuretics (water pills; e.g., Hydrochlorothiazide, Indapamide, Metolazone)
• tiotropium
• tolcapone
• Tolterodine
• topiramate
• Tramadol
• Tranylcypromine
• Trazodone
• trimeprazine
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• umeclidinium
• Zolpidem
• Zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Hydroxyzine. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Hydroxyzine.

Abnormal heart rhythms: Hydroxyzine can cause abnormal heart rhythms. Certain medications (e.g., Sotalol, quinidine, thioridazine, Chlorpromazine, droperidol, Pimozide,  moxifloxacin, Mefloquine, pentamidine, arsenic trioxide, probucol, Tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation and should not be used in combination with hydroxyzine. You are more at risk for this type of abnormal heart rhythm and its complications if you:

• are female
• are older than 65 years of age
• have a family history of sudden cardiac death
• have a history of heart disease or abnormal heart rhythms
• have a slow heart rate
• have congenital prolongation of the QT interval
• have Diabetes
• have had a Stroke
• have low potassium, magnesium, or calcium levels
• have nutritional deficiencies

If you have heart disease and abnormal heart rhythms, or people are taking certain medications (e.g., Verapamil, atazanavir), discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

Breathing problems: People with breathing problems such as asthma, emphysema, or chronic Bronchitis may find that hydroxyzine makes breathing more difficult. It can dry the mucus in the lungs, making it more difficult to clear the lungs. If you experience difficulty breathing, stop taking the medication and contact your doctor.

Digestive system problems: Antihistamines, such as hydroxyzine, cause the passage of food though the digestive system to slow down. If you have any condition that already slows down the movement of food through the stomach and intestines, hydroxyzine may make this worse.

Drowsiness/reduced alertness: Hydroxyzine may cause drowsiness or dizziness, affecting your ability to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by Hydroxyzine.

Enlarged prostate and urinary difficulties: Hydroxyzine may worsen urinary difficulties. If you have an enlarged prostate or difficulty starting urination, including a blockage from the bladder, discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

Epilepsy: Hydroxyzine should be used with caution by people with epilepsy, as it may increase the risk for seizures. If you have a history of seizures, discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

Glaucoma: Hydroxyzine may cause a slight increase in pressure in the eye and therefore should be used with caution by anyone with glaucoma. If you have glaucoma, discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

If you notice vision changes while you are taking Hydroxyzine, contact your doctor.

Kidney function: The kidneys are partially responsible for removing Hydroxyzine from your body. Kidney Disease or reduced kidney function may cause Hydroxyzine to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Hydroxyzine to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

Myasthenia Gravis: Hydroxyzine may worsen the muscle weakness experienced by people with myasthenia gravis. Hydroxyzine should be used with caution if you have myasthenia gravis.

Sedation: The sedating effect of hydroxyzine must be considered when the medication is used at the same time as other sedating medications such as narcotics, non-narcotic pain relievers, sleeping pills, sedatives, barbiturates, or alcohol.

Thyroid disease: Hydroxyzine may cause symptoms of an overactive thyroid gland (Hyperthyroidism). If you have thyroid problems, discuss with your doctor how Hydroxyzine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Hydroxyzine, and whether any special monitoring is needed.

Pregnancy: Hydroxyzine should not be used during early pregnancy. It should be used during later pregnancy only if the potential benefits outweigh the risks.

Breast-feeding: It is not known if hydroxyzine passes into breast milk. If you are a breast-feeding mother and are taking Hydroxyzine, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Seniors: Seniors may be at increased risk for the sedating and impaired coordination effects of Hydroxyzine. Seniors should use extra caution, for example, when getting up during the night.