If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

• bitter taste in the mouth,
• drowsiness,
• burning feeling inside the nose, 
• sneezing fits,
• nausea,
• weight gain,
• muscle aches
• red eyes 
• strange feelings on the skin (e.g., pins and needles, crawling sensation) 

Azelastine is an antihistamine.  It blocks the action of histamine which is responsible for allergic symptoms such as runny/itching/stuffy nose, sneezing and post-nasal drip.

Serious allergic reaction to this drug is unlikely, but seek immediate medical attention if any of these symptoms occur: rash, itching, swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

Use with caution:

• if you have kidney problems
• if you are driving, using machinery or doing any acitivity requiring alertness (may cause drowsiness)

Drug interactions:  Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of:

• cimetidine
• drugs that cause drowsiness such as: other antihistamines (e.g., diphenhydramine), anti-anxiety drugs (e.g., diazepam), anti-seizure drugs (e.g., phenobarbital), medicine for sleep (e.g., zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., risperidone, quetiapine), antidepressants (e.g.,amitriptyline, mirtazapine), tranquilizers (e.g. lorazepam, clonazepam).

Use in pregnancy and breastfeeding.  Limited data available.  Consult your doctor or pharmacist before use.