Most over-the-counter (OTC) nasal sprays have as a main ingredient oxymetazoline. These medications include Afrin, 4-Way, Neo-Synephrine, Duramist, Mucinex Full Force, Nasin, Sinarest Nasal, Nasacon, Genasal, Nostrilla and Vicks Sinex, among others. According to the Mayo Clinic, you should blow your nose before spraying the medication into each nostril while sniffing briskly.
Congestion
While oxymetazoline is intended to clear congestion, at least temporarily, it can also increase congestion or cause a runny nose. These side effects may be serious, so consult your physician as soon as possible. Stop taking the medication until or unless it is cleared by your doctor for your use.
Nasal Irritation
Irritation of the nose may be a possible side effect of using a nasal spray containing oxymetazoline. You may experience stinging in the nose, a dry feeling or a burning sensation. These types of side effects do not require a doctor's attention. They may disappear or fade as you continue to use the nasal spray. If these side effects do not vanish, then consult your physician or discontinue use.
Nasal Discharge
It is possible for a nasal spray to cause discharges from the nose to increase. This may happen immediately after nasal spray use or later. Since the point of using a nasal spray is to clear, at least temporarily, congestion, mucus may be expelled. Again, this side effect may fade with regular use of the medication.
Sneezing
Oxymetazoline may cause you to sneeze. This is another side effect that may fade with continued proper use of a nasal spray.
Overdose
Side effects that may occur if you use too much of a nasal spray---more than the recommended dosage---include weakness, vision blurring, insomnia, irregular or rapid heartbeat, trembling, headaches, lightheadedness, nervousness, dizziness, high blood pressure and drowsiness. According to the Mayo Clinic, these side effects may affect children more than adults because they may absorb more of it into their bodies.
