Symptoms of overdose can be similar to the medication’s side effects, but are usually more severe. A severe overdose can result in a coma or death. Patients exhibiting any of these symptoms should contact their physicians immediately:

• Extreme tiredness
• Sweating
• Dizziness
• Slow heartbeat

When decongestant nasal sprays are used more frequently or longer than recommended (usually more than three to five days) rebound congestion (rhinitis medicamentosa) can result. This condition usually consists of nasal swelling and congestion, which are often the same symptoms the nasal spray was being used to treat. Once symptoms appear, they will often not subside even after the use of the nasal spray is discontinued. For this reason, using nasal spray decongestants longer than directed can lead to a type of dependency. Individuals using nasal spray decongestants should be careful to follow the directions on the package and should use the sprays only when necessary.