Patients with a history of certain health problems should use caution when taking allergy medications. They also should disclose certain lifestyle information to physicians before taking the medication. These conditions include:

• Previous allergic reactions to medications
• Other allergies, including those to pollens and foods
• Urinary tract problems
• Prostate problems
• Heart disease
• Glaucoma (a group of diseases that affect the optic nerve, which connects that eye to the brain)
• Stomach ulcers
• Thyroid disease
• Liver disease
• High blood pressure
• Intestinal obstruction
• Kidney disease
• Diabetes mellitus
• Blood vessel disease
• Asthma
• Emphysema
• Chronic bronchitis
• Amebiasis (a parasitic infection)
• Injuries to the nose, or sores inside the nose
• Osteoporosis (a bone disease)
• Pregnancy or breastfeeding
• Pheochromocytoma (a rare tumor)
• Arrhythmias (heart rhythm disorders)