There are many important Parnate warnings and precautions to be aware of before starting the drug, including information on who should not take the medication. You should not take Parnate if you have high blood pressure, are about to undergo elective surgery, have liver problems, or are allergic to any components of the medicine. Possible side effects of Parnate include dangerously high blood pressure, low blood sugar, and suicidal thoughts or behavior.

• Heart disease
• High blood pressure (hypertension)
• A history of stroke, transient ischemic attack (TIA or "mini-stroke"), or other bleeding in the brain (such as a subarachnoid hemorrhage)
• Pheochromocytoma, a certain type of adrenal tumor
• An upcoming surgery or procedure involving general or local anesthetics
• Liver disease, including liver failure or cirrhosis
• Frequent headaches
• Bipolar disorder or a family history of bipolar disorder (also known as manic depression)
• A history of suicide attempts or suicidal thoughts
• Kidney problems, including kidney failure (renal failure)
• Seizures or epilepsy
• An upcoming radiology procedure
• An overactive thyroid (hyperthyroidism) or are taking thyroid medications
• Any allergies, including allergies to foods, dyes, or preservatives.
   

• Are pregnant or thinking of becoming pregnant
• Are breastfeeding
• Drink alcohol regularly.