PRECAUTIONS: Tell your doctor your medical history, especially of: heart or blood vessel disease, stomach ulcers, diarrhea, pheochromocytoma, asthma, fever, allergies (especially drug allergies). This medication should be used only when clearly needed during pregnancy. It is not known if guanadrel passes into breast milk. Consult with your doctor before breast-feeding. To avoid dizziness and lightheadedness when rising from a seated or lying position, change positions slowly. Avoid prolonged standing and be careful on stairs. Limit your intake of alcoholic beverages while taking this medication. Alcohol can lead to excessive drowsiness or fainting. Also avoid hot showers, saunas, or prolonged exercise as excessive heat can worsen dizziness.

DRUG INTERACTIONS: Tell your doctor of all medications you use (both prescription and nonprescription), especially of: antidepressants, MAO inhibitors (e.g., furazolidone, linezolid, moclobemide, phenelzine, selegiline, tranylcypromine), drugs used for mental or emotional conditions (haloperidol, loxapine, or phenothiazines such as chlorpromazine), drugs used for diabetes, high blood pressure medications, drugs used to promote weight loss. Do not take any medication for coughs, colds or allergies without first checking with your doctor or pharmacist. Some of these products contain ingredients which can increase blood pressure (e.g., phenylephrine, pseudoephedrine). Do not start or stop any medicine without doctor or pharmacist approval.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include nausea, vomiting, unusual dizziness, blurred vision, fainting, and loss of consciousness.

NOTES: It is important to have your blood pressure checked regularly while taking this medication. Learn how to monitor your blood pressure. Discuss this with your doctor. Do not allow anyone else to take this medication.

Report Problems to the Food and Drug Administration You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088. Need help identifying pills and medications? Use the pill identifier tool on RxList.