Before taking hyoscyamine, tell your doctor or pharmacist if you are allergic to it; or to atropine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: enlarged prostate, urinary blockage problems, certain stomach/intestinal problems (such as slow gut, blockage, severe ulcerative colitis, infection), personal or family history of glaucoma (angle-closure type), overactive thyroid, heart problems (such as coronary heart disease, heart failure, fast heartbeat, arrhythmias), high blood pressure, kidney disease, heartburn problems (acid reflux, hiatal hernia), certain nervous system problem (autonomic neuropathy), myasthenia gravis.

Contact lens wearers may need to use wetting eye drops since this medication can cause dry eyes.

This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This drug may increase the risk for heatstroke because it decreases sweating. Avoid becoming overheated in hot weather, saunas, and during exercise or other strenuous activity.

Older adults may be more sensitive to the side effects of this drug, especially confusion, drowsiness, unusual excitement, constipation, and difficulty urinating. Confusion and drowsiness can increase the risk of falling.

Children may be more sensitive to the side effects of this drug.

During pregnancy, hyoscyamine should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk. Consult your doctor before breastfeeding.