Hyoscyamine is used to treat many different stomach and intestinal disorders, including peptic ulcer and irritable bowel syndrome. It is also used to control muscle spasms in the bladder, kidneys, or digestive tract, and to reduce stomach acid.

Hyoscyamine is sometimes used to reduce tremors and rigid muscles in people with symptoms of Parkinson's disease.

Hyoscyamine is also used as a drying agent to control excessive salivation, runny nose, or excessive sweating.

Hyoscyamine may also be used for purposes not listed in this medication guide.

You should not use hyoscyamine if you are allergic to it, or if you have:

• a bladder obstruction or other urination problems;
• an enlarged prostate;
• a stomach or bowel obstruction (including paralytic ileus);
• severe ulcerative colitis, or toxic megacolon;
• glaucoma; or
• myasthenia gravis.

Hyoscyamine is not approved for use by anyone younger than 2 years old.

Tell your doctor if you have ever had:

• heart problems;
• high blood pressure;
• kidney disease;
• a colostomy or ileostomy;
• a thyroid disorder; or
• hiatal hernia with GERD (gastroesophageal reflux disease).

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

Use Symax SR (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using hyoscyamine and call your doctor at once if you have:

• anxiety, confusion, hallucinations, unusual thoughts or behavior;
• weakness, memory problems;
• slurred speech;
• problems with balance or muscle movement;
• diarrhea; o
• pounding heartbeats or fluttering in your chest.

Common side effects may include:

• dizziness, drowsiness, feeling weak or tired;
• decreased sweating, decreased urination;
• blurred vision;
• rash;
• dry mouth, decreased sense of taste;
• stomach pain, nausea, vomiting, bloating;
• diarrhea, constipation;
• headache;
• sleep problems (insomnia); or
• impotence, loss of interest in sex, or trouble having an orgasm.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Avoid taking antacids at the same time you take hyoscyamine. Antacids can make it harder for your body to absorb hyoscyamine. If you use an antacid, take it after you have taken hyoscyamine and eaten a meal.

Drinking alcohol with this medicine can cause side effects.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Hyoscyamine can decrease sweating and you may be more prone to heat stroke.

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.