Hyoscyamine produces many effects in the body, including relief from muscle spasms.

Hyoscyamine also reduces the fluid secretions of many organs and glands in the body, such as the stomach, pancreas, lungs, saliva glands, sweat glands, and nasal passages.

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.

Do not take hyoscyamine if you are allergic to it, or if you have kidney disease, a bladder or intestinal obstruction, severe ulcerative colitis, toxic megacolon, glaucoma, or myasthenia gravis.

Before taking hyoscyamine, tell your doctor if you have heart disease, congestive heart failure, a heart rhythm disorder, high blood pressure, overactive thyroid, or hiatal hernia with gastroesophageal reflux disease.

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.

Hyoscyamine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Drinking alcohol can increase drowsiness and dizziness while you are taking hyoscyamine.

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

Do not take hyoscyamine if you are allergic to it, or if you have:

• kidney disease;

• an enlarged prostate or problems with urination;

• intestinal blockage;

• severe ulcerative colitis, or toxic megacolon;

• glaucoma; or

• myasthenia gravis.

To make sure you can safely take hyoscyamine, tell your doctor if you have any of these other conditions:

• heart disease, congestive heart failure;

• a heart rhythm disorder;

• high blood pressure;

• overactive thyroid; or

• hiatal hernia with GERD (gastroesophageal reflux disease).

FDA pregnancy category C. It is not known whether hyoscyamine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Hyoscyamine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.