L-hyoscyamine produces many effects in the body, including relief from spasms of the gastrointestinal tract (stomach and intestines), the bladder, and the biliary tract. This is helpful in controlling conditions such as colitis, spastic bladder, diverticulitis, infant colic, renal and biliary colic, peptic ulcer, irritable bowel syndrome, splenic flexure syndrome, and pancreatitis.

L-hyoscyamine also reduces the secretions of many organs, thereby helping to control conditions such as excessive stomach acid production, excessive secretion from the pancreas, and excessive sweating and drooling associated with diseases like Parkinson’s disease. In addition, L-hyoscyamine is used before surgery to reduce secretions of the nose, lungs, salivary glands, and stomach, and it is even used to help dry up excessive mucus production associated with diseases, colds, and infections.

L-hyoscyamine also has effects on the eyes and on the heart.

L-hyoscyamine may also be used for purposes other than those listed in this medication guide.

Take L-hyoscyamine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water.

To ensure that you get a correct dose, measure the liquid form of L-hyoscyamine with a special dose-measuring spoon or cup, not with a regular tablespoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

Do not crush, chew, or open the capsules. Swallow them whole. They are specially formulated to release slowly in your body.

Store L-hyoscyamine at room temperature away from moisture and heat.

Many other drugs may increase the side effects of L-hyoscyamine. Before taking this medication, tell your doctor if you are taking any of the following medicines:

• amantadine (Symmetrel);

• quinidine (Quinaglute, Cardioquin, Quinora, Quinidex);

• antihistamines such as diphenhydramine (Benadryl, many others), brompheniramine (Dimetapp, Bromphen, many others), triprolidine (Actifed, others), and chlorpheniramine (Chlor-Trimeton, others), which are found in many over-the-counter and prescription cough, cold and allergy medications;

• decongestants and appetite suppressants such as phenylpropanolamine (Dexatrim, others), phenylephrine (Neo-Synephrine, others), and pseudoephedrine (Sudafed, others), which are also found in many over-the-counter and prescription products;

• phenothiazines such as chlorpromazine (Thorazine) and prochlorperazine (Compazine);

• other commonly used phenothiazines, including fluphenazine (Prolixin), mesoridazine (Serentil), perphenazine (Trilafon), thioridazine (Mellaril), trifluoperazine (Stelazine), and promazine (Sparine);

• tricyclic antidepressants such as amitriptyline (Elavil, Endep), doxepin (Sinequan), and nortriptyline (Pamelor); or

• other commonly used tricyclic antidepressants, including amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), imipramine (Tofranil), protriptyline (Vivactil), and trimipramine (Surmontil).

L-hyoscyamine may increase the level of digoxin (Lanoxin, Lanoxicaps) in your blood. Tell your doctor if you are taking digoxin so that your digoxin levels can be monitored and changes in your dosage can be made if necessary.

Drugs other than those listed here may also interact with L-hyoscyamine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Use caution when driving, operating machinery, or performing other hazardous activities. L-hyoscyamine may cause dizziness, drowsiness, or blurred vision. If you experience dizziness, drowsiness or blurred vision, avoid these activities.

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking L-hyoscyamine.

Avoid becoming overheated in hot weather. L-hyoscyamine increases the risk of heat stroke because it causes decreased sweating.

Seek emergency medical attention.

Symptoms of a L-hyoscyamine overdose include headache; nausea; vomiting; dry mouth; difficulty swallowing; blurred vision; dilated pupils; hot, dry skin; dizziness; drowsiness; confusion; anxiety; seizures; weak pulse; and an irregular heartbeat.

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.

Use caution when driving, operating machinery, or performing other hazardous activities. L-hyoscyamine may cause dizziness, drowsiness, or blurred vision. If you experience dizziness, drowsiness or blurred vision, avoid these activities.

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking L-hyoscyamine.

Avoid becoming overheated in hot weather. L-hyoscyamine increases the risk of heat stroke because it causes decreased sweating.

Do not take L-hyoscyamine if you have

• kidney disease;

• a blockage of your urinary tract (difficulty urinating);

• a blockage in your intestines, severe ulcerative colitis, or ulcerative colitis complicated by toxic megacolon;

• glaucoma; or

• myasthenia gravis.

Before taking this medication, tell your doctor if you have

• numbness or tingling in your hands or feet;

• liver disease;

• ulcerative colitis;

• thyroid problems;

• high blood pressure, an irregular heartbeat, or any type of heart disease;

• hiatal hernia or reflux disease;

• enlargement of the prostate; or

• asthma, chronic lung disease, or allergies.

You may not be able to take L-hyoscyamine, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.

It is not known whether L-hyoscyamine will harm an unborn baby. Do not take L-hyoscyamine without first talking to your doctor if you are pregnant.

It is not known whether L-hyoscyamine passes into breast milk. Do not take L-hyoscyamine without first talking to your doctor if you are breast-feeding a baby.

Your pharmacist has more information about L-hyoscyamine written for health professionals that you may read.

L-hyoscyamine is available with a prescription under several brand names in tablets, timed-release capsules, drops, and elixir formulations. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you.