What is Hyoscyamine: Uses, Warnings & Interactions

Updated May 16, 2025  •  Published Dec 30, 2020

Hyoscyamine is a generic prescription drug that treats a variety of medical problems, including digestive system illnesses, overactive bladder, Parkinson’s disease, and other issues. Hyoscyamine reduces muscle spasticity and contractions. As a widely used drug, hyoscyamine is available in a large variety of oral formats.

Hyoscyamine overview

BRAND NAMES:

  • Anaspaz, Hyosyne, Levbid, Levsin, Levsin SL, NuLev, Oscimin

Generic Names:

  • Hyoscyamine sulfate

Uses:

  • Reduces muscle activity, including muscle spasms in the digestive system and urinary tract. Dries and reduces secretions, such as reducing acid in the stomach, runny nose due to allergies, and sweating and salivation in Parkinson’s.

Therapeutic Classes:

  • Gastrointestinal antispasmodic, antisecretory agent, anticholinergic

Forms:

  • Tablet, chewable tablet, orally disintegrating tablet, sublingual tablet, extended-release tablet, oral solution (liquid), elixir (liquid), injectable

How it’s taken:

  • By mouth or injection

What is Hyoscyamine used for?

Hyoscyamine treats a wide range of medical conditions, including stomach ulcers, overactive bladder, gastrointestinal spasms, diverticulitis, intestinal swelling, diarrhea, irritable bowel syndrome, infant belly pain, runny nose, and Parkinson’s disease. Doctors may also use hyoscyamine injections before surgery, endoscopy, or radiological procedures.

What form(s) does Hyoscyamine come in

  • Tablet, chewable tablet, orally disintegrating tablet, sublingual tablet

    • 0.125 mg

  • Extended-release tablet

    • 0.375 mg

  • Oral solution

    • 0.125 mg/mL

  • Elixir

    • 0.125 mg/5 mL

  • Injection

    • 0.5 mg/mL

What are common Hyoscyamine doses?

  • For adults and children 12 years of age and older: 0.125–0.250 (one to two tablets) of immediate-release hyoscyamine taken every four hours OR 0.375–0.75 (one to two tablets) mg extended-release tablets taken every 12 hours

  • For children 2–11 years of age: 0.0625–0.125 (one-half tablet to one tablet) of immediate-release hyoscyamine taken every four hours

Common Hyoscyamine prescriptions

  • Hyoscyamine Sulfate
    15ml of 0.125mg/ml bottle

  • Hyoscyamine Sulfate
    473ml of 0.125mg/5ml bottle

  • Hyoscyamine Sulfate
    15ml of 0.125mg/ml ml of oral solution

  • Hyoscyamine Sulfate
    0.125mg tablet

  • Hyoscyamine Sulfate
    0.125mg tablet disintegrating

  • Hyoscyamine Sulfate
    0.125mg tablet sublingual

  • Hyoscyamine Sulfate
    1ml of 0.5mg/ml vial

How to take Hyoscyamine

  • Take this medicine as directed.

  • Take doses on an empty stomach 60 minutes before eating.

  • Swallow immediate-release hyoscyamine tablets whole with a drink of water.

  • Swallow extended-release hyoscyamine tablets whole with a drink of water. Do not chew or break the tablet.

  • Chewable tablets can be chewed or allowed to dissolve on the tongue.

    • Chewable tablets can be taken with or without water.

  • Orally disintegrating tablets can be swallowed or allowed to dissolve on the tongue.

    • Some orally disintegrating tablets can be taken sublingually. Ask the prescriber or pharmacist.

    • Orally disintegrating tablets can be taken with a drink of water.

  • Sublingual tablets should be placed under the tongue and kept there until completely dissolved.

    • Some sublingual tablets can be swallowed or dissolved on the tongue. Ask the pharmacist or prescriber.

    • Sublingual tablets can be taken with water.

  • Measure the oral solution or elixir with a marked measuring spoon, oral syringe, or medicine cup. If the medicine comes with a dropper, use the dropper to measure each dose.

  • Store hyoscyamine in a light-resistant closed container at room temperature.

What to do if you miss a dose of Hyoscyamine

  • Take a dose as soon as you remember. 

  • If it is almost time for your next dose, wait until then and take a regular dose. 

  • Do not take extra medicine to make up for a missed dose.

Hyoscyamine contraindications

  • This medicine is not right for everyone. 

  • Do not use it if you have:

    • Glaucoma

    • Urinary obstruction

    • Gastrointestinal obstruction

    • Intestinal paralysis

    • Myasthenia gravis

    • Known allergies to hyoscyamine

  • Some emergency and life-threatening medical conditions are also contraindicated:

    • Extreme colon swelling (toxic megacolon)

    • Uncontrolled bleeding with unstable cardiovascular status (low blood pressure, insufficient circulation, and rapid heart rate)

Hyoscyamine warnings

  • Tell any doctor or other healthcare provider who treats you that you are using this medicine.

  • The doctor may require follow-up visits to monitor your condition. Keep all appointments.

  • Tell the prescriber if you are pregnant, breastfeeding, or have:

    • Glaucoma

    • Trouble urinating

    • Digestive system problems

    • Heart disease

    • Heart failure

    • Heart rhythm abnormalities

    • High blood pressure

    • Kidney disease

    • Hiatal hernia associated with gastric reflux

  • Hyoscyamine can cause serious problems, including slowed gastrointestinal passage or psychosis.

  • This medicine may cause you to sweat less and overheat. Avoid hot temperatures.

  • This medicine may cause dizziness, drowsiness, or blurred vision. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

  • This medicine may reduce salivation, increasing the risk of dental cavities, gum disease, and yeast infections in the mouth.

Hyoscyamine interactions

  • Some drugs or supplements can affect how hyoscyamine works. Tell the prescriber about all prescription drugs, over-the-counter medications, and supplements being taken, particularly:

    • Other anticholinergic drugs

    • Drugs that treat muscle weakness

    • Narcotic pain medicine

    • Diarrhea treatments

    • MAO inhibitors (MAOIs)

    • Tricyclic antidepressants

    • Antihistamines

    • Phenothiazine drugs

    • Amantadine, cyclopropane, ketoconazole, metoclopramide, potassium chloride, quinidine

  • If you take an antacid, do not take it at the same time you take hyoscyamine. Take each hyoscyamine dose at least 60 minutes before a meal and at least two hours before taking an antacid.

Hyoscyamine side effects

Serious side effects

Talk to a doctor if you notice any signs or symptoms of a possible serious side effect, including:

  • Blurred vision that does not improve

  • Fast heartbeat, dizziness

  • Hallucinations, confusion, disorientation, memory loss, decreased anxiety, insomnia, unusual mannerisms

  • Allergic reaction: Itching, hives, rash, facial, mouth, or throat swelling

Less serious side effects

  • Dry mouth

  • Dilated pupils, blurred vision

  • Drowsiness

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