Hyoscyamine 0.375mg ER Tablets
It is used to slow the speed in the stomach and GI (gastrointestinal) tract.It is used to treat diarrhea.It is used to treat GI (gastrointestinal) ulcers.It is used to treat irritable bowel syndrome.It is used to treat muscle spasms of the GI (gastrointestinal) tract, gallbladder system, or urinary system.It is used to treat a runny nose.It is used to treat Parkinson's disease.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antispasmodic, Anticholinergic
Pharmacologic Class
Muscarinic acetylcholine receptor antagonist
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Hyoscyamine is a medication that helps relax the muscles in your stomach, intestines, and bladder. It can reduce cramps, spasms, and excessive secretions. It's often used for conditions like irritable bowel syndrome or to help with bladder control.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. Take your medication 30 to 60 minutes before meals. It's essential to avoid taking antacids at the same time as your medication. If you have questions about taking antacids with your medication, consult your doctor. Swallow your medication whole, without chewing, breaking, or crushing it.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you're unsure about the best way to dispose of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
What to Do If You Miss a Dose
If you take your medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and return to your regular schedule. Do not take two doses at the same time or take extra doses. If you use your medication as needed, do not take it more frequently than directed by your doctor.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. Take your medication 30 to 60 minutes before meals. It's essential to avoid taking antacids at the same time as your medication. If you have questions about taking antacids with your medication, consult your doctor. Swallow your medication whole, without chewing, breaking, or crushing it.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you're unsure about the best way to dispose of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
What to Do If You Miss a Dose
If you take your medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and return to your regular schedule. Do not take two doses at the same time or take extra doses. If you use your medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Avoid activities requiring mental alertness, such as driving or operating machinery, until you know how this medication affects you, as it can cause dizziness or blurred vision.
- Stay hydrated to help with dry mouth, a common side effect.
- Increase fiber intake and fluid intake to help prevent constipation.
- Avoid alcohol, as it can increase drowsiness and other side effects.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
0.375 mg orally every 12 hours
Dose Range:
0.375 - 0.75 mg
Condition-Specific Dosing:
irritableBowelSyndrome:
0.375 mg orally every 12 hours
pepticUlcerDiseaseAdjunct:
0.375 mg orally every 12 hours
neurogenicBladder:
0.375 mg orally every 12 hours
preoperativeReductionOfSecretions:
0.375 mg orally every 12 hours
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established (ER formulation generally not recommended for children under 12 years)
Adolescent:
Generally, for adolescents 12 years and older, dosing may be similar to adult dosing, but specific ER pediatric data is limited. Consult product-specific labeling.
Dose Adjustments
Renal Impairment:
Mild:
No specific dose adjustment recommended, but use with caution due to renal excretion.
Moderate:
Use with caution; monitor for increased anticholinergic effects. Consider lower starting dose or extended dosing interval.
Severe:
Use with extreme caution; significant accumulation may occur. Contraindicated in obstructive uropathy. Consider avoiding use.
Dialysis:
Not well studied; likely not dialyzable. Avoid use if possible due to potential for accumulation and increased anticholinergic effects.
Hepatic Impairment:
Mild:
No specific dose adjustment recommended.
Moderate:
Use with caution; monitor for increased anticholinergic effects.
Severe:
Use with caution; monitor for increased anticholinergic effects. Consider lower starting dose.
Pharmacology
Mechanism of Action
Hyoscyamine is a belladonna alkaloid that acts as a competitive antagonist of acetylcholine at peripheral muscarinic receptors. It inhibits the action of acetylcholine on smooth muscles, secretory glands, and the central nervous system. This leads to decreased gastrointestinal motility and spasm, reduced gastric acid secretion, decreased salivary and bronchial secretions, and mydriasis.
Pharmacokinetics
Absorption:
Bioavailability:
Not precisely quantified for ER, but well absorbed from the GI tract.
Tmax:
Approximately 4-6 hours for extended-release formulations.
FoodEffect:
Food may delay absorption but does not significantly affect the extent of absorption.
Distribution:
Vd:
Not precisely quantified, but widely distributed throughout the body.
ProteinBinding:
Not precisely quantified, but generally low.
CnssPenetration:
Limited at therapeutic doses, but can cross the blood-brain barrier, especially at higher doses, leading to CNS effects.
Elimination:
HalfLife:
Approximately 3.5 to 13 hours (variable for ER formulations, depending on release profile).
Clearance:
Not precisely quantified.
ExcretionRoute:
Primarily renal (urine).
Unchanged:
Approximately 13% to 50% excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Within 20-30 minutes (for immediate release; ER onset is slower).
PeakEffect:
Approximately 4-6 hours (for ER formulation).
DurationOfAction:
Up to 12 hours (for ER formulation).
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Diarrhea
Confusion
Mood changes
Changes in behavior
Hallucinations (seeing or hearing things that are not there)
Memory problems or loss
Trouble sleeping
Changes in speech
Changes in balance
Changes in eyesight, eye pain, or severe eye irritation
Difficulty urinating
Lack of sweating during physical activity or in warm temperatures
Fever
Flushing
Fast or abnormal heartbeat
Erectile dysfunction
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Dizziness, drowsiness, fatigue, or weakness
Blurred vision
Constipation
Dry mouth
Dry eyes
Headache
Nausea or vomiting
Stomach pain
Changes in taste
Feeling anxious or restless
* Feeling full
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Diarrhea
Confusion
Mood changes
Changes in behavior
Hallucinations (seeing or hearing things that are not there)
Memory problems or loss
Trouble sleeping
Changes in speech
Changes in balance
Changes in eyesight, eye pain, or severe eye irritation
Difficulty urinating
Lack of sweating during physical activity or in warm temperatures
Fever
Flushing
Fast or abnormal heartbeat
Erectile dysfunction
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. If you notice any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Dizziness, drowsiness, fatigue, or weakness
Blurred vision
Constipation
Dry mouth
Dry eyes
Headache
Nausea or vomiting
Stomach pain
Changes in taste
Feeling anxious or restless
* Feeling full
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dry mouth that interferes with speaking or swallowing
- Significant blurred vision or eye pain
- Difficulty urinating or inability to urinate
- Severe constipation
- Fast or irregular heartbeat
- Confusion, disorientation, or hallucinations (especially in older adults)
- Rash or allergic reaction
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including:
+ Bowel obstruction
+ Bleeding disorders
+ Diarrhea
+ Enlarged colon
+ Glaucoma
+ Heart problems
+ Myasthenia gravis
+ Slow-moving gastrointestinal (GI) tract
+ Abnormalities of the esophagus
+ Ulcerative colitis
+ Urinary retention or difficulty passing urine
Please note that this list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor.
To ensure safe treatment, inform your doctor and pharmacist about:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* All your health problems
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm it is safe to do so.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including:
+ Bowel obstruction
+ Bleeding disorders
+ Diarrhea
+ Enlarged colon
+ Glaucoma
+ Heart problems
+ Myasthenia gravis
+ Slow-moving gastrointestinal (GI) tract
+ Abnormalities of the esophagus
+ Ulcerative colitis
+ Urinary retention or difficulty passing urine
Please note that this list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor.
To ensure safe treatment, inform your doctor and pharmacist about:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* All your health problems
Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm it is safe to do so.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Before operating a vehicle or engaging in any activity that requires alertness and clear vision, wait until you understand how this medication affects you.
Consult your doctor before consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions.
There is a risk of heat stroke associated with this medication, especially in hot weather or during physical activity. Therefore, it is crucial to exercise caution in these situations.
To manage dry mouth, practice good oral hygiene, and consider sucking on hard, sugar-free candy or chewing sugar-free gum. Regular dental check-ups are also recommended.
If you notice what appears to be a tablet in your stool, do not be alarmed, as this is a normal occurrence. However, if you have concerns, discuss them with your doctor.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects. Additionally, be aware that different brands of this medication may be suitable for children of various ages, so consult your doctor before administering it to a child.
When giving this medication to a child, exercise caution, as the risk of certain side effects may be higher in pediatric patients.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor, as it is necessary to discuss the potential benefits and risks to both you and your baby.
Before operating a vehicle or engaging in any activity that requires alertness and clear vision, wait until you understand how this medication affects you.
Consult your doctor before consuming alcohol, using marijuana or other cannabis products, or taking prescription or over-the-counter medications that may impair your reactions.
There is a risk of heat stroke associated with this medication, especially in hot weather or during physical activity. Therefore, it is crucial to exercise caution in these situations.
To manage dry mouth, practice good oral hygiene, and consider sucking on hard, sugar-free candy or chewing sugar-free gum. Regular dental check-ups are also recommended.
If you notice what appears to be a tablet in your stool, do not be alarmed, as this is a normal occurrence. However, if you have concerns, discuss them with your doctor.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects. Additionally, be aware that different brands of this medication may be suitable for children of various ages, so consult your doctor before administering it to a child.
When giving this medication to a child, exercise caution, as the risk of certain side effects may be higher in pediatric patients.
If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor, as it is necessary to discuss the potential benefits and risks to both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe dry mouth
- Dilated pupils (mydriasis)
- Blurred vision
- Flushing of the skin
- Hot, dry skin
- Fever
- Tachycardia (rapid heart rate)
- Hypertension (high blood pressure)
- Urinary retention
- Paralytic ileus
- CNS effects: restlessness, tremor, ataxia, confusion, disorientation, hallucinations, delirium, convulsions, coma
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive and may include physostigmine (an acetylcholinesterase inhibitor) for severe anticholinergic toxicity.
Drug Interactions
Contraindicated Interactions
- Potassium chloride (solid oral dosage forms) - increased risk of GI lesions due to delayed transit time.
Major Interactions
- Other anticholinergics (e.g., tricyclic antidepressants, phenothiazines, antihistamines, quinidine, disopyramide) - additive anticholinergic effects.
- Opioid analgesics - increased risk of severe constipation and/or paralytic ileus.
- Antacids - may interfere with absorption of hyoscyamine (administer hyoscyamine before meals and antacids after meals).
Moderate Interactions
- Drugs that slow GI motility (e.g., loperamide) - increased risk of constipation.
- Drugs whose absorption is pH-dependent (e.g., ketoconazole, digoxin) - hyoscyamine may affect gastric pH and alter absorption.
- Metoclopramide - antagonistic effects on GI motility.
Monitoring
Baseline Monitoring
Baseline symptoms (e.g., abdominal pain, spasm, urinary urgency)
Rationale: To assess efficacy of treatment.
Timing: Prior to initiation of therapy
Ophthalmic examination (for narrow-angle glaucoma)
Rationale: Hyoscyamine is contraindicated in narrow-angle glaucoma.
Timing: Prior to initiation of therapy, if risk factors present
Urinary flow assessment (for prostatic hypertrophy or obstructive uropathy)
Rationale: Hyoscyamine can cause urinary retention and is contraindicated in obstructive uropathy.
Timing: Prior to initiation of therapy, if risk factors present
Routine Monitoring
Symptom relief (e.g., reduction in spasms, pain)
Frequency: Regularly during therapy
Target: Patient-reported improvement
Action Threshold: Lack of improvement or worsening symptoms may require dose adjustment or alternative therapy.
Anticholinergic side effects (e.g., dry mouth, blurred vision, urinary hesitancy/retention, constipation, tachycardia, CNS effects)
Frequency: Regularly during therapy, especially during dose titration
Target: Minimal to tolerable side effects
Action Threshold: Severe or intolerable side effects may require dose reduction or discontinuation.
Bowel movements
Frequency: Regularly
Target: Regular, non-constipated bowel habits
Action Threshold: Significant constipation may require intervention or dose adjustment.
Symptom Monitoring
- Dry mouth
- Blurred vision
- Difficulty urinating or urinary retention
- Constipation
- Dizziness
- Drowsiness
- Headache
- Nervousness
- Tachycardia or palpitations
- Confusion or disorientation (especially in elderly)
Special Patient Groups
Pregnancy
Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans.
Trimester-Specific Risks:
First Trimester:
Potential for developmental effects, though human data is limited.
Second Trimester:
Potential for fetal effects, though human data is limited.
Third Trimester:
May inhibit uterine contractions and cause fetal tachycardia. Use with caution near term.
Lactation
Hyoscyamine is excreted into breast milk. Due to the potential for serious adverse reactions in nursing infants (e.g., anticholinergic effects, decreased milk production), a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Infant Risk:
Risk L3 (Moderate Concern) - Potential for anticholinergic effects (e.g., sedation, constipation, dry mouth) in the infant. May also decrease milk supply.
Pediatric Use
Safety and effectiveness in pediatric patients under 12 years of age have not been established for extended-release formulations. Immediate-release formulations may be used in younger children with careful dose titration. Children are more susceptible to the toxic effects of anticholinergics.
Geriatric Use
Elderly patients are more susceptible to the anticholinergic side effects of hyoscyamine, particularly CNS effects (e.g., confusion, disorientation, memory impairment), urinary retention, and constipation. Use with caution and consider lower starting doses. Avoid in patients with dementia or cognitive impairment.
Clinical Information
Clinical Pearls
- Hyoscyamine ER is designed for twice-daily dosing; do not crush, chew, or break the tablets as this will destroy the extended-release properties and may lead to rapid absorption and increased side effects.
- Educate patients on common anticholinergic side effects (dry mouth, blurred vision, constipation, urinary hesitancy) and when to report them.
- Caution patients about potential for heat prostration in hot environments due to decreased sweating.
- Monitor elderly patients closely for CNS effects and urinary retention.
- Consider alternative therapies for patients with narrow-angle glaucoma, obstructive uropathy, or severe ulcerative colitis, as hyoscyamine is contraindicated in these conditions.
Alternative Therapies
- Dicyclomine (another anticholinergic antispasmodic)
- Peppermint oil (for IBS symptoms)
- Fiber supplements (for IBS-C)
- Loperamide (for IBS-D)
- Tricyclic antidepressants (low dose for IBS pain)
- SSRIs (for IBS with anxiety/depression)
- Alpha-blockers (for benign prostatic hyperplasia symptoms, if urinary retention is a concern)
Cost & Coverage
Average Cost:
$30 - $150 per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (for generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.