Buscopan: Uses, Dosage & Side Effects
A prescription antispasmodic injection used to relieve smooth muscle spasms in the gastrointestinal, biliary, and urogenital tracts
Buscopan (hyoscine butylbromide) is an antispasmodic medication that relieves cramps and spasms in the smooth muscle of internal organs. Available as a prescription-only injection (20 mg/ml), it is widely used in hospital and clinical settings to treat acute abdominal, biliary, and urogenital cramps, as well as to reduce bowel motility before radiological or endoscopic diagnostic procedures. Because it acts peripherally and does not cross the blood-brain barrier, Buscopan provides targeted relief without central nervous system side effects.
Quick Facts: Buscopan
Key Takeaways
- Buscopan injection is a fast-acting antispasmodic that relieves smooth muscle cramps in the gastrointestinal tract, biliary system, urinary tract, and reproductive organs within 1–10 minutes depending on the route of administration.
- It works by blocking muscarinic receptors on smooth muscle cells and does not cross the blood-brain barrier, meaning it has no central nervous system effects such as sedation or confusion.
- The injection is commonly used in clinical settings for acute colic, diagnostic imaging preparation, and endoscopic procedures where bowel relaxation is needed.
- Buscopan must not be used in patients with narrow-angle glaucoma, megacolon, mechanical gastrointestinal obstruction, myasthenia gravis, or prostatic enlargement with urinary retention.
- The most common side effects are increased heart rate, accommodation disturbances, dizziness, and dry mouth, which are typically mild and transient.
What Is Buscopan and What Is It Used For?
Buscopan is the brand name for hyoscine butylbromide (also known as scopolamine butylbromide or butylscopolamine), a quaternary ammonium anticholinergic compound. Unlike its closely related compound hyoscine hydrobromide (scopolamine), which readily crosses the blood-brain barrier and causes central effects such as sedation and motion sickness relief, hyoscine butylbromide carries a permanent positive charge on its nitrogen atom. This critical structural difference prevents it from crossing the blood-brain barrier, confining its pharmacological effects to the peripheral nervous system and smooth muscle tissue.
The medication works by competitively blocking muscarinic acetylcholine receptors (primarily M2 and M3 subtypes) on the smooth muscle cells that line the walls of the gastrointestinal tract, biliary ducts, pancreatic duct, urinary tract, and the uterus and fallopian tubes. By inhibiting the action of acetylcholine at these receptors, Buscopan prevents the calcium influx that triggers smooth muscle contraction, thereby producing a powerful antispasmodic effect. The result is relaxation of involuntary muscle spasms that cause cramping pain in these organ systems.
In clinical practice, Buscopan injection is used in several important settings. It is frequently administered for the treatment of acute spasmodic pain (colic) arising from the gastrointestinal tract, such as intestinal cramps, gastric spasms, and irritable bowel-related acute episodes. Biliary colic, caused by gallstones obstructing the biliary ducts, and renal colic, caused by kidney stones passing through the ureter, are both conditions where Buscopan provides effective symptomatic relief by relaxing the smooth muscle surrounding the obstruction.
One of the most common clinical applications of Buscopan injection is as a pre-medication before diagnostic procedures. In radiology, it is routinely administered before barium enema examinations, CT colonography (virtual colonoscopy), and MRI of the abdomen to reduce bowel peristalsis and improve image quality. During endoscopic procedures such as colonoscopy, esophagogastroduodenoscopy (EGD), and endoscopic retrograde cholangiopancreatography (ERCP), Buscopan is used to reduce bowel motility and facilitate examination of the mucosal surface.
The injection formulation provides rapid onset of action: when administered intravenously, the antispasmodic effect begins within 1–2 minutes; when given intramuscularly or subcutaneously, onset occurs within approximately 5–10 minutes. The duration of the antispasmodic effect is relatively short, typically lasting 15–30 minutes, which makes it particularly well-suited for procedural use where only a brief period of smooth muscle relaxation is required. For sustained relief in non-procedural settings, repeated doses may be necessary.
It is important to distinguish between the various formulations of Buscopan available in different countries. The injection formulation (20 mg/ml solution in 1 ml ampoules) discussed in this article is a prescription-only medicine administered by healthcare professionals. In some countries, oral tablet formulations of hyoscine butylbromide are available and may be obtained over the counter for the self-treatment of recurrent abdominal cramps. The pharmacokinetic properties differ substantially between formulations: the oral bioavailability of hyoscine butylbromide is very low (less than 1%), whereas parenteral administration provides complete systemic availability.
What Should You Know Before Taking Buscopan?
Contraindications
There are several specific medical conditions in which Buscopan must not be used. Understanding these absolute contraindications is essential for safe administration. Buscopan injection should not be used if you have any of the following conditions:
- Known allergy (hypersensitivity): Do not use Buscopan if you are allergic to hyoscine butylbromide or any of the other ingredients in the injection (sodium chloride and water for injections).
- Prostatic enlargement with urinary retention: Buscopan relaxes the detrusor muscle of the bladder, which can worsen urinary retention in men with benign prostatic hyperplasia (BPH) who already have difficulty emptying the bladder.
- Mechanical gastrointestinal obstruction (stenosis): In cases of mechanical bowel obstruction, the use of an antispasmodic agent can mask symptoms of obstruction, delay diagnosis, and potentially worsen the clinical situation.
- Megacolon: Toxic megacolon or other forms of colonic dilatation are worsened by anticholinergic agents that further reduce bowel motility. Administration in these conditions can be dangerous.
- Myasthenia gravis: This autoimmune neuromuscular condition involves impaired acetylcholine transmission at the neuromuscular junction. Anticholinergic agents like Buscopan can exacerbate muscle weakness in these patients.
- Untreated narrow-angle glaucoma: Anticholinergic medications can trigger an acute rise in intraocular pressure in patients with anatomically narrow drainage angles. This can precipitate an acute glaucoma attack, which is a medical emergency requiring immediate ophthalmological treatment.
Warnings and Precautions
Buscopan can contribute to raised intraocular pressure if you have an undiagnosed narrow-angle glaucoma. Contact an ophthalmologist immediately if you experience pain in one or both eyes, rapid vision deterioration, or eye redness after receiving a Buscopan injection.
Even when Buscopan is not absolutely contraindicated, there are several circumstances that require special caution and medical supervision during treatment. Your doctor will carefully assess the risks and benefits before administering the injection in these situations.
Cases of anaphylaxis, including anaphylactic shock, have been reported following Buscopan injection. Contact your doctor or nurse immediately if you develop sudden itching, swelling around the eyes, mouth, or lips, warmth in the face, or difficulty breathing or swallowing. These may be signs of a severe allergic reaction requiring immediate treatment.
If you have cardiovascular disease, treatment with Buscopan should be administered under medical supervision with appropriate monitoring. The anticholinergic effects of the drug can increase heart rate (tachycardia), which may be clinically significant in patients with coronary artery disease, heart failure, cardiac arrhythmias, or hypertension. Your heart rate and blood pressure should be monitored during and after injection.
Patients who are taking anticoagulant (blood-thinning) medications should not receive Buscopan by intramuscular injection due to the risk of intramuscular bleeding (hematoma formation). In these patients, the injection should be administered either subcutaneously (under the skin) or by slow intravenous injection to avoid this complication.
If severe, unexplained abdominal pain persists or worsens after receiving Buscopan, and particularly if accompanied by fever, nausea, vomiting, changes in bowel movements, abdominal tenderness, falling blood pressure, fainting, or blood in the stool, seek immediate medical attention. In such cases, the underlying cause of the symptoms must be investigated urgently, as Buscopan may mask signs of a serious surgical condition.
Pregnancy and Breastfeeding
The safety of Buscopan during pregnancy has not been sufficiently established through clinical studies in pregnant women. Animal reproductive toxicity studies have not shown direct or indirect harmful effects on embryonic or fetal development, fertility, or postnatal development. However, as a precautionary measure, Buscopan injection is not recommended during pregnancy unless the potential benefits clearly outweigh the potential risks. If you are pregnant, think you may be pregnant, or are planning to become pregnant, always consult your doctor before receiving this medication.
It is not known whether hyoscine butylbromide or its metabolites are excreted into human breast milk. Due to this lack of information, Buscopan injection is not recommended during breastfeeding as a precautionary measure. Your doctor will advise you on whether to discontinue breastfeeding or to avoid using Buscopan, taking into account the benefit of breastfeeding for the child and the benefit of therapy for you.
There is no clinical data on whether hyoscine butylbromide affects human fertility. Pre-clinical animal studies have not indicated any effects on fertility, but human data are lacking.
Driving and Operating Machinery
No formal studies have been conducted to evaluate the effect of Buscopan on the ability to drive or operate machinery. However, treatment with Buscopan can cause visual accommodation disturbances (difficulty focusing at different distances) and dizziness. If you experience blurred vision, difficulty focusing, or dizziness after receiving a Buscopan injection, you should not drive a vehicle or operate machinery until these effects have completely resolved. You are personally responsible for assessing your fitness to drive or perform tasks requiring alertness after receiving this medication.
Buscopan injection contains less than 1 mmol (23 mg) of sodium per dose, meaning it is essentially sodium-free. This is relevant for patients on sodium-restricted diets or those with conditions requiring strict sodium monitoring.
How Does Buscopan Interact with Other Drugs?
Hyoscine butylbromide can interact with several classes of medications, primarily through additive anticholinergic effects. Anticholinergic effects include dilated pupils, increased heart rate, reduced saliva production, dry mouth, constipation, and reduced intestinal motility. When multiple anticholinergic medications are used simultaneously, these effects can become clinically significant and potentially dangerous. Always inform your doctor or nurse about all medications, supplements, and herbal remedies you are currently taking.
Major Interactions
| Interacting Drug | Effect | Clinical Advice |
|---|---|---|
| Tricyclic & tetracyclic antidepressants | Additive anticholinergic effects including increased risk of urinary retention, constipation, dry mouth, tachycardia, and visual disturbances | Monitor closely for signs of anticholinergic toxicity. Dose adjustment may be necessary. Inform your doctor about all antidepressants you are taking. |
| Antihistamines (first-generation) | Enhanced anticholinergic side effects including sedation, dry mouth, urinary retention, and blurred vision | Use combination with caution. Second-generation antihistamines (e.g., cetirizine, loratadine) have fewer anticholinergic effects and may be preferred. |
| Antipsychotics (phenothiazines, butyrophenones) | Additive anticholinergic effects may increase the risk of paralytic ileus, urinary retention, hyperthermia, and cognitive impairment | Monitor for signs of anticholinergic syndrome. Use the lowest effective dose of both agents. |
| Disopyramide | Enhanced anticholinergic and cardiac effects, including increased risk of tachycardia and QT prolongation | Avoid concurrent use if possible. If necessary, cardiac monitoring is recommended. |
| Beta-agonists and other tachycardia-inducing drugs | Buscopan may further increase heart rate when combined with medications that already raise heart rate | Monitor heart rate closely. Use with caution in patients with cardiovascular disease. |
Minor Interactions
| Interacting Drug | Effect | Clinical Advice |
|---|---|---|
| Metoclopramide | Mutual reduction of gastrointestinal effects; metoclopramide promotes GI motility while Buscopan inhibits it, potentially canceling each other's GI actions | Avoid concurrent use when possible. If both are required, administer at different times and monitor therapeutic response. |
| Tiotropium, Ipratropium (inhaled anticholinergics) | Additive anticholinergic effects, particularly dry mouth, urinary retention, and constipation | Generally well tolerated in combination as inhaled agents have limited systemic absorption. Monitor for cumulative anticholinergic burden. |
| Atropine and other anticholinergic agents | Additive anticholinergic effects across multiple organ systems | Avoid combining multiple anticholinergic agents when possible. If necessary, use the lowest effective doses and monitor closely. |
| Dopamine antagonists (domperidone) | Buscopan may reduce the prokinetic effects of domperidone on gastric motility | Space administration if both are clinically required. Monitor GI symptom control. |
Elderly patients are particularly susceptible to the cumulative anticholinergic effects of multiple medications (anticholinergic burden). When Buscopan is administered to older patients who are already taking one or more medications with anticholinergic properties, there is an increased risk of confusion, urinary retention, constipation, falls, and cognitive impairment. Healthcare providers should carefully assess the total anticholinergic burden before administering Buscopan to elderly patients.
What Is the Correct Dosage of Buscopan?
Buscopan injection is always administered by a doctor, nurse, or other qualified healthcare professional. The dose is determined based on the clinical indication, the severity of the spasm, and the patient's overall medical condition. The fundamental principle is to use the lowest effective dose for the shortest duration necessary.
Adults
Standard Dosing
Single dose: 20 mg (1 ampoule) to 40 mg (2 ampoules)
Route of administration: Intramuscular (IM), subcutaneous (SC), or slow intravenous (IV) injection
Maximum daily dose: 100 mg (5 ampoules) in any 24-hour period
Important: Each ampoule contains 1 ml of solution at a concentration of 20 mg/ml. Intravenous injection should be administered slowly.
Procedural Use (Diagnostic Imaging & Endoscopy)
Pre-procedure dose: 20 mg (1 ampoule) administered intravenously immediately before the procedure
Onset of action: 1–2 minutes after IV injection; 5–10 minutes after IM/SC injection
Duration of action: Approximately 15–30 minutes
Repeat dosing: An additional dose may be given during the procedure if spasm recurs, up to the maximum daily dose
Special Populations
| Population | Dosage | Notes |
|---|---|---|
| Elderly | 20–40 mg per dose; start low | Increased sensitivity to anticholinergic effects. Monitor heart rate and for urinary retention. Consider cumulative anticholinergic burden. |
| Renal impairment | No specific dose adjustment in product literature | Use with caution. Monitor for increased or prolonged effects. Hyoscine butylbromide is partially excreted renally. |
| Hepatic impairment | No specific dose adjustment in product literature | Use with caution. Hyoscine butylbromide is primarily metabolized hepatically. Reduced clearance may occur. |
| Patients on anticoagulants | Same dose; change route | Do NOT give intramuscularly due to bleeding risk. Administer subcutaneously or by slow intravenous injection instead. |
Duration of Treatment
Buscopan injection should not be used daily over extended periods without a thorough medical investigation to determine the underlying cause of the abdominal pain or spasms. The injection is intended for acute symptom relief and procedural use, not for chronic daily administration. If symptoms persist or recur frequently, your doctor should investigate the underlying condition and consider alternative long-term treatment strategies.
Overdose
In the event of overdose, anticholinergic symptoms may occur, including urinary retention, dry mouth, facial flushing, dilated pupils, tachycardia, inhibition of gastrointestinal motility, and transient visual disturbances. Treatment is symptomatic: in cases of severe anticholinergic symptoms, parasympathomimetic agents (such as neostigmine) may be administered under medical supervision. Patients with glaucoma should receive pilocarpine eye drops. Cardiovascular complications should be managed according to standard protocols.
What Are the Side Effects of Buscopan?
Like all medications, Buscopan can cause side effects, although not everyone experiences them. Most of the side effects are a direct consequence of the anticholinergic (parasympatholytic) mechanism of action and tend to be mild, dose-dependent, and self-limiting. The following frequency categories are used: common (affects up to 1 in 10 people) and not known (frequency cannot be estimated from available data).
Common
May affect up to 1 in 10 people
- Increased heart rate (tachycardia)
- Accommodation disturbances (difficulty focusing at different distances)
- Dizziness
- Dry mouth (xerostomia)
Not Known
Frequency cannot be estimated from available data
- Anaphylactic shock and anaphylactoid reactions (severe allergic reactions)
- Dilated pupils (mydriasis)
- Raised intraocular pressure (increased eye pressure)
- Flushing (warmth and redness of the skin)
- Blood pressure decrease (hypotension)
- Dyspnea (shortness of breath)
- Skin reactions (rash, urticaria, erythema, pruritus)
- Hypohidrosis (reduced or absent sweating)
- Fluid retention (edema)
Contact your doctor or nurse immediately if you experience any signs of a severe allergic reaction (anaphylaxis) after receiving Buscopan injection, including: itching, redness and swelling of the skin and mucous membranes; difficulty breathing or swallowing, coughing; dizziness or fainting; nausea, vomiting, or diarrhea. Anaphylactic reactions require immediate emergency treatment as they can be life-threatening.
The common side effects listed above are direct consequences of the peripheral anticholinergic action of hyoscine butylbromide. Tachycardia occurs because blockade of vagal (parasympathetic) M2 receptors on the heart removes the inhibitory effect on heart rate. Accommodation disturbances result from relaxation of the ciliary muscle in the eye. Dry mouth is caused by reduced secretion from the salivary glands. These effects are generally mild, dose-dependent, and resolve spontaneously as the drug effect wears off.
The reported cases of anaphylaxis and severe allergic reactions, while rare, highlight the importance of administering Buscopan injection in a clinical setting where emergency resuscitation equipment is readily available. Healthcare providers should be prepared to manage anaphylaxis according to current guidelines, including the use of intramuscular epinephrine (adrenaline) as the first-line treatment.
If you notice any side effects not listed above, or if any of the listed side effects become severe or persistent, inform your doctor or nurse. Reporting suspected adverse reactions after marketing authorization is important for ongoing monitoring of the benefit-risk balance of the medicine.
How Should You Store Buscopan?
Buscopan injection does not require any special storage conditions. The ampoules should be stored in their original carton to protect from light. As with all medications, keep Buscopan out of the sight and reach of children. Do not use this medicine after the expiry date stated on the carton and ampoule label after “EXP.” The expiry date refers to the last day of the stated month.
Each ampoule is intended for single use only. Once opened, any unused solution should be discarded immediately. Do not use the solution if it appears discolored, cloudy, or contains visible particles. Compatibility studies with other injectable solutions have not been performed; therefore, do not mix Buscopan with other medications in the same syringe or infusion container.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures help to protect the environment and reduce the risk of accidental exposure to pharmaceutical substances.
What Does Buscopan Contain?
Buscopan injection is a clear, colorless solution for injection. Each ampoule contains exactly 1 ml of solution. The formulation is deliberately simple, consisting of only the active substance and two excipients necessary for pharmaceutical stability and isotonicity.
| Component | Role | Amount |
|---|---|---|
| Hyoscine butylbromide | Active ingredient (antispasmodic) | 20 mg |
| Sodium chloride | Excipient (isotonicity agent) | Quantity sufficient |
| Water for injections | Excipient (solvent) | To 1 ml |
The injection is supplied in type I glass ampoules. Each carton contains 5 ampoules. Glass ampoules provide excellent chemical inertness and protect the solution from degradation. The simple aqueous formulation means that Buscopan injection does not contain preservatives, antimicrobial agents, antioxidants, sugars, or any common allergens such as lactose, gluten, or tartrazine.
Hyoscine butylbromide (chemical name: (1α,2β,4β,5α,7β)-9-butyl-7-(2-hydroxy-1-oxo-2-phenylpropoxy)-9-methyl-3-oxa-9-azoniatricyclo[3.3.1.0²⁴]nonane bromide) has a molecular weight of 440.37 g/mol and a molecular formula of C₂₁H₃₀BrNO₄. It is a white or almost white, crystalline powder that is freely soluble in water.
Frequently Asked Questions About Buscopan
Buscopan injection is used to relieve smooth muscle spasms (cramps) in the gastrointestinal tract, biliary system, pancreatic duct, urinary tract, and reproductive organs. It is commonly administered in hospitals for acute abdominal cramps, biliary colic (gallstone pain), renal colic (kidney stone pain), and as a pre-medication before radiological or endoscopic diagnostic procedures to reduce bowel motility and improve image quality or ease of examination.
There is insufficient clinical evidence to confirm the safety of Buscopan injection during pregnancy. While animal studies have not shown harmful effects, the injection is not recommended during pregnancy as a precautionary measure. Always consult your doctor before receiving any medication if you are pregnant, think you may be pregnant, or are planning to become pregnant.
The most common side effects (affecting up to 1 in 10 patients) include increased heart rate (tachycardia), difficulty focusing the eyes at different distances (accommodation disturbances), dizziness, and dry mouth. These are related to the anticholinergic mechanism of the drug and are usually mild and self-limiting, resolving as the drug effect wears off (typically within 15–30 minutes).
When administered intravenously, Buscopan begins to work within 1–2 minutes. When given intramuscularly or subcutaneously, the onset of action is approximately 5–10 minutes. The antispasmodic effect typically lasts for 15–30 minutes, though this can vary between patients depending on the severity of the spasm and individual factors.
Yes, Buscopan can enhance the anticholinergic effects of other medications including tricyclic antidepressants, antihistamines, antipsychotics, disopyramide, and inhaled anticholinergics such as tiotropium and ipratropium. Using Buscopan with metoclopramide may reduce the gastrointestinal effects of both drugs. Medications that increase heart rate may have their cardiac effects further amplified when combined with Buscopan. Always inform your healthcare provider about all medications you are taking.
Buscopan injection (20 mg/ml solution) is a prescription-only formulation administered by healthcare professionals via intramuscular, subcutaneous, or intravenous routes. It has rapid onset (1–10 minutes) and is used for acute spasms and diagnostic procedures. Buscopan tablets (available in some countries as an over-the-counter product) are taken orally and have a much slower onset but are suitable for self-treatment of recurring abdominal cramps. The oral bioavailability of hyoscine butylbromide is less than 1%, so the tablet relies primarily on a local effect within the gastrointestinal lumen.
References
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