Usage
Fenpiverinium bromide is an anticholinergic agent primarily used to treat smooth muscle spasms. It’s classified as an antispasmodic and antimuscarinic. While it’s often prescribed in combination with analgesics and other antispasmodics, standalone usage information is limited. Its mechanism of action involves blocking the action of acetylcholine, a neurotransmitter, at muscarinic receptors in smooth muscle, thus inhibiting contractions and reducing spasms.
Alternate Names
No widely recognized alternate names exist for Fenpiverinium. It is sometimes referred to by its bromide salt form (Fenpiverinium bromide). Brand names vary depending on the region and specific combination product; some examples include: Spasmobloc, Regalgan, Spasmalgon, and Spastal. These brands typically include Fenpiverinium in combination with other active ingredients like metamizole sodium and pitofenone hydrochloride.
How It Works
Pharmacodynamics: Fenpiverinium acts as a competitive antagonist at muscarinic cholinergic receptors, primarily M3, located on smooth muscle cells. By blocking acetylcholine’s effects at these receptors, Fenpiverinium reduces smooth muscle tone, motility, and secretions. The overall effect is a reduction in spasms and pain associated with smooth muscle contractions in the gastrointestinal, urinary, and biliary tracts.
Pharmacokinetics: Specific pharmacokinetic data for Fenpiverinium (absorption, distribution, metabolism, and excretion) are not readily available in detailed form. The drug’s absorption, metabolism, half-life, clearance, and route of elimination require further scientific investigation.
Mode of Action: At the molecular level, Fenpiverinium competitively binds to muscarinic receptors, preventing acetylcholine from binding and activating downstream signaling pathways that typically lead to muscle contraction. This competitive inhibition effectively reduces the contractile response of the smooth muscle.
Elimination pathways: Information regarding specific elimination pathways, including renal/hepatic excretion and metabolism by CYP enzymes, requires further research to provide a definitive explanation.
Dosage
Comprehensive, detailed dosage guidelines for Fenpiverinium as a standalone drug are limited. Most available information pertains to combination products containing Fenpiverinium along with other medications like metamizole and pitofenone. The dosages below come from such combination products, specifically Spasmobloc and Regalgan:
Standard Dosage
Adults:
- Spasmobloc: 1-2 tablets, 2-3 times daily. Maximum daily dose: 6 tablets. Each tablet typically contains 0.1 mg of fenpiverinium bromide, along with 500 mg metamizole sodium and 5 mg pitofenone hydrochloride.
- Regalgan: One to two tablets every 4-6 hours as needed, to a maximum of 8 tablets daily. Each Regalgan tablet contains 0.1mg of fenpiverinium bromide, 5mg of pitofenone hydrochloride, and 500mg of acetaminophen.
Children:
- Spasmobloc:
- 12-15 years: 1 tablet, 2-3 times daily. Maximum daily dose: 3 tablets.
- 9-12 years: ½ tablet, 2-3 times daily. Maximum daily dose: 2 tablets.
- Regalgan:
- 10-15 years: One tablet every 4-6 hours as needed, up to 4 doses in 24 hours.
- Under 10 years: Not recommended.
- General: Use in children and adolescents under 18 is generally not recommended without careful consideration and monitoring by a healthcare professional due to potential risks associated with metamizole, a frequent component of Fenpiverinium combination products.
Special Cases:
Specific dosage adjustments for elderly patients, those with renal or hepatic impairment, or with comorbid conditions are not well-defined for Fenpiverinium alone. Consult product-specific guidelines when Fenpiverinium is part of a combination therapy. However, metamizole, which is usually present in combination with Fenpiverinium, should be used with caution in patients with impaired renal or hepatic function and elderly patients.
Clinical Use Cases
Dosage recommendations for specific clinical use cases, such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations, are not specifically established for Fenpiverinium. Dosage would be dependent on the specific clinical situation and in conjunction with other indicated therapies.
Dosage Adjustments
Information about dose modifications based on renal/hepatic dysfunction, metabolic disorders, or genetic polymorphisms are not available for Fenpiverinium as a standalone medication.
Side Effects
Common Side Effects
When used as part of combination products, common side effects believed to be possibly attributed to Fenpiverinium include dry mouth, nausea, vomiting, constipation, and dizziness. These are often mild and transient.
Rare but Serious Side Effects
Serious side effects associated with Fenpiverinium are rare but may include allergic reactions (skin rash, itching, swelling), difficulty urinating, and rapid heart rate.
Long-Term Effects
Data on the long-term effects of Fenpiverinium are limited.
Adverse Drug Reactions (ADR)
Clinically significant ADRs specifically related to Fenpiverinium are not readily available.
Contraindications
Fenpiverinium is contraindicated in individuals with hypersensitivity to the drug, narrow-angle glaucoma, urinary retention, severe gastrointestinal motility disorders (e.g., paralytic ileus, megacolon), myasthenia gravis, and in patients with tachyarrhythmias.
Drug Interactions
Fenpiverinium may interact with other anticholinergic medications, enhancing their effects and potentially leading to increased side effects. Other possible interactions may include:
- Other anticholinergic medications: Concomitant use of these medications can enhance antimuscarinic effects, potentially leading to adverse reactions like urinary retention, constipation, and blurred vision.
- Drugs metabolized by CYP enzymes: Since Fenpiverinium’s metabolism is not yet fully elucidated, interactions with drugs metabolized by CYP enzymes are unknown.
- Other medications commonly taken with fenpiverinium: DrugBank lists numerous interactions including increased risks of adverse events with aclidinium, alfentanil, amantadine, amoxapine, clomipramine, chlorpromazine, chlorprothixene, doxepin, doxylamine, glycopyrrollium and many others. Reduced efficacy has been observed when used in combination with alloin, aprotinin, benzgalantamine, betaine, cinchocaine, cisplatin, decamethonium, dehydrocholic acid, demecarium, diethylcarbamazine, docusate, domperidone, donepezil, edrophonium, glycerin, mechlorethamine, and mefloquine. Increased tachycardia is possible when Fenpiverinium is combined with adenosine, albuterol, amphetamine, anagrelide, arbutamine, benzphetamine, cilostazol, clenbuterol, clonidine, cocaine, dobutamine, dopamine, dopexamine, droxidopa, duloxetine, ephedrine, epinephrine, fenoterol, formoterol, guanabenz and many other medications. Reduced gastrointestinal motility has been observed when Fenpiverinium is used with clozapine. These interactions highlight the importance of consulting a healthcare professional or comprehensive drug interaction resources when prescribing or dispensing Fenpiverinium-containing medications.
Pregnancy and Breastfeeding
The safety of Fenpiverinium during pregnancy and breastfeeding has not been adequately established. Use only if the potential benefits outweigh the risks and under close medical supervision. Some sources suggest avoiding use during pregnancy, especially the first trimester. The amount of Fenpiverinium that passes into breast milk is unknown.
Drug Profile Summary
- Mechanism of Action: Anticholinergic/antimuscarinic, blocks acetylcholine’s action at muscarinic receptors on smooth muscle.
- Side Effects: Dry mouth, nausea, vomiting, constipation, dizziness, urinary retention (potential).
- Contraindications: Glaucoma, urinary retention, gastrointestinal obstruction, myasthenia gravis, tachyarrhythmias.
- Drug Interactions: Other anticholinergics, multiple other medications.
- Pregnancy & Breastfeeding: Limited safety data, use with caution.
- Dosage: Refer to combination product information for specific dosing.
- Monitoring Parameters: Monitor for anticholinergic side effects and therapeutic response.
Popular Combinations
Fenpiverinium is most commonly used in combination with metamizole sodium (analgesic) and pitofenone hydrochloride (antispasmodic). This combination is intended to provide synergistic relief from pain associated with smooth muscle spasms.
Precautions
- Caution should be exercised in patients with pre-existing cardiovascular, hepatic, or renal conditions.
- Elderly patients may be more susceptible to anticholinergic side effects.
- Avoid operating machinery or driving until the effects of the medication are known.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Fenpiverinium?
A: Dosage guidelines for Fenpiverinium as a standalone drug are limited. Most available information refers to its use in combination products with metamizole and pitofenone. Refer to the “Dosage” section for information on combination product dosing.
Q2: What are the primary uses of Fenpiverinium?
A: Fenpiverinium is primarily used to relieve smooth muscle spasms in the gastrointestinal, urinary, and biliary tracts.
Q3: How does Fenpiverinium work?
A: It acts as an anticholinergic, blocking the action of acetylcholine at muscarinic receptors on smooth muscle cells, reducing spasms.
Q4: What are the potential side effects of Fenpiverinium?
A: Common side effects include dry mouth, constipation, nausea, and dizziness. Less common but potentially serious side effects include urinary retention and allergic reactions.
Q5: Who should not take Fenpiverinium?
A: Individuals with conditions such as glaucoma, urinary retention, bowel obstruction, myasthenia gravis, and certain heart conditions should not take Fenpiverinium.
Q6: Can Fenpiverinium be taken during pregnancy or breastfeeding?
A: The safety of Fenpiverinium during pregnancy and breastfeeding has not been well established. It should be used with caution and only if the potential benefits outweigh the risks.
Q7: Does Fenpiverinium interact with other medications?
A: Yes, Fenpiverinium can interact with other medications, especially other anticholinergics. It’s crucial to inform your doctor about all other medications you are taking.
Q8: What should I do if I miss a dose of Fenpiverinium?
A: If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Q9: What are the symptoms of Fenpiverinium overdose?
A: Symptoms of an overdose might include severe anticholinergic effects like confusion, hallucinations, rapid heart rate, difficulty breathing, and seizures. Seek immediate medical attention if an overdose is suspected.
Q10: How should Fenpiverinium be stored?
A: Store Fenpiverinium as directed on the product packaging. Generally, medications should be stored in a cool, dry place away from direct sunlight and out of reach of children.
