Spasmoplex

Uses

Spasmoplex is a muscarinic antagonist used for the treatment of overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and urinary frequency.

Spasmoplex is also used to associated treatment for these conditions: Urinary Bladder, Overactive

How Spasmoplex works

Spasmoplex antagonizes the effect of acetylcholine on muscarinic receptors in cholinergically innervated organs. Its parasympatholytic action reduces the tonus of smooth muscle in the bladder.

Dosage

Spasmoplex dosage

The recommended dose is 20 mg twice daily. Spasmoplex should be dosed at least one hour before meals or given on an empty stomach. Dosage modification is recommended in the following patient populations:

• For patients with severe renal impairment (creatinine clearance less than 30 mL/min), the recommended dose is 20 mg once daily at bedtime.
• In geriatric patients greater than or equal to 75 years of age, dose may be titrated down to 20 mg once daily based upon tolerability.
• Pediatric Use: The safety and effectiveness of Spasmoplex in pediatric patients have not been established.

Side Effects

The following adverse reactions have been identified during post-approval use of trospium chloride. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

• Gastrointestinal: gastritis
• Cardiovascular: palpitations, supraventricular tachycardia, chest pain, syncope,
• hypertensive crisis
• Immunological: Stevens-Johnson syndrome, anaphylactic reaction, angioedema
• Nervous System: dizziness, confusion, vision abnormal, hallucinations, somnolence and delirium
• Musculoskeletal: rhabdomyolysis
• General: rash

Precaution

Risk of Urinary Retention: Spasmoplex should be administered with caution to patients with clinically significant bladder outflow obstruction because of the risk of urinary retention.

Angioedema: Angioedema of the face, lips, tongue, and/or larynx has been reported with trospium chloride, the active ingredient in Spasmoplex. In one case, angioedema occurred after the first dose of trospium chloride. Angioedema associated with upper airway swelling may be life threatening. If involvement of the tongue, hypopharynx, or larynx occurs, Spasmoplex should be promptly discontinued and appropriate therapy and/or measures necessary to ensure a patent airway should be promptly provided.

Decreased Gastrointestinal Motility: Spasmoplex should be administered with caution to patients with gastrointestinal obstructive disorders because of the risk of gastric retention. Spasmoplex ,like other antimuscarinic agents, may decrease gastrointestinal motility and should be used with caution in patients with conditions such as ulcerative colitis, intestinal atony and myasthenia gravis.

Controlled Narrow-angle Glaucoma: In patients being treated for narrow-angle glaucoma, Spasmoplex should only be used if the potential benefits outweigh the risks and in that circumstance only with careful monitoring.

Central Nervous System Effects: Spasmoplex is associated with anticholinergic central nervous system (CNS) effects. A variety of CNS anticholinergic effects have been reported, including dizziness, confusion, hallucinations and somnolence. Patients should be monitored for signs of anticholinergic CNS effects, particularly after beginning treatment or increasing the dose. Advise patients not to drive or operate heavy machinery until they know how Spasmoplex affects them. If a patient experiences anticholinergic CNS effects, dose reduction or drug discontinuation should be considered.

Anticholinergic Adverse Reactions in Patients with Moderate Renal Impairment: Spasmoplex is substantially excreted by the kidney. The effects of moderate renal impairment on systemic exposure are not known but systemic exposure is likely increased. Therefore, anticholinergic adverse reactions (including dry mouth, constipation, dyspepsia, urinary tract infection, and urinary retention) are expected to be greater in patients with moderate renal impairment

Interaction

Digoxin: Concomitant use of Spasmoplex and digoxin did not affect the pharmacokinetics of either drug.

Drugs Eliminated by Active Tubular Secretion: Although demonstrated in a drug-drug interaction study not to affect the pharmacokinetics of digoxin, Spasmoplex has the potential for pharmacokinetic interactions with other drugs that are eliminated by active tubular secretion (e.g., procainamide, pancuronium, morphine, vancomycin, and tenofovir). Coadministration of Spasmoplex with these drugs may increase the serum concentration of Spasmoplex and/or the coadministered drug due to competition for this elimination pathway. Careful patient monitoring is recommended in patients receiving such drugs.

Antimuscarinic Agents: The concomitant use of Spasmoplex with other antimuscarinic agents that produce dry mouth, constipation, and other anticholinergic pharmacological effects may increase the frequency and/or severity of such effects. Spasmoplex may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility.

Metformin: Co-administration of 500 mg metformin immediate release tablets twice daily with Spasmoplex 60 mg extended release reduced the steady-state systemic exposure of trospium by approximately 29% for mean AUC_0-24 and by 34% for mean C_max.

Food Interaction

• Take on an empty stomach. Take at least 1 hour before food as the Cmax and AUC of trospium are reduced by 70-80% when taken with a high fat meal.

[Moderate] ADJUST DOSING INTERVAL: Food may reduce the oral absorption and bioavailability of trospium chloride.

According to the product labeling, administration of trospium chloride with a high fat meal reduced the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 70% to 80% compared to administration while fasting.

MANAGEMENT: To ensure maximal oral absorption, trospium chloride should be administered at least 1 hour before meals or on an empty stomach.

Spasmoplex Alcohol interaction

[Moderate] GENERALLY AVOID:

Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous.

In addition, the potential for abuse may be increased with the combination.

The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system.

No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load.

However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

Alcohol should generally be avoided during therapy with anticholinergic agents.

Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.

Spasmoplex Drug Interaction

Moderate: diphenhydramine, metoprolol, metoprolol, mirabegronMinor: acetaminophenUnknown: aspirin, aspirin, duloxetine, apixaban, omega-3 polyunsaturated fatty acids, fluticasone nasal, atorvastatin, pregabalin, polyethylene glycol 3350, bifidobacterium infantis / lactobacillus acidophilus, levothyroxine, cyanocobalamin, ascorbic acid, cholecalciferol, cetirizine

Spasmoplex Disease Interaction

Major: gastric retention, narrow angle glaucoma, urinary retentionModerate: alcoholism, gastrointestinal obstruction, hepatic impairment, renal impairment

Volume of Distribution

• 395 ± 140 L

Elimination Route

9.6%

Half Life

20 hours

Clearance

• Renal cl=29.07 L/hour

Elimination Route

After administration of oral 14C-trospium chloride, the majority of the dose (85.2%) was recovered in feces and a smaller amount (5.8% of the dose) was recovered in urine; 60% of the radioactivity excreted in urine was unchanged trospium. Spasmoplex mainly undergoes elimination via active tubular secretion, as indicated by the mean renal clearance of 29.07 L/hour, which is about 4-fold higher than average glomerular filtration rate. Spasmoplex is metabolized by ester hydrolysis and excreted by the kidneys by a combination of tubular secretion and glomerular filtration.

Pregnancy & Breastfeeding use

Pregnancy Category C: There are no adequate and well-controlled studies of Spasmoplex in pregnant women. Spasmoplex should be used during pregnancy only if the potential benefit to the patient outweighs the risk to the patient and fetus. Women who become pregnant during Spasmoplex treatment are encouraged to contact their physician.

Nursing Mothers: Spasmoplex chloride (2 mg/kg orally and 50 mcg/kg intravenously) was excreted, to a limited extent (less than 1%), into the milk of lactating rats (primarily as parent compound). It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, Spasmoplex should be used during lactation only if the potential benefit justifies the potential risk to the newborn.

Contraindication

Spasmoplex is contraindicated in patients with:

• Urinary retention
• Gastric retention
• Uncontrolled narrow-angle glaucoma.
• Known hypersensitivity to the drug or its ingredients. Angioedema, rash and anaphylactic reaction have been reported.

Acute Overdose

Overdosage with antimuscarinic agents, including Spasmoplex, can result in severe antimuscarinic effects. Supportive treatment should be provided according to symptoms. In the event of overdosage, electrocardiographic monitoring is recommended. A 7-month-old baby experienced tachycardia and mydriasis after administration of a single dose of trospium 10 mg given by a sibling. The baby’s weight was reported as 5 kg. Following admission into the hospital and about 1 hour after ingestion of the trospium, medicinal charcoal was administered for detoxification. While hospitalized, the baby  experienced mydriasis and tachycardia up to 230 beats per minute. Therapeutic intervention was not deemed necessary. The baby was discharged as completely recovered the following day.

Storage Condition

Store at controlled room temperature 20°-25°C.

Innovators Monograph

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