Cystrin

Uses

Cystrin Chloride is a muscarinic antagonist used for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency. Cystrin Chloride Extended Release Tablets are also used for the treatment of pediatric patients aged 6 years and older with symptoms of detrusor overactivity associated with a neurological condition (e.g., spina bifida).

Cystrin is also used to associated treatment for these conditions: Bladder Spasms, Detrusor Hyperreflexia, Urinary Bladder, Overactive

How Cystrin works

Cystrin acts to relax the bladder by inhibiting the muscarinic action of acetylcholine on smooth muscle, and not skeletal muscle. The active of oxybutynin is metabolite is N-desethyloxybutynin. It competitively inhibits the postganglionic type 1, 2 and 3 muscarinic receptors. The above actions lead to increased urine capacity in the bladder, decreasing urinary urgency and frequency. In addition, oxybutynin delays the initial desire to void.

Dosage

Cystrin dosage

The recommended starting dose of Uricon is 5 mg once daily, with or without food. Dosage may be adjusted in 5 mg increments to achieve a balance of efficacy and tolerability (up to a maximum of 30 mg/day). In general, dosage adjustment may proceed at approximately weekly intervals.

Side Effects

The incidence of dry mouth may occur which is dose-related. Abdominal pain, dry nasal and sinus mucous membranes, back pain, hypertension, palpitation, vasodilatation, flatulence, gastro-esophageal reflux, insomnia, nervousness, confusion, cough, sinusitis, bronchitis, dry skin, rash, impaired urination (hesitancy), urinary retention, etc. may be reported.

Toxicity

The acute oral LD50 in rats is 460 mg/kg.

Overdose information

An overdose with oxybutynin may manifest clinically as CNS overactivity, fever, palpitations, cardiac arrhythmias, urinary retention, respiratory failure, paralysis, in addition to coma. Provide supportive care immediately. Activated charcoal in addition to a cathartic agent should be administered. There have been 2 reports of an overdose with a 100 mg dose of oxybutynin. One case was a 13-year-old boy and another was a 34-year-old woman. Alcohol was also ingested simultaneously in both cases. The patients received supportive treatment and fully recovered.

Precaution

Cystrin Chloride should be used with caution in patients with hepatic or renal impairment, clinically significant bladder outflow obstruction because of the risk of urinary retention, gastrointestinal obstructive disorders because of the risk of gastric retention, conditions such as ulcerative colitis, intestinal atony, and myasthenia gravis, gastro-esophageal reflux and/or who are concurrently taking drugs (such as bisphosphonates) that can cause or exacerbate esophagitis.

Interaction

Anticholinergic agents, cytochrome P450 enzyme inhibitors, such as antimycotic agents (e.g., Ketoconazole, Itraconazole, and Miconazole) or macrolide antibiotics (e.g., erythromycin and clarithromycin), have not been performed. No specific drug-drug interaction studies have been performed with Cystrin.

Food Interaction

• Avoid alcohol.
• Take with or without food.

Cystrin 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.

Cystrin Drug Interaction

Moderate: metoprolol, metoprolol, mirabegron, acetaminophen / hydrocodoneMinor: acetaminophenUnknown: aspirin, aspirin, duloxetine, omega-3 polyunsaturated fatty acids, furosemide, atorvastatin, pregabalin, polyethylene glycol 3350, albuterol, montelukast, levothyroxine, cyanocobalamin, ascorbic acid, cholecalciferol, cetirizine

Cystrin Disease Interaction

Major: autonomic neuropathy, infectious diarrhea, angle-closure glaucoma, GI/urinary obstruction/atony, myasthenia gravisModerate: central nervous system

Volume of Distribution

Cystrin has a wide volume of distribution of 193 L. In rats, oxybutynin penetrates the central nervous system.

Elimination Route

Cystrin should be swallowed whole with the help of liquids. A pharmacokinetic study revealed that oxybutynin was rapidly absorbed, and peak concentrations were reached within about 1 hour of administration, measured at 8.2 ngml-1 and AUC was 16 ngml-1. The biovailability of oxybutynin is about 6%, and the plasma concentration of the active metabolite, desethyloxybutynin is 5 to 12 times greater than that of oxybutynin. Bioavailability is increased in the elderly. Food has been shown to increase the exposure to controlled-release oxybutynin.

Half Life

The plasma elimination half-life is about 2 hours. In the elderly, the elimination half-life is prolonged up to 5 hours.

Elimination Route

Cystrin is heavily cleared by the liver. Under 0.1% of an administered dose is found as unchanged drug in the urine. Less than 0.1% of a single dose of oxybutynin is excreted as desethyloxybutynin.

Pregnancy & Breastfeeding use

Cystrin Chloride should not be given to pregnant women unless, the probable clinical benefits outweigh the possible hazards, caution should be exercised when it is administered to a nursing woman.

Contraindication

Cystrin Chloride is contraindicated in patients with urinary retention, gastric retention, or uncontrolled narrow angle glaucoma and in patients who are at risk for these conditions. It is also contraindicated in patients who have demonstrated hypersensitivity to the drug substance or other components of the product.

Acute Overdose

Anticholinergic effects including CNS excitation (e.g. restlessness, tremor, irritability, convulsions, delirium, hallucinations), flushing, fever, dehydration, cardiac arrhythmia, vomiting, and urinary retention may occur after overdose. Treatment should be symptomatic and supportive. Activated charcoal may be administered.

Storage Condition

Store at 15-30° C

Innovators Monograph

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