Each scored biconvex, engraved blue DITROPAN® (oxybutynin chloride) Tablet contains 5 mg of oxybutynin chloride. Each 5 mL of DITROPAN Syrup contains 5 mg of oxybutynin chloride. Chemically, oxybutynin chloride is d,l (racemic) 4-diethylamino-2-butynyl phenylcyclohexylglycolate hydrochloride. The empirical formula of oxybutynin chloride is C₂₂H₃₁NO₃•HCl. The structural formula appears below:

Oxybutynin chloride is a white crystalline solid with a molecular weight of 393.9. It is readily soluble in water and acids, but relatively insoluble in alkalis.

DITROPAN Tablets also contain calcium stearate, FD&C Blue #1 Lake, lactose, and microcrystalline cellulose.

DITROPAN Syrup also contains citric acid, FD&C Green #3, glycerin, methylparaben, flavor, sodium citrate, sorbitol, sucrose, and water.

DITROPAN Tablets and Syrup are for oral administration.

Therapeutic Category: Antispasmodic, anticholinergic.

DITROPAN® (oxybutynin chloride) is indicated for the relief of symptoms of bladder instability associated with voiding in patients with uninhibited neurogenic or reflex neurogenic bladder (i.e., urgency, frequency, urinary leakage, urge incontinence, dysuria).

Tablets

Adults: The usual dose is one 5-mg tablet two to three times a day. The maximum recommended dose is one 5-mg tablet four times a day. A lower starting dose of 2.5 mg two or three times a day is recommended for the frail elderly.

Pediatric patients over 5 years of age: The usual dose is one 5-mg tablet two times a day. The maximum recommended dose is one 5-mg tablet three times a day.

Syrup

Adults: The usual dose is one teaspoon (5 mg/5 mL) of syrup two to three times a day. The maximum recommended dose is one teaspoon (5 mg/5 mL) of syrup four times a day. A lower starting dose of 2.5 mg two or three times a day is recommended for the frail elderly.

Pediatric patients over 5 years of age: The usual dose is one teaspoon (5 mg/5 mL) of syrup two times a day. The maximum recommended dose is one teaspoon (5 mg/5mL) of syrup three times a day.

DITROPAN® (oxybutynin chloride) Tablets are supplied in bottles of 100 tablets (NDC 17314-9200-1). Blue scored tablets (5 mg) are engraved with DITROPAN on one side with 92 and 00, separated by a horizontal score, on the other side.

DITROPAN Syrup (5 mg/5 mL) is supplied in bottles of 16 fluid ounces (473 mL) (NDC 17314-9201-4).

Pharmacist: Dispense in tight, light-resistant container as defined in the USP. Store at controlled room temperature 59-86°F (15-30°C).

Manufactured by sanofi-aventis U.S. LLC, Kansas City, MO 64137. Distributed and Marketed by Ortho-McNeil Pharmaceutical, Inc., Raritan, NJ 08869. Revised February 2008. FDA Rev date: 2/6/2008

The safety and efficacy of DITROPAN® (oxybutynin chloride) was evaluated in a total of 199 patients in three clinical trials comparing DITROPAN with DITROPAN XL (see Table 3). These participants were treated with DITROPAN 5-20 mg/day for up to 6 weeks. Table 3 shows the incidence of adverse events judged by investigators to be at least possibly related to treatment and reported by at least 5% of patients.

Table 3: Incidence (%) of Adverse Events Reported by ≥ 5% of Patients Using DITROPAN (5-20 mg/day)

The most common adverse events reported by patients receiving DITROPAN 5-20 mg/day were the expected side effects of anticholinergic agents. The incidence of dry mouth was dose-related.

In addition, the following adverse events were reported by 1 to < 5% of patients using DITROPAN (5-20 mg/day) in all studies. Infections and Infestations: nasopharyngitis, upper respiratory tract infection, bronchitis, cystitis, fungal infection; Metabolism and Nutrition Disorders: fluid retention; Psychiatric Disorders: confusional state; Nervous System Disorders: dysgeusia, sinus headache; Eye Disorders: keratoconjunctivitis sicca, eye irritation; Cardiac Disorders: palpitations, sinus arrhythmia; Vascular Disorders: flushing; Respiratory, Thoracic and Mediastinal Disorders: nasal dryness, cough, pharyngolaryngeal pain, dry throat, sinus congestion, hoarseness, asthma, nasal congestion; Gastrointestinal Disorders: diarrhea, abdominal pain, loose stools, flatulence, vomiting, abdominal pain upper, dysphagia, aptyalism, eructation, tongue coated; Skin and Subcutaneous Tissue Disorders: dry skin, pruritis; Musculoskeletal and Connective Tissue Disorders: back pain, arthralgia, pain in extremity, flank pain; Renal and Urinary Disorders: dysuria, pollakiuria; General Disorders and Administration Site Conditions: fatigue, edema peripheral, asthenia, pain, thirst, edema; Investigations: blood pressure increased, blood glucose increased, blood pressure decreased; Injury, Poisoning, and Procedural Complications: fall.

Postmarketing Surveillance

Because postmarketing adverse events 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. The following additional adverse events have been reported from worldwide postmarketing experience with DITROPAN: Psychiatric Disorders: psychotic disorder, agitation, hallucinations; Nervous System Disorders: convulsions; Eye disorders: cycloplegia, mydriasis; Cardiac Disorders: tachycardia; Gastrointestinal Disorders: decreased gastrointestinal motility; Skin and Subcutaneous Tissue Disorders: rash, decreased sweating; Renal and Urinary Disorders: impotence; Reproductive system and breast disorders: Suppression of lactation.

The concomitant use of oxybutynin with other anticholinergic drugs or with other agents which produce dry mouth, constipation, somnolence (drowsiness), and/or other anticholinergic-like effects may increase the frequency and/or severity of such effects.

Anticholinergic agents may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility. This may be of concern for drugs with a narrow therapeutic index.

Mean oxybutynin chloride plasma concentrations were approximately 3-4 fold higher when DITROPAN was administered with ketoconazole, a potent CYP3A4 inhibitor.

Other inhibitors of the cytochrome P450 3A4 enzyme system, such as antimycotic agents (e.g., itraconazole and miconazole) or macrolide antibiotics (e.g., erythromycin and clarithromycin), may alter oxybutynin mean pharmacokinetic parameters (i.e., Cmax and AUC). The clinical relevance of such potential interactions is not known. Caution should be used when such drugs are co-administered.

No information provided.

Central Nervous System Effects

Oxybutynin is associated with anticholinergic central nervous system (CNS) effects (See ADVERSE REACTIONS). A variety of CNS anticholinergic effects have been reported, including hallucinations, agitation, confusion and somnolence. Patients should be monitored for signs of anticholinergic CNS effects, particularly in the first few months after beginning treatment or increasing the dose. If a patient experiences anticholinergic CNS effects, dose reduction or drug discontinuation should be considered.

DITROPAN should be used with caution in patients with preexisting dementia treated with cholinesterase inhibitors due to the risk of aggravation of symptoms.

General

DITROPAN® (oxybutynin chloride) should be used with caution in the frail elderly, in patients with hepatic or renal impairment, and in patients with myasthenia gravis.

DITROPAN may aggravate the symptoms of hyperthyroidism, coronary heart disease, congestive heart failure, cardiac arrhythmias, hiatal hernia, tachycardia, hypertension, myasthenia gravis, and prostatic hypertrophy.

Urinary Retention

DITROPAN should be administered with caution to patients with clinically significant bladder outflow obstruction because of the risk of urinary retention (see CONTRAINDICATIONS).

Gastrointestinal Disorders

DITROPAN should be administered with caution to patients with gastrointestinal obstructive disorders because of the risk of gastric retention (see CONTRAINDICATIONS).

Administration of DITROPAN to patients with ulcerative colitis may suppress intestinal motility to the point of producing a paralytic ileus and precipitate or aggravate toxic megacolon, a serious complication of the disease.

DITROPAN, like other anticholinergic drugs, may decrease gastrointestinal motility and should be used with caution in patients with conditions such as ulcerative colitis, and intestinal atony.

DITROPAN should be used with caution in patients who have gastroesophageal reflux and/or who are concurrently taking drugs (such as bisphosphonates) that can cause or exacerbate esophagitis.

Carcinogenesis, Mutagenesis, Impairment of Fertility

A 24-month study in rats at dosages of oxybutynin chloride of 20, 80, and 160 mg/kg/day showed no evidence of carcinogenicity. These doses are approximately 6, 25, and 50 times the maximum human exposure, based on surface area.

Oxybutynin chloride showed no increase of mutagenic activity when tested in Schizosaccharomyces pompholiciformis, Saccharomyces cerevisiae and Salmonella typhimurium test systems.

Reproduction studies using oxybutynin chloride in the hamster, rabbit, rat, and mouse have shown no definite evidence of impaired fertility.

Pregnancy

Category B. Reproduction studies using oxybutynin chloride in the hamster, rabbit, rat, and mouse have shown no definite evidence of impaired fertility or harm to the animal fetus. The safety of DITROPAN administered to women who are or who may become pregnant has not been established. Therefore, DITROPAN should not be given to pregnant women unless, in the judgment of the physician, the probable clinical benefits outweigh the possible hazards.

Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when DITROPAN is administered to a nursing woman.

Pediatric Use

The safety and efficacy of DITROPAN administration have been demonstrated for pediatric patients 5 years of age and older (see DOSAGE AND ADMINISTRATION).

The safety and efficacy of DITROPAN Tablets and DITROPAN Syrup were studied in 30 and in 26 children, respectively, in a 24-week, open-label trial. Patients were aged 5-15 years, all had symptoms of detrusor overactivity in association with a neurological condition (e.g., spina bifida), all used clean intermittent catheterization, and all were current users of oxybutynin chloride. Study results demonstrated that the administration of DITROPAN was associated with improvement in clinical and urodynamic parameters.

At total daily doses ranging from 5 mg to 15 mg, treatment with DITROPAN Tablets was associated with an increase from baseline in mean urine volume per catheterization from 122 mL to 145 mL, an increase from baseline in mean urine volume after morning awakening from 148 mL to 168 mL, and an increase from baseline in the mean percentage of catheterizations without a leaking episode from 43% to 61%. Urodynamic results in these patients were consistent with the clinical results. Treatment with DITROPAN Tablets was associated with an increase from baseline in maximum cystometric capacity from 230 mL to 279 mL, a decrease from baseline in mean detrusor pressure at maximum cystometric capacity from 36 cm H20 to 33 cm H20, and a reduction in the percentage of patients demonstrating uninhibited detrusor contractions (of at least 15 cm H20) from 39% to 20%.

At total daily doses ranging from 5 mg to 30 mg, treatment with DITROPAN Syrup was associated with an increase from baseline in mean urine volume per catheterization from 113 mL to 133 mL, an increase from baseline in mean urine volume after morning awakening from 143 mL to 165 mL, and an increase from baseline in the mean percentage of catheterizations without a leaking episode from 34% to 63%. Urodynamic results were consistent with these clinical results. Treatment with DITROPAN Syrup was associated with an increase from baseline in maximum cystometric capacity from 192 mL to 294 mL, a decrease from baseline in mean detrusor pressure at maximum cystometric capacity from 46 cm H20 to 37 cm H20, and a reduction in the percentage of patients demonstrating uninhibited detrusor contractions (of at least 15 cm H₂0) from 67% to 28%.

As there is insufficient clinical data for pediatric populations under age 5, DITROPAN is not recommended for this age group.

Geriatric Use

Clinical studies of DITROPAN did not include sufficient numbers of subjects age 65 and over to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between healthy elderly and younger patients; however, a lower initial starting dose of 2.5 mg given 2 or 3 times a day has been recommended for the frail elderly due to a prolongation of the elimination half-life from 2-3 hours to 5 hours.^{2, 3, 4} In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

REFERENCES

2. Hughes KM et al. Measurement of oxybutynin and its N-desethyl metabolite in plasma, and its application to pharmacokinetic studies in young, elderly and frail elderly volunteers. Xenobiotica. 1992; 22 (7): 859-869.

3. Ouslander J et al. Pharmacokinetics and Clinical Effects of Oxybutynin in Geriatric Patients. J. Urol. 1988; 140: 47-50.

4. Yarker Y et al. Oxybutynin: A review of its Pharmacodynamic and Pharmacokinetic Properties, and its Therapeutic Use in Detrusor Instability. Drugs & Aging. 1995; 6(3): 243-262.

Treatment should be symptomatic and supportive. Activated charcoal as well as a cathartic may be administered.

Overdosage with oxybutynin chloride has been associated with anticholinergic effects including central nervous system excitation (e.g., restlessness, tremor, irritability, convulsions, delirium, hallucinations), flushing, fever, dehydration, cardiac arrhythmia, vomiting, and urinary retention. Other symptoms may include hypotension or hypertension, respiratory failure, paralysis, and coma.

Ingestion of 100 mg oxybutynin chloride in association with alcohol has been reported in a 13-year-old boy who experienced memory loss, and a 34 year old woman who developed stupor, followed by disorientation and agitation on awakening, dilated pupils, dry skin, cardiac arrhythmia, and retention of urine. Both patients fully recovered with symptomatic treatment.

DITROPAN® (oxybutynin chloride) is contraindicated in patients with urinary retention, gastric retention and other severe decreased gastrointestinal motility conditions, uncontrolled narrow-angle glaucoma and in patients who are at risk for these conditions.

DITROPAN is also contraindicated in patients who have demonstrated hypersensitivity to the drug substance or other components of the product.

Oxybutynin chloride exerts a direct antispasmodic effect on smooth muscle and inhibits the muscarinic action of acetylcholine on smooth muscle. Oxybutynin chloride exhibits only one fifth of the anticholinergic activity of atropine on the rabbit detrusor muscle, but four to ten times the antispasmodic activity. No blocking effects occur at skeletal neuromuscular junctions or autonomic ganglia (antinicotinic effects).

Oxybutynin chloride relaxes bladder smooth muscle. In patients with conditions characterized by involuntary bladder contractions, cystometric studies have demonstrated that oxybutynin chloride increases bladder (vesical) capacity, diminishes the frequency of uninhibited contractions of the detrusor muscle, and delays the initial desire to void. Oxybutynin chloride thus decreases urgency and the frequency of both incontinent episodes and voluntary urination.

Antimuscarinic activity resides predominately in the R-isomer. A metabolite, desethyloxybutynin, has pharmacological activity similar to that of oxybutynin in in vitro studies.

Pharmacokinetics

Absorption

Following oral administration of DITROPAN, oxybutynin is rapidly absorbed achieving Cmax within an hour, following which plasma concentration decreases with an effective half-life of approximately 2 to 3 hours. The absolute bioavailability of oxybutynin is reported to be about 6% (range 1.6 to 10.9%) for both the tablet and syrup. Wide interindividual variation in pharmacokinetic parameters is evident following oral administration of oxybutynin.

The mean pharmacokinetic parameters for R- and S-oxybutynin are summarized in Table 1. The plasma concentration-time profiles for R- and S-oxybutynin are similar in shape; Figure 1 shows the profile for R-oxybutynin.

Table 1: Mean (SD) R- and S-Oxybutynin Pharmacokinetic Parameters Following Three Doses of DITROPAN 5 mg Administered every 8 Hours (n=23)

Figure 1. Mean R-oxybutynin plasma concentrations following three doses of DITROPAN 5 mg administered every 8 hours for 1 day in 23 healthy adult volunteers

DITROPAN steady-state pharmacokinetics were also studied in 23 pediatric patients with detrusor overactivity associated with a neurological condition (e.g., spina bifida). These pediatric patients were on DITROPAN tablets (n=11) with total daily dose ranging from 7.5 mg to 15 mg (0.22 to 0.53 mg/kg) or DITROPAN syrup (n=12) with total daily dose ranging from 5 mg to 22.5 mg (0.26 to 0.75 mg/kg). Overall, most patients (86.9%) were taking a total daily DITROPAN dose between 10 mg and 15 mg. Sparse sampling technique was used to obtain serum samples. When all available data are normalized to an equivalent of 5 mg twice daily DITROPAN, the mean pharmacokinetic parameters derived for R- and S-oxybutynin and R- and S-desethyloxybutynin are summarized in Table 2a (for tablet) and Table 2b (for syrup). The plasma-time concentration profiles for R- and S-oxybutynin are similar in shape; Figure 2 shows the profile for R-oxybutynin when all available data are normalized to an equivalent of 5 mg twice daily.

Table 2a: Mean ± SD R- and S-Oxybutynin and R- and S-Desethyloxybutynin Pharmacokinetic Parameters In Children Aged 5-15 Following Administration of 7.5 mg to 15 mg Total Daily Dose of DITROPAN Tablets (N=11) All Available Data Normalized to an Equivalent of DITROPAN Tablets 5 mg BID or TID at Steady State

Table 2b: Mean ± SD R- and S-Oxybutynin and R- and S-Desethyloxybutynin Pharmacokinetic Parameters In Children Aged 5-15 Following Administration of 5 mg to 22.5 mg Total Daily Dose of DITROPAN Syrup (N=12) All Available Data Normalized to an Equivalent of DITROPAN Syrup 5 mg BID or TID at Steady State

Figure 2. Mean steady-state (±SD) R-oxybutynin plasma concentrations following administration of total daily DITROPAN dose of 5 mg to 30 mg (0.21 mg/kg to 0.77 mg/kg) in children 5-15 years of age. - Plot represents all available data normalized to the equivalent of DITROPAN 5 mg BID or TID at steady state

Food Effects

Data in the literature suggests that oxybutynin solution co-administered with food resulted in a slight delay in absorption and an increase in its bioavailability by 25% (n=18). ¹

Distribution

Plasma concentrations of oxybutynin decline biexponentially following intravenous or oral administration. The volume of distribution is 193 L after intravenous administration of 5 mg oxybutynin chloride.

Metabolism

Oxybutynin is metabolized primarily by the cytochrome P450 enzyme systems, particularly CYP3A4 found mostly in the liver and gut wall. Its metabolic products include phenylcyclohexylglycolic acid, which is pharmacologically inactive, and desethyloxybutynin, which is pharmacologically active.

Excretion

Oxybutynin is extensively metabolized by the liver, with less than 0.1% of the administered dose excreted unchanged in the urine. Also, less than 0.1% of the administered dose is excreted as the metabolite desethyloxybutynin.

Clinical Studies

DITROPAN was well tolerated in patients administered the drug in controlled studies of 30 days' duration and in uncontrolled studies in which some of the patients received the drug for 2 years.

REFERENCES

1. Yong C et al. Effect of Food on the Pharmacokinetics of Oxybutynin in normal subjects. Pharm Res. 1991; 8 (Suppl.): S-320.

Patients should be informed that heat prostration (fever and heat stroke due to decreased sweating) can occur when anticholinergics such as oxybutynin chloride are administered in the presence of high environmental temperature.

Because anticholinergic agents such as oxybutynin may produce drowsiness (somnolence), or blurred vision, patients should be advised to exercise caution.

Patients should be informed that alcohol may enhance the drowsiness caused by anticholinergic agents such as oxybutynin.

IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.

OXYBUTYNIN - ORAL

(ox-ee-BYOU-tih-nin KLOR-ide)

COMMON BRAND NAME(S): Ditropan

USES: Oxybutynin is used to treat certain bladder and urinary conditions (e.g., overactive bladder). It relaxes the muscles in the bladder to help decrease problems of urgency and frequent urination. Oxybutynin belongs to a class of drugs known as antispasmodics.

The manufacturer does not recommend using this medication in children younger than 5 years of age.

HOW TO USE: Take this medication by mouth, usually 2-3 times a day, or as directed by your doctor. It may be taken with or without food. The dosage is based on your medical condition and response to therapy. The length of treatment is determined by your doctor, who may suggest periodic trials off the drug to evaluate whether you still need to be taking it.

When using the syrup, measure the dose out carefully with a medication spoon/cup.

Use this medication regularly in order to get the most benefit from it. Remember to use it at the same times each day.

Inform your doctor if your condition persists or worsens.

SIDE EFFECTS: Dry mouth, dizziness, drowsiness, blurred vision, dry eyes, nausea, vomiting, upset stomach, stomach pain, constipation, diarrhea, headache, unusual taste in mouth, dry/flushed skin, and weakness may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

To relieve dry mouth, suck on (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water or use a saliva substitute. To relieve dry eyes, use artificial tears or other eye lubricants. Consult your pharmacist for further advice.

To prevent constipation, maintain a diet adequate in fiber, drink plenty of water, and exercise. If you become constipated, consult your pharmacist for help in choosing a laxative (e.g., stimulant-type with stool softener).

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: decreased sexual activity, difficulty urinating, fast/pounding heartbeat, signs of kidney infection (e.g., burning/painful/frequent urination, lower back pain, fever), mental/mood changes, swelling of arms/legs/ankles/feet, vision problems (including eye pain).

Tell your doctor immediately if any of these rare but very serious side effects occur: seizures, stomach/intestinal blockage (e.g., persistent nausea/vomiting, prolonged constipation).

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching, swelling, severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking oxybutynin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: active internal bleeding, untreated/uncontrolled glaucoma (narrow-angle), severe blockage/slowed movement of stomach/intestines (e.g., gastric retention, paralytic ileus), decreased bladder emptying activity (urinary retention).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: bladder disease (e.g., bladder outflow blockage), certain muscle disease (myasthenia gravis), heart disease (e.g., congestive heart failure, coronary artery disease, arrhythmias), high blood pressure, liver disease, kidney disease, loss of mental abilities (dementia), certain nervous system disorder (autonomic neuropathy), enlarged prostate gland (benign prostatic hypertrophy-BPH), stomach/intestinal disease (e.g., acid reflux disease, hiatal hernia, ulcerative colitis), overactive thyroid (hyperthyroidism).

This drug may make you dizzy, drowsy or cause blurred vision; use caution engaging in activities requiring alertness such as driving or using machinery. Limit use of alcoholic beverages.

This drug may increase the risk for heatstroke because it causes decreased sweating. Avoid becoming overheated in hot weather, saunas, and during exercise or other strenuous activity.

Caution is advised when using this drug in the elderly because they may be more sensitive to its effects.

This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Your healthcare professionals (e.g., doctor or pharmacist) may already be aware of any possible drug interactions and may be monitoring you for it. Do not start, stop or change the dosage of any medicine before checking with them first.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: anticholinergic drugs (e.g., atropine, glycopyrrolate, scopolamine ), other antispasmodic drugs (e.g., clidinium, dicyclomine, propantheline), certain anti-Parkinson's drugs (e.g., benztropine, trihexyphenidyl), belladonna alkaloids, bisphosphonate drugs (e.g., alendronate, etidronate, risedronate), desmopressin, drugs affecting liver enzymes that remove oxybutynin from your body (such as azole antifungals-including ketoconazole, macrolide antibiotics-including erythromycin, cimetidine, rifamycins-including rifabutin, St. John's wort, certain anti-seizure medicines-including carbamazepine), potassium tablets/capsules, pramlintide.

Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-anxiety drugs (e.g., diazepam), anti-seizure drugs (e.g., phenobarbital), medicine for sleep (e.g., zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., phenothiazines such as chlorpromazine or tricyclics such as amitriptyline), tranquilizers.

Check the labels on all your medicines (e.g., cough-and-cold products) because they may contain drowsiness-causing ingredients. Ask your pharmacist about the safe use of those products.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include: delirium and paralysis.

NOTES: Do not share this medication with others.

MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store at room temperature between 59-86 degrees F (15-30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised August 2008 Copyright(c) 2008 First DataBank, Inc.