Oablok

External appearance: A skin patch with an adhesive layer applied to the backing plate.
The outer layer is light brown to brown. When the protective cover is peeled off, the patient will notice that the surface of the adhesive layer is semi-transparent and has a distinctive smell.
Size: 73.0 Millimeters x 73.0 Millimeters.
Surface area: 52.5 square centimeters.
Excipients/Inactive Ingredients: Fragrance (phenylethyl alcohol), alicyclic saturated hydrocarbon resin, styrene-isoprene-styrene block copolymers, liquid paraffin, polyisobutylene, anhydrous sodium acetate, 2-ethylhexyl acrylate/vinyl-acetate copolymer solution, cholesterol and glacial acetic acid.

Pharmacology: Pharmacodynamics: Mechanism of action: Oxybutynin hydrochloride has a direct effect on the relaxation of smooth muscle (calcium antagonistic effect) including effects on the nervous system (antimuscarinic effects) which may influence the stomach. Urinating causes the muscles of the bladder to release tension.
Ability to bind to muscarinic receptors: In binding studies using muscarinic receptors M1, M2, M3, M4, and M5, oxybutynin inhibited the competitive binding of muscarinic receptors M1, M2, M3, M4, and M5. [H]-N-methylscopolamine and has been shown to have high binding capacity for muscarinic receptors M3 and M4 (in vitro).
Effects on separated smooth muscles: In studies using isolated smooth muscles of rats, guinea pigs, and humans, oxybutynin inhibited contractions induced by acetylcholine (acetylcholine-induced) and carbachol-induced contraction results from anticholinergic effects. In addition, high doses of oxybutynin inhibit contractions induced by potassium (potassium-induced) (direct effect on bladder smooth muscle) DEO, a metabolite of this drug, has shown anticholinergic effects as well as smooth muscle-suppressing effects. It is a direct stimulant of the bladder similar to oxybutynin. This drug is thought to have an effect on improving overactive contractions of the detrusor muscles of the bladder by blocking muscarinic receptors in the bladder (in test tube).
Effects on the function of the urinary system: In a study measuring bladder pressure in rats, (bladder function measurement (cystometry)) found that the drug Oxybutynin prolongs the time it takes to urinate in a dose-dependent manner.
Pharmacokinetics: Drug absorption: Single dose: When applying oxybutynin hydrochloride (HCL) transdermal patch (73.5 mg/35.0 square centimeter) to the lower abdomen of healthy male and female adults for 24 hours as a single use, the plasma concentrations of oxybutynin and N-desethyl oxybutynin (DEO), its active metabolite, reached peak levels at 18.0 hours and 24.0 hours after dosing, respectively. The Cmax values were 5.2 ng/mL and 5.0 ng/mL, respectively. The elimination half-lives of oxybutynin and DEO were 15.3 hours and 15.4 hours, respectively, after the removal of the patch from the skin, respectively.
Remarks: 1) Pharmacokinetic profile (PK profile) of oxybutynin HCI transdermal patch (73.5 mg/35.0 square centimeter) is equivalent to OABLOK Ex PATCH (see Multiple doses in healthy adults as follows). (See Figure 1 and Table 1.)

Click on icon to see table/diagram/image


Click on icon to see table/diagram/image

Tmax values: When applying oxybutynin hydrochloride patch (73.5 mg/35.0 square centimeter) to the lower back and thighs, the AUC0-1 values for oxybutynin were observed to be approximately 1.37 times greater in the lower back and 1.48 times greater in the thighs, compared to the AUC value observed when oxybutynin hydrochloride transdermal patch was applied to the lower abdomen.
Multiple doses in healthy adults: When applying the patch containing oxybutynin hydrochloride (Oxybutynin HCL) (52.5 mg/25 square centimeters or 105 mg/50 square centimeters) to the lower abdomen in healthy male adults once a day for 7 days, in multiple doses, the linearity of pharmacokinetic parameters (AUC0-23.5 and Cmax) was observed for both oxybutynin and DEO doses between 52.5 mg and 105 mg (remarks 2).
In repeated dosing, it was found that the drug concentration almost reached a steady state at the second dose. (See Table 2.)

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PK profile of OABLOK EX PATCH can be deduced based on the patch size.
Additional studies for OABLOK Ex PATCH: The pharmacokinetics of plasma oxybutynin in post-application were studied in healthy female adults when the patch was administered once daily for 7 days as multiple doses. After the administration of OABLOK EX (oxybutynin) patch, the plasma concentration of oxybutynin reached the Cmax of 5.45 ng/mL at 12 hours on day 1 and 7.87 ng/mL at 12 hours on day 7, respectively. The AUC0-24 values were 84.4 and 157 ng/mL, respectively. When administering the oxybutynin hydrochloride transdermal patch (Oxybutynin HCL) (73.5 mg/35.0 square centimeter), the plasma concentration of oxybutynin reached the Cmax value of 5.55 ng/mL at 12 hours on day 1 and 8.14 ng/mL at 12 hours on day 7, respectively. The AUC0-24 values were 86.7 and 163 ng/mL, respectively.
OABLOK Ex PATCH and Oxybutynin HCl transdermal patch (73.5 mg/35.0 cm²) were considered to be bioequivalent in pharmacokinetic parameters (PK parameters) at the first and seventh doses after administration. (See Figure 2 and Table 3.)

Click on icon to see table/diagram/image


Click on icon to see table/diagram/image

NOTE 3) Pharmacokinetic profile (PK profile) of the Oxybutynin hydrochloride transdermal patch (Oxybutynin HCI) (73.5 mg/35.0 square centimeter) same as OABLOK Ex PATCH.
Multiple doses (Patients with overactive bladder): In patients with overactive bladder. When using skin patches Oxybutynin HCI (73.5 milligrams/35.0 square centimeters)^{Note 4)}.
Multiple dosage form: Apply to the lower abdomen, lower back, or legs once a day continuously. At 52 weeks, mean plasma concentrations of oxybutynin and DEO were nearly constant at 12, 28, and 52 weeks after the first dose. The concentration of oxybutynin in the plasma is still within the range. Estimated on the basis of pharmacokinetics of the drug in available studies. A single dose is therefore considered to be the biokinetic profile of the drug. Can be compared between adults who are healthy people and patients with overactive bladder.
⁴⁾ Pharmacokinetic profile (PK profile) of Oxybutynin HCI transdermal patch (73.5 mg/35.0 square centimeter) same as OABLOK Ex PATCH see Multiple doses in healthy adults as previously mentioned.
Drug distribution: Tissue drug distribution in male SD rats using skin patches containing [14C]-oxybutynin HCI is applied to the skin on the back for 48 hours as a single dose. Found a wide distribution of radioactivity through tissues and found to have high concentrations, especially in the skin.
Location of the patch: Harderian glands, white fat, and liver. After the patch is removed, the concentration of radioactivity in each tissue is decreased in the same way as found in the radioactivity concentration in the plasma. There was no accumulation of the drug in the skin at the application site after repeated administration.
Transmission to the fetus: When administered [14C]-oxybutynin hydrochloride orally to pregnant rats, distribution of the drug was found in the embryonic tissues. However, the drug concentration in the embryonic tissues was lower than the drug concentration in the embryonic tissues blood of mother animal.
Binding to plasma proteins: Medication changes Oxybutynin is converted to metabolites including DEO, which is an active metabolite in the liver. In addition, studies in human liver microsomes indicate that Oxybutynin is metabolized mainly by CYP3A4 and CYP3A5 enzymes (see Precautions for specific patients under Precautions and Interactions).
Removal of drugs from the body in healthy adult males: When applying a skin patch containing Oxybutynin HCI 52.5 mg^{Note 5)} to the lower abdomen once a day for 7 days in a multiple dose regimen. Rate of drug elimination in the urine the total dose (of oxybutynin and four metabolites) at 144 and 168 hours after the first dose (at the time of the seventh dose) was 1.4% of the dose. In addition, compounds that were eliminated in the urine were found to be phenyl-cyclohexylglycolic acid (3.8%), 4-hydroxyl-Ndesethyloxybutynin (30.8%), and 4-hydroxylphenylcyclohexylglycolic acid (65.4%) and no oxybutynin or DEO were detected or detected in small quantities. The data obtained were similar to the use of a transdermal patch containing 105 mg of the active ingredient.
^{Note 5)} Drug elimination rate of OABLOK EX PATCH, 73.5 mg/52.5 square centimeter. It can be estimated to be 52.5 mg/25 sq. cm regardless of patch size.

Used for the treatment of painful overactive bladder. Sudden urination, frequent urination, and incontinence.

The usual adult dosage is 1 patch (oxybutynin hydrochloride 73.5 mg) once daily. Apply to the lower abdomen, lower back, or thigh and change the skin patch every 24 hours.

Symptoms: Inability to urinate, dilated pupils, extreme excitement, rapid heartbeat, etc.
Treatment regimen: Remove the patch immediately from the application site. Appropriate treatment should be administered to address each symptom. For example, catheterization may be inserted to treat incontinence and pilocarpine may be administered to treat dilated pupils, etc.

This medicine is prohibited in the following patients: Patients who are unable to urinate may get worse as a result of the anticholinergic effect which inhibits contraction of bladder body.
Patients with angle-closure glaucoma [symptoms may worsen because of the anticholinergic effects which increases intraocular pressure].
Patients with severe heart disease [the workload of the heart may increase because of anticholinergic effects which causes abnormally fast heartbeat and palpitations].
Patients with distal stomach obstruction, small intestine obstruction, or small intestinal obstruction [symptoms may worsen as a result from anticholinergic effects which will inhibit contractions and movements of the smooth muscles of the stomach, food and intestines].
Patients with poor stomach or intestinal contractions [symptoms may be worsened by anticholinergic effects which reduces the ability to move the stomach and intestines].
Patients with muscle weakness (myasthenia gravis) [symptoms may be worsened by anticholinergic effects which reduces muscle tightness].
Patients with a history of hypersensitivity to the components of this drug.
Patients who are breastfeeding.

Precautions related to Indications: There should be an adequate history of the patient to check.
Be sure of the patient's clinical symptoms before using this medicine, as the same symptoms may be seen in other diseases as well [e.g., infections at urinary tract, urinary tract stones, cancer, lower urinary tract cancers (such as bladder cancer and prostate cancer)] should be diagnosed in order to screen out other diseases using urinalysis, etc. Special tests should also be considered as necessary.
In patients with lower urinary tract obstruction (such as an enlarged prostate), treatment of such obstruction should be given priority.
This medicine should not be used in patients with dementia or impairment of mental abilities that are unable to recognize symptoms of gastritis urine can be squeezed too quickly.
Important Precautions: Patients should be cautioned to use when operating potentially hazardous machinery, such as automobiles, while using this drug because of the potential for interference with eye focus (e.g., visual disturbances, blurry vision), dizziness and/or drowsiness.
In patients with lower urinary tract obstruction such as enlarged prostate, the volume of urine remaining in the bladder should be measured before using this medicine, special tests should also be done. If necessary, it should follow up adequately after use with observation of the volume of urine remaining in the bladder, which may increase (see Precautions for patients with specific history as follows and Adverse Reactions).
If after using this medicine patient doesn't get better, do not continue using this medicine. Consideration should be given to other appropriate treatment.
Skin symptoms may occur after using this medicine, change the location of use of this medicine each time. If skin symptoms appear, should be treated adequately, such as using topical steroids or topical skin medications. Take an antihistamine or stop or temporarily discontinue use of this medicine (see Adverse Reactions).
Anticholinergic effect may induce. There is less sweating. This leads to intolerance of temperature increases outside the body and results in a rapid increase in body temperature. Therefore, when using the drug under high temperature conditions, the patient should be cautioned. Be careful about increased body temperature.
Precautions for patients with specific history: Patients with a history and complications of the following diseases: Patients with lower urinary tract obstruction (such as enlarged prostate) may cause urinary incontinence due to possible anticholinergic effects (see Important Precautions as previously mentioned and Adverse Reactions).
Patients with hyperthyroidism hypersensitivity: Sympathetic hyperactivities such as an abnormally fast heartbeat, symptoms may worsen due to its anticholinergic effects.
Patients with a heart attack: Sympathetic activity may be enhanced.
Patients with cardiac arrhythmias: This medicine may increase heart rate in patients with rapid cardiac arrhythmias due to the effect of parasympathetic activity which induces a predominant state of the sympathetic nervous system.
Patients with ulcerative colitis: Patients may develop toxic megacolon.
Patients with Parkinson's disease or those with cerebral artery abnormalities: Symptoms may worsen or psychotic symptoms may appear. Patients with dementia or cognitive impairment: Symptoms maybe worsen due to anticholinergic effects.
Patients with kidney impairment: Patients with serious kidney abnormalities: Delayed renal excretion may occur.
Patients with liver impairment: Patients with serious liver disorders: This medicine is mainly metabolized in the liver which may increase the risk of adverse reactions (see Pharmacology: Pharmacokinetics under Actions).
Use in Children: This medicine is not recommended for patients younger than 20 years old.
There are no clinical studies in children.
Use in the Elderly: Overall physiological function decreases in the elderly.

Pregnancy: Women who are or may be pregnant should avoid using this medicine, if possible.
Breastfeeding: This medicine should not be used during breastfeeding as oxybutynin has been reported to pass into breast milk in animal studies (in rats) (see Contraindications).

The following adverse reactions may occur. Therefore, adequate monitoring is advised and if the adverse reactions occur, discontinue the use of the medication and seek appropriate medical care.
Clinically significant adverse reactions: Thrombocytopenia.
Intestinal obstruction due to paralysis of the intestinal muscles (ileus paralytic). If constipation, severe bloating, etc., occur, discontinue the use of this medicine and seek appropriate medical care (see Contraindications).
Inability to urinate (see Contraindications, Important Precautions and Precautions for patients with specific history under Precautions).
Other adverse reactions: See Table 4.

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Oxybutynin is structurally metabolized mainly by the hepatic drug-converting enzyme CYP3A4 (see Pharmacology: Pharmacokinetics under Actions). Precautions for concomitant use (this product should be used with caution when used in combination with the following medicines): See Table 5.

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How to use this medicine: How to apply the medicine: 1. Before using this medication, peel off the clear film attached to the top of the patch.
2. This medicine should be applied once a day continuously. Therefore, carefully consider the application time carefully and take bathing schedules into consideration.
Application site: 1. Avoid areas where belts are worn, as rubbing with the clothes may unintentionally remove the patch.
2. Do not apply this medicine to broken skin, wounds, skin with rash/dermatitis, and avoid using the same application site repeatedly.
3. Wipe and dry the application site, then apply this medicine to clean areas.
How to remove the used patch and apply a new one: 1. Carefully and slowly peel off the patch from the skin to avoid skin irritation.
2. If this medicine comes off before it is time to apply a new patch, apply the new patch immediately.
3. Change the application site each time; avoid applying to the same site repeatedly.

Storage and disposal: Do not store in an environment with a temperature higher than 30°C.
After opening the package, keep this medication in the closed zipped package.
Do not use the patch after opening the package for longer than 14 days.
Residual medicine will remain on the patch for 24 hours after use, fold the used patch in half with the adhesive side inside and discard use.

Drugs for Bladder & Prostate Disorders

G04BD04 - oxybutynin ; Belongs to the class of urinary antispasmodics.

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