Oxybutynin

BRAND NAMES:

Ditropan – Ditropan is available both in tablets and syrup which contains 5mg of Oxybutynin chloride as the main active ingredient which helps in treatment.

Gelnique – It is available in the form of gel which contains oxybutynin as the main active ingredient that helps in treating bladder issues.

Kentera – Kentera is available as transdermal patches of strengths of 3 and 9 mg.

Oxytrol – Oxybutynin is the major active ingredient present in the form of patches which helps treat the overactive bladder.

MECHANISM OF ACTION:

Oxybutynin acts as an antispasmodic against smooth muscle, especially in the bladder. The active metabolite of oxybutynin is N-desethyloxybutynin. It exhibits the postganglionic muscarinic receptors, consequently blocking the muscarinic effect of acetylcholine and leading to the relaxation of the bladder smooth muscles of the bladder. So oxybutynin increases bladder capacity and reduces urinary urgency and frequency. 

PHARMACOKINETICS:

Absorption: The drug reaches its peak plasma concentration within 1 hour. After the oral administration of oxybutynin chloride release tablets have an absolute bioavailability of 6% approximately. The bioavailability will be increased up to 25% approximately when it is co-administrated with food. 

Distribution: The volume of the distribution of oxybutynin is 193L.

Metabolism: It is metabolized in the liver. Oxybutynin is metabolized by the cytochrome P450 enzyme systems, and processed by CYPA4. It produces two metabolites, phenyl cyclohexyl glycolic acid and desethyloxybutynin.

Excretion: Less than 0.1% of the administered dose is excreted unchanged in the urine and less than 0.1% is excreted as the desethyloxybutyin metabolite.

PHARMACODYNAMICS:

Oxybutynin exerts antispasmodic actions on the bladder, relieving the uncomfortable symptoms of an overactive bladder, including urinary urgency and frequency. These actions occur through the inhibition of muscarine receptors.

DOSAGE AND ADMINISTRATION:

Oxybutynin comes in tablets, syrup, patches, and extended-release tablets. The drug dose will be varied for each patient. The amount of medicine given is determined by its strength, daily doses, intervals between doses, and the patient's condition. For treating bladder problems

Extended-release tablets for oral dosage forms

• In adults, the recommended dosage starts from 5 or 10mg once a day. The dose should not be range more than 30mg per day.
• Children years of age or above the starting recommended dose is 5mg once a day. The dose should not be range more than 20 mg per day.

Syrup or tablets for oral dosage forms

• In adults and children aged above 12 years the recommended dose is 5mg two or three times a day.
• Children between 5 - 12 years, the recommended dose is 5 mg two or three times a day. The dose should not be range more than 5 mg per day.

CONTRAINDICATIONS:

Oxybutynin is not recommended for people with urinary retention, bladder obstruction, dysmotility, obstructive gastric diseases, or narrow-angle glaucoma.

DRUG INTERACTIONS:

Interacting Some drugs along with oxybutynin may cause severe side effects or can decrease the functioning of the actual drug. So before taking this drug, it is required to discuss with the doctor the other medications used for the other treatments. Below are some medications which interact with oxybutynin.

• Antihistamines – Allergy, cough and cold.
• Parkison disease – Benztropine, trihexyphenidyl
• Stomach problems – Dicyclomine, Hyoscyamine 
• Travel sickness – Scopolamine
• Medications for fung
• Atropine
• Clarithromycin
• Erythromycin
• Ipratropium

FOOD INTERACTIONS:

Avoid alcohol. It can be taken with or without food.

ADVERSE EFFECTS:

• Painful urination
• Pounding of heartbeat
• Confusiness
• Rash
• Hives
• Dry mouth
• Blurred vision
• Stomach pain
• Constipation
• Diarrhea
• Change in ability to taste food
• Headache
• Heartburn
• Dry eyes, nose and skin
• Drowsiness
• Nervousness
• Flushing
• Back or joint pains
• Difficulty in sleeping
• Swelling of ankles, legs

TOXICITY:

Taking an overdose of medicine than prescribed can lead to some toxic effects.

• Uncontrollable shaking of the body
• Irritability
• Hallucinations
• Seizures
• Irregular heartbeat
• Difficulty in urination
• Slowing and difficulty in breathing
• Black circle in the center of eyes
• Fever
• Memory loss
• Agitation
• Coma
• Unable to move