BMA Concise Guide to Medicine & Drugs

Oxybutynin

Brand names Contimin, Cystrin, Ditropan, Kentera, Lyrinel XL

Used in the following combined preparations None

QUICK REFERENCE

Drug group Drug for urinary disorders

Overdose danger rating High

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Oxybutynin is an anticholinergic and antispasmodic drug used to treat urinary incontinence and frequency in adults and bedwetting in children. It works by reducing bladder contraction, allowing the bladder to hold more urine. The drug stops bladder spasms and delays the desire to empty the bladder. It also has some local anaesthetic effect.

The drug’s usefulness is limited to some extent by its side effects, especially in children and the elderly. It can aggravate conditions such as an enlarged prostate or coronary heart disease in the elderly. Children are more susceptible to effects on the central nervous system (CNS), such as restlessness, disorientation, hallucinations, and seizures.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, liquid, patches.

Frequency and timing of doses 2–4 x daily (tablets, liquid); 1–2 x weekly (patch).

Adult dosage range 10–20mg daily (tablets, liquid); 36mg twice weekly (patch).

Onset of effect 1 hour (tablets, liquid); 24–48 hours (patch).

Duration of action Up to 10 hours (tablets, liquid); 96 hours (patch).

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect liquid from light.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next (tablets and liquid). Apply when you remember (patches).

Stopping the drug Do not stop taking the drug without consulting your doctor; symptoms may recur.

OVERDOSE ACTION

Seek immediate medical advice in all cases. Take emergency action if symptoms such as breathing difficulty, seizures, or loss of consciousness occur.

POSSIBLE ADVERSE EFFECTS

Oxybutynin can produce a wide range of adverse effects, and an adjustment in dosage is necessary in children and the elderly to minimize these effects. Common adverse effects include dry mouth, constipation, nausea, facial flushing, and difficulty in passing urine. More rarely, there may be blurred vision, eye pain, headache, or confusion. Discuss with your doctor if any of these are severe or if you develop dry skin. If a rash occurs, you should stop taking the drug and consult your doctor. Oxybutinin can also precipitate glaucoma.

INTERACTIONS

General note Oxybutynin reduces gastric motility (spontaneous stomach movements that move stomach contents into the intestine) and so may affect the absorption of other oral drugs.

Other anticholinergic drugs If oxybutynin is taken with other drugs that have anticholinergic effects, the risk of anticholinergic side effects is increased.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have liver or kidney problems.

· You have heart problems.

· You have an enlarged prostate.

· You have hiatus hernia.

· You have ulcerative colitis.

· You have glaucoma.

· You are taking other medicines.

Pregnancy Safety not established. Discuss with your doctor.

Breast-feeding The drug passes into breast milk and its safety in breast-feeding has not been established. Discuss with your doctor.

Infants and children Not recommended under 5 years. Reduced dose necessary in older children.

Over 60 Reduced dose necessary.

Driving and hazardous work Avoid such activities until you have learned how oxybutynin affects you because the drug can cause drowsiness, disorientation, and blurred vision.

Alcohol Avoid. Alcohol increases the sedative effects of oxybutynin.

PROLONGED USE

No special problems. The need for continued treatment may be reviewed after six months.

Monitoring Periodic eye tests for glaucoma may be performed.