Myotonine 25 mg (Bethanechol Chloride)

1. Name Of The Medicinal Product

Myotonine ®( bethanechol chloride).

2. Qualitative And Quantitative Composition

Each 25mg tablet weighs 440mg; total active ingredient 25mg bethanechol chloride USPXXIV

3. Pharmaceutical Form

Each 25mg tablet is white, flat with bevelled edge and with a cross score and embossed “MY25”.

4. Clinical Particulars

4.1 Therapeutic Indications

Urinary retention -indicated for the treatment of acute postoperative and postpartum non-obstructive (functional) urinary retention and neurogenic atony of the urinary bladder with retention.

Reflux oesophagitis; treatment of reflux associated with decreased pressure of the lower oesophageal sphincter or delayed gastric emptying.

4.2 Posology And Method Of Administration

Administration orally by tablets.

Adults: 10mg –25mg three or four times daily, taken half an hour before food. Occasionally it may be necessary to initiate therapy with a 50mg dose.

Children: The experience with children is limited therefore no recommended dose is given.

4.3 Contraindications

Intestinal or urinary obstruction, recent myocardial infarction, recent intestinal anastomosis.

4.4 Special Warnings And Precautions For Use

A severe cholinergic reaction is likely if bethanechol chloride is administered IV or IM. This reaction has also rarely occurred in cases of hypersensitivity or overdose.

4.5 Interaction With Other Medicinal Products And Other Forms Of Interaction

Cholinergics, other, especially cholinesterase inhibitors.

Ganglionic blocking agents such as mecamylamine, pentolinium and trimethaphan.

Procainamide or quinidine.

4.6 Pregnancy And Lactation

Should not be used during pregnancy or lactation.

4.7 Effects On Ability To Drive And Use Machines

In some cases the ability to drive and operate machinery may be impaired.

4.8 Undesirable Effects

Nausea, vomiting, sweating and intestinal colic.

4.9 Overdose

The symptoms of overdose include nausea, salivation, lachrymation, eructation, involuntary defecation and urination, transient dyspnoea, palpitation, bradycardia and peripheral vasodilation leading to hypertension, transient heart block and a feeling of constriction under the sternum.

Procedure: The stomach should be emptied by aspiration or lavage. Give atropine sulphate 1-2mg intravenously, intramuscularly or subcutaneously to control muscarinic effects. The dose may be repeated every 2-4 hours as necessary.

Supportive treatment includes intravenous administration of diazepam 5-10mg: muscle twitching may be controlled by small doses of tubocararine (together with assisted respiration): oxygen may be required.

5. Pharmacological Properties

5.1 Pharmacodynamic Properties

Bethanechol is a synthetic choline ester of carbamic acid which possesses a significant acetylcholine-like activity. It is active after oral administration.As a consequence of the very slow hydrolysation by acetylcholinesterase bethanechol has a prolonged action as has been demonstrated in the urinary tract. The onset of action occurs after oral administration within an hour.

The major pharmacological effects of bethanechol result from interaction of the drug with muscarinic receptor sites of smooth muscles, especially those of the urinary bladder and gastrointestinal tract.

In addition, minor but important nicotinic effects have been noted. In usual therapeutic doses, bethanechol does not cross the blood brain barrier.

5.2 Pharmacokinetic Properties

Studies not available.

5.3 Preclinical Safety Data

N/A

6. Pharmaceutical Particulars

6.1 List Of Excipients

Calcium sulphate dihydrate BP.

Maize starch BP.

Talc BP(iron free)

6.2 Incompatibilities

Major –none known.

6.3 Shelf Life

The shelf life of Myotonine tablets is currently two years from date of manufacture.

6.4 Special Precautions For Storage

Keep out of reach of children and away from direct heat or light sources.

Store below 25ºC.

6.5 Nature And Contents Of Container

The container is of polypropylene with a tamper-evident polyethylene cap and closure. A filla may be inserted to reduce the risk of tablet breakage due to ullage.

Each container is filled with 100 tablets.

6.6 Special Precautions For Disposal And Other Handling

7. Marketing Authorisation Holder

Glenwood Laboratories UK Ltd.

Jenkins Dale

Chatham

Kent

ME4 5RD

8. Marketing Authorisation Number(S)

Myotonine 25mg 00245/5010R.

9. Date Of First Authorisation/Renewal Of The Authorisation

February 2003

10. Date Of Revision Of The Text

November 2003,February 2000, April 1996,July 1995.