Gtn 300mcg
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
GTN 300mcg
Glyceryl Trinitrate 300 micrograms Tablets
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains 300 micrograms Glyceryl Trinitrate (2% on mannitol) equivalent to 0.3mg glyceryl trinitrate
Excipients: Contains lactose
For the full list of excipients, see section 6.1.
3 PHARMACEUTICAL FORM
Sublingual tablet (tablets)
Plain white biconvex tablets
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
A short acting vasodilator for the prophylaxis and treatment of attacks of angina pectoris.
4.2. Posology and Method of Administration
Adults and the elderly
One tablet to be allowed to dissolve slowly under the tongue. The treatment may be repeated as necessary. If pain persists for more than 15 minutes medical care should be sought.
Children
Not recommended for children
4.3. Contraindications
Marked anaemia, closed angle glaucoma, head trauma, cerebral haemorrhage, hypersensitivity to nitrates, hypotensive conditions and hypovolaemia, hypertrophic obstructive cardiomyopathy, aortic stenosis, cardiac tamponade, constrictive pericarditis, mitral stenosis.
Co-administration with sildenafil, tadalafil and vardenafil. These drugs have shown to significantly potentiate the hypotensive effects of nitrates. Glyceryl Trinitrate may reduce the anticoagulant effect of heparin. Its simultaneous administration with heparin is therefore contra-indicated.
4.4. Special Warnings and Precautions for Use
Caution should be exercised in cases of severe hepatic or renal impairment; hypothyroidism, malnutrition, hypothermia, head trauma, cerebral haemorrhage or a recent history of myocardial infarction.
Tolerance may develop after regular long term use.
4.5. Interactions with other Medicaments and other forms of Interaction
When used with anti-muscarinic, anti-arrhythmic or tricyclic antidepressant drugs the effect of Glyceryl trinitrate may be lost (due to failure to dissolve under the tongue). The hypotensive effects of nitrates are potentiated by concurrent administration of sildenafil, tadalafil and vardenafil. (see Contraindications).
Heparin: See Contraindications.
Hypotensive effect of nitrates antagonised by: Carbenoxalone (ulcer healing drug), oestrogens, corticosteroids and NSAIDs.
Hypotensive effect of nitrates enhanced by: sublingual apomorphine and alcohol.
Nitrates enhance the hypotensive effect of: Angiotensin II receptor agonists. Hydralazine, minoxidil or nitroprusside, baclofen and tizanadine, moxonidine, levadopa, methyldopa, MAOI’s, moxisylate (thyroxamine), diuretics,
diazoxide, clonidine, Calcium channel blockers, Beta-blockers, anxiolytics and hypnotics and phenothiazine.
Other drugs which can also enhance the hypotensive effects of nitrates are general anaesthetics.
4.6. Pregnancy and Lactation
There is some evidence of hazard in animals when nitrates have been given in pregnancy. Avoid in pregnancy unless there is no safer alternative. Problems in breast feeding have not been documented.
4.7. Effects on Ability to Drive and Use Machines
Dizziness is a known side effect, if affected, patients should not drive or operate machinery.
4.8. Undesirable Effects
The following side effects have been reported: Throbbing headache, facial flushing, dizziness, postural hypotension and tachycardia. Paradoxical bradycardia has been reported. More rarely there may be localised feeling of discomfort in the mouth or tongue and blistering or ulcers have been reported.
4.9. Overdose
Symptoms:
Vomiting, restlessness, hypotension, cyanosis, methaemoglobinaemia. Severe poisoning may result in bradycardia, respiratory depression and psychosis. Treatment:
Remove any tablet from the mouth and place the patient in a recumbent position with the head down. If recovery is not rapid or in the case of known severe poisoning, the stomach should be emptied to prevent further absorption and general supportive measures, such as oxygen, assisted respiration and plasma expanders employed as necessary. If methaeglobinaemia has occurred it can be treated with methylene blue. Intravenous injection of 1 - 4 mg/kg body weight.
Pharmacodynamic properties
5.1
Glyceryl trinitrate relaxes smooth muscle, including vascular muscle. The precise mechanism of action is not fully understood but it is thought that the cause is a reduction of myocardial oxygen demand.
5.2. Pharmacokinetic Properties
Glyceryl trinitrate is rapidly absorbed sublingually. Metabolism occurs mainly in the liver and blood by glutathione - organic nitrate reductase to dinitrates which are less potent vasodilators than trinitrates. Half life is 1 to 4 minutes.
5.3. Preclinical Safety Data
None stated
6 PHARMACEUTICAL PARTICULARS
6.1 List of excipients
Mannitol
Acacia
Lactose
Talc
Stearic Acid Magnesium Stearate
6.2. Incompatibilities
Not applicable
6.3 Shelf life
Unopened: 24 months.
After first opening: Discard 8 weeks after first opening.
6.4. Special Precautions for Storage
Store in a dry place below 25 °C. Protect from light.
6.5 Nature and contents of container
Amber glass bottle with aluminium wadded cap packed in a cardboard carton along with a patient leaflet.
Pack size: 100 tablets.
6.6 Special precautions for disposal
• After removing a tablet, close the cap tightly
• Do not transfer the tablets to another container
• Do not put any packing material into the bottle with the tablets
• If you do not use the tablets within 8 weeks of first opening the bottle, obtain a fresh supply and return the old tablets to the pharmacist for disposal
7 MARKETING AUTHORISATION HOLDER
Macarthys Laboratories Ltd T/A Martindale Pharmaceuticals Bampton Road,
Harold Hill,
Romford,
RM3 8UG
8 MARKETING AUTHORISATION NUMBER(S)
PL 01883/5958R
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION
28/11/2005
10 DATE OF REVISION OF THE TEXT
16/10/2013