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Interactions
Disturbance of blood sugar control. As with all hypoglycaemics,
caution should be observed in administering thiazide diuretics to patients on gliclazide therapy,
since thiazides have been reported to aggravate the diabetic state. Other drugs which may adversely
affect blood sugar control with hypoglycaemic agents in some patients include barbiturates, glucocorticoids and oestrogens.
Potentiation of hypoglycaemic effect. Certain drugs
may potentiate the effect of gliclazide and thereby increase the risk of hypoglycaemia. These include insulin,
biguanides, sulphonamides, oxyphenbutazone, phenylbutazone, clofibrate, salicylates, coumarin derivatives,
chloramphenicol, MAOIs, β-blockers, cimetidine and ethanol.
Alcohol. Acute alcohol intoxication potentiates
the hypoglycaemic action of all sulphonylurea agents. Furthermore, ingestion d alcohol may cause a
disulfiram-like reaction with characteristic flushing of the face, throbbing headache, giddiness, tachypnoea, tachycardia or angina pectoris.
Chronic alcohol abuse may, as a result of liver
enzyme induction, stimulate the metabolism of sulphonylurea drugs and shorten plasma half-life and duration of action.
Adverse Reactions
Adverse reactions have occurred in some 12% of
cases in clinical studies. However, approximately 2% of patients were withdrawn from therapy
because of adverse reactions, notably hypoglycaemia, gastrointestinal disturbances
(constipation, nausea, epigastric discomfort and heartburn), dermatological reactions
(rash and transient itching), and biochemical abnormalities (elevated serum creatinine,
increased serum alkaline phosphatase, raised serum AST, elevated BUN and raised serum bilirubin).
Headache, slight disulfiram-like reactions and lassitude have also been reported.
As is the case with all forms of antidiabetic therapy,
hypoglycaemic reactions may occur following Glyade administration.
Severe hypoglycaemia, though uncommon, may occur in patients receiving gliclazide.
Serious reactions which have been reported with
other sulphonylureas are leucopenia, thrombocytopenia, agranulocytosis, pancytopenia haemolytic anaemia,
cholestatic jaundice and gastrointestinal haemorrhage. These reactions have not been reported with gliclazide.
Dosage and Administration
The dosage of gliclazide should be carefully titrated
to maintain optimal control at the various possible dose levels. Dosage should be initiated at 40mg ½ tablet)
daily and may be increased if necessary up to 320mg (4 tablets) daily. Doses up to 160mg daily may
be taken in a single dose but preferably at the same time each morning. Doses in excess of 160mg should be taken in divided doses in the morning and evening.
In general, the dosage will be dependent upon the
severity of the glycaemia with ongoing adjustments made in order to obtain the optimal response at the lowest dosage.
Treatment with gliclazide does not obviate the necessity for maintaining standard dietary regulations.
Transferring to gliclazide. Patients who have previously been treated with
sulphonylureas or biguanides alone or in combination may be transferred to gliclazide. When gliclazide
is administered as sole therapy (eg. biguanides plus sulphonylureas), careful observation of
the patient is essential during the transitional phase. It is recommended that insulin treated patients should not be transferred to gliclazide therapy.
Overdosage
Symptoms. Manifestations of severe hypoglycaemia
result from overdosage. Hypoglycaemia caused by sulphonylurea agents differs in several aspects
from insulin coma. Warning symptoms are often absent, neurological syndromes are frequent and coma is often prolonged.
Treatment. Consciousness should be restored by the administration of intravenous
glucose or glucagon injection, care being taken to ensure against return of hypoglycaemia by constant monitoring of the blood sugar level.
Presentation
Glyade, 80mg tablet: white, flat bevelled edged,
marked 'GZ80' on one side with a double score on the other • Blisters 100's.
Storage Conditions and Shelf Life
Store below 30°C. Shelf life: 3 years
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