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Ascorbic Acid 500mg Tablets

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SUMMARY OF PRODUCT CHARACTERISTICS

1 NAME OF THE MEDICINAL PRODUCT

Ascorbic Acid 500mg Tablets

2 QUALITATIVE AND QUANTITATIVE COMPOSITION

Ascorbic Acid 500mg

3    PHARMACEUTICAL FORM

Tablets

4 CLINICAL PARTICULARS

4.1    Therapeutic indications

Vitamin C deficiency Treatment and prevention of scurvy

4.2    Posology and method of administration

For oral use. Chew tablets before swallowing.

Adults

Therapeutic use: at least 250mg daily in divided doses.

Prophylactic use: 25-75mg daily.

Maximum of 1000mg daily.

Children (4-12 years)

Half the adult dose (at least 125mg daily in divided doses).

Elderly

As for other adults.

As the dietary intake of vitamin C may be less in the elderly, they have greater risk of presenting with vitamin C deficiency.

4.3    Contraindications

Ascorbic acid should not be given to patients with hyperoxaluria.

4.4    Special warnings and precautions for use

Increased intake of ascorbic acid over a prolonged period may result in increased renal clearance of ascorbic acid, and deficiency may result if the intake is reduced or withdrawn rapidly.

Interference with serological testing

Ascorbic acid may interfere with tests and assays for urinary glucose, giving false-negative results with methods utilising glucose oxidase with indicator (e.g. Labstix, Testape) and falsepositive results with neocuproin methods. Estimation of uric acid by phosphotungstate or uricase with copper reduction and measurement of creatine in non-deproteinised serum may also be affected. High doses of ascorbic acid may give false-negative readings in faecal occult blood tests.

4.5 Interactions with other medicinal products and other forms of interaction

Ascorbic acid increases the renal excretion of amphetamine. The plasma concentration of ascorbate is decreased by smoking and oral contraceptives.

Ascorbic acid increases the absorption of iron.

Concomitant administration of aspirin and ascorbic acid may interfere with absorption of ascorbic acid. Renal excretion of salicylate is not affected and does not lead to reduced antiinflammatory effects of aspirin.

Concomitant administration of aluminium-containing antacids may increase urinary aluminium elimination. Concurrent administration of antacids and ascorbic acid is not recommended, especially in patients with renal insufficiency.

Co-administration with amygdalin (a complementary medicine) can cause cyanide toxicity.

Concurrent administration of ascorbic acid with desferrioxamine enhances urinary iron excretion. Cases of cardiomyopathy and congestive heart failure have been reported in patients with idiopathic haemochromatosis and thalassaemias receiving desferrioxamine who were subsequently given ascorbic acid. Ascorbic acid should be used with caution in these patients and cardiac function monitored.

Ascorbic acid may interfere with biochemical determinations of creatinine, uric acid and glucose in samples of blood and urine.

4.6    Fertility, pregnancy and lactation

For ascorbic acid no clinical data on exposed pregnancies are available.

Animal studies do not indicate direct or harmful effects with respect to pregnancy, embryonal/foetal development, parturition or postnatal development.

Pregnant women should exercise caution.

Ascorbic acid is excreted in breast milk. Though again caution should be exercised, no evidence exists suggesting such excretion is hazardous to the infant.

4.7    Effects on ability to drive and use machines

On the basis of the product’s pharmacodynamic profile and reported adverse events, ascorbic acid has no known effect on an individual’s ability to drive or operate machinery.

Undesirable effects

4.8


Gastrointestinal disturbances: nausea, vomiting and stomach cramps.

Large doses of ascorbic acid may cause diarrhoea.

Flushing or redness of skin, headache.

Patients known to be at risk of hyperoxaluria should not ingest ascorbic acid doses exceeding 1gm daily, as there may be increased urinary oxalate excretion. However, such risk has not been demonstrated in normal, non-hyper oxaluric individuals. Ascorbic acid has been implicated in precipitating haemolytic anaemia in certain individuals deficient of glucose-6-phosphate dehydrogenase. Increased intake of ascorbic acid over a prolonged period may result in increased renal clearance of ascorbic acid, and deficiency may result if the intake is reduced or withdrawn rapidly. Doses of more than 600mg daily have a diuretic effect.

4.9    Overdose

At doses of over 3g per day unabsorbed ascorbic acid is mainly excreted unmetabolised in the faeces. Absorbed ascorbic acid additional to the body’s needs is rapidly eliminated. Large doses of ascorbic acid may cause diarrhoea and the formation of renal oxalate calculi. Symptomatic treatment may be required.

Ascorbic acid may cause acidosis or haemolytic anaemia in certain individuals with a deficiency of glucose 6-phosphate dyhydrogenase. Renal failure can occur with massive ascorbic acid overdosage.

Gastric lavage may be given if ingestion is recent otherwise general supportive measures should be employed as required

5    PHARMACOLOGICAL PROPERTIES

5.1    Pharmacodynamic properties

Ascorbic acid, coupled with dehydroascorbic acid to which it is reversibly oxidised, has a variety of functions in cellular oxidation processes. Ascorbic acid is required in several important hydroxylations, including the conversion of proline to hydroxyproline (and thus in collagen formation e.g. for intercellular substances and during wound healing); the formation of the neurotransmitters 5-hydroxytryptamine from tryptophan and noradrenaline from dopamine, and the biosynthesis of carnitine from lysine and methionine. Ascorbic acid appears to have an important role in metal ion metabolism, including the gastrointestinal absorption of iron and its transport between plasma and storage organs. There is evidence that ascorbic acid is required for normal leucocyte functions and that it participates in the detoxification of numerous foreign substances by the hepatic microsomal system. Deficiency of ascorbic acid leads to scurvy, which may be manifested by weakness, fatigue, dyspnoea, aching bones, perifollicular hyperkeratoses, petechiae and ecchymoses, swelling and bleeding of the gums, hypochromic anaemia and other haematopoietic disorders, together with reduced residence to infections and impaired would healing.

5.2    Pharmacokinetic properties

Ascorbic acid is well absorbed from the gastro-intestinal tract, and is widely distributed to all tissues. Body stores of ascorbic acid normally are about 1.5g. The concentration is higher in leucocytes and platelets than in erythrocytes and plasma. Ascorbic acid additional to the body’s needs, generally amounts above 200mg daily, is rapidly eliminated; unmetabolised

ascorbic acid and its inactive metabolic products are chiefly excreted in the urine. The amount of ascorbic acid excreted unchanged in the urine is dose-dependent and may be accompanied by mild diuresis.

5.3    Preclinical safety data

There is no pre-clinical data of relevance to a prescriber which is additional to that already included in other sections of the SmPC.

6    PHARMACEUTICAL PARTICULARS

6.1 List of excipients

Microcrystalline cellulose, stearic acid and magnesium stearate.

6.2    Incompatibilities

None known

6.3    Shelf life

36 months

6.4    Special precautions for    storage

Do not store above 25°C. Keep the container tightly closed. Store in the original container.

6.5    Nature and contents of container

The tablet container is made of polypropylene material with low-density polyethylene caps. A low-density polyethylene bag contains the leaflet in the pot.

Tablet container containing 28, 100, 500 or 1000 tablets. Not all pack sizes may be marketed.

6.6    Special precautions for disposal

Always close the cap securely after use.

7    MARKETING AUTHORISATION HOLDER

Athlone Pharmaceuticals Limited

Ballymurray

Co. Roscommon

Ireland

8 MARKETING AUTHORISATION NUMBER(S)

PL 30464/0057

9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE AUTHORISATION

21/07/2000

16/11/2005

10 DATE OF REVISION OF THE TEXT

12/11/2013