Initial treatment of clinically relevant vitamin D deficiency in adults.

Posology

Recommended dose: One bottle (25 000 I.U.) weekly.

After first month, lower doses may be considered, dependent upon desirable serum levels of 25-hydroxycolecalciferol (25(OH)D), the severity of the disease and the patient´ s response to treatment.

Alternatively, national posology recommendations in treatment of vitamin D deficiency can be followed.

Special population

Dosage in hepatic impairment

No dose adjustment is required.

Dosage in renal impairment

Patients with mild or moderate renal impairment: no specific adjustment is required

Colecalciferol must not be used in patients with severe renal impairment.

Paediatric population

THORENS 25 000 I.U. /2.5 ml is not recommended in children and adolescents under 18 years of age.

Pregnancy and breastfeeding

THORENS 25 000 I.U. /2.5 ml is not recommended

Method of administration

Patients should be advised to take THORENS preferably with meal (see section 5.2 Pharmacokinetic properties - “ Absorption” ).

The product should be shaken before use.

THORENS has a taste of olive oil. THORENS can be taken as is from the bottle or to facilitate intake it can also mixed with a small amount of cold or lukewarm food immediately prior to use. The patient should be sure to take the entire dose.

See also section 6.6 Special precautions for handling and disposal.

Hypersensitivity to the active ingredient, colecalciferol (vitamin D₃), or to any of the excipients listed in section 6.1.

Hypercalcaemia, hypercalciuria

Hypervitaminosis D

Kidney stones (nephrolithiasis, nephrocalcinosis) in patients with current chronic hypercalcaemia

Severe renal impairment

Vitamin D₃ should be used with caution in patients with impairment of renal function and the effect on calcium and phosphate levels should be monitored. The risk of soft tissue calcification should be taken into account. In patients with severe renal insufficiency, vitamin D in the form of colecalciferol is not metabolised normally and other forms of vitamin D have to be used.

Caution is required in patients receiving treatment for cardiovascular disease (see section 4.5 Interaction with other medicinal products and other forms of interaction - cardiac glycosides including digitalis).

THORENS should be prescribed with caution in patients with sarcoidosis, due to a possible increase in the metabolism of vitamin D₃ in its active form. In these patients the serum and urinary calcium levels should be monitored.

Allowances should be made for the total dose of vitamin D₃ in cases associated with treatments already containing vitamin D, foods enriched with vitamin D₃, cases using milk enriched with vitamin D, and the patient's level of sun exposure.

There is no clear evidence for causation between vitamin D₃ supplementation and renal stones, but the risk is plausible, especially in the context of concomitant calcium supplementation. The need for additional calcium supplementation should be considered for individual patients. Calcium supplements should be given under close medical supervision.

During long-term treatment with a daily dose exceeding 1 000 I.U. vitamin D₃ the serum calcium values must be monitored.

Concomitant use of anticonvulsants (such as phenytoin) or barbiturates (and possibly other drugs that induce hepatic enzymes) may reduce the effect of vitamin D₃ by metabolic inactivation.

In cases of treatment with thiazide diuretics, which decrease urinary elimination of calcium, monitoring of serum calcium concentration is recommended.

Concomitant use of glucocorticoids can decrease the effect of vitamin D₃.

In cases of treatment with drugs containing digitalis and other cardiac glycosides, the administration of vitamin D₃ may increases the risk of digitalis toxicity (arrhythmia). Strict medical supervision is needed, together with serum calcium concentration and electrocardiographic monitoring if necessary.

Simultaneous treatment with ion exchange resin such as cholestyramine, colestipol hydrochloride, orlistat or laxative such as paraffin oil may reduce the gastrointestinal absorption of vitamin D₃.

The cytotoxic agent actinomycin and imidazole antifungal agents interfere with vitamin D₃ activity by inhibiting the conversion of 25-hydroxyvitamin D₃ to 1,25-dihydroxyvitamin D₃ by the kidney enzyme, 25-hydroxyvitamin D-1-hydroxylase.

THORENS 25 000 I.U. /2.5ml oral solution is not recommended in pregnancy and lactation. A low strength formulation should be used.

Pregnancy

There are no or limited amount of data from the use of colecalciferol (vitamin D₃) in pregnant women. Studies in animals have shown reproductive toxicity (see section 5.3 Preclinical safety data). The recommended daily intake for pregnant women is 400 I.U., however, in women who are considered to be vitamin D₃ deficient a higher dose may be required (up to 2 000 I.U. /day - 10 drops with the oral drops presentation). During pregnancy women should follow the advice of their medical practitioner as their requirements may vary depending on the severity of their disease and their response to treatment.

Breast-feeding

Vitamin D3 and its metabolites are excreted in breast milk. Vitamin D₃ can be prescribed while the patient is breast-feeding if necessary. This supplementation does not replace the administration of vitamin D₃ in the neonate.

Overdose in infants induced by nursing mothers has not been observed, however, when prescribing additional vitamin D₃ to a breast-fed child the practitioner should consider the dose of any additional vitamin D₃ given to the mother.

Fertility

There are no data on the effect of THORENS on fertility. However, normal endogenous levels of vitamin D are not expected to have any adverse effects on fertility.

There are no data on the effects of THORENS on the ability to drive. However, an effect on this ability is unlikely.

Adverse reactions are listed below, by system organ class and frequency. Frequencies are defined as: uncommon (>1/1,000, <1/100) or rare (>1/10,000, <1/1,000).

Metabolism and nutrition disorders

Uncommon: Hypercalcaemia and hypercalciuria

Skin and subcutaneous disorders:

Rare: pruritus, rash, and urticaria.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Discontinue THORENS when calcaemia exceeds 10.6 mg/dl (2.65 mmol/l) or if the calciuria exceeds 300 mg/24 hours in adults or 4-6 mg/kg/day in children. An overdose manifests as hypercalcaemia and hypercalciuria, the symptoms of which include the following: nausea, vomiting, thirst, constipation, polyuria, polydipsia and dehydration.

Chronic overdosage may lead to vascular and organ calcification, as a result of hypercalcaemia.

Treatment in cases of overdose

Discontinue administration of THORENS and initiate rehydration.

Pharmacotherapeutic group: vitamin D₃ and analogues, colecalciferol

ATC Code: A11CC05

In its biologically active form vitamin D₃ stimulates intestinal calcium absorption, incorporation of calcium into the osteoid, and release of calcium from bone tissue. In the small intestine it promotes rapid and delayed calcium uptake. The passive and active transport of phosphate is also stimulated. In the kidney, it inhibits the excretion of calcium and phosphate by promoting tubular resorption. The production of parathyroid hormone (PTH) in the parathyroids is inhibited directly by the biologically active form of vitamin D₃. PTH secretion is inhibited additionally by the increased calcium uptake in the small intestine under the influence of biologically active vitamin D₃.

The pharmacokinetics of vitamin D₃ is well known.

Absorption

Vitamin D₃ is well absorbed from the gastro-intestinal tract in the presence of bile, so the administration with the major meal of the day might therefore facilitate the absorption of vitamin D₃.

Distribution and biotransformation

It is hydroxylated in the liver to form 25-hydroxy-colecalciferol and then undergoes further hydroxylation in the kidney to form the active metabolite 1,25-dihydroxy-colecalciferol (calcitriol).

Elimination

The metabolites circulate in the blood bound to a specific α – globin, vitamin D₃ and its metabolites are excreted mainly in the bile and faeces.

Characteristics in Specific Groups of Subjects or Patients

A 57% lower metabolic clearance rate is reported in subjects with renal impairment as compared with that of healthy volunteers.

Decreased absorption and increased elimination of vitamin D₃ occurs in subjects with malabsorption.

Obese subjects are less able to maintain vitamin D₃ levels with sun exposure, and are likely to require larger oral doses of vitamin D₃ to replace deficits.

Pre-clinical studies conducted in various animal species have demonstrated that toxic effects occur in animals at doses much higher than those required for therapeutic use in humans.

In toxicity studies at repeated doses, the effects most commonly reported were increased calciuria and decreased phosphaturia and proteinuria.

Hypercalcaemia has been reported in high doses. In a state of prolonged hypercalcaemia, histological alterations (calcification) were more frequently borne by the kidneys, heart, aorta, testes, thymus and intestinal mucosa.

Colecalciferol (vitamin D₃) has been shown to be teratogenic at high doses in animals.

At doses equivalent to those used therapeutically, colecalciferol (vitamin D₃) has no teratogenic activity.

Colecalciferol (vitamin D₃) has no potential mutagenic or carcinogenic activity.

Refined olive oil.

In absence of compatibility studies, this medicinal product must not be mixed with other medicinal products.

4 years.

Do not store above 30° C.

Do not freeze or refrigerate.

Keep the bottle in the outer carton in order to protect from light.

Amber glass Type III bottle of 5 ml containing 2.5 ml oral solution, sealed by a cap made of polypropylene and polyethylene.

Packs of 1 single dose bottle and 4 single dose bottles.

Not all pack sizes may be marketed.

You should preferably take THORENS together with meal (see section 5.2 Pharmacokinetic properties - “ Absorption” ).

Do not store any product or food mixture that contains this medicine for use at a later time or a next meal (see section 4.2 Posology and method of administration).

Any unused medicinal product or waste material should be disposed of in accordance with the local requirements.