THORENS Capsule, hard Ref.[27638] Active ingredients: Vitamin D3

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 must be used with particular caution in patients treated with benzothiadiazine derivatives (see section 4.5 Interaction with other medicinal products and other forms of interaction) and in immobilized patients (risk of hypercalcaemia and hypercalciuria). Plasma and urinary calcium levels should be monitored in these patients.

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.

THORENS should not be taken if pseudohypoparathyroidism is present (the need for vitamin D may be reduced by the sometimes normal sensitivity to vitamin D, with a risk of long-term overdose). In such cases, more manageable vitamin D derivatives are available."

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 IU 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.

Rifampicin may reduce the effectiveness of colecalciferol due to hepatic enzyme induction.

Isoniazid may reduce the effectiveness of colecalciferol due to inhibition of the metabolic activation of colecalciferol.

THORENS 25.000 IU capsules 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). Long-term overdose must be avoided during pregnancy, since the resulting protracted hypercalcaemia may lead to physical and mental retardation, supravalvular aortic stenosis and retinopathy in the child. The recommended daily intake for pregnant women is 400 IU, however, in women who are considered to be vitamin D₃ deficient a higher dose may be required (up to 2000 IU/day). 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. Treatment of pregnant women with high-dose vitamin D is not recommended.

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. Treatment with high-dose vitamin D in breast-feeding women is not recommended.

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.

Not applicable.