Interactions : אינטראקציות

4.5   Interaction with other medicinal products and other forms of interaction

Anticholinergic agents may potentially alter the absorption of some concomitantly administered medicinal products due to anticholinergic effects on gastrointestinal motility.

Anticholinergic medicinal products should be used with caution in patients who are concurrently taking medicinal products (such as bisphosphonates) that can cause or exacerbate oesophagitis.

Due to dry mouth, sublingually administered nitrates may dissolve to a lesser extent, which can lead to decreased therapeutic effect of the nitrates. Patients treated with sublingual nitrates should therefore be instructed to moisten the oral mucosa before use (see section 4.4).

Oxybutynin is metabolised by cytochrome P 450 isoenzyme CYP 3A4. By applying oxybutynin intravesically, this first-pass metabolism is mainly circumvented. However, interactions with medicinal products that inhibit cytochrome P 450 isoenzyme CYP 3A4 cannot be ruled out. This should be borne in mind when using azole antifungals (e.g. ketoconazole) or macrolide antibiotics (e.g. erythromycin) concurrently with oxybutynin.

The anticholinergic activity of oxybutynin is increased by concurrent use of other anticholinergics or medicinal products with anticholinergic activity, such as amantadine and other anticholinergic antiparkinsonian medicinal products (e.g. biperiden, levodopa), antihistamines, antipsychotics (e.g.
phenothiazines, butyrophenones, clozapine), quinidine, tricyclic antidepressants, atropine and related compounds like atropinic antispasmodics, dipyridamole.

Oxybutynin may antagonise prokinetic therapy.

Concomitant use with cholinesterase inhibitors may result in reduced cholinesterase inhibitor efficacy.