PCE Dispertab and Tolvaptan (Samsca)

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Erythromycin may increase the blood levels of tolvaptan in some patients. Serious nervous system side effects such as difficulty swallowing, trouble speaking, muscle weakness, trouble controlling body movements, confusion, mood changes, seizures, and coma may occur due to too rapid correction of salt levels in the blood. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

GENERALLY AVOID: Coadministration with inhibitors of CYP450 3A4 may significantly increase the plasma concentrations of tolvaptan, which is almost exclusively metabolized by the isoenzyme. The interaction has been studied with ketoconazole, a potent CYP450 3A4 inhibitor. When a single 30 mg oral dose of tolvaptan was administered to 19 healthy volunteers following pretreatment with ketoconazole 200 mg/day for 3 days, tolvaptan peak plasma concentration (Cmax) increased by 3.5-fold and systemic exposure (AUC) increased by 5.4-fold, although 24-hour urine output increased by just 1.3-fold due to the saturable nature of tolvaptan's effect on urinary excretion rate. The impact of moderate CYP450 3A4 inhibitors has not been adequately assessed. According to the product labeling, grapefruit juice has been shown to increase tolvaptan exposure by 1.8-fold. However, the potency of grapefruit juice as an inhibitor of CYP450 3A4 depends on its strength, which was not specified.

Concomitant use of tolvaptan with moderate CYP450 3A4 inhibitors should generally be avoided unless no alternatives exist and benefits outweigh potential risks. A lower dosage of tolvaptan should be considered. Serum sodium concentration and neurologic status should be closely monitored during coadministration. Too rapid correction of hyponatremia increases the risk of osmotic demyelination syndrome, which is associated with dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma, and death. Discontinuation or interruption of tolvaptan therapy should be considered in patients who develop too rapid a rise in serum sodium.

PCE Dispertab

Generic Name: erythromycin

Brand name: EES. Granules, EES-400 Filmtab, EryPed 200, EryPed 400, Ery-Tab, Erythrocin Lactobionate, Erythrocin Stearate Filmtab, PCE Dispertab, E. E. S, EryPed, Erythrocin, Erythromycin Filmtabs, Erythromycin Lactobionate - IV

Synonyms: PCE Dispertab (Oral), PCE, PCE (Oral)

What is PCE Dispertab?

Tolvaptan (Samsca)

Generic Name: tolvaptan

Brand name: Samsca, Jynarque

Synonyms: Tolvaptan

What is Tolvaptan (Samsca)?