Interaction between Alendronic acid and Etelcalcetide
Major Synergy

ID DDInter42 and DDInter688
Interaction Concomitant use of etelcalcetide with other medicines known to lower serum calcium may increase the risk of hypocalcemia. The proposed mechanism is additive reduction in serum calcium levels. Significant decreases in serum calcium may cause paraesthesias, myalgias, muscle spasms, seizures, QT interval prolongation, and ventricular arrhythmia. Etelcalcetide given alone may lead to severe hypocalcemia requiring concomitant treatment with therapies to increase serum calcium levels.
Management Close monitoring of corrected serum calcium levels is recommended if etelcalcetide is used in combination with other medications known to lower serum calcium, such as denosumab, calcitonin, foscarnet, bisphosphonates, or loop diuretics. It is recommended that the patient's corrected serum calcium level should be measured within one week of initiation or dose adjustment of etelcalcetide and monitored approximately every 4 weeks. In addition, the manufacturer product labeling should be consulted for management guidelines in the event of a reduction in corrected serum calcium levels below the lower limit of the normal range and/or symptoms of hypocalcemia. Patients should also be advised to contact their health care professional if they experience symptoms of hypocalcemia, such as numbness or tingling in the fingers, toes, or around the mouth, muscle spasms, twitches or cramps, seizures, confusion, and irregular heartbeats.
References
Alternative for Alendronic acid M05B
Cholecalciferol
Alternative for Etelcalcetide H05B
Doxercalciferol
Salmon calcitonin

Potential Metabolism Interactions

Substrate-Substrate Interaction：If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction：Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction：Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.