Hi Mo, I think that there is a possible contraindication with taking calcium tabs at the same time as, or near to, taking your TKI. If you are taking chewable calcium that is probably in the form of calcium carbonate you should take your drug at least 2 or 3 hours away from taking calcium carbonate preparations.
It seems that drugs that elevate the gastric PH (like antacids) will affect absorbtion of TKI drugs- and therefore the plasma concentration will be under the required level for the drug to work well.
TKIs seem to need a low (acidic) gastric PH to ensure enough is absorbed into the blood.
I would advise you take and calcium away from TKI therapy..ie wait until either the TKI or the Calcium has been fully metabolised.
This is my (non-expert)understanding but you really should check with HH doctors.
I did a quick search and found drug to drug contraindications on Drugs.com...
see info on 4 TKIs below- however I couldn't find imatinib.
Dasatinib: http://www.drugs.com/drug-interactions/calcium-carbonate-with-dasatinib-...
Non-clinical data indicate that the solubility of dasatinib is pH-dependent. Therefore, co-administration with antacids or agents with acid-neutralizing effects may reduce the oral bio-availability of dasatinib.
Nilotinib: http://www.drugs.com/drug-interactions/calcium-carbonate-with-nilotinib-...
http://www.drugs.com/drug-interactions/calcium-carbonate-with-nilotinib-...
bosutinib: http://www.drugs.com/drug-interactions/bosulif-with-calcium-carbonate-34...
Concurrent administration of agents that increase gastric pH such as H2-receptor antagonists or antacids may decrease the oral bioavailability of bosutinib and reduce its concentrations in plasma. The solubility of bosutinib decreases rapidly when the pH is above 5, resulting in reduced absorption.
Ponatinib: http://www.drugs.com/drug-interactions/calcium-carbonate-with-iclusig-46...
GENERALLY AVOID: Co-administration with drugs that elevate the gastric pH such as proton pump inhibitors, H2-receptor antagonists, and antacids may decrease the oral bioavailability of ponatinib and reduce its concentrations in plasma. The interaction has not been evaluated in a clinical study. However, the aqueous solubility of ponatinib has been shown to be pH-dependent, with higher pH resulting in decreased solubility.
