▶Intravenouscalcium saltsincrease the concentration of
digoxin. Avoid.oAnecdotal
▶Oralcalcium saltsdecrease the absorption ofdolutegravir.
Dolutegravirshould be taken 2 hours before or 6 hours after
calcium salts.oStudy
▶Oralcalcium saltsdecrease the absorption ofeltrombopag.
Eltrombopagshould be taken 2 hours before or 4 hours after
calcium salts.rStudy
▶Calcium carbonatedecreases the absorption of
hydroxychloroquine. Separate administration by at least
4 hours.oStudy
▶Calcium carbonatedecreases the absorption ofiron (oral).
Calcium carbonateshould be taken 1 hour before or 2 hours
afteriron (oral).oStudy
▶Calcium carbonateis predicted to decrease the exposure to
ledipasvir. Separate administration by 4 hours.o
Theoretical
▶Calcium carbonatedecreases the absorption ofquinolones
(ciprofloxacin). Separate administration by 2 hours.o
Study
▶Calcium carbonatedecreases the absorption ofquinolones
(norfloxacin).Norfloxacinshould be taken 2 hours before or
4 hours aftercalcium carbonate.oStudy
▶Calcium carbonategreatly decreases the exposure to
raltegravir(high-dose). Avoid.rStudy
▶Calcium carbonateis predicted to slightly decrease the
exposure torilpivirine.Calcium carbonateshould be taken
2 hours before or 4 hours afterrilpivirine.rTheoretical
▶Calcium carbonateis predicted to decrease the absorption of
tetracyclines. Separate administration by 2 to 3 hours.
oTheoretical
▶Thiazide diureticsincrease the risk of hypercalcaemia when
given withcalcium salts.rAnecdotal
▶Oralcalcium saltsare predicted to decrease the absorption of
thyroid hormones(levothyroxine). Separate administration by at
least 4 hours.oAnecdotal
▶Calcium carbonateis predicted to decrease the concentration
ofvelpatasvir. Separate administration by 4 hours.o
Anecdotal
▶Oralcalcium saltsdecrease the absorption ofzinc.o
Study
Canagliflozin→seeTABLE 14p. 850 (antidiabetic drugs),TABLE 8p. 848
(hypotension)
▶Rifampicinmoderately decreases the exposure tocanagliflozin.
Adjustcanagliflozindose.oStudy
Canakinumab→see monoclonal antibodies
Candesartan→see angiotensin-II receptor antagonists
Cangrelor→seeTABLE 4p. 847 (antiplatelet effects)
Cannabis extract→seeTABLE 11p. 849 (CNS depressant effects)
▶Antiepileptics(carbamazepine, fosphenytoin, phenobarbital,
phenytoin, primidone)are predicted to decrease the exposure
tocannabis extract. Avoid.rTheoretical→Also seeTABLE 11
p. 849
▶Antifungals, azoles(itraconazole, ketoconazole, voriconazole)are
predicted to increase the exposure tocannabis extract. Use
with caution and adjust dose.oTheoretical
▶Cobicistatis predicted to increase the exposure tocannabis
extract. Use with caution and adjust dose.oTheoretical
▶Enzalutamideis predicted to decrease the exposure to
cannabis extract. Avoid.rTheoretical
▶HIV-protease inhibitorsare predicted to increase the exposure
tocannabis extract. Use with caution and adjust dose.
oTheoretical
▶Idelalisibis predicted to increase the exposure tocannabis
extract. Use with caution and adjust dose.oTheoretical
▶Macrolides(clarithromycin)are predicted to increase the
exposure tocannabis extract. Use with caution and adjust
dose.oTheoretical
▶Mitotaneis predicted to decrease the exposure tocannabis
extract. Avoid.rTheoretical
▶Rifampicinis predicted to decrease the exposure tocannabis
extract. Avoid.rTheoretical
Capecitabine→seeTABLE 15p. 850 (myelosuppression)
▶Allopurinolis predicted to decrease the effects ofcapecitabine.
Avoid.rStudy
▶Capecitabineincreases the concentration ofantiepileptics
(fosphenytoin, phenytoin).rAnecdotal
▶Capecitabineincreases the effects ofcoumarins. Monitor INR
and adjust dose.oAnecdotal
▶Folatesare predicted to increase the risk of toxicity when
given withcapecitabine.rAnecdotal
▶H 2 receptor antagonists(cimetidine)are predicted to slightly
increase the exposure tocapecitabine.rTheoretical
▶Live vaccinesare predicted to increase the risk of generalised
infection (possibly life-threatening) when given with
capecitabine. Public Health England advises avoid (refer to
Green Book).rTheoretical
▶Metronidazoleis predicted to increase the risk of capecitabine
toxicity when given withcapecitabine.rTheoretical
Capreomycin→seeTABLE 2p. 847 (nephrotoxicity),TABLE 19p. 851
(ototoxicity)
Captopril→see ACE inhibitors
Carbamazepine→see antiepileptics
Carbapenems
ertapenem.imipenem.meropenem..
▶Carbapenemsdecrease the concentration ofantiepileptics
(valproate). Avoid.rAnecdotal
▶Gancicloviris predicted to increase the risk of seizures when
given withimipenem. Avoid.rAnecdotal
▶Valgancicloviris predicted to increase the risk of seizures when
given withimipenem. Avoid.rAnecdotal
Carbidopa
▶Iron (oral)is predicted to decrease the exposure tocarbidopa.
oTheoretical
Carbimazole→seeTABLE 15p. 850 (myelosuppression)
▶Carbimazoleaffects the concentration ofdigoxin. Monitor and
adjust dose.oTheoretical
▶Carbimazoledecreases the effects ofmetyrapone. Avoid.
oTheoretical
Carboplatin→see platinum compounds
Carfilzomib→seeTABLE 15p. 850 (myelosuppression)
Carmustine→see alkylating agents
Carvedilol→see beta blockers, non-selective
Caspofungin
▶Antiepileptics(carbamazepine, fosphenytoin, phenytoin)are
predicted to decrease the concentration ofcaspofungin. Adjust
caspofungindose,p. 372.oTheoretical
▶Ciclosporinslightly increases the exposure tocaspofungin.
rStudy
▶Corticosteroids(dexamethasone)are predicted to decrease the
concentration ofcaspofungin. Adjustcaspofungindose,p. 372.
oTheoretical
▶Efavirenzis predicted to decrease the concentration of
caspofungin. Adjust dose.oStudy
▶Nevirapineis predicted to decrease the concentration of
caspofungin. Adjust dose.oTheoretical
▶Rifampicindecreases the concentration ofcaspofungin. Adjust
caspofungindose,p. 372.oStudy
Cefaclor→see cephalosporins
Cefadroxil→see cephalosporins
Cefalexin→see cephalosporins
Cefixime→see cephalosporins
Cefotaxime→see cephalosporins
Cefradine→see cephalosporins
Ceftaroline→see cephalosporins
Ceftazidime→see cephalosporins
Ceftobiprole→see cephalosporins
Ceftolozane→see cephalosporins
Ceftriaxone→see cephalosporins
Cefuroxime→see cephalosporins
Celecoxib→see NSAIDs
Celiprolol→see beta blockers, selective
Cephalosporins→seeTABLE 2p. 847 (nephrotoxicity)cefaclor.cefadroxil.cefalexin.cefixime.cefotaxime.cefradine.
ceftaroline.ceftazidime.ceftobiprole.ceftolozane.ceftriaxone.
cefuroxime..
▶Ceftobiproleis predicted to increase the exposure tobosentan.
oTheoreticalBNFC 2018 – 2019 Calcium salts—Cephalosporins 893
Interactions|Appendix 1A1