Irinotecan(continued)
▶Live vaccinesare predicted to increase the risk of generalised
infection (possibly life-threatening) when given with
irinotecan. Public Health England advises avoid (refer to
Green Book).rTheoretical
▶Macrolides(clarithromycin)are predicted to increase the risk of
toxicity when given withirinotecan. Avoid.oStudy
▶Mitotaneis predicted to decrease the exposure toirinotecan.
Avoid.rStudy→Also seeTABLE 15p. 850
▶Irinotecanis predicted to decrease the effects of
neuromuscular blocking drugs, non-depolarising.o
Theoretical
▶Pitolisantis predicted to decrease the exposure toirinotecan.
qTheoretical
▶Rifampicinis predicted to decrease the exposure toirinotecan.
Avoid.rStudy
▶Rolapitantis predicted to increase the exposure toirinotecan.
Avoid or monitor.oStudy
▶St John’s Wortslightly decreases the exposure toirinotecan.
Avoid.rStudy
▶Irinotecanis predicted to increase the risk of prolonged
neuromuscular blockade when given withsuxamethonium.
oTheoretical
Iron (injectable)
ferric carboxymaltose.iron dextran.iron isomaltoside 1000.iron
sucrose..
▶Chloramphenicoldecreases the efficacy of intravenousiron
(injectable).oAnecdotal
Iron (oral)
ferric maltol.ferrous fumarate.ferrous gluconate.ferrous sulfate
.polysaccharide-iron complex.sodium feredetate..▶Antacidsdecrease the absorption ofiron (oral).Iron (oral)
should be taken 1 hour before or 2 hours afterantacids.
oStudy
▶Iron (oral)is predicted to decrease the absorption of oral
bisphosphonates(ibandronic acid). Avoidiron (oral)for at least
6 hours before or 1 hour afteribandronic acid.o
Theoretical
▶Iron (oral)decreases the absorption ofbisphosphonates
(risedronate). Separate administration by at least 2 hours.
oStudy
▶Iron (oral)decreases the absorption ofbisphosphonates(sodium
clodronate). Avoidiron (oral)for 2 hours before or 1 hour after
sodium clodronate.oStudy
▶Calcium salts(calcium carbonate)decrease the absorption of
iron (oral).Calcium carbonateshould be taken 1 hour before or
2 hours afteriron (oral).oStudy
▶Iron (oral)is predicted to decrease the exposure tocarbidopa.
oTheoretical
▶Chloramphenicoldecreases the efficacy of oraliron (oral).
oTheoretical
▶Iron (oral)decreases the absorption ofdolutegravir.
Dolutegravirshould be taken 2 hours before or 6 hours after
iron (oral).oStudy
▶Iron (oral)is predicted to decrease the absorption of
eltrombopag.Eltrombopagshould be taken 2 hours before or
4 hours afteriron (oral).rTheoretical
▶Iron (oral)is predicted to decrease the absorption of
entacapone. Separate administration by at least 2 hours.
oTheoretical
▶Iron (oral)decreases the absorption oflevodopa.o
Study
▶Iron (oral)decreases the effects ofmethyldopa.oStudy
▶Iron (oral)is predicted to decrease the absorption of
penicillamine. Separate administration by at least 2 hours.
nStudy
▶Iron (oral)decreases the exposure toquinolones. Separate
administration by at least 2 hours.oStudy
▶Iron (oral)decreases the absorption oftetracyclines.
Tetracyclinesshould be taken 2 to 3 hours afteriron (oral).
oStudy
▶Iron (oral)decreases the absorption ofthyroid hormones
(levothyroxine). Separate administration by at least 4 hours.
oStudy▶Trientinepotentially decreases the absorption ofiron (oral).
oTheoretical
▶Zincis predicted to decrease the efficacy ofiron (oral)andiron
(oral)is predicted to decrease the efficacy ofzinc.o
Study
Iron chelators
deferasirox.desferrioxamine.dexrazoxane..
▶Deferasiroxis predicted to increase the exposure to
aminophylline. Avoid.oTheoretical
▶Antacids(aluminium hydroxide)are predicted to decrease the
exposure todeferasirox. Avoid.oTheoretical
▶Antiepileptics(carbamazepine, fosphenytoin, phenobarbital,
phenytoin, primidone)are predicted to decrease the exposure
todeferasirox. Monitor serum ferritin and adjust dose.
oTheoretical
▶Ascorbic acidis predicted to increase the risk of cardiovascular
side-effects when given withdesferrioxamine.r
Theoretical
▶Aspirin(high-dose) is predicted to increase the risk of
gastrointestinal bleeds when given withdeferasirox.r
Theoretical
▶Bisphosphonatesare predicted to increase the risk of
gastrointestinal bleeding when given withdeferasirox.r
Theoretical
▶Deferasiroxis predicted to increase the exposure toclozapine.
Avoid.oTheoretical
▶Corticosteroidsare predicted to increase the risk of
gastrointestinal bleeding when given withdeferasirox.r
Theoretical
▶HIV-protease inhibitors(ritonavir)are predicted to decrease the
exposure todeferasirox. Monitor serum ferritin and adjust
dose.oTheoretical
▶Live vaccinesare predicted to increase the risk of generalised
infection (possibly life-threatening) when given with
dexrazoxane. Avoid.rTheoretical
▶NSAIDsare predicted to increase the risk of gastrointestinal
bleeding when given withdeferasirox.rTheoretical
▶Deferasiroxmoderately increases the exposure torepaglinide.
Avoid.oStudy
▶Rifampicinis predicted to decrease the exposure to
deferasirox. Monitor serum ferritin and adjust dose.o
Study
▶Deferasiroxis predicted to increase the exposure toselexipag.
Adjust dose.oStudy
▶Deferasiroxincreases the exposure totheophylline. Avoid.
oStudy
▶Deferasiroxis predicted to increase the exposure totizanidine.
Avoid.oTheoretical
Iron dextran→see iron (injectable)
Iron isomaltoside 1000→see iron (injectable)
Iron sucrose→see iron (injectable)
Isavuconazole→see antifungals, azoles
Isocarboxazid→see monoamine-oxidase A and B inhibitors, irreversible
Isoflurane→see volatile halogenated anaesthetics
Isometheptene→see sympathomimetics, vasoconstrictor
Isoniazid→seeTABLE 1p. 847 (hepatotoxicity),TABLE 12p. 850
(peripheral neuropathy)
FOOD AND LIFESTYLEAvoid tyramine or histamine rich foods,
as tachycardia, palpitation, hypotension,flushing, headache,
dizziness, and sweating reported.
▶Isoniazidis predicted to affect the clearance ofaminophylline.
rTheoretical
▶Isoniazidmarkedly increases the concentration ofantiepileptics
(carbamazepine)andantiepileptics(carbamazepine)increase
the risk of hepatotoxicity when given withisoniazid. Monitor
concentration and adjust dose.rStudy→Also seeTABLE 1
p. 847
▶Isoniazidincreases the concentration ofantiepileptics
(fosphenytoin, phenytoin).oStudy→Also seeTABLE 12
p. 850
▶Cycloserineincreases the risk of CNS toxicity when given with
isoniazid. Monitor and adjust dose.oStudy938 Irinotecan—Isoniazid BNFC 2018 – 2019
Interactions|Appendix 1A1