H 2 receptor antagonists(continued)
▶H 2 receptor antagonistsare predicted to decrease the exposure
toerlotinib.Erlotinibshould be taken 2 hours before or
10 hours afterH 2 receptor antagonists.oStudy
▶Cimetidineincreases the concentration offampridine. Avoid.
rTheoretical
▶Cimetidineslightly increases the exposure tofluorouracil.
rStudy
▶H 2 receptor antagonistsare predicted to slightly to moderately
decrease the exposure togefitinib.oStudy
▶H 2 receptor antagonistsdecrease the exposure toHIV-protease
inhibitors(atazanavir). Monitor and adjust dose.oStudy
▶Cimetidineis predicted to decrease the clearance of
hydroxychloroquine.oTheoretical
▶H 2 receptor antagonistsare predicted to decrease the
absorption oflapatinib. Avoid.oTheoretical
▶H 2 receptor antagonistsare predicted to decrease the exposure
toledipasvir. Adjust dose, seeledipasvir with sofosbuvirp. 401.
oStudy
▶H 2 receptor antagonists(cimetidine, ranitidine)are predicted to
increase the exposure tolomitapide. Separate administration
by 12 hours.oTheoretical
▶Cimetidineslightly increases the exposure tomacrolides
(erythromycin).oStudy
▶Cimetidineincreases the concentration ofmebendazole.
oStudy
▶Cimetidineslightly increases the exposure tometformin.
Monitor and adjust dose.oStudy
▶Cimetidineslightly increases the exposure tomirtazapine. Use
with caution and adjust dose.oTheoretical
▶Cimetidineincreases the exposure tomoclobemide. Adjust
moclobemidedose.nStudy
▶H 2 receptor antagonistsare predicted to decrease the
absorption ofnilotinib.H 2 receptor antagonistsshould be taken
10 hours before or 2 hours afternilotinib,p. 560.nTheoretical
▶Cimetidineincreases the concentration ofopioids(alfentanil).
Use with caution and adjust dose.rStudy
▶Cimetidineincreases the exposure toopioids(fentanyl).
oStudy
▶H 2 receptor antagonistsare predicted to decrease the exposure
topazopanib.H 2 receptor antagonistsshould be taken 10 hours
before or 2 hours afterpazopanib.oTheoretical
▶Cimetidineincreases the exposure tophenindione.r
Anecdotal
▶Cimetidinemoderately increases the exposure topraziquantel.
oStudy
▶H 2 receptor antagonistsare predicted to decrease the exposure
torilpivirine.H 2 receptor antagonistsshould be taken 12 hours
before or 4 hours afterrilpivirine.rStudy
▶Cimetidineslightly increases the exposure toroflumilast.
oStudy
▶H 2 receptor antagonistspotentially decrease the exposure to
sofosbuvir. Adjust dose, seeledipasvir with sofosbuvirp. 401,
sofosbuvir with velpatasvir, and sofosbuvir with velpatasvir and
voxilaprevir.oStudy
▶Cimetidineslightly increases the exposure toSSRIs(citalopram,
escitalopram). Adjust dose.oStudy
▶Cimetidineslightly increases the exposure toSSRIs(paroxetine,
sertraline).oStudy
▶Cimetidineis predicted to increase the risk of toxicity when
given withtegafur.rTheoretical
▶Cimetidineincreases the concentration oftheophylline. Adjust
dose.rStudy
▶Cimetidineincreases the exposure totricyclic antidepressants.
oStudy
▶H 2 receptor antagonistsare predicted to decrease the
concentration ofvelpatasvir. Adjust dose, seesofosbuvir with
velpatasvir.oStudy
▶Cimetidineslightly increases the exposure tovenlafaxine.n
Study
▶Cimetidineslightly increases the exposure tozolmitriptan.
Adjustzolmitriptandose,p. 292.nStudy
Haloperidol→seeTABLE 8p. 848 (hypotension),TABLE 9p. 849 (QT-
interval prolongation),TABLE 11p. 849 (CNS depressant effects),
TABLE 10p. 849 (antimuscarinics)FOOD AND LIFESTYLEDose adjustment might be necessary if
smoking started or stopped during treatment.
▶Antiepileptics(carbamazepine, fosphenytoin, phenobarbital,
phenytoin, primidone)decrease the concentration of
haloperidol. Adjust dose.oStudy→Also seeTABLE 11
p. 849
▶Haloperidolpotentially increases the risk of overheating and
dehydration when given withantiepileptics(zonisamide). Avoid
in children.rTheoretical
▶Antifungals, azoles(itraconazole)increase the concentration of
haloperidol.oStudy
▶Haloperidolis predicted to decrease the effects ofdopamine
receptor agonists. Avoid.oTheoretical→Also seeTABLE 8
p. 848→Also seeTABLE 9p. 849→Also seeTABLE 10p. 849
▶Enzalutamidedecreases the concentration ofhaloperidol.
Adjust dose.oStudy
▶Haloperidolpotentially opposes the effects ofglycerol
phenylbutyrate.oTheoretical
▶Haloperidolis predicted to decrease the antihypertensive
effects ofguanethidine. Monitor and adjust dose.o
Theoretical→Also seeTABLE 8p. 848
▶HIV-protease inhibitors(ritonavir)are predicted to increase the
exposure tohaloperidol.rTheoretical
▶Haloperidoldecreases the effects oflevodopa.rStudy→
Also seeTABLE 8p. 848
▶Mitotanedecreases the concentration ofhaloperidol. Adjust
dose.oStudy
▶Rifampicindecreases the concentration ofhaloperidol. Adjust
dose.oStudy
▶Haloperidolpotentially decreases the effects ofsodium
phenylbutyrate.oAnecdotal
▶SSRIs(fluoxetine)increase the concentration ofhaloperidol.
Adjust dose.oAnecdotal
▶SSRIs(fluvoxamine)increase the concentration ofhaloperidol.
Adjust dose.oStudy
▶Venlafaxineslightly increases the exposure tohaloperidol.
rStudy→Also seeTABLE 9p. 849→Also seeTABLE 11p. 849
Heparin (unfractionated)→seeTABLE 16p. 851 (increased serum
potassium),TABLE 3p. 847 (anticoagulant effects)
▶Ranibizumabincreases the risk of bleeding events when given
withheparin (unfractionated).rTheoretical
HIV-protease inhibitors→seeTABLE 9p. 849 (QT-interval
prolongation)
atazanavir.darunavir.fosamprenavir.lopinavir.ritonavir.
saquinavir.tipranavir..▶Caution on concurrent use ofatazanavir,lopinavir with
ritonavir,orritonavirwith drugs that prolong the PR
interval.
▶Concurrent use ofsaquinavirwith drugs that prolong the
PR interval is contra-indicated.
▶Caution with concurrent use oftipranavirwith drugs that
increase risk of bleeding.
▶Tipranavirslightly decreases the exposure toabacavir. Avoid.
rStudy
▶HIV-protease inhibitorsare predicted to increase the exposure
toabiraterone.rTheoretical
▶HIV-protease inhibitors(lopinavir, ritonavir, saquinavir)are
predicted to increase the exposure toafatinib. Separate
administration by 12 hours.oStudy
▶Ritonaviris predicted to decrease the exposure toagomelatine.
oTheoretical
▶Ritonavirdecreases the exposure toalbendazole.o
Study
▶HIV-protease inhibitorsare predicted to markedly increase the
exposure toaldosterone antagonists(eplerenone). Avoid.r
Study
▶HIV-protease inhibitors(ritonavir, saquinavir)are predicted to
increase the exposure toaliskiren.oTheoretical
▶HIV-protease inhibitorsincrease the exposure toalmotriptan.
nStudy
▶HIV-protease inhibitorsare predicted to moderately increase
the exposure toalpha blockers(alfuzosin, tamsulosin). Use with
caution or avoid.oStudy928 H 2 receptor antagonists—HIV-protease inhibitors BNFC 2018 – 2019
Interactions|Appendix 1A1