Norethisterone(continued)
▶Rifabutinis predicted to decrease the efficacy of
norethisterone. For FSRH guidance, seeContraceptives,
interactionsp. 497.rAnecdotal
▶Rifampicinis predicted to decrease the efficacy of
norethisterone. For FSRH guidance, seeContraceptives,
interactionsp. 497.rAnecdotal
▶St John’s Wortis predicted to decrease the efficacy of
norethisterone. MHRA advises avoid. For FSRH guidance, see
Contraceptives, interactionsp. 497.rAnecdotal
▶Sugammadexis predicted to decrease the exposure to
norethisterone. Use additional contraceptive precautions.
rTheoretical
▶Ulipristalis predicted to decrease the efficacy of
norethisterone. Avoid.rTheoretical
Norfloxacin→see quinolones
Nortriptyline→see tricyclic antidepressants
NSAIDs→seeTABLE 18p. 851 (hyponatraemia),TABLE 2p. 847
(nephrotoxicity),TABLE 16p. 851 (increased serum potassium),TABLE 4
p. 847 (antiplatelet effects)
aceclofenac.acemetacin.benzydamine.bromfenac.celecoxib.
dexibuprofen.dexketoprofen.diclofenac.etodolac.etoricoxib.
felbinac.fenoprofen.flurbiprofen.ibuprofen.indometacin.
ketoprofen.ketorolac.mefenamic acid.meloxicam.nabumetone.
naproxen.nepafenac.parecoxib.piroxicam.sulindac.tenoxicam.
tiaprofenic acid.tolfenamic acid..ROUTE-SPECIFIC INFORMATIONSince systemic absorption can
follow topical application, the possibility of interactions
should be borne in mind.
▶Celecoxibis predicted to increase the exposure to
antiarrhythmics(flecainide, propafenone). Monitor and adjust
dose.oTheoretical
▶Antifungals, azoles(fluconazole)moderately increase the
exposure tocelecoxib. Adjustcelecoxibdose.oStudy
▶Antifungals, azoles(fluconazole)increase the exposure to
parecoxib. Monitor and adjust dose.oStudy
▶Antifungals, azoles(voriconazole)slightly increase the exposure
todiclofenac. Monitor and adjust dose.oStudy
▶Antifungals, azoles(voriconazole)moderately increase the
exposure toibuprofen. Adjust dose.oStudy
▶NSAIDsare predicted to increase the risk of gastrointestinal
irritation when given withbisphosphonates(alendronic acid,
ibandronic acid).oStudy
▶NSAIDsare predicted to increase the risk of renal impairment
when given withbisphosphonates(sodium clodronate).r
Theoretical
▶Ceritinibis predicted to increase the exposure toNSAIDs
(celecoxib, diclofenac). Adjust dose.oTheoretical
▶Ciclosporinincreases the concentration ofdiclofenac.r
Study→Also seeTABLE 2p. 847→Also seeTABLE 16p. 851
▶Etoricoxibslightly increases the exposure tocombined
hormonal contraceptives.oStudy
▶NSAIDsincrease the risk of gastrointestinal bleeding when
given withcorticosteroids.rStudy
▶NSAIDsincrease the risk of renal impairment when given with
daptomycin.oTheoretical
▶Indometacinincreases the concentration ofdigoxin.r
Study
▶Erlotinibis predicted to increase the risk of gastrointestinal
perforation when given withNSAIDs.rTheoretical
▶Etoricoxibslightly increases the exposure tohormone
replacement therapy.oStudy
▶NSAIDsare predicted to increase the risk of gastrointestinal
bleeding when given withiron chelators(deferasirox).r
Theoretical
▶NSAIDsincrease the concentration oflithium. Monitor and
adjust dose.rStudy
▶NSAIDsare predicted to increase the risk of toxicity when
given withmethotrexate. Monitor and adjust dose.r
Study→Also seeTABLE 2p. 847
▶NSAIDs(high-dose) are predicted to decrease the efficacy of
mifamurtide. Avoid.rTheoretical
▶Nicorandilis predicted to increase the risk of gastrointestinal
perforation when given withNSAIDs.rTheoretical▶NSAIDsare predicted to increase the exposure topemetrexed.
Use with caution or avoid.rTheoretical→Also seeTABLE 2
p. 847
▶NSAIDspotentially increase the risk of seizures when given
withquinolones.rTheoretical
▶Regorafenibis predicted to increase the exposure to
mefenamic acid. Avoid.oTheoretical→Also seeTABLE 4
p. 847
▶Rifampicinmoderately decreases the exposure toNSAIDs
(celecoxib, diclofenac, etoricoxib).oStudy
▶NSAIDsincrease the risk of acute renal failure when given with
thiazide diuretics.rTheoretical→Also seeTABLE 18p. 851
▶Zidovudineincreases the risk of haematological toxicity when
given withNSAIDs.rStudy→Also seeTABLE 2p. 847
Obeticholic acid
▶Obeticholic aciddecreases the anticoagulant effect of
coumarins(warfarin).rStudy
▶Obeticholic acidis predicted to increase the exposure to
theophylline.rTheoretical
▶Obeticholic acidis predicted to increase the exposure to
tizanidine.rTheoretical
Obinutuzumab→see monoclonal antibodies
Ocrelizumab→see monoclonal antibodies
Octreotide
▶Octreotidedecreases the absorption of oralciclosporin. Adjust
ciclosporindose,p. 519.rAnecdotal
▶Octreotide(short-acting) decreases the exposure totelotristat
ethyl.Telotristat ethylshould be taken at least 30 minutes
beforeoctreotide.oStudy
Ofatumumab→see monoclonal antibodies
Ofloxacin→see quinolones
Olanzapine→seeTABLE 8p. 848 (hypotension),TABLE 15p. 850
(myelosuppression),TABLE 11p. 849 (CNS depressant effects)
FOOD AND LIFESTYLEDose adjustment might be necessary if
smoking started or stopped during treatment.▶Antiepileptics(carbamazepine)potentially decrease the
exposure toolanzapine. Monitor and adjust dose.o
Study
▶Antiepileptics(phenytoin)are predicted to decrease the
exposure toolanzapine. Monitor and adjust dose.o
Study
▶Olanzapineis predicted to decrease the effects ofdopamine
receptor agonists. Avoid.oTheoretical→Also seeTABLE 8
p. 848
▶HIV-protease inhibitors(ritonavir)are predicted to decrease the
exposure toolanzapine. Monitor and adjust dose.o
Study
▶Leflunomideis predicted to decrease the exposure to
olanzapine. Monitor and adjust dose.oStudy→Also see
TABLE 15p. 850
▶Olanzapinedecreases the effects oflevodopa. Avoid or monitor
worsening parkinsonian symptoms.rAnecdotal→Also see
TABLE 8p. 848
▶Rifampicinis predicted to decrease the exposure toolanzapine.
Monitor and adjust dose.oStudy
▶SSRIs(fluvoxamine)moderately increase the exposure to
olanzapine. Adjust dose.rAnecdotal
▶Teriflunomideis predicted to decrease the exposure to
olanzapine. Monitor and adjust dose.oStudy
Olaparib→seeTABLE 15p. 850 (myelosuppression)
FOOD AND LIFESTYLEBitter (Seville) orange is predicted to
increase the exposure to olaparib.
▶Antiarrhythmics(dronedarone)are predicted to increase the
exposure toolaparib. Avoid moderate inhibitors of CYP3A4 or
adjustolaparibdose.oTheoretical
▶Antiepileptics(carbamazepine, fosphenytoin, phenobarbital,
phenytoin, primidone)are predicted to decrease the exposure
toolaparib. Avoid.oTheoretical
▶Antifungals, azoles(fluconazole, isavuconazole, posaconazole)
are predicted to increase the exposure toolaparib. Avoid
moderate inhibitors of CYP3A4 or adjustolaparibdose.
oTheoretical966 Norethisterone—Olaparib BNFC 2018 – 2019
Interactions|Appendix 1A1