methaemoglobinaemia when given with topicalprilocaine.
Use with caution or avoid.rTheoretical→Also seeTABLE 11
p. 849
▶Antiepileptics(phenytoin)are predicted to decrease the
exposure toropivacaine.oTheoretical
▶Antimalarials(chloroquine, primaquine)are predicted to
increase the risk of methaemoglobinaemia when given with
topicalprilocaine. Use with caution or avoid.rTheoretical
▶Dapsoneis predicted to increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Use with caution or avoid.rTheoretical
▶HIV-protease inhibitors(ritonavir)are predicted to decrease the
exposure toropivacaine.oTheoretical
▶Leflunomideis predicted to decrease the exposure to
ropivacaine.oTheoretical
▶Metoclopramideis predicted to increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Avoid.rTheoretical
▶Nitratesare predicted to increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Avoid.rTheoretical
▶Nitrofurantoinis predicted to increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Use with caution or avoid.rTheoretical
▶Paracetamolis predicted to increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Use with caution or avoid.rTheoretical
▶Rifampicinis predicted to decrease the exposure to
ropivacaine.oTheoretical
▶Sodium nitroprussideis predicted to increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Use with caution or avoid.rTheoretical
▶SSRIs(fluvoxamine)decrease the clearance ofropivacaine.
Avoid prolonged use.oStudy
▶Sulfonamidespotentially increase the risk of
methaemoglobinaemia when given with topicalprilocaine.
Use with caution or avoid.rAnecdotal
▶Teriflunomideis predicted to decrease the exposure to
ropivacaine.oTheoretical
Anagrelide→seeTABLE 9p. 849 (QT-interval prolongation),TABLE 4
p. 847 (antiplatelet effects)
▶Combined hormonal contraceptivesare predicted to increase
the exposure toanagrelide.oTheoretical
▶Quinolones(ciprofloxacin)are predicted to increase the
exposure toanagrelide.oTheoretical
▶SSRIs(fluvoxamine)are predicted to increase the exposure to
anagrelide.oTheoretical→Also seeTABLE 4p. 847
Anakinra→seeTABLE 15p. 850 (myelosuppression)
▶Live vaccinesare predicted to increase the risk of generalised
infection (possibly life-threatening) when given with
anakinra. Public Health England advises avoid (refer to Green
Book).rTheoretical
Angiotensin-II receptor antagonists→seeTABLE 7p. 848 (first-
dose hypotension),TABLE 8p. 848 (hypotension),TABLE 16p. 851
(increased serum potassium)
azilsartan.candesartan.eprosartan.irbesartan.losartan.
olmesartan.telmisartan.valsartan..
▶Angiotensin-II receptor antagonistsincrease the risk of renal
impairment when given withaliskiren. Use with caution or
avoidaliskirenin selected patients.rStudy→Also see
TABLE 8p. 848→Also seeTABLE 16p. 851
▶Angiotensin-II receptor antagonistspotentially increase the
concentration oflithium. Monitor concentration and adjust
dose.rAnecdotal
Antacids
aluminium hydroxide.magnesium carbonate.magnesium
trisilicate..SEPARATION OF ADMINISTRATIONAntacids should preferably
not be taken at the same time as other drugs since they might
impair absorption. Antacids might damage enteric coatings
designed to prevent dissolution in the stomach.▶Antacidsare predicted to decrease the absorption ofalkylating
agents(estramustine). Avoid.oStudy
▶Antacidsdecrease the absorption ofantiepileptics(gabapentin).
Gabapentinshould be taken 2 hours afterantacids.o
Study
▶Antacidsdecrease the absorption ofantifungals, azoles
(itraconazole)(capsule).Antacidsshould be taken 1 hour
before or 2 hours afteritraconazole.oStudy
▶Antacidsdecrease the absorption ofantifungals, azoles
(ketoconazole). Separate administration by at least 2 hours.
oStudy
▶Antacidsdecrease the absorption ofantihistamines, non-sedating
(fexofenadine). Separate administration by 2 hours.nStudy
▶Antacidsdecrease the absorption ofantimalarials(chloroquine).
Separate administration by at least 4 hours.oStudy
▶Antacidsare predicted to decrease the absorption of
antimalarials(proguanil). Separate administration by at least
2 hours.oStudy
▶Antacidsdecrease the absorption ofaspirin(high-dose).
oStudy
▶Antacidsdecrease the absorption ofbisphosphonates
(alendronic acid).Alendronic acidshould be taken at least
30 minutes beforeantacids.oStudy
▶Antacidsare predicted to decrease the absorption of
bisphosphonates(ibandronic acid). Avoidantacidsfor at least
6 hours before or 1 hour afteribandronic acid.o
Theoretical
▶Antacidsdecrease the absorption ofbisphosphonates
(risedronate). Separate administration by at least 2 hours.
oStudy
▶Antacidsdecrease the absorption ofbisphosphonates(sodium
clodronate). Avoidantacidsfor 2 hours before or 1 hour after
sodium clodronate.oStudy
▶Antacidsare predicted to decrease the absorption ofbosutinib.
Bosutinibshould be taken at least 12 hours beforeantacids.
oTheoretical
▶Antacidsare predicted to decrease the absorption ofceritinib.
Separate administration by 2 hours.oTheoretical
▶Oralaluminium hydroxidedecreases the absorption of
chenodeoxycholic acid.oStudy
▶Antacidsare predicted to decrease the absorption ofcholic
acid. Separate administration by 5 hours.nTheoretical
▶Antacidsare predicted to decrease the absorption of
corticosteroids(deflazacort). Separate administration by
2 hours.oTheoretical
▶Antacidsdecrease the absorption ofcorticosteroids
(dexamethasone).oStudy
▶Antacidsdecrease the absorption ofdasatinib. Separate
administration by at least 2 hours.oStudy
▶Aluminium hydroxideis predicted to decrease the absorption
ofdeferiprone. Avoid.oTheoretical
▶Antacidsdecrease the absorption ofdigoxin. Separate
administration by 2 hours.nStudy
▶Antacidsare predicted to decrease the absorption of
dipyridamole(immediate release tablets).oTheoretical
▶Antacidsmoderately decrease the exposure todolutegravir.
Dolutegravirshould be taken 2 hours before or 6 hours after
antacids.oStudy
▶Antacidsdecrease the absorption ofeltrombopag.Eltrombopag
should be taken 2 hours before or 4 hours afterantacids.
rStudy
▶Antacidsmoderately decrease the exposure toelvitegravir.
Separate administration by at least 4 hours.oStudy
▶Aluminium hydroxideincreases the risk of blocked enteral or
nasogastric tubes when given withenteral feeds.o
Study
▶Antacidsare predicted to decrease the absorption oferlotinib.
Antacidsshould be taken 4 hours before or 2 hours after
erlotinib.oTheoretical
▶Antacidsslightly to moderately decrease the exposure to
fibrates(gemfibrozil).oStudy
▶Antacidsare predicted to slightly decrease the exposure to
gefitinib.oTheoretical
▶Antacidsare predicted to decrease the absorption ofHIV-
protease inhibitors(atazanavir).Atazanavirshould be taken
2 hours before or 1 hour afterantacids.rTheoreticalBNFC 2018 – 2019 Anaesthetics, local—Antacids 857
Interactions|Appendix 1A1