is predicted to increase the exposure to topotecan.

Study → Also see TABLE 15 p. 1378

▶ Rolapitant is predicted to increase the exposure to topotecan.

Avoid or monitor.oStudy

▶ St John’s Wort is predicted to decrease the exposure to

topotecan.rTheoretical

▶ Tedizolid is predicted to increase the exposure to topotecan.

Avoid.oStudy

▶ Teriflunomide is predicted to increase the exposure to

topotecan.oStudy

▶ Velpatasvir

r

is predicted to increase the exposure to topotecan.

Theoretical

▶ Vemurafenib is predicted to increase the exposure to

topotecan.rStudy

▶ Venetoclax

o

is predicted to increase the exposure to topotecan.

Theoretical

▶ Voxilaprevir is predicted to increase the concentration of

topotecan. Avoid.rTheoretical

Torasemide → see loop diuretics

Toremifene → see TABLE 5 p. 1375 (thromboembolism), TABLE 9 p. 1377

(QT-interval prolongation)

▶ Antiepileptics (carbamazepine, fosphenytoin, phenobarbital,

phenytoin, primidone) are predicted to decrease the exposure

to toremifene. Adjust dose.oStudy

▶ Antifungals, azoles (itraconazole, ketoconazole, voriconazole) are

predicted to increase the exposure to

Theoretical → Also see TABLE 9 p. 1377

toremifene.o ▶ Cobicistat

o

is predicted to increase the exposure to toremifene.

Theoretical

▶ Toremifene is predicted to increase the anticoagulant effect of

coumarins.rTheoretical

▶ Enzalutamide is predicted to decrease the exposure to

toremifene. Adjust dose.oStudy

▶ HIV-protease inhibitors are predicted to increase the exposure

to toremifene.oTheoretical → Also see TABLE 9 p. 1377

▶ Idelalisib

o

is predicted to increase the exposure to toremifene.

Theoretical

▶ Macrolides (clarithromycin) are predicted to increase the

exposure to toremifene.oTheoretical → Also see TABLE 9

p. 1377

▶ Mitotane is predicted to decrease the exposure to toremifene.

Adjust dose.oStudy

▶ Rifampicin is predicted to decrease the exposure to toremifene.

Adjust dose.oStudy

▶ Thiazide diuretics are predicted to increase the risk of

hypercalcaemia when given with toremifene.rTheoretical

Trabectedin → see TABLE 1 p. 1375 (hepatotoxicity), TABLE 15 p. 1378

(myelosuppression)

▶ Antiepileptics (carbamazepine, fosphenytoin, phenobarbital,

phenytoin, primidone) are predicted to decrease the exposure

to trabectedin. Avoid.rTheoretical → Also see TABLE 1 p. 1375

▶ Antifungals, azoles (itraconazole, ketoconazole, voriconazole) are

predicted to increase the exposure to trabectedin. Avoid or

adjust dose.rTheoretical → Also see TABLE 1 p. 1375

▶ Cobicistat is predicted to increase the exposure to trabectedin.

Avoid or adjust dose.rTheoretical

▶ Enzalutamide is predicted to decrease the exposure to

trabectedin. Avoid.rTheoretical

▶ HIV-protease inhibitors are predicted to increase the exposure

to trabectedin. Avoid or adjust dose.rTheoretical

▶ Idelalisib is predicted to increase the exposure to trabectedin.

Avoid or adjust dose.rTheoretical → Also see TABLE 15

p. 1378

▶ Live vaccines are predicted to increase the risk of generalised

infection (possibly life-threatening) when given with

trabectedin. Public Health England advises avoid (refer to

Green Book).rTheoretical

▶ Macrolides (clarithromycin) are predicted to increase the

exposure to

Theoretical

trabectedin. Avoid or adjust dose.r

▶ Mitotane is predicted to decrease the exposure to trabectedin.

Avoid.rTheoretical → Also see TABLE 15 p. 1378

▶ Rifampicin is predicted to decrease the exposure to

trabectedin. Avoid.rTheoretical

Tramadol → see opioids

Trametinib

▶ Antiarrhythmics (amiodarone, dronedarone) are predicted to

increase the concentration of trametinib.oTheoretical

▶ Antifungals, azoles (itraconazole, ketoconazole) are predicted to

increase the concentration of trametinib.oTheoretical

▶ Calcium channel blockers (verapamil) are predicted to increase

the concentration of trametinib.oTheoretical

▶ Ciclosporin is predicted to increase the concentration of

trametinib.oTheoretical

▶ HIV-protease inhibitors (lopinavir, ritonavir, saquinavir) are

predicted to increase the concentration of

o

trametinib.

Theoretical

▶ Lapatinib is predicted to increase the concentration of

trametinib.oTheoretical

▶ Macrolides are predicted to increase the concentration of

trametinib.oTheoretical

▶ Ranolazine is predicted to increase the concentration of

trametinib.oTheoretical

▶ Vemurafenib is predicted to increase the concentration of

trametinib.oTheoretical

Trandolapril → see ACE inhibitors

Tranexamic acid → see TABLE 5 p. 1375 (thromboembolism)

Tranylcypromine → see monoamine-oxidase A and B inhibitors,

irreversible

Trastuzumab → see monoclonal antibodies

Trastuzumab emtansine → see monoclonal antibodies

Trazodone → see TABLE 13 p. 1378 (serotonin syndrome), TABLE 11

p. 1377 (CNS depressant effects)

▶ Antiarrhythmics (dronedarone) are predicted to increase the

exposure to trazodone.oTheoretical

▶ Antiepileptics (carbamazepine) decrease the concentration of

trazodone. Adjust dose.oAnecdotal

▶ Antifungals, azoles (fluconazole, isavuconazole, posaconazole)

are predicted to increase the exposure to

Theoretical

trazodone.o ▶ Antifungals, azoles (itraconazole, ketoconazole, voriconazole) are

predicted to moderately increase the exposure to trazodone.

Avoid or adjust dose.oStudy

▶ Aprepitant

o

is predicted to increase the exposure to trazodone.

Theoretical

▶ Calcium channel blockers (diltiazem, verapamil) are predicted to

increase the exposure to trazodone.oTheoretical

▶ Cobicistat is predicted to moderately increase the exposure to

trazodone. Avoid or adjust dose.oStudy

▶ Crizotinib

o

is predicted to increase the exposure to trazodone.

Theoretical

▶ HIV-protease inhibitors are predicted to moderately increase

Study

the exposure to trazodone. Avoid or adjust dose.o ▶ Idelalisib is predicted to moderately increase the exposure to

trazodone. Avoid or adjust dose.oStudy

BNF 78 Topotecan —Trazodone 1547

Interactions | Appendix 1

A1

Trazodone (continued)

▶ Imatinib

o

is predicted to increase the exposure to trazodone.

Theoretical

▶ Macrolides (clarithromycin) are predicted to moderately

increase the exposure to

o

trazodone. Avoid or adjust dose.

Study

▶ Macrolides (erythromycin) are predicted to increase the

exposure to trazodone.oTheoretical

▶ Netupitant

o

is predicted to increase the exposure to trazodone.

Theoretical

▶ Nilotinib

o

is predicted to increase the exposure to trazodone.

Theoretical

Tree pollen extract

GENERAL INFORMATION Desensitising vaccines should be

avoided in patients taking beta-blockers (adrenaline might be

ineffective in case of a hypersensitivity reaction) or ACE

inhibitors (risk of severe anaphylactoid reactions).

Treosulfan → see alkylating agents

Tretinoin → see retinoids

Triamcinolone → see corticosteroids

Triamterene → see potassium-sparing diuretics

Tricyclic antidepressants → see TABLE 18 p. 1379 (hyponatraemia),

TABLE 8 p. 1376 (hypotension), TABLE 13 p. 1378 (serotonin syndrome),

TABLE 9 p. 1377 (QT-interval prolongation), TABLE 10 p. 1377

(antimuscarinics)

amitriptyline . clomipramine . dosulepin . doxepin .imipramine . lofepramine . nortriptyline .trimipramine.

ROUTE-SPECIFIC INFORMATION Since systemic absorption can

follow topical application, the possibility of interactions of

topical doxepin should be borne in mind.

▶ Antiarrhythmics (dronedarone) are predicted to increase the

exposure to

Theoretical →

tricyclic antidepressants

Also see TABLE 9 p. 1377

. Avoid.r

▶ Antiarrhythmics (propafenone) are predicted to increase the

concentration of

Theoretical → Also see

tricyclic antidepressants

TABLE 10 p. 1377

.o ▶ Antiepileptics (carbamazepine) decrease the exposure to

tricyclic antidepressants. Adjust dose.oStudy → Also see

TABLE 18 p. 1379

▶ Antiepileptics (phenobarbital, primidone) are predicted to

decrease the exposure to

Study

tricyclic antidepressants.o ▶ Tricyclic antidepressants (clomipramine, imipramine) potentially

increase the risk of overheating and dehydration when given

with

Theoretical

antiepileptics (zonisamide). Avoid in children.r

▶ Bupropion is predicted to increase the exposure to tricyclic

antidepressants

Study → Also see TABLE 13

. Monitor for toxicity and adjust dose.

p. 1378

r

▶ Cinacalcet is predicted to increase the exposure to tricyclic

antidepressants

Study

. Monitor for toxicity and adjust dose.r

▶ Tricyclic antidepressants decrease the antihypertensive effects

of clonidine. Monitor and adjust dose.oAnecdotal →

Also see TABLE 8 p. 1376

▶ Cobicistat is predicted to slightly increase the exposure to

tricyclic antidepressants.nStudy

▶ Darifenacin is predicted to increase the exposure to tricyclic

antidepressants.oTheoretical → Also see TABLE 10 p. 1377

▶ Eliglustat is predicted to increase the exposure to nortriptyline.

Adjust dose.oTheoretical

▶ Tricyclic antidepressants are predicted to decrease the

antihypertensive effects of guanethidine.oStudy → Also

see TABLE 8 p. 1376

▶ H2 receptor antagonists (cimetidine) increase the exposure to

tricyclic antidepressants.oStudy

▶ HIV-protease inhibitors (ritonavir, tipranavir) are predicted to

increase the exposure to

Theoretical

tricyclic antidepressants.o ▶ Tricyclic antidepressants potentially increase the risk of

neurotoxicity when given with lithium.rAnecdotal → Also

see TABLE 13 p. 1378 → Also see TABLE 9 p. 1377

▶ Amitriptyline

o

decreases the effects of metyrapone. Avoid.

Theoretical

▶ Tricyclic antidepressants are predicted to increase the risk of

severe toxic reaction when given with

r

moclobemide. Avoid.

Theoretical → Also see TABLE 13 p. 1378

▶ Tricyclic antidepressants are predicted to increase the risk of

severe toxic reaction when given with monoamine-oxidase A

and B inhibitors, irreversible. Avoid and for 14 days after

stopping the MAOI.rTheoretical → Also see TABLE 8

p. 1376 → Also see TABLE 13 p. 1378

▶ Tricyclic antidepressants are predicted to decrease the effects

of moxonidine. Avoid.oTheoretical → Also see TABLE 8

p. 1376

▶ Tricyclic antidepressants are predicted to decrease the efficacy

of pitolisant.nTheoretical

▶ SSRIs (fluoxetine, paroxetine) are predicted to increase the

exposure to tricyclic antidepressants. Monitor for toxicity and

adjust dose.rStudy → Also see TABLE 18 p. 1379 → Also see

TABLE 13 p. 1378

▶ SSRIs (fluvoxamine) markedly increase the exposure to

clomipramine. Adjust dose.rStudy → Also see TABLE 18

p. 1379 → Also see TABLE 13 p. 1378

▶ SSRIs (fluvoxamine) increase the exposure to tricyclic

antidepressants

Study → Also see

(amitriptyline, imipramine)

TABLE 18 p. 1379 → Also see TABLE 13

. Adjust dose.

p. 1378

r

▶ Sucralfate is predicted to decrease the absorption of tricyclic

antidepressants.oStudy

▶ Tricyclic antidepressants increase the effects of

sympathomimetics, vasoconstrictor (adrenaline/epinephrine,

noradrenaline/norepinephrine, phenylephrine)

Study

. Avoid.r

▶ Tricyclic antidepressants are predicted to decrease the effects

of

Study

sympathomimetics, vasoconstrictor (ephedrine). Avoid.r

▶ Terbinafine is predicted to increase the exposure to tricyclic

antidepressants

Study

. Monitor for toxicity and adjust dose.r

▶ Tricyclic antidepressants increase the risk of cardiac

arrhythmias and hypotension when given with

o

thiopental.

Study → Also see TABLE 8 p. 1376

Trientine

▶ Trientine

o

potentially decreases the absorption of iron (oral).

Theoretical

▶ Trientine

o

potentially decreases the absorption of zinc.

Theoretical

Trifluoperazine → see phenothiazines

Trihexyphenidyl → see TABLE 10 p. 1377 (antimuscarinics)

Trimethoprim → see TABLE 18 p. 1379 (hyponatraemia), TABLE 2 p. 1375

(nephrotoxicity), TABLE 16 p. 1379 (increased serum potassium)

▶ Trimethoprim increases the concentration of antiepileptics

(fosphenytoin, phenytoin).oStudy

▶ Antimalarials (pyrimethamine) increase the risk of side-effects

when given with trimethoprim.rStudy

▶ Trimethoprim is predicted to increase the anticoagulant effect

of coumarins.rStudy

▶ Dapsone increases the exposure to trimethoprim and

trimethoprim increases the exposure to dapsone.rStudy

▶ Trimethoprim

Study

increases the concentration of digoxin.o ▶ Trimethoprim is predicted to increase the exposure to

dopamine receptor agonists

o

(pramipexole). Adjust dose.

Study

▶ Trimethoprim

o

slightly increases the exposure to lamivudine.

Study

▶ Trimethoprim is predicted to increase the risk of side-effects

when given with methotrexate. Avoid.rTheoretical → Also

see TABLE 2 p. 1375

▶ Trimethoprim slightly increases the exposure to repaglinide.

Avoid or monitor blood glucose.oStudy

▶ Rifampicin

Study

decreases the exposure to trimethoprim.o ▶ Trimethoprim is predicted to decrease the efficacy of

sapropterin.oTheoretical

Trimipramine → see tricyclic antidepressants

Tropicamide → see TABLE 10 p. 1377 (antimuscarinics)

1548 Trazodone —Tropicamide BNF 78

Interactions | Appendix 1

A1

Trospium → see TABLE 10 p. 1377 (antimuscarinics)

Tryptophan → see TABLE 13 p. 1378 (serotonin syndrome)

▶ Tryptophan

o

greatly decreases the concentration of levodopa.

Study

▶ Tryptophan increases the risk of side-effects when given with

monoamine-oxidase A and B inhibitors, irreversible

Anecdotal → Also see TABLE 13 p. 1378

.r

Typhoid vaccine, oral → see live vaccines

Ulipristal

▶ Antiarrhythmics (dronedarone) are predicted to increase the

exposure to

o

ulipristal. Avoid if used for uterine fibroids.

Study

▶ Antiepileptics (carbamazepine, eslicarbazepine, fosphenytoin,

oxcarbazepine, perampanel, phenobarbital, phenytoin,

primidone, rufinamide, topiramate) decrease the efficacy of

ulipristal. For FSRH guidance, see Contraceptives,

interactions p. 794.rAnecdotal

▶ Antifungals, azoles (fluconazole, isavuconazole, posaconazole)

are predicted to increase the exposure to ulipristal. Avoid if

used for uterine fibroids.oStudy

▶ Antifungals, azoles (itraconazole, ketoconazole, voriconazole) are

predicted to increase the exposure to ulipristal. Avoid if used

for uterine fibroids.rStudy

▶ Aprepitant decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Bosentan decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Calcium channel blockers (diltiazem, verapamil) are predicted to

increase the exposure to ulipristal. Avoid if used for uterine

fibroids.oStudy

▶ Cobicistat is predicted to increase the exposure to ulipristal.

Avoid if used for uterine fibroids.rStudy

▶ Ulipristal is predicted to decrease the efficacy of combined

hormonal contraceptives. Avoid.rTheoretical

▶ Crizotinib is predicted to increase the exposure to ulipristal.

Avoid if used for uterine fibroids.oStudy

▶ Ulipristal is predicted to decrease the efficacy of desogestrel.

Avoid.rTheoretical

▶ Efavirenz decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Enzalutamide is predicted to markedly decrease the exposure

to

r

ulipristal. Avoid and for 4 weeks after stopping ulipristal.

Theoretical

▶ Ulipristal is predicted to decrease the efficacy of etonogestrel.

Avoid.rTheoretical

▶ Fosaprepitant decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Grapefruit juice is predicted to increase the exposure to

ulipristal. Avoid if used for uterine fibroids.oTheoretical

▶ Griseofulvin potentially decreases the efficacy of ulipristal. For

FSRH guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ HIV-protease inhibitors (atazanavir, darunavir, fosamprenavir,

lopinavir, saquinavir, tipranavir) are predicted to increase the

exposure to

Study

ulipristal. Avoid if used for uterine fibroids.r

▶ HIV-protease inhibitors (ritonavir) decrease the efficacy of

ulipristal. For FSRH guidance, see Contraceptives,

interactions p. 794.rAnecdotal

▶ Idelalisib is predicted to increase the exposure to ulipristal.

Avoid if used for uterine fibroids.rStudy

▶ Imatinib is predicted to increase the exposure to ulipristal.

Avoid if used for uterine fibroids.oStudy

▶ Ulipristal is predicted to decrease the efficacy of

levonorgestrel. Avoid.rTheoretical

▶ Lumacaftor is predicted to decrease the efficacy of ulipristal.

Use additional contraceptive precautions.rTheoretical

▶ Macrolides (clarithromycin) are predicted to increase the

exposure to

Study

ulipristal. Avoid if used for uterine fibroids.r

▶ Macrolides (erythromycin) are predicted to increase the

exposure to

o

ulipristal. Avoid if used for uterine fibroids.

Study

▶ Modafinil decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Netupitant is predicted to increase the exposure to ulipristal.

Avoid if used for uterine fibroids.oStudy

▶ Nevirapine decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Nilotinib is predicted to increase the exposure to ulipristal.

Avoid if used for uterine fibroids.oStudy

▶ Ulipristal is predicted to decrease the efficacy of

norethisterone. Avoid.rTheoretical

▶ Rifabutin decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ Rifampicin decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

▶ St John’s Wort decreases the efficacy of ulipristal. For FSRH

guidance, see

Anecdotal

Contraceptives, interactions p. 794.r

Umeclidinium → see TABLE 10 p. 1377 (antimuscarinics)

Urokinase → see TABLE 3 p. 1375 (anticoagulant effects)

Ursodeoxycholic acid

▶ Antacids are predicted to decrease the absorption of

ursodeoxycholic acid

o

. Separate administration by 2 hours.

Theoretical

▶ Ursodeoxycholic acid affects the concentration of ciclosporin.

Use with caution and adjust dose.rAnecdotal

▶ Fibrates are predicted to decrease the efficacy of

ursodeoxycholic acid. Avoid.rTheoretical

Ustekinumab → see monoclonal antibodies

Valaciclovir → see TABLE 2 p. 1375 (nephrotoxicity)

▶ Valaciclovir is predicted to increase the exposure to

aminophylline.rAnecdotal

▶ Mycophenolate is predicted to increase the risk of

haematological toxicity when given with

Theoretical

valaciclovir.o ▶ Valaciclovir is predicted to increase the exposure to

theophylline.rTheoretical

Valganciclovir → see TABLE 15 p. 1378 (myelosuppression), TABLE 2

p. 1375 (nephrotoxicity)

▶ Valganciclovir is predicted to increase the risk of seizures when

given with carbapenems (imipenem). Avoid.rAnecdotal

▶ Valganciclovir is predicted to increase the exposure to

didanosine.oStudy

▶ Mycophenolate is predicted to increase the risk of

haematological toxicity when given with

o