Risk Factor C (Monitor therapy)

Abiraterone Acetate

The serum content of abiraterone acetate may drop when using rifabutin.

Barbiturates

The metabolism of barbiturates may be accelerated by rifamycin derivatives.

BCG Vaccine (Immunization)

Antibiotics may reduce the BCG vaccine's therapeutic effect (Immunization).

Benzhydrocodone

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Benzhydrocodone. Specifically, the serum concentrations of hydrocodone may be reduced.

Bosentan

May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers).

Cabozantinib

Rifabutin may decrease the serum concentration of Cabozantinib.

CloZAPine

CYP3A4 Inducers (Moderate) may decrease the serum concentration of CloZAPine.

Codeine

CYP3A4 Inducers (Moderate) may decrease serum concentrations of the active metabolite(s) of Codeine.

Crizotinib

Crizotinib's serum levels may drop if you take rifabutin.

CYP3A4 Inducers (Moderate)

May lower the serum level of CYP3A4 substrates (High risk with Inducers).

CYP3A4 Substrates (High risk with Inducers)

The serum concentration of CYP3A4 Substrates may drop when taking CYP3A4 Inducers (Moderate) (High risk with Inducers). Apixaban and Rivaroxaban are exceptions.

Dapsone (Systemic)

Deferasirox

May lower the serum level of CYP3A4 substrates (High risk with Inducers).

Enzalutamide

Enzalutamide's serum levels may drop if you take rifabutin.

Estriol (Systemic)

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Estriol (Systemic).

Estriol (Topical)

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Estriol (Topical).

Everolimus

Rifabutin may decrease the serum concentration of Everolimus.

FentaNYL

CYP3A4 Inducers (Moderate) may decrease the serum concentration of FentaNYL.

Glecaprevir and Pibrentasvir

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Glecaprevir and Pibrentasvir.

HYDROcodone

The serum levels of HYDROcodone may drop in response to CYP3A4 Inducers (Moderate).

Ibrutinib

Ibrutinib's serum levels may be decreased by CYP3A4 Inducers (Moderate).

Ifosfamide

The active metabolite(s) of ifosfamide may be present in lower serum quantities when CYP3A4 Inducers (Moderate) are present. The active metabolite(s) of ifosfamide may be present in higher serum concentrations when CYP3A4 Inducers (Moderate) are used.

Irinotecan Products

The serum concentrations of the active metabolite(s) of irinotecan products may drop after taking rifabutin. Particularly, serum levels of SN-38 could be decreased. The serum levels of rifabutin-containing products may drop.

Isoniazid

Rifamycin Derivatives may enhance the hepatotoxic effect of Isoniazid. Even so, this is a frequently employed combination regimen.

Ivacaftor

Rifabutin may decrease the serum concentration of Ivacaftor.

Ivosidenib

May lower the serum level of CYP3A4 substrates (High risk with Inducers).

Lactobacillus and Estriol

The therapeutic effects of Lactobacillus and Estriol may be reduced by antibiotics.

Mirodenafil

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Mirodenafil.

Naldemedine

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Naldemedine.

Nevirapine

Rifabutin may decrease the serum concentration of Nevirapine. Nevirapine may decrease the serum concentration of Rifabutin. Nevirapine may increase the serum concentration of Rifabutin.

Nilotinib

Rifabutin may decrease the serum concentration of Nilotinib.

Pexidartinib

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pexidartinib.

Pitolisant

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pitolisant.

Raltegravir

Raltegravir's serum concentration may drop if you take rifabutin. Particularly, Cmin, the minimal serum concentration, may be decreased. AUC, or overall raltegravir exposure, may rise.

Rolapitant

The serum concentration of Rolapitant may fall in response to CYP3A4 Inducers (Moderate).

RomiDEPsin

RomiDEPsin serum levels may be reduced by rifabutin.

Sarilumab

May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers).

Siltuximab

May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers).

Sirolimus

Rifabutin may decrease the serum concentration of Sirolimus.

Tocilizumab

May lower the serum level of CYP3A4 substrates (High risk with Inducers).

Upadacitinib

Upadacitinib's serum levels may be decreased by CYP3A4 Inducers (Moderate).

VinCRIStine (Liposomal)

VinCRIStine serum levels may be decreased by rifabutin (Liposomal).

Vitamin K Antagonists (eg, warfarin)

The metabolism of Vitamin K antagonists may be accelerated by rifamycin derivatives.

Zolpidem

CYP3A4 Inducers (Moderate) may lower the level of zolpidem in the blood.

Risk Factor D (Consider therapy modification)

Alfentanil

Rifamycin derivatives may lower the level of alfentanil in the blood. Management: Keep an eye out for signs of diminished alfentanil efficacy. Alfentanil dosages will probably need to be increased. Alternative options include switching from alfentanil to another opioid anaesthetic (such as sufentanil).

Antifungal Agents (Azole Derivatives, Systemic)

May increase the serum concentration of Rifamycin Derivatives. Only rifabutin appears to be affected. Rifamycin Derivatives may decrease the serum concentration of Antifungal Agents (Azole Derivatives, Systemic). Management: Avoid these combinations when possible. Voriconazole and isavuconazonium are considered contraindicated.

Atazanavir

May raise the active metabolite(s) of rifabutin's serum level. Rifabutin's serum levels might be raised by tatazanavir. Reduce the dosage of rifabutin. According to clinical guidelines, atazanavir/ritonavir should be taken 150 mg daily or 300 mg three times per week. For adults, the atazanavir labelling advises a reduction of at least 75%, to 150 mg every other day or 150 mg three times per week.

Brigatinib

The serum concentration of Brigatinib may fall in response to CYP3A4 Inducers (Moderate). Management: Whenever possible, avoid taking brigatinib at the same time as mild CYP3A4 inducers. After seven days of treatment with the current brigatinib dose, increase the daily dose in increments of 30 mg, up to a maximum of twice the dose.

Calcium Channel Blockers

Rifamycin Derivatives may decrease the serum concentration of Calcium Channel Blockers. This primarily affects oral forms of calcium channel blockers. Management: The labeling for some US and Canadian calcium channel blockers contraindicate use with rifampin, however recommendations vary. Consult appropriate labeling. Exceptions: Clevidipine.

Clarithromycin

The active metabolite(s) of clarithromycin may be present in higher serum quantities when CYP3A4 Inducers (Moderate) are present. It is possible for CYP3A4 Inducers (Moderate) to lower the level of clarithromycin in the blood. If a patient is receiving a CYP3A inducer, other antimicrobial therapy should be considered. Drugs that speed up the conversion of 14-hydroxyclarithromycin from clarithromycin may change the clinical action of clarithromycin and reduce its effectiveness.

Cobicistat

Rifabutin serum levels might rise. Reduce the dosage of rifabutin. Clinical recommendations call for giving rifabutin 150 mg three times a day or 300 mg three times a week when combined with cobicistat. The labelling for Cobicistat advises reducing the dosage of rifabutin to 150 mg every other day

CycloSPORINE (Systemic)

Rifamycin Derivatives may increase the metabolism of CycloSPORINE (Systemic).

CYP3A4 Inducers (Strong)

May speed up CYP3A4 substrate metabolism (High risk with Inducers). Management: Take into account a substitute for one of the interfering medications. Specific contraindications may apply to some combinations. 

Dabrafenib

May lower the serum level of CYP3A4 substrates (High risk with Inducers). Management: When possible, look for substitutes for the CYP3A4 substrate. If concurrent therapy cannot be avoided, pay special attention to the substrate's clinical consequences (particularly therapeutic effects).

Daclatasvir

Daclatasvir's serum levels may be lowered by moderate CYP3A4 inducers. Treatment: If daclatasvir is used with a moderate CYP3A4 inducer, increase the dose to 90 mg once daily.

Darunavir

May raise the active metabolite(s) of rifabutin's serum level. Darunavir's serum levels may rise in response to rifabutin. Rifabutin's serum levels may rise in response to darunavir. Reduce the dosage of rifabutin. Darunavir's US labelling advises adults to reduce their dosage by at least 75%, to 150 mg every other day or three times a week. Clinical recommendations advise 300 mg or 150 mg each day.

Doravirine

Rifabutin may lower the level of doravirine in the blood. When coupled with rifabutin,  the dosage of doravirine should be increased to 1 tablet (100 mg) twice daily.  An additional tablet of doravirine (100 mg) should be taken 12 hours after taking  the combination drug doravirine/lamivudine/tenofovir.

Efavirenz

Rifabutin's serum concentration can drop. Efavirenz's serum levels may drop if you take rifabutin. Treatment: Rifabutin adult dose should be increased by 50% if efavirenz is to be used regularly. Consider raising the rifabutin dose if taken with regimens that call for administration 2-3 times per week.

Erdafitinib

Erdafitinib's serum levels may be decreased by CYP3A4 Inducers (Moderate). Management: Erdafitinib dosage adjustments may be necessary. For information, see the entire monograph.

Erlotinib

Rifabutin may decrease the serum concentration of Erlotinib. Management: Avoid combination if possible. If combination must be used, increase erlotinib dose by 50 mg increments every 2 weeks as tolerated, to a maximum of 450 mg/day.

Estrogen Derivatives (Contraceptive)

Rifamycin Derivatives may decrease the serum concentration of Estrogen Derivatives (Contraceptive). Contraceptive failure is possible. Management: Use of an alternative, nonhormonal contraceptive is recommended.

Fosamprenavir

May raise the active metabolite(s) of rifabutin's serum level. Fosamprenavir's serum levels may rise in response to rifabutin. Rifabutin's serum levels may rise as a result of taking fosamprenavir. Reduce the dosage of rifabutin. For more precise advice, see the whole monograph.

GuanFACINE

CYP3A4 Inducers (Moderate) may decrease the serum concentration of GuanFACINE. Management: Increase the guanfacine dose by up to double when initiating guanfacine in a patient taking a moderate CYP3A4 inducer. Increase guanfacine dose gradually over 1 to 2 weeks if initiating a moderate CYP3A4 inducer in a patient already taking guanfacine.

HMG-CoA Reductase Inhibitors (Statins)

Rifamycin Derivatives may decrease the serum concentration of HMG-CoA Reductase Inhibitors (Statins). Management: Consider use of noninteracting antilipemic agents (note: pitavastatin concentrations may increase with rifamycin treatment). Monitor for altered HMG-CoA reductase inhibitor effects. Rifabutin and fluvastatin, or possibly pravastatin, may pose lower risk. Exceptions: Pitavastatin; Rosuvastatin.

Imatinib

Rifamycin Derivatives may decrease the serum concentration of Imatinib. Management: Avoid concurrent use of imatinib with the rifamycin derivatives when possible. If such a combination must be used, increase imatinib dose by at least 50% and monitor the patient's clinical response closely.

Indinavir

May raise the active metabolite(s) of rifabutin's serum level. Indinavir's serum concentration could drop due to rifabutin. Rifabutin's serum levels may rise in response to indinavir. Treatment: In accordance with US labelling, reduce the dose of rifabutin by 50% and raise the dose of adult indinavir to 1 g every 8 hours. Clinical guidelines advise using rifabutin at a dose of 150 mg per day or 300 mg three times per week when combined with indinavir/ritonavir, which is consistent with this.

Lefamulin

Lefamulin's serum levels may be decreased by CYP3A4 Inducers (Moderate). Management: Unless the advantages outweigh the hazards, avoid using lefamulin concurrently with mild CYP3A4 inducers.

Lefamulin (Intravenous)

Lefamulin serum levels may be decreased by moderate CYP3A4 inducers (Intravenous). Management: Lefamulin (intravenous) should not be used concurrently with moderate CYP3A4 inducers unless the advantages outweigh the dangers.

Lopinavir

May raise the active metabolite(s) of rifabutin's serum level. Lopinavir's serum levels may rise in response to rifabutin. Rifabutin's serum levels may rise in response to lopinavir. Reduce the dosage of rifabutin. Clinical recommendations call for 150 mg per day or 300 mg three times per week for people using lopinavir/ritonavir, however US labelling calls for a reduction of at least 75%, to 150 mg every other day or three times per week.

Lorlatinib

The hepatotoxic impact of lorlatinib may be enhanced by CYP3A4 Inducers (Moderate). Lorlatinib's serum levels may be decreased by CYP3A4 Inducers (Moderate). Avoid using lorlatinib in combination with mild CYP3A4 inducers. If such a mixture must be used, AST, ALT, and bilirubin levels should be checked within 48 hours after beginning the mixture and at least three times during the first week of use.

Lorlatinib

May lower the serum level of CYP3A4 substrates (High risk with Inducers). Management: Avoid taking lorlatinib at the same time as any CYP3A4 substrates for which even a small drop in serum levels of the substrate could result in therapeutic failure and negative clinical outcomes.

Lurasidone

Lurasidone's serum levels may be reduced by moderate CYP3A4 inducers. Management: If lurasidone is coupled with mild CYP3A4 inducers, watch for diminished effects.

Macrolide Antibiotics

Rifamycin derivatives' metabolism might be slowed down. Azithromycin (Systemic), Fidaxomicin, Roxithromycin, and Spiramycin are exceptions.

Meperidine

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Meperidine. Management: Consider increasing meperidine dose if concomitant use with moderate CYP3A4 inducers is required. Monitor for signs and symptoms of opioid withdrawal.

Mitotane

May lower the serum level of CYP3A4 substrates (High risk with Inducers). Treatment: When administered in individuals receiving mitotane, doses of CYP3A4 substrates may need to be significantly modified.

Nelfinavir

May raise the active metabolite(s) of rifabutin's serum level. Nelfinavir's serum levels may drop if you take rifabutin. Rifabutin's serum levels can rise as a result of nelfinavir. Management: When used with nelfinavir, the US prescription literature suggests reducing the typical rifabutin dose by at least 50%. In addition, 1250 mg twice daily of nelfinavir is the optimum dosage when combined with rifabutin.

Palbociclib

Palbociclib's serum levels may be decreased by moderate CYP3A4 inducers. Management: The US label doesn't include any advice in particular.

Perampanel

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Perampanel. Management: Increase the perampanel starting dose to 4 mg/day when perampanel is used concurrently with moderate and strong CYP3A4 inducers.

Pitavastatin

Rifamycin Derivatives may increase the serum concentration of Pitavastatin. Management: Limit pitavastatin dose to a maximum of 2 mg/day with concurrent rifampin.

Progestins (Contraceptive)

Rifamycin derivatives may lower progesterone levels in the blood (Contraceptive). Failure with contraception is possible. Management: It is possible for contraceptives to fail. It is advised to use an alternative, nonhormonal method of birth control.

QuiNIDine

QuiNIDine serum levels may be lowered by rifamycin derivatives. Due to the potential for significant quinidine concentration declines, management should consider alternatives to quinidine and rifampin combination therapy. When starting or increasing the dosage of any rifamycin derivative, keep an eye out for any decreasing quinidine concentrations or effects.

Rilpivirine

Rifabutin may lower the level of Rilpivirine in the blood. During rifabutin therapy, increase the adult dose of rilpivirine to 50 mg/day. Reducing the dosage back to 25 mg per day after stopping the rifabutin. It is not advised to use rifabutin with the combination drug of emtricitabine, rilpivirine, and tenofovir alafenamide.

Ritonavir

May raise the active metabolite(s) of rifabutin's serum level. Rifabutin's serum levels may rise as a result of ritonavir. The US prescribing advice for ritonavir suggests lowering rifabutin dosages by at least 75%. For dose advice related to ritonavir-boosted regimens, consult medication interaction monographs addressing concurrently administered protease inhibitors.

Saquinavir

May raise the active metabolite(s) of rifabutin's serum level. Rifabutin's serum levels may rise as a result of saquinavir. Saquinavir's serum levels may drop if you take rifabutin. Reduce the dosage of rifabutin. For adults, the Saquinavir US labelling advises a reduction of at least 75%, to 150 mg every other day or 3 times per week. Clinical recommendations advise using saquinavir/ritonavir with 150 mg daily or 300 mg three times per week.

Sodium Picosulfate

Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic.

St John's Wort

May lower the serum level of CYP3A4 substrates (High risk with Inducers). Management: Take into account a substitute for one of the interfering medications. Specific contraindications may apply to some combinations. the relevant manufacturer's label.

Tacrolimus (Systemic)

Rifamycin Derivatives may decrease the serum concentration of Tacrolimus (Systemic). Management: Consider alternatives when possible. If these combination are used, monitor for reduced tacrolimus concentrations/effects following rifamycin initiation/dose increase, or increased concentrations/effects following rifamycin discontinuation/dose decrease.

Tamoxifen

Rifamycin Derivatives may increase the metabolism of Tamoxifen.

Temsirolimus

Rifamycin Derivatives may decrease the serum concentration of Temsirolimus. Rifamycins will likely cause an even greater decrease in the concentration of the active metabolite sirolimus. Management: Temsirolimus prescribing information recommends against coadministration with strong CYP3A4 inducers such as rifampin; however, if concurrent therapy is necessary, an increase in temsirolimus adult dose to 50 mg/week should be considered.

Tipranavir

May raise the active metabolite(s) of rifabutin's serum level. Rifabutin's serum levels may rise in response to tipranavir. Reduce the dosage of rifabutin. For adults, the US labelling for tipranavir advises a reduction of at least 75%, to 150 mg every other day or 3 times per week. When taken with tipranavir/ritonavir, clinical recommendations indicate 150 mg daily or 300 mg three times per week.

Typhoid Vaccine

The Typhoid Vaccine's therapeutic benefits may be reduced by antibiotics. The only strain impacted is the live attenuated Ty21a strain. Treatment: Patients being treated for typhoid should not receive the live attenuated typhoid vaccine (Ty21a).

Risk Factor X (Avoid combination)

Abemaciclib

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Abemaciclib.

Antihepaciviral Combination Products

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Antihepaciviral Combination Products.

Asunaprevir

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Asunaprevir.

Atovaquone

Rifamycin Derivatives may decrease the serum concentration of Atovaquone.

Axitinib

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Axitinib.

BCG (Intravesical)

Antibiotics may diminish the therapeutic effect of BCG (Intravesical).

Bedaquiline

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Bedaquiline.

Bictegravir

Rifabutin may decrease the serum concentration of Bictegravir.

Bosutinib

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Bosutinib.

Cholera Vaccine

The therapeutic benefit of the cholera vaccine may be reduced by antibiotic use. Management: Cholera vaccine should not be administered to individuals taking systemic antibiotics or within 14 days after taking oral or parenteral antibiotics.

Cobimetinib

Cobimetinib's serum levels may be decreased by CYP3A4 Inducers (Moderate).

Dasabuvir

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Dasabuvir.

Deflazacort

The serum concentrations of the active metabolite(s) of Deflazacort may be lowered by CYP3A4 Inducers (Moderate).

Delavirdine

Delavirdine's metabolism may be accelerated by rifamycin derivatives. Rifamycin derivatives' serum levels may rise in response to delavirdine. Rifabutin serum concentration may rise specifically.

Elbasvir

Elbasvir's serum levels may be reduced by moderate CYP3A4 inducing drugs.

Elvitegravir

May raise the active metabolite(s) of rifabutin's serum level. Elvitegravir's serum concentration may drop if you take rifabutin. Treatment: Rifabutin dosage reduction of at least 75% is needed for single-agent elvitegravir, which translates to a dose of 150 mg for adults every other day or three times a week. It is not advised to use elvitegravir in combination with rifabutin.

Encorafenib

Encorafenib's serum levels may be decreased by CYP3A4 Inducers (Moderate).

Entrectinib

Entrectinib's serum levels may be lowered by moderately potent CYP3A4 inducers.

Etravirine

Etravirine's serum levels may drop if you take rifabutin. Management: Patients who are also on a protease inhibitor or ritonavir should not use rifabutin with etravirine. If etravirine is provided without the use of a protease inhibitor or ritonavir, rifabutin (300 mg daily) may be used with etravirine.

Fedratinib

Fedratinib's serum levels may be affected by CYP3A4 Inducers (Moderate).

Flibanserin

Flibanserin's serum levels may drop if CYP3A4 Inducers (Moderate) are taken.

Grazoprevir

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Grazoprevir.

Ledipasvir

Rifabutin may decrease the serum concentration of Ledipasvir.

Mycophenolate

Rifamycin Derivatives may decrease the serum concentration of Mycophenolate. Specifically, rifamycin derivatives may decrease the concentration of the active metabolite mycophenolic acid.

Neratinib

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Neratinib.

Nisoldipine

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Nisoldipine.

Olaparib

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Olaparib.

Pimavanserin

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pimavanserin.

Pretomanid

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pretomanid.

Ranolazine

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Ranolazine.

Simeprevir

CYP3A4 Inducers (Moderate) may decrease the serum concentration of Simeprevir.

Sofosbuvir

Sofosbuvir's serum levels may drop if you take rifabutin.

Sonidegib

Sonidegib's serum levels may be decreased by CYP3A4 Inducers (Moderate).

Tenofovir Alafenamide

Tenofovir Alafenamide's serum levels could drop due to rifabutin.

Velpatasvir

The serum concentration of Velpatasvir may fall in response to CYP3A4 Inducers (Moderate).

Venetoclax

Venetoclax serum levels may be decreased by CYP3A4 Inducers (Moderate).

Voriconazole

Rifamycin derivatives' serum levels can rise. Rifamycin derivatives may lower the level of voriconazole in the blood.