Advertisement
The Body: The Complete HIV/AIDS Resource
Follow Us Follow Us on Facebook Follow Us on Twitter Download Our App
Professionals >> Visit The Body PROThe Body en Espanol
  
  • Email Email
  • Printable Single-Page Print-Friendly
  • Glossary Glossary
  • PDF PDF

Anti-HIV Drug Interactions

A Guide to the Interactions Found Between Anti-HIV Drugs and Common HIV-Related Therapies

August 2004

Interactions Table (S-Z)

A | B-D | E-I | K-P | R

Saquinavir (Fortovase, soft gel capsule) plus ...
Amprenavir Decreases amprenavir level by 32% and saquinavir level by 19% in blood. No dose adjustment likely required.
Astemizole Should not be used together*. Increases risk of side effects.
Atazanavir Increases saquinavir level by 5–6 fold in blood. Dose changes now under study.
Atorvastatin Should be used together with great caution. Ritonavir + saquinavir increases atorvastatin level by 343% in blood.
Carbamazepine Should be used together with great caution. May decrease saquinavir level in blood.
Cisapride Should not be used together*. Increases risk of side effects.
Clarithromycin Increases saquinavir level by 177% and increases clarithromycin level by 45% (but decreases 14-hydroxy clarithromycin level by 24%) in blood. No dose adjustments currently recommended.
Dihydroergotamine Should not be used together*. Increases risk of side effects.
Delavirdine Increases saquinavir level by 5 times in blood. Reduce saquinavir dose to 800 mg 3 times/day.
Dexamethasone Should be used together with caution. May decrease saquinavir level in blood.
ddI or ddI EC Saquinavir should be taken 2 hours before or after taking ddI or ddI EC. Saquinavir is best taken with food, and ddI and ddI EC should only be taken on an empty stomach.
Efavirenz Decreases efavirenz level by 12% and saquinavir level by 62% in blood. Requires ritonavir boosting.
Ergonovine Should not be used together*. Increases risk of side effects.
Ergotamine Should not be used together*. Increases risk of side effects.
Fluconazole May increase saquinavir level in blood. However, no dose adjustment recommended.
Food High fat meal increases saquinavir level by 93% in blood. Should be taken within 2 hours of a meal.
Garlic supplements Should be used together with great caution. Decreases saquinavir level by 51% in blood.
Grapefruit juice Increases saquinavir level in blood.
Indinavir Increases saquinavir level 3.6–6.2 times in blood.
Itraconazole Increases saquinavir level in blood. However, no dose adjustment recommended.
Kaletra Increases saquinavir trough level by about 3-fold. Saquinavir dose may be reduced to 800 mg twice a day. Optimal dosing is under study.
Ketoconazole Significantly increases saquinavir level in blood. However, no dose adjustment recommended.
Lovastatin Should not be used together*. Increases risk of side effects.
Methylergonovine Should not be used together*. Increases risk of side effects.
Miconazole May increase saquinavir level in blood. However, no dose adjustment recommended.
Midazolam Should not be used together*. Increases risk of side effects.
Nelfinavir Increases nelfinavir level 18% and increases saquinavir level 4 times in blood. Saquinavir dose may be reduced to 800 mg 3 times a day or 1,200 mg twice a day.
Nevirapine Decreases saquinavir level by 24% in blood. Saquinavir may require ritonavir boosting.
Phenobarbital Should be used together with great caution. May decrease saquinavir level in blood.
Phenytoin Should be used together with great caution. May decrease saquinavir level in blood.
Pravastatin Ritonavir + saquinavir decreases pravastatin level by 47% in blood.
Rifabutin Should be used together with great caution. Decreases saquinavir level by 40% in blood. Consider alternative to rifabutin.
Rifampin Should not be used together. Decreases saquinavir level by 84% in blood.
Ritonavir Increases saquinavir level by 1,587% in blood. Adjust doses to saquinavir 1,000 mg + ritonavir 100 mg twice a day.
Sildenafil Should be used together with caution. Increases sildenafil level by 210% in blood. Start sildenafil at no more than 25 mg.
Simvastatin Should not be used together*. May significantly increase simvastatin level in blood and increase risk of side effects. Ritonavir + saquinavir (soft gel) increases simvastatin level by 3,059% in blood.
St. John's Wort Should not be used together. May decrease saquinavir level in blood.
Tedalafil Should be used together with caution. May increase tedalafil level in blood.
Triazolam Should not be used together*. Increases risk of side effects.
Vardenafil Should be used together with caution. May increase vardenafil level in blood.

Saquinavir (Invirase, hard gel capsule) plus ...
Astemizole Should not be used together*. Increases risk of side effects.
Atorvastatin Should be used together with great caution. Ritonavir + saquinavir (soft gel) increases atorvastatin level by 343%.
Bepridil Should be used together with caution. May increase bepridil level in blood. Check for side effects.
Carbamazepine Should not be used together. May decrease saquinavir level in blood.
Clindamycin Should be used with caution. May increase clindamycin level in blood. Check for side effects.
Dapsone May increase dapsone level in blood. Check for dapsone side effects.
ddI or ddI EC Saquinavir should be taken 2 hours before or after taking ddI or ddI EC. Saquinavir is best taken with food, and ddI and ddI EC should only be taken on an empty stomach.
Delavirdine Increases saquinavir level by 5 times in blood. May increase risk of GI side effects and LFTs. Reduce saquinavir dose to 800 mg 3 times a day.
Dexamethasone Should be used together with caution. May decrease saquinavir level in blood.
Diltiazem Should be used together with caution. May increase diltiazem level in blood. Check for side effects.
Felodipine Should be used together with caution. May increase felodipine level in blood. Check for side effects.
Fluconazole May increase saquinavir level in blood. However, no dose adjustment recommended.
Food Increases saquinavir level in blood. Should be taken within 2 hours of a meal.
Grapefruit juice Increases saquinavir level in blood.
Indinavir Increases saquinavir level 4.6–7.2 times in blood.
Itraconazole Increases saquinavir level in blood. However, no dose adjustment recommended.
Ketoconazole Significantly increases saquinavir level in blood. However, no dose adjustment recommended.
Lovastatin Should not be used together*. Increases risk of side effects.
Miconazole May increase saquinavir level in blood. However, no dose adjustment recommended.
Nelfinavir Increases saquinavir level by 4 times and increases nelfinavir level by 18% in blood. Saquinavir dose may be reduced to 800 mg 3 times a day or 1,200 mg twice a day.
Nevirapine Decreases saquinavir level 24% in blood. Saquinavir may require ritonavir boosting.
Nicardipine Should be used together with caution. May increase nicardipine level in blood. Check for side effects.
Nifedipine Should be used together with caution. May increase nifedipine level in blood. Check for side effects.
Nimodipine Should be used together with caution. May increase nimodipine level in blood. Check for side effects.
Nisoldipine Should be used together with caution. May increase nisoldipine level in blood. Check for side effects.
Nitrendipine Should be used together with caution. May increase nitrendipine level in blood. Check for side effects.
Phenobarbital Should not be used together. May decrease saquinavir level in blood.
Phenytoin Should not be used together. May decrease saquinavir level in blood.
Pravastatin Ritonavir + saquinavir (soft gel) decreases pravastatin level by 47% in blood.
Quinidine Should be used with caution. May increase quinidine level in blood. Check for side effects.
Rifabutin Should be used together with great caution. Decreases saquinavir level by 40% in blood. Consider alternative to rifabutin.
Rifampin Should not be used together. Decreases saquinavir level by 84% in blood.
Ritonavir Increases saquinavir level by about 20 times in blood. Adjust doses to saquinavir 1,000 mg + ritonavir 100 mg twice a day.
Simvastatin Should not be used together*. May significantly increase simvastatin level in blood and increase risk of side effects. Ritonavir + saquinavir (soft gel) increases simvastatin level by 3,059% in blood.
St. John's Wort Should not be used together. May decrease saquinavir level in blood.
Triazolam Should be used with caution. May increase triazolam level in blood. Check for side effects.

Advertisement

Stavudine (d4T, Zerit) plus ...
AZT Should not be used together. Decreases anti-HIV activity.
ddC May increase risk of peripheral neuropathy and pancreatitis.
ddI or ddI EC Should be used together with great caution. Increases risk of pancreatitis, especially in pregnant women.
Ganciclovir May increase risk of pancreatitis.
Hydroxyurea Increases anti-HIV activity in test tubes. May increase risk of pancreatitis.
Pentamidine (IV) May increase risk of pancreatitis.
Ribavirin Should not be used together. Decreases anti-HIV activity in test tubes.

Sulfadiazine plus ...
Glipizide Should be used together with caution. May decrease glipizide level in blood. Check blood sugar level and adjust dose accordingly.
Glyburide Should be used together with caution. May decrease glyburide level in blood. Check blood sugar level and adjust dose accordingly.
Tolbutamide Should be used together with caution. May decrease glyburide level in blood. Check blood sugar level and adjust dose accordingly.

Tenofovir (Viread) plus...
Abacavir Should be used together with great caution. Although blood level not affected, tenofovir + abacavir speeds the development of resistance to both.
Adefovir Should not be used together*. Increases risk of kidney toxicity.
Acyclovir Should be used together with caution. May increase risk of kidney toxicity.
Amikacin Should not be used together*. May increase risk of side effects.
Amphotericin B Should not be used together*. May increase risk of side effects.
Atazanavir Increases tenofovir level by 24% and decreases atazanavir level by up to 40% in blood. Atazanavir should be boosted with ritonavir if used with tenofovir.
Cidofovir Should not be used together*. May increase risk of side effects.
ddI or ddI EC Should be used together with great caution. Increases ddI level by 44% in blood. May increase risk of ddI side effects.
Food (high fat meal) Increases tenofovir level by 40% in blood. Tenofovir should be taken with food.
Foscarnet Should be used together with great caution. May increase risk of kidney toxicity.
Ganciclovir Should be used together with great caution. May increase risk of side effects. Check for kidney toxicity.
Gentamycin Should not be used together*. May increase risk of side effects.
Kaletra Increases tenofovir level by about 30% and decreases lopinavir level 15% in blood. No dose adjustment currently recommended.
Pentamidine (IV) Should not be used together*. May increase risk of side effects.
Tobramycin Should not be used together*. May increase risk of side effects.
Valacyclovir Should be used together with caution. May increase risk of kidney toxicity.
Valganciclovir Should not be used together*. May increase risk of side effects.

TMP/SMX (Bactrim, Septra) plus ...
3TC Increases 3TC level by 44% in blood. No dose adjustment recommended. Check for 3TC side effects.
Anticancer drugs May decrease number of red blood cells (anemia) and neutrophils (neutropenia).
AZT Should be used together with caution. May decrease number of red blood cells (anemia) and neutrophils (neutropenia).
Dapsone Increases trimethoprim level by 1.5 times and increases dapsone level by 1.5 times in blood.
ddI or ddI EC Slightly decreases trimethoprim level and increases ddI level in blood. No dose adjustment recommended.
Diuretics May decrease number of platelets in elderly people.
Ganciclovir Should be used together with great caution. May increase risk of bone marrow toxicity.
Indinavir Should be used together with caution. Increases trimethoprim level by 31% in blood.
Methotrexate Should be used with caution. May increase methotrexate level in blood.
Nevirapine Should not be started together for the first 4–6 weeks. May increase risk of rash.
Phenytoin Should be used with caution. May increase phenytoin level in blood. Check for side effects.
Pyrimethamine Should be used together with caution. May increase risk of bone marrow toxicity.
Warfarin Should be used with caution. May increase prothrombin (coagulation) time. Check INR.

Trimetrexate (Neutrexin) plus ...
Acetaminophen May affect trimetrexate and/or acetaminophen level in blood.
Cimetidine May affect trimetrexate and/or cimetidine level in blood.
Clarithromycin May affect trimetrexate and/or clarithromycin level in blood.
Erythromycin May affect trimetrexate and/or erythromycin level in blood.
Fluconazole May affect trimetrexate and/or fluconazole level in blood.
Itraconazole May affect trimetrexate and/or itraconazole level in blood.
Ketoconazole May affect trimetrexate and/or ketoconazole level in blood.
Ranitidine May affect trimetrexate and/or ranitidine level in blood.
Rifabutin Should be used together with caution. May affect trimetrexate and/or rifabutin level in blood.
Rifampin Should be used together with caution. May affect trimetrexate and/or rifampin level in blood.

Trizivir plus ...
Trizivir is a single pill containing 3 anti-HIV drugs, 3TC, abacavir and AZT. If you take Trizivir as part of your regimen, refer separately to drug interactions for 3TC, abacavir and AZT.

Zalcitabine (ddC, Hivid) plus ...
3TC Should not be used together. Decreases anti-HIV activity of both drugs.
Aminoglycosides May increase ddC level in blood and increase risk of peripheral neuropathy. Check for toxicity.
Amphotericin B May increase ddC level in blood and increase risk of peripheral neuropathy. Check for toxicity.
Antacids Decreases ddC level by 25% in blood. Take at least 2 hours apart.
Anticancer drugs May increase risk of peripheral neuropathy.
Chloramphenicol May increase risk of peripheral neuropathy.
Cimetidine Significantly increases ddC level in blood. Check for toxicity; consider lower ddC dose.
Cisplatin May increase risk of peripheral neuropathy.
d4T May increase risk of peripheral neuropathy and pancreatitis.
Dapsone May increase risk of peripheral neuropathy.
ddI or ddI EC Should not be used together. Significantly increases risk of peripheral neuropathy.
Disulfiram May increase risk of peripheral neuropathy.
Doxorubicin May decrease anti-HIV activity of ddC.
Ethionamide May increase risk of peripheral neuropathy.
Food May decrease ddC level in blood.
Foscarnet May increase risk of kidney toxicity and peripheral neuropathy. Check for toxicity.
Glutethimide May increase risk of peripheral neuropathy.
Hydralazine May increase risk of peripheral neuropathy.
Iodoquinol May increase risk of peripheral neuropathy.
Isoniazid May increase risk of peripheral neuropathy.
Metoclopramide Decreases ddC level by 10% in blood.
Metronidazole May increase risk of peripheral neuropathy.
Nitrofurantoin May increase risk of peripheral neuropathy.
Pentamidine (IV) Should be used with great caution. May increase risk of peripheral neuropathy and pancreatitis.
Phenytoin May increase risk of peripheral neuropathy.
Probenecid Significantly increases ddC level in blood. Check for toxicity; consider lower ddC dose.
Ribavirin May increase risk of peripheral neuropathy.
Vincristine May increase risk of peripheral neuropathy.

Zidovudine (AZT, Retrovir) plus ...
Abacavir Increases AZT level by 10% in blood. No dose adjustment recommended.
Amphotericin B May increase risk of bone marrow toxicity.
Amprenavir Increases AZT level by 31% and increases amprenavir level by 13% in blood. No dose adjustment recommended.
Anticancer drugs May increase risk of bone marrow toxicity.
Atovaquone Increases AZT level by 35% in blood. No dose adjustment recommended.
Azithromycin May increase AZT level in blood. No dose adjustment recommended.
Clarithromycin Decreases AZT level by 25% in blood. Consider taking at least 2 hours apart.
d4T Should not be used together. Decreases anti-HIV activity.
Dapsone May increase risk of bone marrow toxicity.
Doxorubicin Should not be used together. Decreases effectiveness and increases toxicity.
Fluconazole Increases AZT level by 74% and may increase fluconazole level in blood. Check for toxicity.
Flucytosine May increase risk of bone marrow toxicity.
Food Fatty foods may decrease AZT level by 57% in blood.
Foscarnet Should be used together with caution. May increase risk of anemia.
Ganciclovir Increases AZT level in blood and may increase risk of neutropenia, anemia and bone marrow toxicity. Avoid combination or use lower AZT dose.
Indinavir Increases anti-HIV activity in test tubes. Increases AZT level by 17–36% in blood. No dose adjustment recommended.
Interferon-alfa Increases anti-HIV activity in test tubes and may increase risk of bone marrow toxicity. Lower AZT dose by 50–75%.
Methadone Increases AZT level by 43% in blood. Check for AZT toxicity.
Nelfinavir Decreases AZT level by 35% in blood. No dose adjustment recommended.
Pentamidine May increase risk of anemia.
Phenytoin May decrease phenytoin and AZT levels in blood. No dose adjustment recommended.
Probenecid Increases AZT level by 106% in blood. Adjusting AZT dose may be necessary.
Pyrimethamine Should be used together with caution. May increase risk of bone marrow toxicity.
Ribavirin Should not be used together. Decreases anti-HIV activity in test tubes.
Rifabutin May decrease AZT level in blood.
Rifampin Decreases AZT level by 47% in blood. May require increase in AZT dose.
Ritonavir Decreases AZT level by 25% in blood. No dose adjustment recommended.
TMP/SMX Should be used together with caution. May decrease number of red blood cells and neutrophils thus increasing risk of anemia.
Valproic Acid Increases AZT level by 80% in blood. Check for AZT toxicity.
Vinblastine May increase risk of bone marrow toxicity.
Vincristine May increase risk of anemia.


Interpreting Directions

Should not be used together
The risk of side effects from a combination is too high for the two medications to be used together.

An asterisk (*) following this phrase means the side effects may be life-threatening.

Should be used together with caution
The risk of side effects from a combination is possible, but not highly common.

Should be used together with great caution
The risk of side effects from a combination is possible, and though not common may be serious if they occur.




  
  • Email Email
  • Printable Single-Page Print-Friendly
  • Glossary Glossary
  • PDF PDF

This article was provided by Project Inform. Visit Project Inform's website to find out more about their activities, publications and services.
 

Tools
 

Advertisement