Skip to main content

Drug Interactions between Caduet and emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

ritonavir atorvastatin

Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil and Caduet (amlodipine / atorvastatin)

ADJUST DOSE: Protease inhibitors (PIs), particularly ritonavir, may significantly increase the plasma concentrations of atorvastatin. The mechanism is PI inhibition of CYP450 3A4 metabolism. In 14 healthy volunteers, ritonavir (400 mg twice a day) and saquinavir (soft gelatin capsule 400 mg twice a day) given for 14 days increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of atorvastatin plus atorvastatin acid (given as atorvastatin 40 mg once a day for 4 days) by 148% and 73%, respectively. In 16 study subjects, amprenavir (given as fosamprenavir 1400 mg twice a day for 2 weeks) increased Cmax and AUC of atorvastatin (10 mg once a day) by 304% and 130%, respectively. These values were increased 184% and 153%, respectively, with ritonavir-fosamprenavir (700 mg-100 mg twice a day). High levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death.

MANAGEMENT: The benefits of using atorvastatin in combination with protease inhibitors should be carefully weighed against the potentially increased risk of myopathy including rhabdomyolysis. A lower dosage of atorvastatin should be considered if concomitant use is required. Atorvastatin labeling recommends that the dosage not exceed 20 mg/day when used in combination with fosamprenavir or with dual protease inhibitor therapy consisting of ritonavir plus darunavir, saquinavir, or fosamprenavir. Use of atorvastatin with the fixed combination of atazanavir-cobicistat is not recommended. The dosage should not exceed 40 mg/day when used with nelfinavir. Nirmatrelvir-ritonavir product labeling advises temporary discontinuation of atorvastatin be considered during treatment with nirmatrelvir-ritonavir. Fluvastatin, pitavastatin, and pravastatin may be safer alternatives, since they are not metabolized by CYP450 3A4. All patients receiving statin therapy should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed.

References (16)
  1. (2001) "Product Information. Norvir (ritonavir)." Abbott Pharmaceutical
  2. (2001) "Product Information. Crixivan (indinavir)." Merck & Co., Inc
  3. (2001) "Product Information. Viracept (nelfinavir)." Agouron Pharma Inc
  4. Malaty LI, Kuper JJ (1999) "Drug interactions of HIV protease inhibitors." Drug Safety, 20, p. 147-69
  5. (2001) "Product Information. Agenerase (amprenavir)." Glaxo Wellcome
  6. Barry M, Mulcahy F, Merry C, Gibbons S, Back D (1999) "Pharmacokinetics and potential interactions amongst antiretroviral agents used to treat patients with HIV infection." Clin Pharmacokinet, 36, p. 289-304
  7. Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57
  8. (2001) "Product Information. Fortovase (saquinavir)." Roche Laboratories
  9. Mangum EM, Graham KK (2001) "Lopinavir-Ritonavir: a new protease inhibitor." Pharmacotherapy, 21, p. 1352-63
  10. Fichtenbaum CJ, Gerber JG, Rosenkranz SL, et al. (2002) "Pharmacokinetic interactions between protease inhibitors and statins in HIV seronegative volunteers: ACTG Study A5047." AIDS, 16, p. 569-577
  11. Piliero PJ (2002) "Interaction between ritonavir and statins." Am J Med, 112, p. 510-1
  12. (2003) "Product Information. Reyataz (atazanavir)." Bristol-Myers Squibb
  13. (2003) "Product Information. Lexiva (fosamprenavir)." GlaxoSmithKline
  14. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  15. (2006) "Product Information. Prezista (darunavir)." Ortho Biotech Inc
  16. US Food and Drug Administration (2021) FACT SHEET FOR HEALTHCARE PROVIDERS EMERGENCY USE AUTHORIZATION FOR PAXLOVID. https://www.fda.gov/media/155050/download

Switch to consumer interaction data

Moderate

amLODIPine ritonavir

Applies to: Caduet (amlodipine / atorvastatin) and emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

MONITOR: Coadministration with CYP450 3A4 inhibitors may increase the plasma concentrations of amlodipine, which is a substrate of the isoenzyme. In 8 elderly hypertensive patients, administration of a single 5 mg dose of amlodipine in combination with the moderate CYP450 3A4 inhibitor diltiazem (180 mg orally daily for 3 days) resulted in a nearly 60% increase in amlodipine peak plasma concentration (Cmax) and systemic exposure (AUC). Associated systolic, diastolic, and standing blood pressures decreased compared to those obtained with amlodipine alone. Erythromycin, another moderate inhibitor, did not significantly alter amlodipine systemic exposure in healthy volunteers. However, pharmacokinetic changes may be more pronounced in elderly patients.

MANAGEMENT: Close monitoring of clinical response and tolerance is recommended if amlodipine is prescribed with potent or moderate CYP450 3A4 inhibitors. Dosage reduction may be required for amlodipine. Patients should be advised to seek medical attention if they experience edema or swelling of the lower extremities; sudden, unexplained weight gain; difficulty breathing; chest pain or tightness; or hypotension as indicated by dizziness, fainting, or orthostasis.

References (5)
  1. (2002) "Product Information. Norvasc (amlodipine)." Pfizer U.S. Pharmaceuticals
  2. Sasaki M, Maeda A, Fujimura A (2001) "Influence of diltiazem on the pharmacokinetics of amlodipine in elderly hypertensive patients." Eur J Clin Pharmacol, 57, p. 85-6
  3. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  4. Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
  5. Cerner Multum, Inc. "Australian Product Information."

Switch to consumer interaction data

Moderate

amLODIPine atorvastatin

Applies to: Caduet (amlodipine / atorvastatin) and Caduet (amlodipine / atorvastatin)

MONITOR: Coadministration with inhibitors of CYP450 3A4 may increase the plasma concentrations of HMG-CoA reductase inhibitors (i.e., statins) that are metabolized by the isoenzyme. Lovastatin and simvastatin are particularly susceptible because of their low oral bioavailability, but others such as atorvastatin and cerivastatin may also be affected. High levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death. Clinically significant interactions have been reported with potent CYP450 3A4 inhibitors such as macrolide antibiotics, azole antifungals, protease inhibitors and nefazodone, and moderate inhibitors such as amiodarone, cyclosporine, danazol, diltiazem and verapamil.

MANAGEMENT: Caution is recommended if atorvastatin, cerivastatin, lovastatin, simvastatin, or red yeast rice (which contains lovastatin) is prescribed with a CYP450 3A4 inhibitor. It is advisable to monitor lipid levels and use the lowest effective statin dose. All patients receiving statin therapy should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed. Fluvastatin, pravastatin, and rosuvastatin are not expected to interact with CYP450 3A4 inhibitors.

References (63)
  1. Spach DH, Bauwens JE, Clark CD, Burke WG (1991) "Rhabdomyolysis associated with lovastatin and erythromycin use." West J Med, 154, p. 213-5
  2. Ayanian JZ, Fuchs CS, Stone RM (1988) "Lovastatin and rhabdomyolysis." Ann Intern Med, 109, p. 682-3
  3. Corpier CL, Jones PH, Suki WN, et al. (1988) "Rhabdomyolysis and renal injury with lovastatin use. Report of two cases in cardiac transplant recipients." JAMA, 260, p. 239-41
  4. East C, Alivizatos PA, Grundy SM, Jones PH, Farmer JA (1988) "Rhabdomyolysis in patients receiving lovastatin after cardiac transplantation." N Engl J Med, 318, p. 47-8
  5. Norman DJ, Illingworth DR, Munson J, Hosenpud J (1988) "Myolysis and acute renal failure in a heart-transplant recipient receiving lovastatin." N Engl J Med, 318, p. 46-7
  6. (2002) "Product Information. Mevacor (lovastatin)." Merck & Co., Inc
  7. (2001) "Product Information. Zocor (simvastatin)." Merck & Co., Inc
  8. Dallaire M, Chamberland M (1994) "Severe rhabdomyolysis in a patient receiving lovastatin, danazol and doxycycline." Can Med Assoc J, 150, p. 1991-4
  9. Campana C, Iacona I, Regassi MB, et al. (1995) "Efficacy and pharmacokinetics of simvastatin in heart transplant recipients." Ann Pharmacother, 29, p. 235-9
  10. Lees RS, Lees AM (1995) "Rhabdomyolysis from the coadministration of lovastatin and the antifungal agent itraconazole." N Engl J Med, 333, p. 664-5
  11. Zhou LX, Finley DK, Hassell AE, Holtzman JL (1995) "Pharmacokinetic interaction between isradipine and lovastatin in normal, female and male volunteers." J Pharmacol Exp Ther, 273, p. 121-7
  12. Neuvonen PJ, Jalava KM (1996) "Itraconazole drastically increases plasma concentrations of lovastatin and lovastatin acid." Clin Pharmacol Ther, 60, p. 54-61
  13. Horn M (1996) "Coadministration of itraconazole with hypolipidemic agents may induce rhabdomyolysis in healthy individuals." Arch Dermatol, 132, p. 1254
  14. (2001) "Product Information. Lipitor (atorvastatin)." Parke-Davis
  15. Jacobson RH, Wang P, Glueck CJ (1997) "Myositis and rhabdomyolysis associated with concurrent use of simvastatin and nefazodone." JAMA, 277, p. 296
  16. Jody DN (1997) "Myositis and rhabdomyolysis associated with concurrent use of simvastatin and nefazodone." JAMA, 277, p. 296-7
  17. (2001) "Product Information. Baycol (cerivastatin)." Bayer
  18. Grunden JW, Fisher KA (1997) "Lovastatin-induced rhabdomyolysis possibly associated with clarithromycin and azithromycin." Ann Pharmacother, 31, p. 859-63
  19. Wong PW, Dillard TA, Kroenke K (1998) "Multiple organ toxicity from addition of erythromycin to long-term lovastatin therapy." South Med J, 91, p. 202-5
  20. Neuvonen PJ, Kantola T, Kivisto KT (1998) "Simvastatin but not pravastatin is very susceptible to interaction with the CYP3A4 inhibitor itraconazole." Clin Pharmacol Ther, 63, p. 332-41
  21. Agbin NE, Brater DC, Hall SD (1997) "Interaction of diltiazem with lovastatin and pravastatin." Clin Pharmacol Ther, 61, p. 201
  22. Kivisto KT, Kantola T, Neuvonen PJ (1998) "Different effects of itraconazole on the pharmacokinetics of fluvastatin and lovastatin." Br J Clin Pharmacol, 46, p. 49-53
  23. Kantola T, Kivisto KT, Neuvonen PJ (1998) "Effect of itraconazole on the pharmacokinetics of atorvastatin." Clin Pharmacol Ther, 64, p. 58-65
  24. Kantola T, Kivisto KT, Neuvonen PJ (1998) "Erythromycin and verapamil considerably increase serum simvastatin and simvastatin acid concentrations." Clin Pharmacol Ther, 64, p. 177-82
  25. Azie NE, Brater DC, Becker PA, Jones DR, Hall SD (1998) "The interaction of diltiazem with lovastatin and pravastatin." Clin Pharmacol Ther, 64, p. 369-77
  26. Lomaestro BM, Piatek MA (1998) "Update on drug interactions with azole antifungal agents." Ann Pharmacother, 32, p. 915-28
  27. Kantola T, Kivisto KT, Neuvonen PJ (1999) "Effect of itraconazole on cerivastatin pharmacokinetics." Eur J Clin Pharmacol, 54, p. 851-5
  28. Malaty LI, Kuper JJ (1999) "Drug interactions of HIV protease inhibitors." Drug Safety, 20, p. 147-69
  29. Siedlik PH, Olson SC, Yang BB, Stern RH (1999) "Erythromycin coadministration increases plasma atorvastatin concentrations." J Clin Pharmacol, 39, p. 501-4
  30. Barry M, Mulcahy F, Merry C, Gibbons S, Back D (1999) "Pharmacokinetics and potential interactions amongst antiretroviral agents used to treat patients with HIV infection." Clin Pharmacokinet, 36, p. 289-304
  31. Rodriguez JA, CrespoLeiro MG, Paniagua MJ, Cuenca JJ, Hermida LF, Juffe A, CastroBeiras A (1999) "Rhabdomyolysis in heart transplant patients on HMG-CoA reductase inhibitors and cyclosporine." Transplant Proc, 31, p. 2522-3
  32. Gruer PJK, Vega JM, Mercuri MF, Dobrinska MR, Tobert JA (1999) "Concomitant use of cytochrome P450 3A4 inhibitors and simvastatin." Am J Cardiol, 84, p. 811-5
  33. Gilad R, Lampl Y (1999) "Rhabdomyolysis induced by simvastatin and ketoconazole treatment." Clin Neuropharmacol, 22, p. 295-7
  34. Gullestad L, Nordal KP, Berg KJ, Cheng H, Schwartz MS, Simonsen S (1999) "Interaction between lovastatin and cyclosporine A after heart and kidney transplantation." Transplant Proc, 31, p. 2163-5
  35. Yeo KR, Yeo WW, Wallis EJ, Ramsay LE (1999) "Enhanced cholesterol reduction by simvastatin in diltiazem-treated patients." Br J Clin Pharmacol, 48, p. 610-5
  36. Maltz HC, Balog DL, Cheigh JS (1999) "Rhabdomyolysis associated with concomitant use of atorvastatin and cyclosporine." Ann Pharmacother, 33, p. 1176-9
  37. Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57
  38. Jardine A, Holdaas H (1999) "Fluvastatin in combination with cyclosporin in renal transplant recipients: a review of clinical and safety experience." J Clin Pharm Ther, 24, p. 397-408
  39. Mousa O, Brater DC, Sundblad KJ, Hall SD (2000) "The interaction of diltiazem with simvastatin." Clin Pharmacol Ther, 67, p. 267-74
  40. Westphal JF (2000) "Macrolide - induced clinically relevant drug interactions with cytochrome P-450 (CYP) 3A4: an update focused on clarithromycin, azithromycin, and dirithromycin." Br J Clin Pharmacol, 50, p. 285-95
  41. Kusus M, Stapleton DD, Lertora JJL, Simon EE, Dreisbach AW (2000) "Rhabdomyolysis and acute renal failure in a cardiac transplant recipient due to multiple drug interactions." Am J Med Sci, 320, p. 394-7
  42. Lee AJ, Maddix DS (2001) "Rhabdomyolysis secondary to a drug interaction between simvastatin and clarithromycin." Ann Pharmacother, 35, p. 26-31
  43. Yeo KR, Yeo WW (2001) "Inhibitory effects of verapamil and diltiazem on simvastatin metabolism in human liver microsomes." Br J Clin Pharmacol, 51, p. 461-70
  44. Arnadottir M, Eriksson LO, Thysell H, Karkas JD (1993) "Plasma concentration profiles of simvastatin 3-hydroxy- 3-methylglutaryl-coenzyme A reductase inhibitory activity in kidney transplant recipients with and without ciclosporin." Nephron, 65, p. 410-3
  45. Corsini A, Bellosta S, Baetta R, Fumagalli R, Paoletti R, Bernini F (1999) "New insights into the pharmacodynamic and pharmacokinetic properties of statins." Pharmacol Ther, 84, p. 413-28
  46. Garnett WR (1995) "Interactions with hydroxymethylglutaryl-coenzyme A reductase inhibitors." Am J Health Syst Pharm, 52, p. 1639-45
  47. Omar MA, Wilson JP (2002) "FDA adverse event reports on statin-associated rhabdomyolysis." Ann Pharmacother, 36, p. 288-95
  48. Fichtenbaum CJ, Gerber JG, Rosenkranz SL, et al. (2002) "Pharmacokinetic interactions between protease inhibitors and statins in HIV seronegative volunteers: ACTG Study A5047." AIDS, 16, p. 569-577
  49. Amsden GW, Kuye O, Wei GC (2002) "A study of the interaction potential of azithromycin and clarithromycin with atorvastatin in healthy volunteers." J Clin Pharmacol, 42, p. 444-9
  50. Williams D, Feely J (2002) "Pharmacokinetic-Pharmacodynamic Drug Interactions with HMG-CoA Reductase Inhibitors." Clin Pharmacokinet, 41, p. 343-70
  51. Thompson M, Samuels S (2002) "Rhabdomyolysis with simvastatin and nefazodone." Am J Psychiatry, 159, p. 1607
  52. Huynh T, Cordato D, Yang F, et al. (2002) "HMG coA reductase-inhibitor-related myopathy and the influence of drug interactions." Intern Med J, 32(9-10), p. 486-90
  53. Paoletti R, Corsini A, Bellosta S (2002) "Pharmacological interactions of statins." Atheroscler Suppl, 3, p. 35-40
  54. Sipe BE, Jones RJ, Bokhart GH (2003) "Rhabdomyolysis Causing AV Blockade Due to Possible Atorvastatin, Esomeprazole, and Clarithromycin Interaction." Ann Pharmacother, 37, p. 808-11
  55. de Denus S, Spinler SA (2003) "Amiodarone's role in simvastatin-associated rhabdomyolysis." Am J Health Syst Pharm, 60, 1791; author reply 1791-2
  56. Skrabal MZ, Stading JA, Monaghan MS (2003) "Rhabdomyolysis associated with simvastatin-nefazodone therapy." South Med J, 96, p. 1034-5
  57. Andreou ER, Ledger S (2003) "Potential drug interaction between simvastatin and danazol causing rhabdomyolysis." Can J Clin Pharmacol, 10, p. 172-4
  58. Roten L, Schoenenberger RA, Krahenbuhl S, Schlienger RG (2004) "Rhabdomyolysis in association with simvastatin and amiodarone." Ann Pharmacother, 38, p. 978-81
  59. Jacobson TA (2004) "Comparative pharmacokinetic interaction profiles of pravastatin, simvastatin, and atorvastatin when coadministered with cytochrome P450 inhibitors." Am J Cardiol, 94, p. 1140-6
  60. Chouhan UM, Chakrabarti S, Millward LJ (2005) "Simvastatin interaction with clarithromycin and amiodarone causing myositis." Ann Pharmacother, 39, p. 1760-1
  61. Karnik NS, Maldonado JR (2005) "Antidepressant and statin interactions: a review and case report of simvastatin and nefazodone-induced rhabdomyolysis and transaminitis." Psychosomatics, 46, p. 565-8
  62. Neuvonen PJ, Backman JT, Niemi M (2008) "Pharmacokinetic comparison of the potential over-the-counter statins simvastatin, lovastatin, fluvastatin and pravastatin." Clin Pharmacokinet, 47, p. 463-74
  63. (2021) "Product Information. Qelbree (viloxazine)." Supernus Pharmaceuticals Inc

Switch to consumer interaction data

Moderate

amLODIPine lopinavir

Applies to: Caduet (amlodipine / atorvastatin) and emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

MONITOR: Lopinavir in combination with ritonavir has been shown to prolong the PR interval of the electrocardiogram in some patients. Theoretically, coadministration with other agents that prolong the PR interval (e.g., beta blockers, calcium channel blockers, atazanavir, digoxin, lacosamide, mefloquine) may result in additive effects and increased risk of conduction disturbances and atrioventricular block. In a study of 39 healthy adults who were administered lopinavir-ritonavir at a therapeutic dosage of 400 mg-100 mg twice daily and a supratherapeutic dosage of 800 mg-200 mg twice daily, mean changes from baseline in the PR interval ranged from 11.6 to 24.4 msec in the 12 hours postdose on treatment day 3 when exposures were approximately 1.5 and 3-fold higher, respectively, than those observed with recommended once-daily or twice-daily dosages of lopinavir-ritonavir at steady state. After baseline correction, the maximum mean difference from placebo in the PR interval was 24.9 msec for the lower dosage and 31.9 msec for the supratherapeutic dosage. Maximum PR interval observed was 286 msec, and no second- or third-degree heart block occurred. There have been postmarketing reports of asymptomatic prolongation of the PR interval in some patients receiving combination antiretroviral therapy containing lopinavir-ritonavir. Second- and third-degree atrioventricular block have occurred rarely in patients with underlying structural heart disease or preexisting conduction system abnormalities and in patients receiving lopinavir-ritonavir with other drugs known to prolong the PR interval.

MANAGEMENT: Caution is advised if lopinavir-ritonavir is used concomitantly with other agents that prolong the PR interval, particularly those that are metabolized by CYP450 3A4 (e.g., calcium channel blockers) because lopinavir-ritonavir is a potent inhibitor of the isoenzyme. The elderly as well as patients with underlying structural heart disease, preexisting conduction system abnormalities, ischemic heart disease, or cardiomyopathies may be at increased risk for developing cardiac conduction disturbances and atrioventricular block associated with the use of lopinavir-ritonavir. Patients should be advised to notify their physician if they experience dizziness, lightheadedness, fainting, or irregular heartbeat.

References (1)
  1. (2001) "Product Information. Kaletra (lopinavir-ritonavir)." Abbott Pharmaceutical

Switch to consumer interaction data

Moderate

ritonavir tenofovir

Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil and emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

MONITOR: Coadministration with ritonavir, with or without lopinavir, has been suggested in postmarketing reports to increase the proximal tubular intracellular concentrations of tenofovir and potentiate the risk of tenofovir-induced nephrotoxicity. The proposed mechanism is ritonavir inhibition of tenofovir renal tubular secretion into the urine via multidrug resistance protein MRP2. Analysis of data from a compassionate access study in which 271 patients with advanced HIV disease received the combination for a mean duration of 63 weeks revealed no clinically significant nephrotoxicity associated with coadministration. However, there have been case reports of renal failure associated with acute tubular necrosis, Fanconi's syndrome, and nephrogenic diabetes insipidus in patients treated with tenofovir disoproxil fumarate in combination with ritonavir. Some patients had incomplete recovery of renal function more than a year after cessation of tenofovir therapy. Ritonavir given in combination with lopinavir has also been reported to modestly increase the plasma concentrations of tenofovir. In contrast, both slight decreases and no change in lopinavir and ritonavir concentrations have been reported.

MANAGEMENT: Caution is advised if tenofovir disoproxil fumarate is prescribed with ritonavir. Renal function should be monitored regularly, including surveillance for signs of tubulopathy such as glycosuria, acidosis, increases in serum creatinine level, electrolyte disturbances (e.g., hypokalemia, hypophosphatemia), and proteinuria. The same precaution may be applicable during therapy with other protease inhibitors based on their similar pharmacokinetic profile, although clinical data are lacking. Nelfinavir reportedly does not alter the pharmacokinetics of tenofovir, or vice versa. Tenofovir administration should be discontinued promptly if nephropathy develops.

References (8)
  1. (2001) "Product Information. Viread (tenofovir)." Gilead Sciences
  2. Verhelst D, Monge M, Meynard JL, et al. (2002) "Fanconi syndrome and renal failure induced by tenofovir: A first case report." Am J Kidney Dis, 40, p. 1331-3
  3. Creput C, Gonzalez-Canali G, Hill G, Piketty C, Kazatchkine M, Nochy D (2003) "Renal lesions in HIV-1-positive patient treated with tenofovir." AIDS, 17, p. 935-7
  4. Karras A, Lafaurie M, Furco A, et al. (2003) "Tenofovir-related nephrotoxicity in human immunodeficiency virus-infected patients: three cases of renal failure, fanconi syndrome, and nephrogenic diabetes insipidus." Clin Infect Dis, 36, p. 1070-3
  5. Kearney BP, Mittan A, Sayre J, et al. (2003) Pharmacokinetic drug interaction and long term safety profile of tenofovir DF and lopinavir/ritonavir. http://www.icaac.org/ICAAC.asp
  6. Rollot F, Nazal EM, Chauvelot-Moachon L, et al. (2003) "Tenofovir-related fanconi syndrome with nephrogenic diabetes insipidus in a patient with acquired immunodeficiency syndrome: the role of lopinavir-ritonavir-Didanosine." Clin Infect Dis, 37, E174-6
  7. Zimmermann AE, Pizzoferrato T, Bedford J, Morris A, Hoffman R, Braden G (2006) "Tenofovir-associated acute and chronic kidney disease: a case of multiple drug interactions." Clin Infect Dis, 42, p. 283-90
  8. Kapadia J, Shah S, Desai C, et al. (2013) "Tenofovir induced Fanconi syndrome: a possible pharmacokinetic interaction." Indian J Pharmacol, 45, p. 191-2

Switch to consumer interaction data

Moderate

lopinavir tenofovir

Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil and emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

MONITOR: Coadministration with ritonavir, with or without lopinavir, has been suggested in postmarketing reports to increase the proximal tubular intracellular concentrations of tenofovir and potentiate the risk of tenofovir-induced nephrotoxicity. The proposed mechanism is ritonavir inhibition of tenofovir renal tubular secretion into the urine via multidrug resistance protein MRP2. Analysis of data from a compassionate access study in which 271 patients with advanced HIV disease received the combination for a mean duration of 63 weeks revealed no clinically significant nephrotoxicity associated with coadministration. However, there have been case reports of renal failure associated with acute tubular necrosis, Fanconi's syndrome, and nephrogenic diabetes insipidus in patients treated with tenofovir disoproxil fumarate in combination with ritonavir. Some patients had incomplete recovery of renal function more than a year after cessation of tenofovir therapy. Ritonavir given in combination with lopinavir has also been reported to modestly increase the plasma concentrations of tenofovir. In contrast, both slight decreases and no change in lopinavir and ritonavir concentrations have been reported.

MANAGEMENT: Caution is advised if tenofovir disoproxil fumarate is prescribed with ritonavir. Renal function should be monitored regularly, including surveillance for signs of tubulopathy such as glycosuria, acidosis, increases in serum creatinine level, electrolyte disturbances (e.g., hypokalemia, hypophosphatemia), and proteinuria. The same precaution may be applicable during therapy with other protease inhibitors based on their similar pharmacokinetic profile, although clinical data are lacking. Nelfinavir reportedly does not alter the pharmacokinetics of tenofovir, or vice versa. Tenofovir administration should be discontinued promptly if nephropathy develops.

References (8)
  1. (2001) "Product Information. Viread (tenofovir)." Gilead Sciences
  2. Verhelst D, Monge M, Meynard JL, et al. (2002) "Fanconi syndrome and renal failure induced by tenofovir: A first case report." Am J Kidney Dis, 40, p. 1331-3
  3. Creput C, Gonzalez-Canali G, Hill G, Piketty C, Kazatchkine M, Nochy D (2003) "Renal lesions in HIV-1-positive patient treated with tenofovir." AIDS, 17, p. 935-7
  4. Karras A, Lafaurie M, Furco A, et al. (2003) "Tenofovir-related nephrotoxicity in human immunodeficiency virus-infected patients: three cases of renal failure, fanconi syndrome, and nephrogenic diabetes insipidus." Clin Infect Dis, 36, p. 1070-3
  5. Kearney BP, Mittan A, Sayre J, et al. (2003) Pharmacokinetic drug interaction and long term safety profile of tenofovir DF and lopinavir/ritonavir. http://www.icaac.org/ICAAC.asp
  6. Rollot F, Nazal EM, Chauvelot-Moachon L, et al. (2003) "Tenofovir-related fanconi syndrome with nephrogenic diabetes insipidus in a patient with acquired immunodeficiency syndrome: the role of lopinavir-ritonavir-Didanosine." Clin Infect Dis, 37, E174-6
  7. Zimmermann AE, Pizzoferrato T, Bedford J, Morris A, Hoffman R, Braden G (2006) "Tenofovir-associated acute and chronic kidney disease: a case of multiple drug interactions." Clin Infect Dis, 42, p. 283-90
  8. Kapadia J, Shah S, Desai C, et al. (2013) "Tenofovir induced Fanconi syndrome: a possible pharmacokinetic interaction." Indian J Pharmacol, 45, p. 191-2

Switch to consumer interaction data

Drug and food interactions

Moderate

ritonavir food

Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

ADJUST DOSING INTERVAL: Administration with food may modestly affect the bioavailability of ritonavir from the various available formulations. When the oral solution was given under nonfasting conditions, peak ritonavir concentrations decreased 23% and the extent of absorption decreased 7% relative to fasting conditions. Dilution of the oral solution (within one hour of dosing) with 240 mL of chocolate milk or a nutritional supplement (Advera or Ensure) did not significantly affect the extent and rate of ritonavir absorption. When a single 100 mg dose of the tablet was administered with a high-fat meal (907 kcal; 52% fat, 15% protein, 33% carbohydrates), approximately 20% decreases in mean peak concentration (Cmax) and systemic exposure (AUC) were observed relative to administration after fasting. Similar decreases in Cmax and AUC were reported when the tablet was administered with a moderate-fat meal. In contrast, the extent of absorption of ritonavir from the soft gelatin capsule formulation was 13% higher when administered with a meal (615 KCal; 14.5% fat, 9% protein, and 76% carbohydrate) relative to fasting.

MANAGEMENT: Ritonavir should be taken with meals to enhance gastrointestinal tolerability.

References (1)
  1. (2001) "Product Information. Norvir (ritonavir)." Abbott Pharmaceutical

Switch to consumer interaction data

Moderate

atorvastatin food

Applies to: Caduet (amlodipine / atorvastatin)

GENERALLY AVOID: Coadministration with grapefruit juice may increase the plasma concentrations of atorvastatin. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. When a single 40 mg dose of atorvastatin was coadministered with 240 mL of grapefruit juice, atorvastatin peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 16% and 37%, respectively. Greater increases in Cmax (up to 71%) and/or AUC (up to 2.5 fold) have been reported with excessive consumption of grapefruit juice (>=750 mL to 1.2 liters per day). Clinically, high levels of HMG-CoA reductase inhibitory activity in plasma is associated with an increased risk of musculoskeletal toxicity. Myopathy manifested as muscle pain and/or weakness associated with grossly elevated creatine kinase exceeding ten times the upper limit of normal has been reported occasionally. Rhabdomyolysis has also occurred rarely, which may be accompanied by acute renal failure secondary to myoglobinuria and may result in death.

ADJUST DOSING INTERVAL: Fibres such as oat bran and pectin may diminish the pharmacologic effects of HMG-CoA reductase inhibitors by interfering with their absorption from the gastrointestinal tract.

MANAGEMENT: Patients receiving therapy with atorvastatin should limit their consumption of grapefruit juice to no more than 1 liter per day. Patients should be advised to promptly report any unexplained muscle pain, tenderness or weakness, particularly if accompanied by fever, malaise and/or dark colored urine. Therapy should be discontinued if creatine kinase is markedly elevated in the absence of strenuous exercise or if myopathy is otherwise suspected or diagnosed. In addition, patients should either refrain from the use of oat bran and pectin or, if concurrent use cannot be avoided, to separate the administration times by at least 2 to 4 hours.

References (7)
  1. Richter WO, Jacob BG, Schwandt P (1991) "Interaction between fibre and lovastatin." Lancet, 338, p. 706
  2. McMillan K (1996) "Considerations in the formulary selection of hydroxymethylglutaryl coenzyme a reductase inhibitors." Am J Health Syst Pharm, 53, p. 2206-14
  3. (2001) "Product Information. Lipitor (atorvastatin)." Parke-Davis
  4. Boberg M, Angerbauer R, Fey P, Kanhai WK, Karl W, Kern A, Ploschke J, Radtke M (1997) "Metabolism of cerivastatin by human liver microsomes in vitro. Characterization of primary metabolic pathways and of cytochrome P45 isozymes involved." Drug Metab Dispos, 25, p. 321-31
  5. Bailey DG, Malcolm J, Arnold O, Spence JD (1998) "Grapefruit juice-drug interactions." Br J Clin Pharmacol, 46, p. 101-10
  6. Lilja JJ, Kivisto KT, Neuvonen PJ (1999) "Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin." Clin Pharmacol Ther, 66, p. 118-27
  7. Neuvonen PJ, Backman JT, Niemi M (2008) "Pharmacokinetic comparison of the potential over-the-counter statins simvastatin, lovastatin, fluvastatin and pravastatin." Clin Pharmacokinet, 47, p. 463-74

Switch to consumer interaction data

Moderate

lopinavir food

Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

ADJUST DOSING INTERVAL: Food significantly increases the bioavailability of lopinavir from the oral solution formulation of lopinavir-ritonavir. Relative to fasting, administration of lopinavir-ritonavir oral solution with a moderate-fat meal (500 to 682 Kcal; 23% to 25% calories from fat) increased lopinavir peak plasma concentration (Cmax) and systemic exposure (AUC) by 54% and 80%, respectively, whereas administration with a high-fat meal (872 Kcal; 56% from fat) increased lopinavir Cmax and AUC by 56% and 130%, respectively. No clinically significant changes in Cmax and AUC were observed following administration of lopinavir-ritonavir tablets under fed conditions versus fasted conditions. Relative to fasting, administration of a single 400 mg-100 mg dose (two 200 mg-50 mg tablets) with a moderate-fat meal (558 Kcal; 24.1% calories from fat) increased lopinavir Cmax and AUC by 17.6% and 26.9%, respectively, while administration with a high-fat meal (998 Kcal; 51.3% from fat) increased lopinavir AUC by 18.9% but not Cmax. Relative to fasting, ritonavir Cmax and AUC also increased by 4.9% and 14.9%, respectively, with the moderate-fat meal and 10.3% and 23.9%, respectively, with the high-fat meal.

MANAGEMENT: Lopinavir-ritonavir oral solution should be taken with meals to enhance bioavailability and minimize pharmacokinetic variability. Lopinavir-ritonavir tablets may be taken without regard to meals.

References (1)
  1. (2001) "Product Information. Kaletra (lopinavir-ritonavir)." Abbott Pharmaceutical

Switch to consumer interaction data

Moderate

amLODIPine food

Applies to: Caduet (amlodipine / atorvastatin)

MONITOR: Many psychotherapeutic and CNS-active agents (e.g., anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, alcohol, muscle relaxants) exhibit hypotensive effects, especially during initiation of therapy and dose escalation. Coadministration with antihypertensives and other hypotensive agents, in particular vasodilators and alpha-blockers, may result in additive effects on blood pressure and orthostasis.

MANAGEMENT: Caution and close monitoring for development of hypotension is advised during coadministration of these agents. Some authorities recommend avoiding alcohol in patients receiving vasodilating antihypertensive drugs. Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients should also avoid driving or operating hazardous machinery until they know how the medications affect them.

References (10)
  1. Sternbach H (1991) "Fluoxetine-associated potentiation of calcium-channel blockers." J Clin Psychopharmacol, 11, p. 390-1
  2. Shook TL, Kirshenbaum JM, Hundley RF, Shorey JM, Lamas GA (1984) "Ethanol intoxication complicating intravenous nitroglycerin therapy." Ann Intern Med, 101, p. 498-9
  3. Feder R (1991) "Bradycardia and syncope induced by fluoxetine." J Clin Psychiatry, 52, p. 139
  4. Ellison JM, Milofsky JE, Ely E (1990) "Fluoxetine-induced bradycardia and syncope in two patients." J Clin Psychiatry, 51, p. 385-6
  5. Rodriguez de la Torre B, Dreher J, Malevany I, et al. (2001) "Serum levels and cardiovascular effects of tricyclic antidepressants and selective serotonin reuptake inhibitors in depressed patients." Ther Drug Monit, 23, p. 435-40
  6. Cerner Multum, Inc. "Australian Product Information."
  7. Pacher P, Kecskemeti V (2004) "Cardiovascular side effects of new antidepressants and antipsychotics: new drugs, old concerns?" Curr Pharm Des, 10, p. 2463-75
  8. Andrews C, Pinner G (1998) "Postural hypotension induced by paroxetine." BMJ, 316, p. 595
  9. (2023) "Product Information. Buprenorphine (buprenorphine)." G.L. Pharma UK Ltd
  10. (2023) "Product Information. Temgesic (buprenorphine)." Reckitt Benckiser Pty Ltd

Switch to consumer interaction data

Moderate

amLODIPine food

Applies to: Caduet (amlodipine / atorvastatin)

MONITOR: Calcium-containing products may decrease the effectiveness of calcium channel blockers by saturating calcium channels with calcium. Calcium chloride has been used to manage acute severe verapamil toxicity.

MANAGEMENT: Management consists of monitoring the effectiveness of calcium channel blocker therapy during coadministration with calcium products.

References (14)
  1. Henry M, Kay MM, Viccellio P (1985) "Cardiogenic shock associated with calcium-channel and beta blockers: reversal with intravenous calcium chloride." Am J Emerg Med, 3, p. 334-6
  2. Moller IW (1987) "Cardiac arrest following intravenous verapamil combined with halothane anaesthesia." Br J Anaesth, 59, p. 522-6
  3. Oszko MA, Klutman NE (1987) "Use of calcium salts during cardiopulmonary resuscitation for reversing verapamil-associated hypotension." Clin Pharm, 6, p. 448-9
  4. Schoen MD, Parker RB, Hoon TJ, et al. (1991) "Evaluation of the pharmacokinetics and electrocardiographic effects of intravenous verapamil with intravenous calcium chloride pretreatment in normal subjects." Am J Cardiol, 67, p. 300-4
  5. O'Quinn SV, Wohns DH, Clarke S, Koch G, Patterson JH, Adams KF (1990) "Influence of calcium on the hemodynamic and anti-ischemic effects of nifedipine observed during treadmill exercise testing." Pharmacotherapy, 10, p. 247
  6. Woie L, Storstein L (1981) "Successful treatment of suicidal verapamil poisoning with calcium gluconate." Eur Heart J, 2, p. 239-42
  7. Morris DL, Goldschlager N (1983) "Calcium infusion for reversal of adverse effects of intravenous verapamil." JAMA, 249, p. 3212-3
  8. Guadagnino V, Greengart A, Hollander G, Solar M, Shani J, Lichstein E (1987) "Treatment of severe left ventricular dysfunction with calcium chloride in patients receiving verapamil." J Clin Pharmacol, 27, p. 407-9
  9. Luscher TF, Noll G, Sturmer T, Huser B, Wenk M (1994) "Calcium gluconate in severe verapamil intoxication." N Engl J Med, 330, p. 718-20
  10. Bar-Or D, Gasiel Y (1981) "Calcium and calciferol antagonise effect of verapamil in atrial fibrillation." Br Med J (Clin Res Ed), 282, p. 1585-6
  11. Lipman J, Jardine I, Roos C, Dreosti L (1982) "Intravenous calcium chloride as an antidote to verapamil-induced hypotension." Intensive Care Med, 8, p. 55-7
  12. McMillan R (1988) "Management of acute severe verapamil intoxication." J Emerg Med, 6, p. 193-6
  13. Perkins CM (1978) "Serious verapamil poisoning: treatment with intravenous calcium gluconate." Br Med J, 2, p. 1127
  14. Moroni F, Mannaioni PF, Dolara A, Ciaccheri M (1980) "Calcium gluconate and hypertonic sodium chloride in a case of massive verapamil poisoning." Clin Toxicol, 17, p. 395-400

Switch to consumer interaction data

Minor

amLODIPine food

Applies to: Caduet (amlodipine / atorvastatin)

The consumption of grapefruit juice may slightly increase plasma concentrations of amlodipine. The mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. Data have been conflicting and the clinical significance is unknown. Monitoring for calcium channel blocker adverse effects (e.g., headache, hypotension, syncope, tachycardia, edema) is recommended.

References (6)
  1. Bailey DG, Arnold JMO, Spence JD (1994) "Grapefruit juice and drugs - how significant is the interaction." Clin Pharmacokinet, 26, p. 91-8
  2. Josefsson M, Zackrisson AL, Ahlner J (1996) "Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers." Eur J Clin Pharmacol, 51, p. 189-93
  3. Bailey DG, Malcolm J, Arnold O, Spence JD (1998) "Grapefruit juice-drug interactions." Br J Clin Pharmacol, 46, p. 101-10
  4. Vincent J, Harris SI, Foulds G, Dogolo LC, Willavize S, Friedman HL (2000) "Lack of effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of amlodipine." Br J Clin Pharmacol, 50, p. 455-63
  5. Josefsson M, Ahlner J (2002) "Amlodipine and grapefruit juice." Br J Clin Pharmacol, 53, 405; discussion 406
  6. Kane GC, Lipsky JJ (2000) "Drug-grapefruit juice interactions." Mayo Clin Proc, 75, p. 933-42

Switch to consumer interaction data

Minor

tenofovir food

Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil

Food enhances the oral absorption and bioavailability of tenofovir, the active entity of tenofovir disoproxil fumarate. According to the product labeling, administration of the drug following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of tenofovir by approximately 14% and 40%, respectively, compared to administration in the fasting state. However, administration with a light meal did not significantly affect the pharmacokinetics of tenofovir compared to administration in the fasting state. Food delays the time to reach tenofovir Cmax by approximately 1 hour. Tenofovir disoproxil fumarate may be administered without regard to meals.

References (1)
  1. (2001) "Product Information. Viread (tenofovir)." Gilead Sciences

Switch to consumer interaction data

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.


Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.