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Drug Interactions between Complete Acid Reducer plus Antacid and Reyataz

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

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Interactions between your drugs

Major

famotidine atazanavir

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide) and Reyataz (atazanavir)

ADJUST DOSE: Concurrent administration of H2-receptor antagonists may decrease the oral bioavailability of atazanavir and substantially reduce its concentrations in plasma. Atazanavir solubility decreases with increasing pH, thus inhibition of gastric acid secretion may interfere with dissolution of the drug. Subtherapeutic antiretroviral drug levels may lead to reduced viral susceptibility and development of resistance.

ADJUST DOSE: Concurrent administration of atazanavir/cobicistat or atazanavir/ritonavir with tenofovir and H2-receptor antagonists may decrease the oral bioavailability of atazanavir by an additional 10% to 20%, compared to concurrent use with an H2 antagonist alone.

MANAGEMENT: When used with atazanavir/cobicistat or atazanavir/ritonavir once daily in adults, the dosage of the H2-receptor antagonist should be no more than the equivalent of famotidine 40 mg twice daily in antiretroviral treatment-naive patients and 20 mg twice daily in treatment-experienced patients. Atazanavir/cobicistat or atazanavir/ritonavir should be administered simultaneously with, and/or at least 10 hours after, the H2-receptor antagonist. If tenofovir is also prescribed, no additional precaution is necessary in treatment-naive patients, whereas the dosage of atazanavir/ritonavir should be increased to 400 mg/100 mg once a day in treatment-experienced patients. All three antiretroviral agents should be administered as a single daily dose with food. In the event that ritonavir is not tolerated by a treatment-naive patient, atazanavir may be administered at an increased dosage of 400 mg once daily at least 2 hours before and at least 10 hours after the H2-receptor antagonist. Dosage of the H2-receptor antagonist should not exceed the equivalent of famotidine 20 mg twice daily. Atazanavir without ritonavir is not recommended for treatment-experienced patients with prior virologic failure or pregnant women. For treatment-experienced pregnant women during the second or third trimester, when atazanavir is coadministered with either an H2-receptor antagonist or tenofovir, atazanavir 400 mg with ritonavir 100 mg once daily is recommended. There are insufficient data to recommend an atazanavir dosage for use with both an H2-receptor antagonist and tenofovir in treatment-experienced pregnant women. No dosage adjustment is required for postpartum patients. However, patients should be closely monitored for adverse events because atazanavir exposures could be higher during the first 2 months after delivery. Coadministration of atazanavir/cobicistat in combination with tenofovir and an H2 receptor antagonist should generally be avoided. There are insufficient data to recommend an atazanavir/cobicistat dosage for use with both an H2-receptor antagonist and tenofovir.

References

  1. Durant J, Clevenbergh P, Garraffo R, Halfon P, Icard S, DelGiudice P, Montagne N, Schapiro JM, Dellamonica P "Importance of protease inhibitor plasma levels in HIV-infected patients treated with genotypic-guided therapy: pharmacological data from the Viradapt Study." Aids 14 (2000): 1333-9
  2. "Product Information. Reyataz (atazanavir)." Bristol-Myers Squibb (2003):
  3. Ray JE, Marriott D, Bloch MT, McLachlan AJ "Therapeutic drug monitoring of atazanavir: surveillance of pharmacotherapy in the clinic." Br J Clin Pharmacol 60 (2005): 291-9
  4. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  5. "Drug interactions. Atazanavir and acid-reducing agents." TreatmentUpdate 18 (2006): 4
  6. Klein CE, Chiu YL, Cai Y, et al. "Effects of Acid-reducing agents on the pharmacokinetics of lopinavir/ritonavir and ritonavir-boosted atazanavir." J Clin Pharmacol 48 (2008): 553-62
  7. Agarwala S, Eley T, Persson A, et al. "Effect of famotidine 20 and 40 mg dosing regimens on the bioavailability of atazanavir with ritonavir in combination with tenofovir in healthy subjects. http://www.natap.org/2007/CROI/croi_62.htm" (2013):
  8. "Product Information. Evotaz (atazanavir-cobicistat)." Bristol-Myers Squibb (2015):
View all 8 references

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Moderate

calcium carbonate atazanavir

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide) and Reyataz (atazanavir)

ADJUST DOSING INTERVAL: Concurrent administration of antacids or other agents with acid-neutralizing effects may decrease the oral bioavailability of atazanavir and substantially reduce its concentrations in plasma. Atazanavir solubility decreases with increasing pH, thus reduction in gastric acidity may interfere with dissolution of the drug. Subtherapeutic antiretroviral drug levels may lead to reduced viral susceptibility and development of resistance.

MANAGEMENT: Atazanavir should be administered 2 hours before or 1 hour after antacids or other oral agents with acid-neutralizing effects.

References

  1. Durant J, Clevenbergh P, Garraffo R, Halfon P, Icard S, DelGiudice P, Montagne N, Schapiro JM, Dellamonica P "Importance of protease inhibitor plasma levels in HIV-infected patients treated with genotypic-guided therapy: pharmacological data from the Viradapt Study." Aids 14 (2000): 1333-9
  2. "Product Information. Reyataz (atazanavir)." Bristol-Myers Squibb (2003):
  3. Ray JE, Marriott D, Bloch MT, McLachlan AJ "Therapeutic drug monitoring of atazanavir: surveillance of pharmacotherapy in the clinic." Br J Clin Pharmacol 60 (2005): 291-9

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Moderate

magnesium hydroxide atazanavir

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide) and Reyataz (atazanavir)

ADJUST DOSING INTERVAL: Concurrent administration of antacids or other agents with acid-neutralizing effects may decrease the oral bioavailability of atazanavir and substantially reduce its concentrations in plasma. Atazanavir solubility decreases with increasing pH, thus reduction in gastric acidity may interfere with dissolution of the drug. Subtherapeutic antiretroviral drug levels may lead to reduced viral susceptibility and development of resistance.

MANAGEMENT: Atazanavir should be administered 2 hours before or 1 hour after antacids or other oral agents with acid-neutralizing effects.

References

  1. Durant J, Clevenbergh P, Garraffo R, Halfon P, Icard S, DelGiudice P, Montagne N, Schapiro JM, Dellamonica P "Importance of protease inhibitor plasma levels in HIV-infected patients treated with genotypic-guided therapy: pharmacological data from the Viradapt Study." Aids 14 (2000): 1333-9
  2. "Product Information. Reyataz (atazanavir)." Bristol-Myers Squibb (2003):
  3. Ray JE, Marriott D, Bloch MT, McLachlan AJ "Therapeutic drug monitoring of atazanavir: surveillance of pharmacotherapy in the clinic." Br J Clin Pharmacol 60 (2005): 291-9

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Minor

famotidine calcium carbonate

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide) and Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide)

Antacids and some aluminum, calcium, and magnesium salts may decrease the plasma concentrations of H2-receptor antagonists during oral coadministration. The mechanism of interaction is unknown, but may involve reduced oral absorption due to increased gastric pH. Study data vary, with no changes to nearly 60% reductions in systemic exposures (AUCs) reported for cimetidine, famotidine, and ranitidine. The clinical significance has not been established. As a precaution, patients may consider taking H2-receptor antagonists one to two hours before antacids.

References

  1. Donn KH, Eshelman FN, Plachetka JR, et al. "The effects of antacid and propantheline on the absorption of oral ranitidine." Pharmacotherapy 4 (1984): 89-92
  2. Albin H, Vincon G, Demotes-Mainard F, et al. "Effect of aluminium phosphate on the bioavailability of cimetidine and prednisolone." Eur J Clin Pharmacol 26 (1984): 271-3
  3. Lin JH, Chremos AN, Kanovsky SM, Schwartz S, Yeh KC, Kann J "Effects of antacids and food on absorption of famotidine." Br J Clin Pharmacol 24 (1987): 551-3
  4. Bodemar G, Norlander B, Walan A "Diminished absorption of cimetidine caused by antacids." Lancet 02/24/79 (1979): 444-5
  5. Steinberg WM, Lewis JH, Katz DM "Antacids inhibit absorption of cimetidine." N Engl J Med 307 (1982): 400-4
  6. Barzaghi N, Gatti G, Crema F, Perucca E "Impaired bioavailability of famotidine given concurrently with a potent antacid." J Clin Pharmacol 29 (1989): 670-2
  7. Russell WL, Lopez LM, Normann SA, et al. "Effect of antacids on predicted steady-state cimetidine concentrations." Dig Dis Sci 29 (1984): 385-9
  8. Shelly DW, Doering PL, Russell WL, Guild RT, Lopez LM, Perrin J "Effect of concomitant antacid administration on plasma cimetidine concentrations during repetitive dosing." Drug Intell Clin Pharm 20 (1986): 792-5
  9. Albin H, Vincon G, Begaud B, Bistue C, Perez P "Effect of aluminum phosphate on the bioavailability of ranitidine." Eur J Clin Pharmacol 32 (1987): 97-9
  10. Mihaly GW, Marino AT, Webster LK, Jones DB, Louis WJ, Smallwood RA "High dose of antacid (Mylanta II) reduces bioavailability of ranitidine." Br Med J 285 (1982): 998-9
  11. Covington TR, eds., Lawson LC, Young LL "Handbook of Nonprescription Drugs." Washington, DC: American Pharmaceutical Association (1993):
  12. Bachmann KA, Sullivan TJ, Jauregui L, Reese J, Miller K, Levine L "Drug interactions of h-2-receptor antagonists." Scand J Gastroenterol 29 (1994): 14-9
View all 12 references

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Minor

famotidine magnesium hydroxide

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide) and Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide)

Antacids and some aluminum, calcium, and magnesium salts may decrease the plasma concentrations of H2-receptor antagonists during oral coadministration. The mechanism of interaction is unknown, but may involve reduced oral absorption due to increased gastric pH. Study data vary, with no changes to nearly 60% reductions in systemic exposures (AUCs) reported for cimetidine, famotidine, and ranitidine. The clinical significance has not been established. As a precaution, patients may consider taking H2-receptor antagonists one to two hours before antacids.

References

  1. Donn KH, Eshelman FN, Plachetka JR, et al. "The effects of antacid and propantheline on the absorption of oral ranitidine." Pharmacotherapy 4 (1984): 89-92
  2. Albin H, Vincon G, Demotes-Mainard F, et al. "Effect of aluminium phosphate on the bioavailability of cimetidine and prednisolone." Eur J Clin Pharmacol 26 (1984): 271-3
  3. Lin JH, Chremos AN, Kanovsky SM, Schwartz S, Yeh KC, Kann J "Effects of antacids and food on absorption of famotidine." Br J Clin Pharmacol 24 (1987): 551-3
  4. Bodemar G, Norlander B, Walan A "Diminished absorption of cimetidine caused by antacids." Lancet 02/24/79 (1979): 444-5
  5. Steinberg WM, Lewis JH, Katz DM "Antacids inhibit absorption of cimetidine." N Engl J Med 307 (1982): 400-4
  6. Barzaghi N, Gatti G, Crema F, Perucca E "Impaired bioavailability of famotidine given concurrently with a potent antacid." J Clin Pharmacol 29 (1989): 670-2
  7. Russell WL, Lopez LM, Normann SA, et al. "Effect of antacids on predicted steady-state cimetidine concentrations." Dig Dis Sci 29 (1984): 385-9
  8. Shelly DW, Doering PL, Russell WL, Guild RT, Lopez LM, Perrin J "Effect of concomitant antacid administration on plasma cimetidine concentrations during repetitive dosing." Drug Intell Clin Pharm 20 (1986): 792-5
  9. Albin H, Vincon G, Begaud B, Bistue C, Perez P "Effect of aluminum phosphate on the bioavailability of ranitidine." Eur J Clin Pharmacol 32 (1987): 97-9
  10. Mihaly GW, Marino AT, Webster LK, Jones DB, Louis WJ, Smallwood RA "High dose of antacid (Mylanta II) reduces bioavailability of ranitidine." Br Med J 285 (1982): 998-9
  11. Covington TR, eds., Lawson LC, Young LL "Handbook of Nonprescription Drugs." Washington, DC: American Pharmaceutical Association (1993):
  12. Bachmann KA, Sullivan TJ, Jauregui L, Reese J, Miller K, Levine L "Drug interactions of h-2-receptor antagonists." Scand J Gastroenterol 29 (1994): 14-9
View all 12 references

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Drug and food interactions

Moderate

calcium carbonate food

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide)

ADJUST DOSING INTERVAL: Administration with food may increase the absorption of calcium. However, foods high in oxalic acid (spinach or rhubarb), or phytic acid (bran and whole grains) may decrease calcium absorption.

MANAGEMENT: Calcium may be administered with food to increase absorption. Consider withholding calcium administration for at least 2 hours before or after consuming foods high in oxalic acid or phytic acid.

References

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
  3. Cerner Multum, Inc. "Australian Product Information." O 0
  4. Agencia Española de Medicamentos y Productos Sanitarios Healthcare "Centro de información online de medicamentos de la AEMPS - CIMA. https://cima.aemps.es/cima/publico/home.html" (2008):
  5. Mangels AR "Bone nutrients for vegetarians." Am J Clin Nutr 100 (2014): epub
  6. Davies NT "Anti-nutrient factors affecting mineral utilization." Proc Nutr Soc 38 (1979): 121-8
View all 6 references

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Moderate

atazanavir food

Applies to: Reyataz (atazanavir)

ADJUST DOSING INTERVAL: Administration of atazanavir with food enhances oral bioavailability and reduces pharmacokinetic variability. According to the manufacturer, administration with a light meal increased the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of a single 400 mg dose of atazanavir by 57% and 70%, respectively, relative to the fasting state. Administration with a high-fat meal resulted in a mean increase of 35% in atazanavir AUC and no change in Cmax compared to fasting. The coefficient of variation of AUC and Cmax decreased by approximately one-half when given with either a light or high-fat meal compared to the fasting state.

MANAGEMENT: To ensure maximal oral absorption, atazanavir should be administered with or immediately after a meal.

References

  1. "Product Information. Reyataz (atazanavir)." Bristol-Myers Squibb (2003):

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Minor

famotidine food

Applies to: Complete Acid Reducer plus Antacid (calcium carbonate / famotidine / magnesium hydroxide)

H2 antagonists may reduce the clearance of nicotine. Cimetidine, 600 mg given twice a day for two days, reduced clearance of an intravenous nicotine dose by 30%. Ranitidine, 300 mg given twice a day for two days, reduced clearance by 10%. The clinical significance of this interaction is not known. Patients should be monitored for increased nicotine effects when using the patches or gum for smoking cessation and dosage adjustments should be made as appropriate.

References

  1. Bendayan R, Sullivan JT, Shaw C, Frecker RC, Sellers EM "Effect of cimetidine and ranitidine on the hepatic and renal elimination of nicotine in humans." Eur J Clin Pharmacol 38 (1990): 165-9

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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.

See also

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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.

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