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Drug Interactions between Nallpen and Prezcobix

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

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Interactions between your drugs

Moderate

nafcillin darunavir

Applies to: Nallpen (nafcillin) and Prezcobix (cobicistat / darunavir)

MONITOR: Coadministration with drugs that are inducers of CYP450 3A4 may decrease the plasma concentrations of protease inhibitors (PIs), which are primarily metabolized by the isoenzyme.

MANAGEMENT: Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiretroviral drug levels, protease inhibitors should be used cautiously with agents that induce CYP450 3A4, particularly if only one PI is used in the antiretroviral regimen. Coadministration of atazanavir without ritonavir and carbamazepine, phenobarbital, or phenytoin is not recommended. Antiretroviral response should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the antiretroviral regimen adjusted as necessary.

References

  1. "Product Information. Invirase (saquinavir)." Roche Laboratories PROD (2001):
  2. "Product Information. Crixivan (indinavir)." Merck & Co., Inc PROD (2001):
  3. "Product Information. Viracept (nelfinavir)." Agouron Pharma Inc PROD (2001):
  4. Brooks J, Daily J, Schwamm L "Protease inhibitors and anticonvulsants." AIDS Clin Care 9 (1997): 87,90
  5. Barry M, Gibbons S, Back D, Mulcahy F "Protease inhibitors in patients with HIV disease. Clinically important pharmacokinetic considerations." Clin Pharmacokinet 32 (1997): 194-209
  6. "Product Information. Agenerase (amprenavir)." Glaxo Wellcome PROD (2001):
  7. Acosta EP, Henry K, Baken L, Page LM, Fletcher CV "Indinavir concentrations and antiviral effect." Pharmacotherapy 19 (1999): 708-12
  8. Sommadossi JP "HIV protease inhibitors: pharmacologic and metabolic distinctions." AIDS 13 (1999): s29-40
  9. Hugen PWH, Burger DM, Brinkman K, terHofstede HJM, Schuurman R, Koopmans PP, Hekster YA "Carbamazepine-indinavir interaction causes antiretroviral therapy failure." Ann Pharmacother 34 (2000): 465-70
  10. 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
  11. "Product Information. Fortovase (saquinavir)." Roche Laboratories PROD (2001):
  12. "Product Information. Reyataz (atazanavir)." Bristol-Myers Squibb (2003):
  13. "Product Information. Lexiva (fosamprenavir)." GlaxoSmithKline (2003):
  14. Liedtke MD, Lockhart SM, Rathbun RC "Anticonvulsant and antiretroviral interactions." Ann Pharmacother 38 (2004): 482-9
  15. "Product Information. Aptivus (tipranavir)." Boehringer-Ingelheim (2005):
  16. "Product Information. Prezista (darunavir)." Ortho Biotech Inc (2006):
  17. Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
View all 17 references

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Moderate

nafcillin cobicistat

Applies to: Nallpen (nafcillin) and Prezcobix (cobicistat / darunavir)

GENERALLY AVOID: Coadministration with moderate or weak inducers of CYP450 3A4 may reduce the plasma concentrations of cobicistat, which is primarily metabolized by the isoenzyme. The clinical significance is unknown.

MANAGEMENT: Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiretroviral drug levels, concomitant use of antiretroviral regimens containing cobicistat with these inducers should be avoided. Alternative treatment combinations that do not include metabolic inducers should be considered whenever possible. If concomitant use is required, close clinical and laboratory monitoring of antiretroviral response is recommended.

References

  1. Smith DS, Fujimoto JM "Alterations produced by novobiocin during biliary excretion of morphine, morphine-3-glucuronide and other compounds." J Pharmacol Exp Ther 188 (1974): 504-15
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
  4. EMEA. European Medicines Agency "EPARs. European Union Public Assessment Reports. http://www.ema.europa.eu/ema/index.jsp?curl=pages/includes/medicines/medicines_landingpage.jsp&mid" (2007):
  5. Cerner Multum, Inc. "Australian Product Information." O 0
  6. "Product Information. Tybost (cobicistat)." Gilead Sciences (2014):
  7. "Product Information. Genvoya (cobicistat/elvitegravir/emtricitabine/tenofov)." Gilead Sciences (2015):
View all 7 references

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Drug and food interactions

Moderate

nafcillin food

Applies to: Nallpen (nafcillin)

ADJUST DOSING INTERVAL: Certain penicillins may exhibit reduced gastrointestinal absorption in the presence of food. The therapeutic effect of the antimicrobial may be reduced.

MANAGEMENT: The interacting penicillin should be administered one hour before or two hours after meals. Penicillin V and amoxicillin are not affected by food and may be given without regard to meals.

References

  1. Neu HC "Antimicrobial activity and human pharmacology of amoxicillin." J Infect Dis 129 (1974): s123-31
  2. Welling PG, Huang H, Koch PA, Madsen PO "Bioavailability of ampicillin and amoxicillin in fasted and nonfasted subjects." J Pharm Sci 66 (1977): 549-52
  3. McCarthy CG, Finland M "Absorption and excretion of four penicillins." N Engl J Med 263 (1960): 315-26
  4. Cronk GA, Wheatley WB, Fellers GF, Albright H "The relationship of food intake to the absorption of potassium alpha-phenoxyethyl penicillin and potassium phenoxymethyl penicillin from the gastrointestinal tract." Am J Med Sci 240 (1960): 219-25
  5. Klein JO, Sabath LD, Finland M "Laboratory studies on oxacillin. I: in vitro activity against staphylococci and some other bacterial pathogens. II: absorption and urinary excretion in normal young." Am J Med Sci 245 (1963): 399-411
  6. Neuvonen PJ, Elonen E, Pentikainen PJ "Comparative effect of food on absorption of ampicillin and pivampicillin." J Int Med Res 5 (1977): 71-6
View all 6 references

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Moderate

darunavir food

Applies to: Prezcobix (cobicistat / darunavir)

ADJUST DOSING INTERVAL: Food enhances the absorption and oral bioavailability of darunavir administered in combination with low-dose ritonavir. The mechanism is unknown. When administered with food, the peak plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) of darunavir were approximately 30% higher than when administered in the fasting state. Darunavir exposure was similar for the range of meals studied. The total caloric content of the various meals evaluated ranged from 240 Kcal (12 grams fat) to 928 Kcal (56 grams fat).

MANAGEMENT: To ensure maximal oral absorption, darunavir coadministered with ritonavir should be taken with food. The type of food is not important.

References

  1. "Product Information. Prezista (darunavir)." Ortho Biotech Inc (2006):

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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

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