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Drug Interactions between efavirenz / emtricitabine / tenofovir and Painaid

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

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Interactions between your drugs

Moderate

aspirin salicylamide

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide) and Painaid (acetaminophen / aspirin / caffeine / salicylamide)

MONITOR: The combined use of low-dose or high-dose aspirin with other nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the potential for serious gastrointestinal (GI) toxicity, including inflammation, bleeding, ulceration, and perforation. Aspirin at anti-inflammatory dosages or higher may also decrease the plasma concentrations of many NSAIDs. The decreases have ranged from none or small (piroxicam, meloxicam, naproxen, tolmetin) to substantial (flurbiprofen, ibuprofen). However, the therapeutic response does not appear to be affected. Investigators theorize that aspirin may displace NSAIDs from plasma protein binding sites, resulting in increased concentration of unbound, or free, drug available for clearance. The increase in NSAID free fraction, and possibly some contributory anti-inflammatory effect from aspirin, may account for the lack of overall effect on therapeutic response.

MANAGEMENT: Caution is advised if aspirin, particularly at anti-inflammatory dosages, is used with other NSAIDs. Concomitant administration of NSAIDs is considered contraindicated or not recommended with aspirin at analgesic/anti-inflammatory dosages by many NSAID manufacturers. During concomitant therapy, patients should be advised to take the medications with food and to immediately report signs and symptoms of GI ulceration and bleeding such as abdominal pain, bloating, sudden dizziness or lightheadedness, nausea, vomiting, hematemesis, anorexia, and melena.

References

  1. Furst DE, Sarkissian E, Blocka K, et al. "Serum concentrations of salicylate and naproxen during concurrent therapy in patients with rheumatoid arthritis." Arthritis Rheum 30 (1987): 1157-61
  2. Abdel-Rahman MS, Reddi AS, Curro FA, Turkall RM, Kadry AM, Hansrote JA "Bioavailability of aspirin and salicylamide following oral co-administration in human volunteers." Can J Physiol Pharmacol 69 (1991): 1436-42
  3. Gruber CM "Clinical pharmacology of fenoprofen: a review." J Rheumatol 2 (1976): 8-17
  4. Cressman WA, Wortham GF, Plostnieks J "Absorption and excretion of tolemetin in man." Clin Pharmacol Ther 19 (1976): 224-33
  5. Kwan KC, Breault GO, Davis RL, et al. "Effects of concomitant aspirin administration on the pharmacokinetics of indomethacin in man." J Pharmacokinet Biopharm 6 (1978): 451-76
  6. Rubin A, Rodda BE, Warrick P, Gruber CM Jr, Ridolfo RS "Interactions of aspirin with nonsteroidal antiinflammatory drugs in man." Arthritis Rheum 16 (1973): 635-45
  7. Brooks PM, Walker JJ, Bell MA, Buchanan WW, Rhymer AR "Indomethacin--aspirin interaction: a clinical appraisal." Br Med J 3 (1975): 69-11
  8. Tempero KF, Cirillo VJ, Steelman SL "Diflunisal: a review of pharmacokinetic and pharmacodynamic properties, drug interactions, and special tolerability studies in humans." Br J Clin Pharmacol 4 (1977): s31-6
  9. Willis JV, Kendall MJ, Jack DB "A study of the effect of aspirin on the pharmacokinetics of oral and intravenous diclofenac sodium." Eur J Clin Pharmacol 18 (1980): 415-8
  10. Muller FO, Hundt HK, Muller DG "Pharmacokinetic and pharmacodynamic implications of long-term administration of non-steroidal anti-inflammatory agents." Int J Clin Pharmacol Biopharm 15 (1977): 397-402
  11. Hobbs DC, Twomey TM "Piroxicam pharmacokinetics in man: aspirin and antacid interaction studies." J Clin Pharmacol 19 (1979): 270-81
  12. Pawlotsky Y, Chales G, Grosbois B, Miane B, Bourel M "Comparative interaction of aspirin with indomethacin and sulindac in chronic rheumatic diseases." Eur J Rheumatol Inflamm 1 (1978): 18-20
  13. Segre EJ, Chaplin M, Forchielli E, Runkel R, Sevelius H "Naproxen-aspirin interactions in man." Clin Pharmacol Ther 15 (1973): 374-9
  14. Bird HA, Hill J, Leatham P, Wright V "A study to determine the clinical relevance of the pharmacokinetic interaction between aspirin and diclofenac." Agents Actions 18 (1986): 447-9
  15. Brooks PM, Khong T "Flurbiprofen-aspirin interaction: a double-blind crossover study." Curr Med Res Opin 5 (1977): 53-7
  16. Grennan DM, Ferry DG, Ashworth ME, Kenny RE, Mackinnnon M "The aspirin-ibuprofen interaction in rheumatoid arthritis." Br J Clin Pharmacol 8 (1979): 497-503
  17. Williams RL, Upton RA, Buskin JN, Jones RM "Ketoprofen-aspirin interactions." Clin Pharmacol Ther 30 (1981): 226-31
  18. Kaiser DG, Brooks CD, Lomen PL "Pharmacokinetics of flurbiprofen." Am J Med 80 (1986): 10-5
  19. Kahn SB, Hubsher JA "Effects of oxaprozin alone or in combination with aspirin on hemostasis and plasma protein binding." J Clin Pharmacol 23 (1983): 139-46
  20. "Product Information. Mobic (meloxicam)." Boehringer-Ingelheim PROD (2001):
  21. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  22. Cerner Multum, Inc. "Australian Product Information." O 0
View all 22 references

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Moderate

acetaminophen efavirenz

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide) and efavirenz / emtricitabine / tenofovir

MONITOR: Coadministration of efavirenz with other agents known to induce hepatotoxicity may potentiate the risk of liver injury. Efavirenz has been associated with hepatotoxicity during postmarketing use. Among reported cases of hepatic failure, a few occurred in patients with no preexisting hepatic disease or other identifiable risk factors.

MANAGEMENT: The risk of hepatic injury should be considered when efavirenz is used in combination with other agents that are potentially hepatotoxic (e.g., acetaminophen; alcohol; androgens and anabolic steroids; antituberculous agents; azole antifungal agents; ACE inhibitors; cyclosporine (high dosages); disulfiram; endothelin receptor antagonists; interferons; ketolide and macrolide antibiotics; kinase inhibitors; minocycline; nonsteroidal anti-inflammatory agents; other HIV reverse transcriptase inhibitors; proteasome inhibitors; retinoids; sulfonamides; tamoxifen; thiazolidinediones; tolvaptan; vincristine; zileuton; anticonvulsants such as carbamazepine, hydantoins, felbamate, and valproic acid; lipid-lowering medications such as fenofibrate, lomitapide, mipomersen, niacin, and statins; herbals and nutritional supplements such as black cohosh, chaparral, comfrey, DHEA, kava, pennyroyal oil, and red yeast rice). Patients should be advised to seek medical attention if they experience potential signs and symptoms of hepatotoxicity such as fever, rash, itching, anorexia, nausea, vomiting, fatigue, malaise, right upper quadrant pain, dark urine, pale stools, and jaundice. Monitoring of liver function tests should occur before and during treatment, especially in patients with underlying hepatic disease (including hepatitis B or C coinfection) or marked transaminase elevations. The benefit of continued therapy with efavirenz should be considered against the unknown risks of significant liver toxicity in patients who develop persistent elevations of serum transaminases greater than five times the upper limit of normal.

References

  1. "Product Information. Sustiva (efavirenz)." DuPont Pharmaceuticals PROD (2001):
  2. Elsharkawy AM, Schwab U, McCarron B, et al. "Efavirenz induced acute liver failure requiring liver transplantation in a slow drug metaboliser." J Clin Virol 58 (2013): 331-3

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Moderate

efavirenz tenofovir

Applies to: efavirenz / emtricitabine / tenofovir and efavirenz / emtricitabine / tenofovir

MONITOR: Coadministration of efavirenz with other agents known to induce hepatotoxicity may potentiate the risk of liver injury. Efavirenz has been associated with hepatotoxicity during postmarketing use. Among reported cases of hepatic failure, a few occurred in patients with no preexisting hepatic disease or other identifiable risk factors.

MANAGEMENT: The risk of hepatic injury should be considered when efavirenz is used in combination with other agents that are potentially hepatotoxic (e.g., acetaminophen; alcohol; androgens and anabolic steroids; antituberculous agents; azole antifungal agents; ACE inhibitors; cyclosporine (high dosages); disulfiram; endothelin receptor antagonists; interferons; ketolide and macrolide antibiotics; kinase inhibitors; minocycline; nonsteroidal anti-inflammatory agents; other HIV reverse transcriptase inhibitors; proteasome inhibitors; retinoids; sulfonamides; tamoxifen; thiazolidinediones; tolvaptan; vincristine; zileuton; anticonvulsants such as carbamazepine, hydantoins, felbamate, and valproic acid; lipid-lowering medications such as fenofibrate, lomitapide, mipomersen, niacin, and statins; herbals and nutritional supplements such as black cohosh, chaparral, comfrey, DHEA, kava, pennyroyal oil, and red yeast rice). Patients should be advised to seek medical attention if they experience potential signs and symptoms of hepatotoxicity such as fever, rash, itching, anorexia, nausea, vomiting, fatigue, malaise, right upper quadrant pain, dark urine, pale stools, and jaundice. Monitoring of liver function tests should occur before and during treatment, especially in patients with underlying hepatic disease (including hepatitis B or C coinfection) or marked transaminase elevations. The benefit of continued therapy with efavirenz should be considered against the unknown risks of significant liver toxicity in patients who develop persistent elevations of serum transaminases greater than five times the upper limit of normal.

References

  1. "Product Information. Sustiva (efavirenz)." DuPont Pharmaceuticals PROD (2001):
  2. Elsharkawy AM, Schwab U, McCarron B, et al. "Efavirenz induced acute liver failure requiring liver transplantation in a slow drug metaboliser." J Clin Virol 58 (2013): 331-3

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Moderate

efavirenz emtricitabine

Applies to: efavirenz / emtricitabine / tenofovir and efavirenz / emtricitabine / tenofovir

MONITOR: Coadministration of efavirenz with other agents known to induce hepatotoxicity may potentiate the risk of liver injury. Efavirenz has been associated with hepatotoxicity during postmarketing use. Among reported cases of hepatic failure, a few occurred in patients with no preexisting hepatic disease or other identifiable risk factors.

MANAGEMENT: The risk of hepatic injury should be considered when efavirenz is used in combination with other agents that are potentially hepatotoxic (e.g., acetaminophen; alcohol; androgens and anabolic steroids; antituberculous agents; azole antifungal agents; ACE inhibitors; cyclosporine (high dosages); disulfiram; endothelin receptor antagonists; interferons; ketolide and macrolide antibiotics; kinase inhibitors; minocycline; nonsteroidal anti-inflammatory agents; other HIV reverse transcriptase inhibitors; proteasome inhibitors; retinoids; sulfonamides; tamoxifen; thiazolidinediones; tolvaptan; vincristine; zileuton; anticonvulsants such as carbamazepine, hydantoins, felbamate, and valproic acid; lipid-lowering medications such as fenofibrate, lomitapide, mipomersen, niacin, and statins; herbals and nutritional supplements such as black cohosh, chaparral, comfrey, DHEA, kava, pennyroyal oil, and red yeast rice). Patients should be advised to seek medical attention if they experience potential signs and symptoms of hepatotoxicity such as fever, rash, itching, anorexia, nausea, vomiting, fatigue, malaise, right upper quadrant pain, dark urine, pale stools, and jaundice. Monitoring of liver function tests should occur before and during treatment, especially in patients with underlying hepatic disease (including hepatitis B or C coinfection) or marked transaminase elevations. The benefit of continued therapy with efavirenz should be considered against the unknown risks of significant liver toxicity in patients who develop persistent elevations of serum transaminases greater than five times the upper limit of normal.

References

  1. "Product Information. Sustiva (efavirenz)." DuPont Pharmaceuticals PROD (2001):
  2. Elsharkawy AM, Schwab U, McCarron B, et al. "Efavirenz induced acute liver failure requiring liver transplantation in a slow drug metaboliser." J Clin Virol 58 (2013): 331-3

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Minor

aspirin caffeine

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide) and Painaid (acetaminophen / aspirin / caffeine / salicylamide)

One study has reported that coadministration of caffeine and aspirin lead to a 25% increase in the rate of appearance and 17% increase in maximum concentration of salicylate in the plasma. A significantly higher area under the plasma concentration time curve of salicylate was also reported when both drugs were administered together. The exact mechanism of this interaction has not been specified. Physicians and patients should be aware that coadministration of aspirin and caffeine may lead to higher salicylate levels faster.

References

  1. Yoovathaworn KC, Sriwatanakul K, Thithapandha A "Influence of caffeine on aspirin pharmacokinetics." Eur J Drug Metab Pharmacokinet 11 (1986): 71-6

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Drug and food interactions

Major

acetaminophen food

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide)

GENERALLY AVOID: Chronic, excessive consumption of alcohol may increase the risk of acetaminophen-induced hepatotoxicity, which has included rare cases of fatal hepatitis and frank hepatic failure requiring liver transplantation. The proposed mechanism is induction of hepatic microsomal enzymes during chronic alcohol use, which may result in accelerated metabolism of acetaminophen and increased production of potentially hepatotoxic metabolites.

MANAGEMENT: In general, chronic alcoholics should avoid regular or excessive use of acetaminophen. Alternative analgesic/antipyretic therapy may be appropriate in patients who consume three or more alcoholic drinks per day. However, if acetaminophen is used, these patients should be cautioned not to exceed the recommended dosage (maximum 4 g/day in adults and children 12 years of age or older).

References

  1. Kaysen GA, Pond SM, Roper MH, Menke DJ, Marrama MA "Combined hepatic and renal injury in alcoholics during therapeutic use of acetaminophen." Arch Intern Med 145 (1985): 2019-23
  2. O'Dell JR, Zetterman RK, Burnett DA "Centrilobular hepatic fibrosis following acetaminophen-induced hepatic necrosis in an alcoholic." JAMA 255 (1986): 2636-7
  3. Seeff LB, Cuccherini BA, Zimmerman HJ, Adler E, Benjamin SB "Acetaminophen hepatotoxicity in alcoholics." Ann Intern Med 104 (1986): 399-404
  4. Thummel KE, Slattery JT, Nelson SD "Mechanism by which ethanol diminishes the hepatotoxicity of acetaminophen." J Pharmacol Exp Ther 245 (1988): 129-36
  5. McClain CJ, Kromhout JP, Peterson FJ, Holtzman JL "Potentiation of acetaminophen hepatotoxicity by alcohol." JAMA 244 (1980): 251-3
  6. Kartsonis A, Reddy KR, Schiff ER "Alcohol, acetaminophen, and hepatic necrosis." Ann Intern Med 105 (1986): 138-9
  7. Prescott LF, Critchley JA "Drug interactions affecting analgesic toxicity." Am J Med 75 (1983): 113-6
  8. "Product Information. Tylenol (acetaminophen)." McNeil Pharmaceutical PROD (2002):
  9. Whitcomb DC, Block GD "Association of acetaminopphen hepatotoxicity with fasting and ethanol use." JAMA 272 (1994): 1845-50
  10. Bonkovsky HL "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA 274 (1995): 301
  11. Nelson EB, Temple AR "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA 274 (1995): 301
  12. Zimmerman HJ, Maddrey WC "Acetaminophen (paracetamol) hepatotoxicity with regular intake of alcohol: analysis of instances of therapeutic misadventure." Hepatology 22 (1995): 767-73
View all 12 references

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Moderate

efavirenz food

Applies to: efavirenz / emtricitabine / tenofovir

ADJUST DOSING INTERVAL: Administration with food increases the plasma concentrations of efavirenz and may increase the frequency of adverse reactions. According to the product labeling, administration of efavirenz capsules (600 mg single dose) with a high-fat/high-caloric meal (894 kcal, 54 g fat, 54% calories from fat) or a reduced-fat/normal-caloric meal (440 kcal, 2 g fat, 4% calories from fat) was associated with mean increases of 39% and 51% in efavirenz peak plasma concentration (Cmax) and 22% and 17% in systemic exposure (AUC), respectively, compared to administration under fasted conditions. For efavirenz tablets, administration of a single 600 mg dose with a high-fat/high-caloric meal (approximately 1000 kcal, 500-600 kcal from fat) resulted in a 79% increase in mean Cmax and a 28% increase in mean AUC of efavirenz relative to administration under fasted conditions.

MANAGEMENT: Efavirenz should be taken on an empty stomach, preferably at bedtime. Dosing at bedtime may improve the tolerability of nervous system symptoms such as dizziness, insomnia, impaired concentration, somnolence, abnormal dreams and hallucinations, although they often resolve on their own after the first 2 to 4 weeks of therapy . Patients should be advised of the potential for additive central nervous system effects when efavirenz is used concomitantly with alcohol or psychoactive drugs, and to avoid driving or operating hazardous machinery until they know how the medication affects them.

References

  1. "Product Information. Sustiva (efavirenz)." DuPont Pharmaceuticals PROD (2001):

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Moderate

aspirin food

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide)

GENERALLY AVOID: The concurrent use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) and ethanol may lead to gastrointestinal (GI) blood loss. The mechanism may be due to a combined local effect as well as inhibition of prostaglandins leading to decreased integrity of the GI lining.

MANAGEMENT: Patients should be counseled on this potential interaction and advised to refrain from alcohol consumption while taking aspirin or NSAIDs.

References

  1. "Product Information. Motrin (ibuprofen)." Pharmacia and Upjohn PROD (2002):

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Moderate

salicylamide food

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide)

GENERALLY AVOID: The concurrent use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) and ethanol may lead to gastrointestinal (GI) blood loss. The mechanism may be due to a combined local effect as well as inhibition of prostaglandins leading to decreased integrity of the GI lining.

MANAGEMENT: Patients should be counseled on this potential interaction and advised to refrain from alcohol consumption while taking aspirin or NSAIDs.

References

  1. "Product Information. Motrin (ibuprofen)." Pharmacia and Upjohn PROD (2002):

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Minor

caffeine food

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide)

The effect of grapefruit juice on the pharmacologic activity of caffeine is controversial. One report suggests that grapefruit juice increases the effect of caffeine. The proposed mechanism is inhibition of cytochrome P-450 metabolism of caffeine. However, a well-conducted pharmacokinetic/pharmacodynamic study did not demonstrate this effect. The clinical significance of this potential interaction is unknown.

References

  1. "Grapefruit juice interactions with drugs." Med Lett Drugs Ther 37 (1995): 73-4
  2. Maish WA, Hampton EM, Whitsett TL, Shepard JD, Lovallo WR "Influence of grapefruit juice on caffeine pharmacokinetics and pharmacodynamics." Pharmacotherapy 16 (1996): 1046-52

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Minor

tenofovir food

Applies to: efavirenz / emtricitabine / tenofovir

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. "Product Information. Viread (tenofovir)." Gilead Sciences (2001):

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Minor

aspirin food

Applies to: Painaid (acetaminophen / aspirin / caffeine / salicylamide)

One study has reported that coadministration of caffeine and aspirin lead to a 25% increase in the rate of appearance and 17% increase in maximum concentration of salicylate in the plasma. A significantly higher area under the plasma concentration time curve of salicylate was also reported when both drugs were administered together. The exact mechanism of this interaction has not been specified. Physicians and patients should be aware that coadministration of aspirin and caffeine may lead to higher salicylate levels faster.

References

  1. Yoovathaworn KC, Sriwatanakul K, Thithapandha A "Influence of caffeine on aspirin pharmacokinetics." Eur J Drug Metab Pharmacokinet 11 (1986): 71-6

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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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