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Drug Interactions between Neo HC and Symfi Lo

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

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Interactions between your drugs

Major

HYDROcodone efavirenz

Applies to: Neo HC (chlorpheniramine / hydrocodone / phenylephrine) and Symfi Lo (efavirenz / lamivudine / tenofovir)

MONITOR CLOSELY: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of opioids that are primarily metabolized by the isoenzyme such as butorphanol, fentanyl, hydrocodone, and oxycodone. Reduced efficacy or withdrawal symptoms may occur in patients maintained on their narcotic pain regimen following the addition of a CYP450 3A4 inducer. Conversely, discontinuation of the inducer may increase opioid plasma concentrations and potentiate the risk of overdose and fatal respiratory depression.

MANAGEMENT: Pharmacologic response to the opioid should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the opioid dosage adjusted as necessary.

References

  1. "Product Information. Mycobutin (rifabutin)." Pharmacia and Upjohn PROD (2001):
  2. "Product Information. Rifadin (rifampin)." Hoechst Marion Roussel PROD (2001):
  3. "Product Information. Duragesic Transdermal System (fentanyl)." Janssen Pharmaceutica, Titusville, NJ.
  4. "Product Information. OxyContin (oxycodone)." Purdue Frederick Company PROD (2001):
  5. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  6. "Product Information. Ionsys (fentanyl)." Ortho McNeil Pharmaceutical (2006):
  7. Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
  8. Cerner Multum, Inc. "Australian Product Information." O 0
  9. "Product Information. Zohydro ER (hydrocodone)." Zogenix, Inc (2013):
  10. "Product Information. Butorphanol Tartrate (butorphanol)." Apotex Corporation (2017):
View all 10 references

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Moderate

chlorpheniramine HYDROcodone

Applies to: Neo HC (chlorpheniramine / hydrocodone / phenylephrine) and Neo HC (chlorpheniramine / hydrocodone / phenylephrine)

MONITOR: Central nervous system- and/or respiratory-depressant effects may be additively or synergistically increased in patients taking multiple drugs that cause these effects, especially in elderly or debilitated patients. Sedation and impairment of attention, judgment, thinking, and psychomotor skills may increase.

MANAGEMENT: During concomitant use of these drugs, patients should be monitored for potentially excessive or prolonged CNS and respiratory depression. Cautious dosage titration may be required, particularly at treatment initiation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References

  1. Hamilton MJ, Bush M, Smith P, Peck AW "The effects of bupropion, a new antidepressant drug, and diazepam, and their interaction in man." Br J Clin Pharmacol 14 (1982): 791-7
  2. Stambaugh JE, Lane C "Analgesic efficacy and pharmacokinetic evaluation of meperidine and hydroxyzine, alone and in combination." Cancer Invest 1 (1983): 111-7
  3. Sotaniemi EA, Anttila M, Rautio A, et al. "Propranolol and sotalol metabolism after a drinking party." Clin Pharmacol Ther 29 (1981): 705-10
  4. Grabowski BS, Cady WJ, Young WW, Emery JF "Effects of acute alcohol administration on propranolol absorption." Int J Clin Pharmacol Ther Toxicol 18 (1980): 317-9
  5. Lemberger L, Rowe H, Bosomworth JC, Tenbarge JB, Bergstrom RF "The effect of fluoxetine on the pharmacokinetics and psychomotor responses of diazepam." Clin Pharmacol Ther 43 (1988): 412-9
  6. MacLeod SM, Giles HG, Patzalek G, Thiessen JJ, Sellers EM "Diazepam actions and plasma concentrations following ethanol ingestion." Eur J Clin Pharmacol 11 (1977): 345-9
  7. Divoll M, Greenblatt DJ, Lacasse Y, Shader RI "Benzodiazepine overdosage: plasma concentrations and clinical outcome." Psychopharmacology (Berl) 73 (1981): 381-3
  8. Naylor GJ, McHarg A "Profound hypothermia on combined lithium carbonate and diazepam treatment." Br Med J 2 (1977): 22
  9. Stovner J, Endresen R "Intravenous anaesthesia with diazepam." Acta Anaesthesiol Scand 24 (1965): 223-7
  10. Driessen JJ, Vree TB, Booij LH, van der Pol FM, Crul JF "Effect of some benzodiazepines on peripheral neuromuscular function in the rat in-vitro hemidiaphragm preparation." J Pharm Pharmacol 36 (1984): 244-7
  11. Feldman SA, Crawley BE "Interaction of diazepam with the muscle-relaxant drugs." Br Med J 1 (1970): 336-8
  12. Ochs HR, Greenblatt DJ, Verburg-Ochs B "Propranolol interactions with diazepam, lorazepam and alprazolam." Clin Pharmacol Ther 36 (1984): 451-5
  13. Desager JP, Hulhoven R, Harvengt C, Hermann P, Guillet P, Thiercelin JF "Possible interactions between zolpidem, a new sleep inducer and chlorpromazine, a phenothiazine neuroleptic." Psychopharmacology (Berl) 96 (1988): 63-6
  14. Tverskoy M, Fleyshman G, Ezry J, Bradley EL, Jr Kissin I "Midazolam-morphine sedative interaction in patients." Anesth Analg 68 (1989): 282-5
  15. "Product Information. Iopidine (apraclonidine ophthalmic)." Alcon Laboratories Inc PROD
  16. Greiff JMC, Rowbotham D "Pharmacokinetic drug interactions with gastrointestinal motility modifying agents." Clin Pharmacokinet 27 (1994): 447-61
  17. Greb WH, Buscher G, Dierdorf HD, Koster FE, Wolf D, Mellows G "The effect of liver enzyme inhibition by cimetidine and enzyme induction by phenobarbitone on the pharmacokinetics of paroxetine." Acta Psychiatr Scand 80 Suppl (1989): 95-8
  18. Markowitz JS, Wells BG, Carson WH "Interactions between antipsychotic and antihypertensive drugs." Ann Pharmacother 29 (1995): 603-9
  19. "Product Information. Ultram (tramadol)." McNeil Pharmaceutical PROD (2001):
  20. "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories PROD (2001):
  21. "Product Information. Ultiva (remifentanil)." Mylan Institutional (formally Bioniche Pharma USA Inc) PROD (2001):
  22. "Product Information. Seroquel (quetiapine)." Astra-Zeneca Pharmaceuticals PROD (2001):
  23. "Product Information. Meridia (sibutramine)." Knoll Pharmaceutical Company PROD (2001):
  24. "Product Information. Tasmar (tolcapone)." Valeant Pharmaceuticals PROD (2001):
  25. Miller LG "Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interactions." Arch Intern Med 158 (1998): 2200-11
  26. "Product Information. Precedex (dexmedetomidine)." Abbott Pharmaceutical PROD (2001):
  27. "Product Information. Trileptal (oxcarbazepine)." Novartis Pharmaceuticals PROD (2001):
  28. Ferslew KE, Hagardorn AN, McCormick WF "A fatal interaction of methocarbamol and ethanol in an accidental poisoning." J Forensic Sci 35 (1990): 477-82
  29. Plushner SL "Valerian: valeriana officinalis." Am J Health Syst Pharm 57 (2000): 328-35
  30. "Product Information. Xatral (alfuzosin)." Sanofi-Synthelabo Canada Inc (2002):
  31. "Product Information. Lexapro (escitalopram)." Forest Pharmaceuticals (2002):
  32. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  33. Cerner Multum, Inc. "Australian Product Information." O 0
  34. "Product Information. Fycompa (perampanel)." Eisai Inc (2012):
  35. "Product Information. Belsomra (suvorexant)." Merck & Co., Inc (2014):
  36. "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc (2015):
View all 36 references

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Moderate

lamiVUDine efavirenz

Applies to: Symfi Lo (efavirenz / lamivudine / tenofovir) and Symfi Lo (efavirenz / lamivudine / 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: Symfi Lo (efavirenz / lamivudine / tenofovir) and Symfi Lo (efavirenz / lamivudine / 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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Drug and food interactions

Major

HYDROcodone food

Applies to: Neo HC (chlorpheniramine / hydrocodone / phenylephrine)

GENERALLY AVOID: Alcohol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics including hydrocodone. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.

GENERALLY AVOID: Consumption of alcohol while taking some sustained-release formulations of hydrocodone may cause rapid release of the drug, resulting in high systemic levels of hydrocodone that may be potentially lethal. Alcohol apparently can disrupt the release mechanism of some sustained-release formulations. In study subjects, the rate of absorption of hydrocodone from an extended-release formulation was found to be affected by coadministration with 40% alcohol in the fasted state, as demonstrated by an average 2.4-fold (up to 3.9-fold in one subject) increase in hydrocodone peak plasma concentration and a decrease in the time to peak concentration. Alcohol also increased the extent of absorption by an average of 1.2-fold (up to 1.7-fold in one subject).

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of hydrocodone. The proposed mechanism is inhibition of CYP450 3A4-mediated metabolism of hydrocodone by certain compounds present in grapefruit. Increased hydrocodone concentrations could conceivably increase or prolong adverse drug effects and may cause potentially fatal respiratory depression.

MANAGEMENT: Patients taking sustained-release formulations of hydrocodone should not consume alcohol or use medications that contain alcohol. In general, potent narcotics such as hydrocodone should not be combined with alcohol. Patients should also avoid consumption of grapefruit or grapefruit juice during treatment with hydrocodone.

References

  1. "Product Information. Zohydro ER (hydrocodone)." Zogenix, Inc (2013):

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Moderate

chlorpheniramine food

Applies to: Neo HC (chlorpheniramine / hydrocodone / phenylephrine)

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References

  1. Warrington SJ, Ankier SI, Turner P "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology 15 (1986): 31-7
  2. Gilman AG, eds., Nies AS, Rall TW, Taylor P "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc. (1990):
  3. "Product Information. Fycompa (perampanel)." Eisai Inc (2012):
  4. "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc (2015):
View all 4 references

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Moderate

efavirenz food

Applies to: Symfi Lo (efavirenz / lamivudine / 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

phenylephrine food

Applies to: Neo HC (chlorpheniramine / hydrocodone / phenylephrine)

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

References

  1. Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res 1 (1979): 45-52
  2. Cavanaugh JH, Griffith JD, Oates JA "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther 11 (1970): 656
  3. "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc PROD (2001):
  4. "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals PROD (2001):
  5. "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals PROD (2001):
  6. "Product Information. Focalin (dexmethylphenidate)." Mikart Inc (2001):
  7. "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company (2002):
View all 7 references

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Minor

tenofovir food

Applies to: Symfi Lo (efavirenz / lamivudine / 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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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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