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Drug Interactions between amitriptyline and vardenafil

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

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Interactions between your drugs

Moderate

amitriptyline vardenafil

Applies to: amitriptyline and vardenafil

MONITOR: Theoretically, concurrent use of two or more drugs that can cause QT interval prolongation may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. The risk of an individual agent or a combination of these agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: Caution and clinical monitoring are recommended if multiple agents associated with QT interval prolongation are prescribed together. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

References (7)
  1. Glassman AH, Bigger JT Jr (2001) "Antipsychotic drugs: prolonged QTc interval, torsade de pointes, and sudden death." Am J Psychiatry, 158, p. 1774-82
  2. Witchel HJ, Hancox JC, Nutt DJ (2003) "Psychotropic drugs, cardiac arrhythmia, and sudden death." J Clin Psychopharmacol, 23, p. 58-77
  3. Iannini PB (2002) "Cardiotoxicity of macrolides, ketolides and fluoroquinolones that prolong the QTc interval." Expert Opin Drug Saf, 1, p. 121-8
  4. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  5. Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
  6. Cerner Multum, Inc. "Australian Product Information."
  7. EMA. European Medicines Agency. European Union (2013) EMA - List of medicines under additional monitoring. http://www.ema.europa.eu/ema/index.jsp?curl=pages/regulation/document_listing/document_listing_000366.jsp&mid=WC0b01ac058067c852

Drug and food interactions

Moderate

vardenafil food

Applies to: vardenafil

MONITOR: Grapefruit juice may increase the plasma concentrations of orally administered drugs that are substrates of the CYP450 3A4 isoenzyme. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Because grapefruit juice inhibits primarily intestinal rather than hepatic CYP450 3A4, the magnitude of interaction is greatest for those drugs that undergo significant presystemic metabolism by CYP450 3A4 (i.e., drugs with low oral bioavailability). In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients who regularly consume grapefruit or grapefruit juice should be monitored for adverse effects and altered plasma concentrations of drugs that undergo significant presystemic metabolism by CYP450 3A4. Grapefruit and grapefruit juice should be avoided if an interaction is suspected. Orange juice is not expected to interact with these drugs.

References (32)
  1. Edgar B, Bailey D, Bergstrand R, et al. (1992) "Acute effects of drinking grapefruit juice on the pharmacokinetics and dynamics on felodipine and its potential clinical relevance." Eur J Clin Pharmacol, 42, p. 313-7
  2. Jonkman JH, Sollie FA, Sauter R, Steinijans VW (1991) "The influence of caffeine on the steady-state pharmacokinetics of theophylline." Clin Pharmacol Ther, 49, p. 248-55
  3. Bailey DG, Arnold JM, Munoz C, Spence JD (1993) "Grapefruit juice--felodipine interaction: mechanism, predictability, and effect of naringin." Clin Pharmacol Ther, 53, p. 637-42
  4. Bailey DG, Arnold JMO, Spence JD (1994) "Grapefruit juice and drugs - how significant is the interaction." Clin Pharmacokinet, 26, p. 91-8
  5. Sigusch H, Hippius M, Henschel L, Kaufmann K, Hoffmann A (1994) "Influence of grapefruit juice on the pharmacokinetics of a slow release nifedipine formulation." Pharmazie, 49, p. 522-4
  6. Bailey DG, Arnold JM, Strong HA, Munoz C, Spence JD (1993) "Effect of grapefruit juice and naringin on nisoldipine pharmacokinetics." Clin Pharmacol Ther, 54, p. 589-94
  7. Yamreudeewong W, Henann NE, Fazio A, Lower DL, Cassidy TG (1995) "Drug-food interactions in clinical practice." J Fam Pract, 40, p. 376-84
  8. (1995) "Grapefruit juice interactions with drugs." Med Lett Drugs Ther, 37, p. 73-4
  9. Hukkinen SK, Varhe A, Olkkola KT, Neuvonen PJ (1995) "Plasma concentrations of triazolam are increased by concomitant ingestion of grapefruit juice." Clin Pharmacol Ther, 58, p. 127-31
  10. Min DI, Ku YM, Geraets DR, Lee HC (1996) "Effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of quinidine in healthy volunteers." J Clin Pharmacol, 36, p. 469-76
  11. Majeed A, Kareem A (1996) "Effect of grapefruit juice on cyclosporine pharmacokinetics." Pediatr Nephrol, 10, p. 395
  12. Clifford CP, Adams DA, Murray S, Taylor GW, Wilkins MR, Boobis AR, Davies DS (1996) "Pharmacokinetic and cardiac effects of terfenadine after inhibition of its metabolism by grapefruit juice." Br J Clin Pharmacol, 42, p662
  13. 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
  14. Kantola T, Kivisto KT, Neuvonen PJ (1998) "Grapefruit juice greatly increases serum concentrations of lovastatin and lovastatin acid." Clin Pharmacol Ther, 63, p. 397-402
  15. Ozdemir M, Aktan Y, Boydag BS, Cingi MI, Musmul A (1998) "Interaction between grapefruit juice and diazepam in humans." Eur J Drug Metab Pharmacokinet, 23, p. 55-9
  16. Bailey DG, Malcolm J, Arnold O, Spence JD (1998) "Grapefruit juice-drug interactions." Br J Clin Pharmacol, 46, p. 101-10
  17. Bailey DG, Kreeft JH, Munoz C, Freeman DJ, Bend JR (1998) "Grapefruit juice felodipine interaction: Effect of naringin and 6',7'-dihydroxybergamottin in humans." Clin Pharmacol Ther, 64, p. 248-56
  18. Garg SK, Kumar N, Bhargava VK, Prabhakar SK (1998) "Effect of grapefruit juice on carbamazepine bioavailability in patients with epilepsy." Clin Pharmacol Ther, 64, p. 286-8
  19. Lilja JJ, Kivisto KT, Neuvonen PJ (1998) "Grapefruit juice-simvastatin interaction: Effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors." Clin Pharmacol Ther, 64, p. 477-83
  20. Fuhr U, Maier-Bruggemann A, Blume H, et al. (1998) "Grapefruit juice increases oral nimodipine bioavailability." Int J Clin Pharmacol Ther, 36, p. 126-32
  21. 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
  22. Eagling VA, Profit L, Back DJ (1999) "Inhibition of the CYP3A4-mediated metabolism and P-glycoprotein-mediated transport of the HIV-I protease inhibitor saquinavir by grapefruit juice components." Br J Clin Pharmacol, 48, p. 543-52
  23. Damkier P, Hansen LL, Brosen K (1999) "Effect of diclofenac, disulfiram, itraconazole, grapefruit juice and erythromycin on the pharmacokinetics of quinidine." Br J Clin Pharmacol, 48, p. 829-38
  24. Lee AJ, Chan WK, Harralson AF, Buffum J, Bui BCC (1999) "The effects of grapefruit juice on sertraline metabolism: An in vitro and in vivo study." Clin Ther, 21, p. 1890-9
  25. Dresser GK, Spence JD, Bailey DG (2000) "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet, 38, p. 41-57
  26. Gunston GD, Mehta U (2000) "Potentially serious drug interactions with grapefruit juice." S Afr Med J, 90, p. 41
  27. Takanaga H, Ohnishi A, Maatsuo H, et al. (2000) "Pharmacokinetic analysis of felodipine-grapefruit juice interaction based on an irreversible enzyme inhibition model." Br J Clin Pharmacol, 49, p. 49-58
  28. Libersa CC, Brique SA, Motte KB, et al. (2000) "Dramatic inhibition of amiodarone metabolism induced by grapefruit juice." Br J Clin Pharmacol, 49, p. 373-8
  29. Bailey DG, Dresser GR, Kreeft JH, Munoz C, Freeman DJ, Bend JR (2000) "Grapefruit-felodipine interaction: Effect of unprocessed fruit and probable active ingredients." Clin Pharmacol Ther, 68, p. 468-77
  30. Zaidenstein R, Soback S, Gips M, Avni B, Dishi V, Weissgarten Y, Golik A, Scapa E (2001) "Effect of grapefruit juice on the pharmacokinetics of losartan and its active metabolite E3174 in healthy volunteers." Ther Drug Monit, 23, p. 369-73
  31. Sato J, Nakata H, Owada E, Kikuta T, Umetsu M, Ito K (1993) "Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects." Eur J Clin Pharmacol, 44, p. 295-8
  32. Flanagan D (2005) "Understanding the grapefruit-drug interaction." Gen Dent, 53, 282-5; quiz 286
Moderate

amitriptyline food

Applies to: amitriptyline

GENERALLY AVOID: Concomitant use of ethanol and a tricyclic antidepressant (TCA) may result altered TCA plasma levels and efficacy, and additive impairment of motor skills, especially driving skills. Acute ethanol ingestion may inhibit TCA metabolism, while chronic ingestion of large amounts of ethanol may induce hepatic TCA metabolism.

MANAGEMENT: Patients should be advised to avoid alcohol during TCA therapy. Alcoholics who have undergone detoxification should be monitored for decreased TCA efficacy. Dosage adjustments may be required.

References (7)
  1. Dorian P, Sellers EM, Reed KL, et al. (1983) "Amitriptyline and ethanol: pharmacokinetic and pharmacodynamic interaction." Eur J Clin Pharmacol, 25, p. 325-31
  2. Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
  3. Sandoz M, Vandel S, Vandel B, Bonin B, Allers G, Volmat R (1983) "Biotransformation of amitriptyline in alcoholic depressive patients." Eur J Clin Pharmacol, 24, p. 615-21
  4. Ciraulo DA, Barnhill JG, Jaffe JH (1988) "Clinical pharmacokinetics of imipramine and desipramine in alcoholics and normal volunteers." Clin Pharmacol Ther, 43, p. 509-18
  5. Seppala T, Linnoila M, Elonen E, Mattila MJ, Makl M (1975) "Effect of tricyclic antidepressants and alcohol on psychomotor skills related to driving." Clin Pharmacol Ther, 17, p. 515-22
  6. Ciraulo DA, Barnhill JG, Jaffe JH, Ciraulo AM, Tarmey MF (1990) "Intravenous pharmacokinetics of 2-hydroxyimipramine in alcoholics and normal controls." J Stud Alcohol, 51, p. 366-72
  7. Ciraulo DA, Alderson LM, Chapron DJ, Jaffe JH, Subbarao B, Kramer PA (1982) "Imipramine disposition in alcoholics." J Clin Psychopharmacol, 2, p. 2-7
Moderate

amitriptyline food

Applies to: amitriptyline

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.

References (4)
  1. (2024) "Product Information. Cytisine (cytisinicline)." Consilient Health Ltd
  2. jeong sh, Newcombe D, sheridan j, Tingle M (2015) "Pharmacokinetics of cytisine, an a4 b2 nicotinic receptor partial agonist, in healthy smokers following a single dose." Drug Test Anal, 7, p. 475-82
  3. Vaughan DP, Beckett AH, Robbie DS (1976) "The influence of smoking on the intersubject variation in pentazocine elimination." Br J Clin Pharmacol, 3, p. 279-83
  4. Zevin S, Benowitz NL (1999) "Drug interactions with tobacco smoking: an update" Clin Pharmacokinet, 36, p. 425-38

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.

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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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