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Drug Interactions between Lotensin and potassium iodide / theophylline

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

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Interactions between your drugs

Major

benazepril potassium iodide

Applies to: Lotensin (benazepril) and potassium iodide / theophylline

MONITOR CLOSELY: Concomitant use of angiotensin converting enzyme (ACE) inhibitors and potassium salts may increase the risk of hyperkalemia. Inhibition of ACE results in decreased aldosterone secretion, which in turn causes potassium retention. In one report, a significant increase in serum potassium level (3.88 +/- 0.41 to 4.84 +/- 0.45 mEq/L) was observed within one or two days following the addition of captopril in five patients who were treated with regimens that included potassium supplements or potassium-sparing diuretics. Three patients had laboratory-diagnosed hyperkalemia, including one patient receiving potassium supplementation who had a 66% increase in serum potassium. Levels remained elevated until potassium supplementation or captopril therapy was reduced or discontinued. In a postmarketing survey of patients who were prescribed enalapril in England between April and December 1985, researchers identified ten cases where enalapril appeared to have contributed to a deterioration in renal function and subsequent death. All ten patients had hyperkalemia, and seven were also receiving moderate to high dosages of potassium-sparing diuretics and/or potassium supplements. Hyperkalemia was felt to be the immediate cause of death in two of them. Risk factors for developing severe or life-threatening hyperkalemia may include renal impairment, diabetes, old age, severe or worsening heart failure, dehydration, and concomitant use of other agents that block the renin-angiotensin-aldosterone system or otherwise increase serum potassium levels.

MANAGEMENT: Caution is advised if ACE inhibitors must be used concurrently with potassium salts, particularly in patients with renal impairment, diabetes, old age, severe or worsening heart failure, dehydration, or concomitant therapy with other agents that increase serum potassium such as nonsteroidal anti-inflammatory drugs, beta-blockers, cyclosporine, heparin, tacrolimus, trimethoprim, and licorice. The combination should generally be avoided in these patients unless absolutely necessary and the benefits outweigh the potential risks. Serum potassium and renal function should be checked prior to initiating therapy and regularly thereafter. Patients should be given counseling on the appropriate levels of potassium and fluid intake, and advised to seek medical attention if they experience signs and symptoms of hyperkalemia such as nausea, vomiting, weakness, listlessness, tingling of the extremities, paralysis, confusion, weak pulse, and a slow or irregular heartbeat.

References

  1. Speirs CJ, Dollery CT, Inman WH, et al. (1988) "Postmarketing surveillance of enalapril II: investigation of the potential role of enalapril in deaths with renal failure." Br Med J, 297, p. 830-2
  2. Packer M, Lee WH (1986) "Provocation of hyper- and hypokalemic sudden death during treatment with and withdrawal of converting-enzyme inhibition in severe chronic congestive heart failure." Am J Cardiol, 57, p. 347-8
  3. Burnakis TG, Mioduch HJ (1984) "Combined therapy with captopril and potassium supplementation: a potential for hyperkalemia." Arch Intern Med, 144, p. 2371-2
  4. Warren SE, O'Connor DT (1980) "Hyperkalemia resulting from captopril administration." JAMA, 244, p. 2551-2
  5. Chan TY, Critchley JA (1992) "Life-threatening hyperkalaemia in an elderly patient receiving captopril, furosemide (frusemide) and potassium supplements." Drug Saf, 7, p. 159-61
  6. Walmsley RN, White GH, Cain M, McCarthy PJ, Booth J (1984) "Hyperkalemia in the elderly." Clin Chem, 30, p. 1409-12
  7. Stoltz ML, Andrews CE Jr (1990) "Severe hyperkalemia during very-low-calorie diets and angiotensin converting enzyme use ." JAMA, 264, p. 2737-8
  8. Ponce SP, Jennings AE, Madias NE, Harrington JT (1985) "Drug-induced hyperkalemia." Medicine (Baltimore), 64, p. 357-70
  9. Lawson DH, O'Connor PC, Jick H (1982) "Drug attributed alterations in potassium handling in congestive cardiac failure." Eur J Clin Pharmacol, 23, p. 21-5
  10. Lawson DH (1974) "Adverse reactions to potassium chloride." Q J Med, 43, p. 433-40
  11. (2001) "Product Information. K-Dur (potassium chloride)." Schering Corporation
  12. Good CB, McDermott L (1995) "Diet and serum potassium in patients on ACE inhibitors." JAMA, 274, p. 538
  13. Graves JW (1998) "Hyperkalemia due to a potassium-based water softener." N Engl J Med, 339, p. 1790-1
  14. Obialo CI, Ofili EO, Mirza T (2002) "Hyperkalemia in congestive heart failure patients aged 63 to 85 years with subclinical renal disease." Am J Cardiol, 90, p. 663-5
  15. Atlas SA, Case DB, Sealey JE, Laragh JH, McKinstry DN (1979) "Interruption of the renin-angiotensin system in hypertensive patients by captopril induces sustained reduction in aldosterone secretion, potassium retention and natriuresis." Hypertension, 1, p. 279-80
  16. Schuna AA, Schmidt GR, Pitterle ME (1986) "Serum potassium concentrations after initiation of captopril therapy." Clin Pharm, 5, p. 920-3
  17. Jarman PR, Mather HM (2003) "Diabetes may be independent risk factor for hyperkalaemia." BMJ, 327, p. 812
  18. Ray K, Dorman S, Watson R (1999) "Severe hyperkalaemia due to the concomitant use of salt substitutes and ACE inhibitors in hypertension: a potentially life threatening interaction." J Hum Hypertens, 13, p. 717-20
  19. Reardon LC, Macpherson DS (1998) "Hyperkalemia in outpatients using angiotensin-converting enzyme inhibitors. How much should we worry?" Arch Intern Med, 158, p. 26-32
  20. Perazella MA (2000) "Drug-induced hyperkalemia: old culprits and new offenders." Am J Med, 109, p. 307-14
  21. Jarman PR, Kehely AM, Mather HM (1995) "Hyperkalaemia in diabetes: prevalence and associations." Postgrad Med J, 71, p. 551-2
  22. Perazella MA, Mahnensmith RL (1997) "Hyperkalemia in the elderly: drugs exacerbate impaired potassium homeostasis." J Gen Intern Med, 12, p. 646-56
  23. Schoolwerth AC, Sica DA, Ballermann BJ, Wilcox CS, Council on the Kidney in Cardiovascular Disease and the Council for High Blood Pressure Research of the American Heart Association (2001) "Renal considerations in angiotensin converting enzyme inhibitor therapy: a statement for healthcare professionals from the Council on the Kidney in Cardiovascular Disease and the Council for High Blood Pressure Research of the American Heart Association." Circulation, 104, p. 1985-91
  24. Large DM, Carr PH, Laing I, Davies M (1984) "Hyperkalaemia in diabetes mellitus--potential hazards of coexisting hyporeninaemic hypoaldosteronism." Postgrad Med J, 60, p. 370-3
View all 24 references

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Drug and food interactions

Moderate

theophylline food

Applies to: potassium iodide / theophylline

GENERALLY AVOID: Coadministration with caffeine may increase the serum concentrations of theophylline. The proposed mechanism involves competitive inhibition of theophylline metabolism via CYP450 1A2, as well as metabolic conversion of caffeine to theophylline in vivo and saturation of theophylline metabolism at higher serum concentrations. In six healthy male volunteers (all smokers), serum concentrations of theophylline (administered as aminophylline 400 mg single oral dose) were significantly higher following consumption of caffeine (2 to 7 cups of instant coffee over 24 hours, equivalent to approximately 120 to 630 mg of caffeine) than after caffeine deprivation for 48 hours. Caffeine consumption also increased the apparent elimination half-life of theophylline by an average of 32% and reduced its total body clearance by 23%. In another study, steady-state concentration and area under the concentration-time curve of theophylline (1200 mg intravenously over 24 hours) increased by 23% and 40%, respectively, in eight healthy volunteers following administration of caffeine (300 mg orally three times a day).

MANAGEMENT: Given the narrow therapeutic index of theophylline, patients should limit or avoid significant fluctuations in their intake of pharmacologic as well as dietary caffeine.

ADJUST DOSING INTERVAL: Administration of theophylline with continuous enteral nutrition may reduce the serum levels or the rate of absorption of theophylline. The mechanism has not been reported. In one case, theophylline levels decreased by 53% in a patient receiving continuous nasogastric tube feedings and occurred with both theophylline tablet and liquid formulations, but not with intravenous aminophylline.

MANAGEMENT: When administered to patients receiving continuous enteral nutrition , some experts recommend that the tube feeding should be interrupted for at least 1 hour before and 1 hour after the dose of theophylline is given; rapid-release formulations are preferable, and theophylline levels should be monitored.

References

  1. 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
  2. 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
  3. Wohlt PD, Zheng L, Gunderson S, Balzar SA, Johnson BD, Fish JT (2009) "Recommendations for the use of medications with continuous enteral nutrition." Am J Health Syst Pharm, 66, p. 1438-67

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Moderate

benazepril food

Applies to: Lotensin (benazepril)

GENERALLY AVOID: Moderate-to-high dietary intake of potassium can cause hyperkalemia in some patients who are using angiotensin converting enzyme (ACE) inhibitors. In some cases, affected patients were using a potassium-rich salt substitute. ACE inhibitors can promote hyperkalemia through inhibition of the renin-aldosterone-angiotensin (RAA) system.

MANAGEMENT: It is recommended that patients who are taking ACE inhibitors be advised to avoid moderately high or high potassium dietary intake. Particular attention should be paid to the potassium content of salt substitutes.

References

  1. (2002) "Product Information. Vasotec (enalapril)." Merck & Co., Inc
  2. Good CB, McDermott L (1995) "Diet and serum potassium in patients on ACE inhibitors." JAMA, 274, p. 538
  3. Ray K, Dorman S, Watson R (1999) "Severe hyperkalaemia due to the concomitant use of salt substitutes and ACE inhibitors in hypertension: a potentially life threatening interaction." J Hum Hypertens, 13, p. 717-20

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Moderate

benazepril food

Applies to: Lotensin (benazepril)

MONITOR: Many psychotherapeutic and CNS-active agents (e.g., anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, alcohol, muscle relaxants) exhibit hypotensive effects, especially during initiation of therapy and dose escalation. Coadministration with antihypertensives and other hypotensive agents, in particular vasodilators and alpha-blockers, may result in additive effects on blood pressure and orthostasis.

MANAGEMENT: Caution and close monitoring for development of hypotension is advised during coadministration of these agents. Some authorities recommend avoiding alcohol in patients receiving vasodilating antihypertensive drugs. Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia.

References

  1. Sternbach H (1991) "Fluoxetine-associated potentiation of calcium-channel blockers." J Clin Psychopharmacol, 11, p. 390-1
  2. Shook TL, Kirshenbaum JM, Hundley RF, Shorey JM, Lamas GA (1984) "Ethanol intoxication complicating intravenous nitroglycerin therapy." Ann Intern Med, 101, p. 498-9
  3. Feder R (1991) "Bradycardia and syncope induced by fluoxetine." J Clin Psychiatry, 52, p. 139
  4. Ellison JM, Milofsky JE, Ely E (1990) "Fluoxetine-induced bradycardia and syncope in two patients." J Clin Psychiatry, 51, p. 385-6
  5. Rodriguez de la Torre B, Dreher J, Malevany I, et al. (2001) "Serum levels and cardiovascular effects of tricyclic antidepressants and selective serotonin reuptake inhibitors in depressed patients." Ther Drug Monit, 23, p. 435-40
  6. Cerner Multum, Inc. "Australian Product Information."
  7. Pacher P, Kecskemeti V (2004) "Cardiovascular side effects of new antidepressants and antipsychotics: new drugs, old concerns?" Curr Pharm Des, 10, p. 2463-75
  8. Andrews C, Pinner G (1998) "Postural hypotension induced by paroxetine." BMJ, 316, p. 595
View all 8 references

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Moderate

theophylline food

Applies to: potassium iodide / theophylline

GENERALLY AVOID: Coadministration with caffeine may increase the serum concentrations of theophylline. The proposed mechanism involves competitive inhibition of theophylline metabolism via CYP450 1A2, as well as metabolic conversion of caffeine to theophylline in vivo and saturation of theophylline metabolism at higher serum concentrations. In six healthy male volunteers (all smokers), serum concentrations of theophylline (administered as aminophylline 400 mg single oral dose) were significantly higher following consumption of caffeine (2 to 7 cups of instant coffee over 24 hours, equivalent to approximately 120 to 630 mg of caffeine) than after caffeine deprivation for 48 hours. Caffeine consumption also increased the apparent elimination half-life of theophylline by an average of 32% and reduced its total body clearance by 23%. In another study, steady-state concentration and area under the concentration-time curve of theophylline (1200 mg intravenously over 24 hours) increased by 23% and 40%, respectively, in eight healthy volunteers following administration of caffeine (300 mg orally three times a day).

MANAGEMENT: Given the narrow therapeutic index of theophylline, patients should limit or avoid significant fluctuations in their intake of pharmacologic as well as dietary caffeine.

References

  1. 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
  2. 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

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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.

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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.

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