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Drug Interaction Report

4 potential interactions and/or warnings found for the following 2 drugs:

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Interactions between your drugs

Moderate

dilTIAZem multivitamin, prenatal

Applies to: diltiazem, Vynatal 1 Plus 1 (multivitamin, prenatal)

MONITOR: Calcium-containing products may decrease the effectiveness of calcium channel blockers by saturating calcium channels with calcium. Calcium chloride has been used to manage acute severe verapamil toxicity.

MANAGEMENT: Management consists of monitoring the effectiveness of calcium channel blocker therapy during coadministration with calcium products.

References

  1. Henry M, Kay MM, Viccellio P (1985) "Cardiogenic shock associated with calcium-channel and beta blockers: reversal with intravenous calcium chloride." Am J Emerg Med, 3, p. 334-6
  2. Moller IW (1987) "Cardiac arrest following intravenous verapamil combined with halothane anaesthesia." Br J Anaesth, 59, p. 522-6
  3. Oszko MA, Klutman NE (1987) "Use of calcium salts during cardiopulmonary resuscitation for reversing verapamil-associated hypotension." Clin Pharm, 6, p. 448-9
  4. Schoen MD, Parker RB, Hoon TJ, et al. (1991) "Evaluation of the pharmacokinetics and electrocardiographic effects of intravenous verapamil with intravenous calcium chloride pretreatment in normal subjects." Am J Cardiol, 67, p. 300-4
  5. O'Quinn SV, Wohns DH, Clarke S, Koch G, Patterson JH, Adams KF (1990) "Influence of calcium on the hemodynamic and anti-ischemic effects of nifedipine observed during treadmill exercise testing." Pharmacotherapy, 10, p. 247
  6. Woie L, Storstein L (1981) "Successful treatment of suicidal verapamil poisoning with calcium gluconate." Eur Heart J, 2, p. 239-42
  7. Morris DL, Goldschlager N (1983) "Calcium infusion for reversal of adverse effects of intravenous verapamil." JAMA, 249, p. 3212-3
  8. Guadagnino V, Greengart A, Hollander G, Solar M, Shani J, Lichstein E (1987) "Treatment of severe left ventricular dysfunction with calcium chloride in patients receiving verapamil." J Clin Pharmacol, 27, p. 407-9
  9. Luscher TF, Noll G, Sturmer T, Huser B, Wenk M (1994) "Calcium gluconate in severe verapamil intoxication." N Engl J Med, 330, p. 718-20
  10. Bar-Or D, Gasiel Y (1981) "Calcium and calciferol antagonise effect of verapamil in atrial fibrillation." Br Med J (Clin Res Ed), 282, p. 1585-6
  11. Lipman J, Jardine I, Roos C, Dreosti L (1982) "Intravenous calcium chloride as an antidote to verapamil-induced hypotension." Intensive Care Med, 8, p. 55-7
  12. McMillan R (1988) "Management of acute severe verapamil intoxication." J Emerg Med, 6, p. 193-6
  13. Perkins CM (1978) "Serious verapamil poisoning: treatment with intravenous calcium gluconate." Br Med J, 2, p. 1127
  14. Moroni F, Mannaioni PF, Dolara A, Ciaccheri M (1980) "Calcium gluconate and hypertonic sodium chloride in a case of massive verapamil poisoning." Clin Toxicol, 17, p. 395-400
View all 14 references

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Drug and food interactions

Moderate

dilTIAZem food

Applies to: diltiazem

MONITOR: Like many CNS-active agents, alcohol can exhibit hypotensive effects. Coadministration with antihypertensive agents including diltiazem may result in additive effects on blood pressure and orthostasis.

MONITOR: Grapefruit juice may increase the plasma concentrations of orally administered diltiazem in some patients. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. In a study of ten healthy male volunteers, administration of a single 120 mg oral dose of immediate-release diltiazem in combination with 250 mL of grapefruit juice increased the diltiazem peak plasma concentration (Cmax) and systemic exposure (AUC) by an average of 22% and 20%, respectively, compared to administration with water. The time to reach Cmax (Tmax) and the terminal half-life were not affected, and no statistically significant differences in blood pressure and heart rate were observed during administration with grapefruit juice relative to water. In a different study, repeated administration of 200 mL of grapefruit juice at 0, 2, 4, 8 and 12 hours had no significant effect on the Cmax or AUC of a single 120 mg oral dose of diltiazem, but increased its half-life from 4.1 to 5.1 hours. The ratios for the N-demethyl and deacetyl metabolites to diltiazem were also not affected by grapefruit juice. However, because pharmacokinetic interactions involving grapefruit juice are often subject to a high degree of interpatient variability, the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients should be advised that alcohol may potentiate the hypotensive effects of diltiazem, especially during the initiation of therapy and following a dosage increase. Caution should be exercised when rising from a sitting or recumbent position, and patients should notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients who regularly consume grapefruit or grapefruit juice should be monitored for increased adverse effects of diltiazem such as such as headache, irregular heartbeat, edema, unexplained weight gain, and chest pain. Grapefruit and grapefruit juice should be avoided if an interaction is suspected.

References

  1. Bailey DG, Arnold JMO, Spence JD (1994) "Grapefruit juice and drugs - how significant is the interaction." Clin Pharmacokinet, 26, p. 91-8
  2. Sigusch H, Henschel L, Kraul H, Merkel U, Hoffmann A (1994) "Lack of effect of grapefruit juice on diltiazem bioavailability in normal subjects." Pharmazie, 49, p. 675-9
  3. Bailey DG, Malcolm J, Arnold O, Spence JD (1998) "Grapefruit juice-drug interactions." Br J Clin Pharmacol, 46, p. 101-10
  4. Christensen H, Asberg A, Holmboe AB, Berg KJ (2002) "Coadministration of grapefruit juice increases systemic exposure of diltiazem in healthy volunteers." Eur J Clin Pharmacol, 58, p. 515-520
  5. Cerner Multum, Inc. "UK Summary of Product Characteristics."
View all 5 references

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Moderate

multivitamin, prenatal food

Applies to: Vynatal 1 Plus 1 (multivitamin, prenatal)

ADJUST DOSING INTERVAL: Concomitant use of some oral medications may reduce the bioavailability of orally administered iron, and vice versa.

Food taken in conjunction with oral iron supplements may reduce the bioavailability of the iron. However, in many patients intolerable gastrointestinal side effects occur necessitating administration with food.

MANAGEMENT: Ideally, iron products should be taken on an empty stomach (i.e., at least 1 hour before or 2 hours after meals), but if this is not possible, administer with meals and monitor the patient more closely for a subtherapeutic effect. Some studies suggest administration of iron with ascorbic acid may enhance bioavailability. In addition, administration of oral iron products and some oral medications should be separated whenever the bioavailability of either agent may be decreased. Consult the product labeling for specific separation times and monitor clinical responses as appropriate.

References

  1. "Product Information. Feosol (ferrous sulfate)." SmithKline Beecham
  2. (2021) "Product Information. Accrufer (ferric maltol)." Shield Therapeutics

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Moderate

dilTIAZem food

Applies to: diltiazem

MONITOR: Calcium-containing products may decrease the effectiveness of calcium channel blockers by saturating calcium channels with calcium. Calcium chloride has been used to manage acute severe verapamil toxicity.

MANAGEMENT: Management consists of monitoring the effectiveness of calcium channel blocker therapy during coadministration with calcium products.

References

  1. Henry M, Kay MM, Viccellio P (1985) "Cardiogenic shock associated with calcium-channel and beta blockers: reversal with intravenous calcium chloride." Am J Emerg Med, 3, p. 334-6
  2. Moller IW (1987) "Cardiac arrest following intravenous verapamil combined with halothane anaesthesia." Br J Anaesth, 59, p. 522-6
  3. Oszko MA, Klutman NE (1987) "Use of calcium salts during cardiopulmonary resuscitation for reversing verapamil-associated hypotension." Clin Pharm, 6, p. 448-9
  4. Schoen MD, Parker RB, Hoon TJ, et al. (1991) "Evaluation of the pharmacokinetics and electrocardiographic effects of intravenous verapamil with intravenous calcium chloride pretreatment in normal subjects." Am J Cardiol, 67, p. 300-4
  5. O'Quinn SV, Wohns DH, Clarke S, Koch G, Patterson JH, Adams KF (1990) "Influence of calcium on the hemodynamic and anti-ischemic effects of nifedipine observed during treadmill exercise testing." Pharmacotherapy, 10, p. 247
  6. Woie L, Storstein L (1981) "Successful treatment of suicidal verapamil poisoning with calcium gluconate." Eur Heart J, 2, p. 239-42
  7. Morris DL, Goldschlager N (1983) "Calcium infusion for reversal of adverse effects of intravenous verapamil." JAMA, 249, p. 3212-3
  8. Guadagnino V, Greengart A, Hollander G, Solar M, Shani J, Lichstein E (1987) "Treatment of severe left ventricular dysfunction with calcium chloride in patients receiving verapamil." J Clin Pharmacol, 27, p. 407-9
  9. Luscher TF, Noll G, Sturmer T, Huser B, Wenk M (1994) "Calcium gluconate in severe verapamil intoxication." N Engl J Med, 330, p. 718-20
  10. Bar-Or D, Gasiel Y (1981) "Calcium and calciferol antagonise effect of verapamil in atrial fibrillation." Br Med J (Clin Res Ed), 282, p. 1585-6
  11. Lipman J, Jardine I, Roos C, Dreosti L (1982) "Intravenous calcium chloride as an antidote to verapamil-induced hypotension." Intensive Care Med, 8, p. 55-7
  12. McMillan R (1988) "Management of acute severe verapamil intoxication." J Emerg Med, 6, p. 193-6
  13. Perkins CM (1978) "Serious verapamil poisoning: treatment with intravenous calcium gluconate." Br Med J, 2, p. 1127
  14. Moroni F, Mannaioni PF, Dolara A, Ciaccheri M (1980) "Calcium gluconate and hypertonic sodium chloride in a case of massive verapamil poisoning." Clin Toxicol, 17, p. 395-400
View all 14 references

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Therapeutic duplication warnings

No duplication 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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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.