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Drug Interactions between amitriptyline and hydrochlorothiazide / methyldopa

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

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Interactions between your drugs

Moderate

amitriptyline hydroCHLOROthiazide

Applies to: amitriptyline and hydrochlorothiazide / methyldopa

MONITOR: Phenothiazines, tricyclic antidepressants (TCAs), and some antipsychotic (neuroleptic) agents may potentiate the blood pressure lowering capabilities of other drugs with hypotensive effects due to their peripheral alpha-1 adrenergic blocking activity. Orthostatic hypotension and syncope associated with vasodilation may occur, particularly during initial dosing and/or parenteral administration of the phenothiazine, TCA, or neuroleptic. The severity of this interaction may be affected by the agent's affinity for the alpha-1 adrenoceptor. One in vitro study demonstrated an affinity for the alpha-1 adrenoceptor for some of these medications that was similar to, or greater than, those of alpha blocker medications used to treat hypertension. Examples of drugs evaluated in this study with a high affinity included amitriptyline, clomipramine, chlorpromazine, clozapine, doxepin, flupenthixol, lurasidone, nortriptyline, perphenazine, paliperidone, quetiapine, risperidone, sertindole, and ziprasidone. On the other hand, examples of those with lower affinities included aripiprazole, lofepramine, protriptyline, sulpiride, and amisulpride.

MANAGEMENT: Close clinical monitoring for development of hypotension is recommended if phenothiazines, tricyclic antidepressants (TCAs), or certain antipsychotic (neuroleptic) agents are used in patients receiving antihypertensive medications or vasodilators. A lower starting dosage and slower titration of the phenothiazine, TCA, or neuroleptic may be appropriate, especially in the elderly. It may also be advisable to consider using a phenothiazine, TCA, or neuroleptic medication with a lower affinity for the alpha-1 adrenoceptor when possible. Patients should be counseled to avoid rising abruptly from a sitting or recumbent position and to notify their healthcare provider if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients should also avoid driving or operating hazardous machinery until they know how the medications affect them.

References

  1. Fruncillo R, Gibbons W, Vlasses P, Ferguson R "Severe hypotension associated with concurrent clonidine and antipsychotic medication." Am J Psychiatry 142 (1985): 274
  2. White WB "Hypotension with postural syncope secondary to the combination of chlorpromazine and captopril." Arch Intern Med 146 (1986): 1833-4
  3. "Product Information. Clozaril (clozapine)." Novartis Pharmaceuticals PROD (2001):
  4. "Product Information. Risperdal (risperidone)." Janssen Pharmaceuticals PROD (2001):
  5. Aronowitz JS, Chakos MH, Safferman AZ, Lieberman JA "Syncope associated with the combination of clozapine and enalapril." J Clin Psychopharmacol 14 (1994): 429-30
  6. Markowitz JS, Wells BG, Carson WH "Interactions between antipsychotic and antihypertensive drugs." Ann Pharmacother 29 (1995): 603-9
  7. "Product Information. Zyprexa (olanzapine)." Lilly, Eli and Company PROD (2001):
  8. "Product Information. Seroquel (quetiapine)." Astra-Zeneca Pharmaceuticals PROD (2001):
  9. "Product Information. Geodon (ziprasidone)." Pfizer U.S. Pharmaceuticals PROD (2001):
  10. "Product Information. Abilify (aripiprazole)." Bristol-Myers Squibb (2002):
  11. "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc (2015):
  12. Proudman RGW, Pupo AS, Baker JG "The affinity and selectivity of alpha-adrenoceptor antagonists, antidepressants, and antipsychotics for the human alpha1A, alpha1B, and alpha1D-adrenoceptors." Pharmacol Res Perspect 8 (2020): e00602
View all 12 references

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Minor

methyldopa amitriptyline

Applies to: hydrochlorothiazide / methyldopa and amitriptyline

Isolated reports have suggested that tricyclic antidepressants may decrease the antihypertensive effect of methyldopa. These reports have not been confirmed by other small studies.

References

  1. Reid JL, Porsius AJ, Zamboulis C, Polak G, Hamilton CA, Dean CR "The effects of desmethylimipramine on the pharmacological actions of alpha methyldopa in man." Eur J Clin Pharmacol 16 (1979): 75-80
  2. White AG "Methyldopa and amitriptyline." Lancet 2 (1965): 441

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Drug and food interactions

Moderate

methyldopa food

Applies to: hydrochlorothiazide / methyldopa

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 "Fluoxetine-associated potentiation of calcium-channel blockers." J Clin Psychopharmacol 11 (1991): 390-1
  2. Shook TL, Kirshenbaum JM, Hundley RF, Shorey JM, Lamas GA "Ethanol intoxication complicating intravenous nitroglycerin therapy." Ann Intern Med 101 (1984): 498-9
  3. Feder R "Bradycardia and syncope induced by fluoxetine." J Clin Psychiatry 52 (1991): 139
  4. Ellison JM, Milofsky JE, Ely E "Fluoxetine-induced bradycardia and syncope in two patients." J Clin Psychiatry 51 (1990): 385-6
  5. Rodriguez de la Torre B, Dreher J, Malevany I, et al. "Serum levels and cardiovascular effects of tricyclic antidepressants and selective serotonin reuptake inhibitors in depressed patients." Ther Drug Monit 23 (2001): 435-40
  6. Cerner Multum, Inc. "Australian Product Information." O 0
  7. Pacher P, Kecskemeti V "Cardiovascular side effects of new antidepressants and antipsychotics: new drugs, old concerns?" Curr Pharm Des 10 (2004): 2463-75
  8. Andrews C, Pinner G "Postural hypotension induced by paroxetine." BMJ 316 (1998): 595
View all 8 references

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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

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

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Moderate

hydroCHLOROthiazide food

Applies to: hydrochlorothiazide / methyldopa

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 "Fluoxetine-associated potentiation of calcium-channel blockers." J Clin Psychopharmacol 11 (1991): 390-1
  2. Shook TL, Kirshenbaum JM, Hundley RF, Shorey JM, Lamas GA "Ethanol intoxication complicating intravenous nitroglycerin therapy." Ann Intern Med 101 (1984): 498-9
  3. Feder R "Bradycardia and syncope induced by fluoxetine." J Clin Psychiatry 52 (1991): 139
  4. Ellison JM, Milofsky JE, Ely E "Fluoxetine-induced bradycardia and syncope in two patients." J Clin Psychiatry 51 (1990): 385-6
  5. Rodriguez de la Torre B, Dreher J, Malevany I, et al. "Serum levels and cardiovascular effects of tricyclic antidepressants and selective serotonin reuptake inhibitors in depressed patients." Ther Drug Monit 23 (2001): 435-40
  6. Cerner Multum, Inc. "Australian Product Information." O 0
  7. Pacher P, Kecskemeti V "Cardiovascular side effects of new antidepressants and antipsychotics: new drugs, old concerns?" Curr Pharm Des 10 (2004): 2463-75
  8. Andrews C, Pinner G "Postural hypotension induced by paroxetine." BMJ 316 (1998): 595
View all 8 references

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Moderate

methyldopa food

Applies to: hydrochlorothiazide / methyldopa

ADJUST DOSING INTERVAL: The oral bioavailability and pharmacologic effects of methyldopa may be decreased during concurrent administration with iron-containing products. The proposed mechanism is chelation of methyldopa by the iron cation, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract. In one study, five hypertensive patients receiving chronic methyldopa therapy (250 mg to 1500 mg daily) all had elevated blood pressure following the addition of ferrous sulfate 325 mg three times daily for 2 weeks. The systolic pressure had increased by more than 15 mmHg in three of the patients and the diastolic pressure increased by more than 10 mmHg in two. Blood pressure returned to baseline within 7 days of discontinuing the iron. In 12 normal subjects, administration of methyldopa 500 mg with ferrous sulfate 325 mg or ferrous gluconate 600 mg resulted in an 88% and 79% reduction, respectively, in the renal excretion of unmetabolized, free methyldopa compared to administration of methyldopa alone. In another study, administration of ferrous sulfate simultaneously with methyldopa reduced the bioavailability of methyldopa by 83%, while administration one hour or two hours before methyldopa reduced its bioavailability by 55% and 42%, respectively.

MANAGEMENT: Until more information is available, patients receiving methyldopa in combination with iron-containing products should be advised to separate the times of administration by as much as possible. Patients should be monitored closely for altered hypertensive effect and methyldopa dosage increased as necessary. Selection of an alternative antihypertensive therapy may be necessary.

References

  1. Campbell N, Paddock V, Sundaram R "Alteration of methyldopa absorption, metabolism, and blood pressure control caused by ferrous sulfate and ferrous gluconate." Clin Pharmacol Ther 43 (1988): 381-6
  2. Campbell NR, Campbell RR, Hasinoff BB "Ferrous sulfate reduces methyldopa absorption: methyldopa: iron complex formation as a likely mechanism." Clin Invest Med 6 (1990): 329-32
  3. Campbell NR, Hasinoff BB "Iron supplements: a common cause of drug interactions." Br J Clin Pharmacol 31 (1991): 251-5

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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.

Further information

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

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