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Drug Interactions between Phentride and Unipres

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

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Interactions between your drugs

Moderate

hydrALAZINE hydroCHLOROthiazide

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine) and Unipres (hydralazine / hydrochlorothiazide / reserpine)

MONITOR: Concomitant treatment with other antihypertensive agents or vasodilators, including alpha-adrenoreceptor antagonists, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta-adrenergic blockers, calcium channel blockers, diuretics and nitrates, may potentiate the hypotensive effects of hydralazine and dihydralazine.

MANAGEMENT: Blood pressure and heart rate should be closely monitored when hydralazine or dihydralazine is used with other agents that can induce hypotension.

References

  1. "Product Information. Apresoline (hydralazine)." Sterimax Inc (2022):
  2. "Product Information. Hydralazine (hydralazine)." Advanz Pharma (2022):

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Moderate

hydrALAZINE reserpine

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine) and Unipres (hydralazine / hydrochlorothiazide / reserpine)

MONITOR: Concomitant treatment with other antihypertensive agents or vasodilators, including alpha-adrenoreceptor antagonists, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta-adrenergic blockers, calcium channel blockers, diuretics and nitrates, may potentiate the hypotensive effects of hydralazine and dihydralazine.

MANAGEMENT: Blood pressure and heart rate should be closely monitored when hydralazine or dihydralazine is used with other agents that can induce hypotension.

References

  1. "Product Information. Apresoline (hydralazine)." Sterimax Inc (2022):
  2. "Product Information. Hydralazine (hydralazine)." Advanz Pharma (2022):

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Moderate

hydroCHLOROthiazide reserpine

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine) and Unipres (hydralazine / hydrochlorothiazide / reserpine)

MONITOR: The hypotensive effects of thiazide diuretics and alpha-adrenergic blockers may be additive. Postural hypotension may occur.

MANAGEMENT: Hemodynamic responses should be monitored during coadministration, especially during the first few weeks of therapy. Patients should be advised to take the alpha-blocker at bedtime and to notify their physician if they experience dizziness or syncope while awake.

References

  1. Achari R, Laddu A "Terazosin: a new alpha adrenoceptor blocking drug." J Clin Pharmacol 32 (1992): 520-3
  2. Kuokkanen K, Mattila MJ "Demonstration of an additive antihypertensive effect of prazosin and polythiazide in out-patient." Curr Ther Res Clin Exp 17 (1975): 431-6
  3. Pool JL "Combination antihypertensive therapy with terazosin and other antihypertensive agents: results of clinical trials." Am Heart J 122 (1991): 926-31
  4. Cohen J "Long-term efficacy and safety of terazosin alone and in combination with other antihypertensive agents." Am Heart J 122 (1991): 919-25
  5. "Product Information. Xatral (alfuzosin)." Sanofi-Synthelabo Canada Inc (2002):
View all 5 references

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Moderate

reserpine phentermine

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine) and Phentride (phentermine)

MONITOR: Central nervous system (CNS) stimulants, particularly the amphetamines, may decrease the hypotensive effect of postganglionic adrenergic blocking agents such as guanadrel, guanethidine and rauwolfia alkaloids, which work by depleting catecholamine stores from adrenergic nerve endings. CNS stimulants can have peripheral sympathetic activity, thus they may elevate blood pressure on their own as well as antagonize some of the antiadrenergic effect produced by these hypotensive agents. Amphetamines reportedly also may displace the blocking agent, guanethidine, and inhibit its uptake by adrenergic neurons. Other mechanisms have also been proposed. In addition to diminished hypotensive response, the interaction has also been reported to produce hypotension and ventricular tachycardia in a patient stabilized on guanethidine shortly after initiating treatment with methylphenidate.

MANAGEMENT: Alternatives to postganglionic adrenergic blocking agents should be considered in hypertensive patients treated with CNS stimulants. If the combination is used, blood pressure and heart rate should be monitored.

References

  1. Ober KF, Wang RI "Drug interactions with guanethidine." Clin Pharmacol Ther 14 (1973): 190-5
  2. Sherman GP, Walton CA "Adrenergic transmission and drug interaction." J Am Pharm Assoc 15 (1975): 86-90
  3. Flegin OT, Morgan DH, Oates JA, Shand DG, Turner P "The mechanism of the reversal of the effect of guanethidine by amphetamines in cat and man." Br J Pharmacol 39 (1970): p253
  4. Follenfant MJ, Robson RD "The antagonism of adrenergic neurone blockade by amphetamine and dexamphetamine in the rat and guinea-pig." Br J Pharmacol 38 (1970): 792
  5. Gerkens JF, McCulloch MW, Wilson J "Mechanism of the antagonism between guanethidine and dexamphetamine." Br J Pharmacol 35 (1969): 563-72
  6. Gulati OD, Dave BT, Gokhale SD, Shah KM "Antagonism of adrenergic neuron blockade in hypertensive subjects." Clin Pharmacol Ther 7 (1966): 510-4
  7. Obianwu HO "Some studies on the mechanism by which d-amphetamine antagonizes guanethidine induced adrenergic neurone blockade." Acta Physiol Scand 75 (1969): 102-10
  8. Deshmankar BS, Leewis JA "Ventricular tachycardia associated with the administration of methylphenidate during guanethidine therapy." Can Med Assoc J 97 (1967): 1166-71
View all 8 references

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Drug and food interactions

Moderate

phentermine food

Applies to: Phentride (phentermine)

GENERALLY AVOID: Alcohol may potentiate the central nervous system and cardiovascular effects of centrally-acting appetite suppressants. In one study, concurrent administration of methamphetamine (30 mg intravenously) and ethanol (1 gm/kg orally over 30 minutes) increased heart rate by 24 beats/minute compared to methamphetamine alone. This increases cardiac work and myocardial oxygen consumption, which may lead to more adverse cardiovascular effects than either agent alone. Subjective effects of ethanol were diminished in the eight study subjects, but those of methamphetamine were not affected. The pharmacokinetics of methamphetamine were also unaffected except for a decrease in the apparent volume of distribution at steady state.

MANAGEMENT: Concomitant use of centrally-acting appetite suppressants and alcohol should be avoided if possible, especially in patients with a history of cardiovascular disease. Patients should be counselled 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. Mendelson J, Jones RT, Upton R, Jacob P 3rd "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther 57 (1995): 559-68
  2. "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn PROD (2001):
  3. "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals (2012):

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Moderate

hydrALAZINE food

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine)

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

hydroCHLOROthiazide food

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine)

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

reserpine food

Applies to: Unipres (hydralazine / hydrochlorothiazide / reserpine)

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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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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