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Drug Interactions between benzphetamine and Uritact-EC

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

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Interactions between your drugs

Major

benzphetamine methylene blue

Applies to: benzphetamine and Uritact-EC (hyoscyamine / methenamine / methylene blue / phenyl salicylate)

CONTRAINDICATED: Centrally-acting sympathomimetic agents (i.e., CNS stimulants), particularly the amphetamines and amphetamine derivatives, may precipitate severe hypertensive reactions and hyperpyrexia in patients treated with monoamine oxidase inhibitors (MAOIs). Death has occurred in some reported cases. The mechanism involves a synergistic sympathomimetic effect due to enhanced norepinephrine storage in adrenergic neurons (MAOI activity) and increased liberation or decreased reuptake of catecholamines (central sympathomimetic activity). MAOIs also slow amphetamine metabolism, which may potentiate amphetamine effect on the release of norepinephrine and other monoamines from adrenergic nerve endings.

MANAGEMENT: In general, CNS stimulants should not be used concurrently with MAOIs or other agents that possess MAOI activity (e.g., furazolidone, linezolid, methylene blue, procarbazine). At least 14 days should elapse between discontinuation of MAOI therapy and initiation of treatment with CNS stimulants.

References

  1. Pettinger WA, Soyangco FG, Oates JA "Inhibition of monoamine oxidase in man by furazolidone." Clin Pharmacol Ther 9 (1968): 442-7
  2. Schulz R, Antonin KH, Hoffmann E, et al. "Tyramine kinetics and pressor sensitivity during monoamine oxidase inhibition by selegiline." Clin Pharmacol Ther 46 (1989): 528-36
  3. Krisko I, Lewis E, Johnson JE "Severe hyperpyrexia due to tranylcypromine-amphetamine toxicity." Ann Intern Med 70 (1969): 559-64
  4. Elis J, Laurence DR, Mattie H, Prichard BN "Modification by monoamine oxidase inhibitors of the effect of some sympathomimetics on blood pressure." Br Med J 2 (1967): 75-8
  5. Goldberg LI "Monoamine oxidase inhibitors: adverse reactions and possible mechanisms." JAMA 190 (1964): 456-62
  6. Sjoqvist F "Psychotropic drugs (2) interaction between monoamine oxidase (MAO) inhibitors and other substances." Proc R Soc Med 58 (1965): 967-78
  7. Harrison WM, McGrath PJ, Stewart JW, Quitkin F "MAOIs and hypertensive crises: the role of OTC drugs." J Clin Psychiatry 50 (1989): 64-5
  8. Wright SP "Hazards with monoamine-oxidase inhibitors: a persistent problem." Lancet 1 (1978): 284-5
  9. Boakes AJ, Laurence DR, Teoh PC, Barar FS, Benedikter LT, Pritchard BN "Interactions between sympathomimetic amines and antidepressant agents in man." Br Med J 1 (1973): 311-5
  10. Dally PJ "Fatal reaction associated with tranylcypromine and methylamphetamine." Lancet 1 (1962): 1235-6
  11. Schildkraut JJ, Klerman GL, Friend DG, Greenblatt M "Biochemical and pressor effects of oral d,l-dihydroxyphenylalanine in patients pretreated with antidepressant drugs." Ann N Y Acad Sci 107 (1963): 1005-15
  12. Smookler S, Bermudez AJ "Hypertensive crisis resulting from an MAO inhibitor and an over-the-counter appetite suppressant." Ann Intern Med 11 (1982): 482-4
  13. Ban TA "Drug interactions with psychoactive drugs." Dis Nerv Syst 36 (1975): 164-6
  14. Darcy PF, Griffin JP "Interactions with drugs used in the treatment of depressive illness." Adverse Drug React Toxicol Rev 14 (1995): 211-31
  15. De Vita VT, Hahn MA, Oliverio VT "Monoamine oxidase inhibition by a new carcinostatic agent, n-isopropyl-a-(2-methylhydrazino)-p-toluamide (MIH). (30590)." Proc Soc Exp Biol Med 120 (1965): 561-5
  16. "Product Information. Ritalin (methylphenidate)." Novartis Pharmaceuticals PROD (2001):
  17. "Product Information. Dexedrine (dextroamphetamine)." SmithKline Beecham PROD (2001):
  18. "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc PROD (2001):
  19. Markowitz JS, Patrick KS "Pharmacokinetic and pharmacodynamic drug interactions in the treatment of attention-deficit hyperactivity disorder." Clin Pharmacokinet 40 (2001): 753-72
  20. "Product Information. Focalin (dexmethylphenidate)." Mikart Inc (2001):
  21. "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company (2002):
  22. "Product Information. Vyvanse (lisdexamfetamine)." Shire US Inc (2007):
View all 22 references

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Moderate

methenamine benzphetamine

Applies to: Uritact-EC (hyoscyamine / methenamine / methylene blue / phenyl salicylate) and benzphetamine

MONITOR: Urinary acidifying agents such as ammonium chloride, sodium acid phosphate, and methenamine salts may lower the blood levels and efficacy of amphetamines. Acidifying the urine has been reported to increase the concentration of the ionized species of the amphetamine molecule, thereby inhibiting renal tubular absorption and increasing its urinary excretion. In one study, approximately 55% of an amphetamine dose was excreted unchanged when the urine was acidic, versus less than 3% when the urine was alkaline. Amphetamine half-life has also been reported to shorten by one-half or more when urine is acidic rather than alkaline. Acidification of the urine has been employed successfully in the treatment of amphetamine overdose.

MANAGEMENT: Patients receiving an amphetamine in combination with urinary acidifying agents should be monitored for potentially diminished pharmacologic response to the amphetamine.

References

  1. Anggard E, Jonsson LE, Hogmark AL, Gunne LM "Amphetamine metabolism in amphetamine psychosis." Clin Pharmacol Ther 14 (1973): 870-80
  2. Davis JM, Kopin IJ, Lemberger L, Axelrod J "Effects of urinary pH on amphetamine metabolism." Ann N Y Acad Sci 179 (1971): 493-501
  3. Beckett AH, Salmon JA, Mitchard M "The relation between blood levels and urinary excretion of amphetamine under controlled acidic and under fluctuating urinary pH values using [C]amphetamine." J Pharm Pharmacol 21 (1969): 251-8
  4. Wilkinson GR, Beckett AH "Absorption, metabolism and excretion of the ephedrines in man. I. The influence of urinary pH and urine volume output." J Pharmacol Exp Ther 162 (1968): 139-47
  5. Beckett AH, Rowland M "Urinary excretion kinetics of amphetamine in man." J Pharm Pharmacol 17 (1965): 628-39
  6. Beckett AH, Rowland M, Turner P "Influence of urinary pH on excretion of amphetamine." Lancet 1 (1965): 303
  7. Beckett AH, Rowland M "Urinary excretion kinetics of methylamphetamine in man." J Pharm Pharmacol 17 (1965): s109-14
  8. Gary NE, Saidi P "Methamphetamine intoxication. A speedy new treatment." Am J Med 64 (1978): 537-40
  9. "Product Information. Dexedrine (dextroamphetamine)." SmithKline Beecham PROD (2001):
View all 9 references

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Drug and food interactions

Moderate

benzphetamine food

Applies to: benzphetamine

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

hyoscyamine food

Applies to: Uritact-EC (hyoscyamine / methenamine / methylene blue / phenyl salicylate)

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References

  1. Linnoila M "Drug effects on psychomotor skills related to driving: interaction of atropine, glycopyrrhonium and alcohol." Eur J Clin Pharmacol 6 (1973): 107-12

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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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