Drug Interaction Report
10 potential interactions and/or warnings found for the following 2 drugs:
- Obezine (phendimetrazine)
- Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
Interactions between your drugs
phenylpropanolamine phendimetrazine
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine), Obezine (phendimetrazine)
CONTRAINDICATED: The efficacy of centrally-acting appetite suppressants in combination with other anorectic agents has not been studied, but available data suggest that combined use may have the potential for serious cardiac problems. In a case-control epidemiological study, the use of anorectic agents was associated with an increased risk of pulmonary hypertension, a rare but often fatal disorder, and use for longer than three months was associated with a 23-fold increase in risk. Increased risk of pulmonary hypertension with repeated courses of therapy cannot be excluded. The use of some anorectic agents such as fenfluramine and dexfenfluramine has been associated with valvular heart disease. Possible contributing factors include use for extended periods of time, higher than recommended dosages, and/or use in combination with other anorectic drugs.
MANAGEMENT: Centrally--acting appetite suppressants should not be used in combination with other anorectic agents, including prescription, over-the-counter, and herbal preparations. In addition, they are not recommended for patients who have used any anorectic agents within the prior year. The potential risk of possible serious adverse effects such as valvular heart disease and pulmonary hypertension should be assessed carefully against the benefit of weight loss, and baseline cardiac evaluation should be considered to detect preexisting valvular heart diseases or pulmonary hypertension prior to initiating treatment. These agents are not recommended for use in patients with known heart murmur or valvular heart disease, severe hypertension, or symptomatic cardiovascular disease including arrhythmias. Patients should be advised to immediately discontinue the medication and contact their physician if they experience potential signs and symptoms of pulmonary hypertension such as new onset or aggravation of exertional dyspnea, chest pain or tightness, syncope, and lower extremity edema.
References
- (2001) "Product Information. Meridia (sibutramine)." Knoll Pharmaceutical Company
- (2001) "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn
- (2012) "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals
- (2012) "Product Information. Diethylpropion Hydrochloride SR (diethylpropion)." Watson Pharmaceuticals
- (2012) "Product Information. Phendimetrazine Tartrate SR (phendimetrazine)." Sandoz Inc
pyrilamine pheniramine
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine), Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
MONITOR: Agents with anticholinergic properties (e.g., sedating antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; disopyramide) may have additive effects when used in combination. Excessive parasympatholytic effects may result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. Central nervous system-depressant effects may also be additively or synergistically increased when these agents are combined, especially in elderly or debilitated patients. Use of neuroleptics in combination with other neuroleptics or anticholinergic agents may increase the risk of tardive dyskinesia. In addition, some neuroleptics and tricyclic antidepressants may cause prolongation of the QT interval and theoretically, concurrent use of two or more drugs that can cause QT interval prolongation may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death.
MANAGEMENT: Caution is advised when agents with anticholinergic properties are combined, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Patients should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and/or hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A reduction in anticholinergic dosages may be necessary if excessive adverse effects develop.
References
- Stadnyk AN, Glezos JD (1983) "Drug-induced heat stroke." Can Med Assoc J, 128, p. 957-9
- Zelman S, Guillan R (1970) "Heat stroke in phenothiazine-treated patients: a report of three fatalities." Am J Psychiatry, 126, p. 1787-90
- Mann SC, Boger WP (1978) "Psychotropic drugs, summer heat and humidity, and hyperplexia: a danger restated." Am J Psychiatry, 135, p. 1097-100
- Warnes H, Lehmann HE, Ban TA (1967) "Adynamic ileus during psychoactive medication: a report of three fatal and five severe cases." Can Med Assoc J, 96, p. 1112-3
- Gershon S, Neubauer H, Sundland DM (1965) "Interaction between some anticholinergic agents and phenothiazines." Clin Pharmacol Ther, 6, p. 749-56
- Sarnquist F, Larson CP Jr (1973) "Drug-induced heat stroke." Anesthesiology, 39, p. 348-50
- Johnson AL, Hollister LE, Berger PA (1981) "The anticholinergic intoxication syndrome: diagnosis and treatment." J Clin Psychiatry, 42, p. 313-7
- Lee BS (1986) "Possibility of hyperpyrexia with antipsychotic and anticholinergic drugs." J Clin Psychiatry, 47, p. 571
- Forester D (1978) "Fatal drug-induced heat stroke." JACEP, 7, p. 243-4
- Moreau A, Jones BD, Banno V (1986) "Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia." Can J Psychiatry, 31, p. 339-41
- Hvizdos AJ, Bennett JA, Wells BG, Rappaport KB, Mendel SA (1983) "Anticholinergic psychosis in a patient receiving usual doses of haloperidol." Clin Pharm, 2, p. 174-8
- Cohen MA, Alfonso CA, Mosquera M (1994) "Development of urinary retention during treatment with clozapine and meclizine [published erratum appears in Am J Psychiatry 1994 Jun;151(6):952]." Am J Psychiatry, 151, p. 619-20
- (2001) "Product Information. Cogentin (benztropine)." Merck & Co., Inc
- Kulik AV, Wilbur R (1982) "Delirium and stereotypy from anticholinergic antiparkinson drugs." Prog Neuropsychopharmacol Biol Psychiatry, 6, p. 75-82
- (2001) "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories
pyrilamine phenyltoloxamine
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine), Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
MONITOR: Agents with anticholinergic properties (e.g., sedating antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; disopyramide) may have additive effects when used in combination. Excessive parasympatholytic effects may result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. Central nervous system-depressant effects may also be additively or synergistically increased when these agents are combined, especially in elderly or debilitated patients. Use of neuroleptics in combination with other neuroleptics or anticholinergic agents may increase the risk of tardive dyskinesia. In addition, some neuroleptics and tricyclic antidepressants may cause prolongation of the QT interval and theoretically, concurrent use of two or more drugs that can cause QT interval prolongation may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death.
MANAGEMENT: Caution is advised when agents with anticholinergic properties are combined, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Patients should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and/or hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A reduction in anticholinergic dosages may be necessary if excessive adverse effects develop.
References
- Stadnyk AN, Glezos JD (1983) "Drug-induced heat stroke." Can Med Assoc J, 128, p. 957-9
- Zelman S, Guillan R (1970) "Heat stroke in phenothiazine-treated patients: a report of three fatalities." Am J Psychiatry, 126, p. 1787-90
- Mann SC, Boger WP (1978) "Psychotropic drugs, summer heat and humidity, and hyperplexia: a danger restated." Am J Psychiatry, 135, p. 1097-100
- Warnes H, Lehmann HE, Ban TA (1967) "Adynamic ileus during psychoactive medication: a report of three fatal and five severe cases." Can Med Assoc J, 96, p. 1112-3
- Gershon S, Neubauer H, Sundland DM (1965) "Interaction between some anticholinergic agents and phenothiazines." Clin Pharmacol Ther, 6, p. 749-56
- Sarnquist F, Larson CP Jr (1973) "Drug-induced heat stroke." Anesthesiology, 39, p. 348-50
- Johnson AL, Hollister LE, Berger PA (1981) "The anticholinergic intoxication syndrome: diagnosis and treatment." J Clin Psychiatry, 42, p. 313-7
- Lee BS (1986) "Possibility of hyperpyrexia with antipsychotic and anticholinergic drugs." J Clin Psychiatry, 47, p. 571
- Forester D (1978) "Fatal drug-induced heat stroke." JACEP, 7, p. 243-4
- Moreau A, Jones BD, Banno V (1986) "Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia." Can J Psychiatry, 31, p. 339-41
- Hvizdos AJ, Bennett JA, Wells BG, Rappaport KB, Mendel SA (1983) "Anticholinergic psychosis in a patient receiving usual doses of haloperidol." Clin Pharm, 2, p. 174-8
- Cohen MA, Alfonso CA, Mosquera M (1994) "Development of urinary retention during treatment with clozapine and meclizine [published erratum appears in Am J Psychiatry 1994 Jun;151(6):952]." Am J Psychiatry, 151, p. 619-20
- (2001) "Product Information. Cogentin (benztropine)." Merck & Co., Inc
- Kulik AV, Wilbur R (1982) "Delirium and stereotypy from anticholinergic antiparkinson drugs." Prog Neuropsychopharmacol Biol Psychiatry, 6, p. 75-82
- (2001) "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories
pheniramine phenyltoloxamine
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine), Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
MONITOR: Agents with anticholinergic properties (e.g., sedating antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; disopyramide) may have additive effects when used in combination. Excessive parasympatholytic effects may result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. Central nervous system-depressant effects may also be additively or synergistically increased when these agents are combined, especially in elderly or debilitated patients. Use of neuroleptics in combination with other neuroleptics or anticholinergic agents may increase the risk of tardive dyskinesia. In addition, some neuroleptics and tricyclic antidepressants may cause prolongation of the QT interval and theoretically, concurrent use of two or more drugs that can cause QT interval prolongation may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death.
MANAGEMENT: Caution is advised when agents with anticholinergic properties are combined, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Patients should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and/or hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A reduction in anticholinergic dosages may be necessary if excessive adverse effects develop.
References
- Stadnyk AN, Glezos JD (1983) "Drug-induced heat stroke." Can Med Assoc J, 128, p. 957-9
- Zelman S, Guillan R (1970) "Heat stroke in phenothiazine-treated patients: a report of three fatalities." Am J Psychiatry, 126, p. 1787-90
- Mann SC, Boger WP (1978) "Psychotropic drugs, summer heat and humidity, and hyperplexia: a danger restated." Am J Psychiatry, 135, p. 1097-100
- Warnes H, Lehmann HE, Ban TA (1967) "Adynamic ileus during psychoactive medication: a report of three fatal and five severe cases." Can Med Assoc J, 96, p. 1112-3
- Gershon S, Neubauer H, Sundland DM (1965) "Interaction between some anticholinergic agents and phenothiazines." Clin Pharmacol Ther, 6, p. 749-56
- Sarnquist F, Larson CP Jr (1973) "Drug-induced heat stroke." Anesthesiology, 39, p. 348-50
- Johnson AL, Hollister LE, Berger PA (1981) "The anticholinergic intoxication syndrome: diagnosis and treatment." J Clin Psychiatry, 42, p. 313-7
- Lee BS (1986) "Possibility of hyperpyrexia with antipsychotic and anticholinergic drugs." J Clin Psychiatry, 47, p. 571
- Forester D (1978) "Fatal drug-induced heat stroke." JACEP, 7, p. 243-4
- Moreau A, Jones BD, Banno V (1986) "Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia." Can J Psychiatry, 31, p. 339-41
- Hvizdos AJ, Bennett JA, Wells BG, Rappaport KB, Mendel SA (1983) "Anticholinergic psychosis in a patient receiving usual doses of haloperidol." Clin Pharm, 2, p. 174-8
- Cohen MA, Alfonso CA, Mosquera M (1994) "Development of urinary retention during treatment with clozapine and meclizine [published erratum appears in Am J Psychiatry 1994 Jun;151(6):952]." Am J Psychiatry, 151, p. 619-20
- (2001) "Product Information. Cogentin (benztropine)." Merck & Co., Inc
- Kulik AV, Wilbur R (1982) "Delirium and stereotypy from anticholinergic antiparkinson drugs." Prog Neuropsychopharmacol Biol Psychiatry, 6, p. 75-82
- (2001) "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories
Drug and food interactions
phenylpropanolamine food
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
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
- Mendelson J, Jones RT, Upton R, Jacob P 3rd (1995) "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther, 57, p. 559-68
- (2001) "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn
- (2012) "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals
pyrilamine food
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled 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
- Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
- (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
- (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc
phendimetrazine food
Applies to: Obezine (phendimetrazine)
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
- Mendelson J, Jones RT, Upton R, Jacob P 3rd (1995) "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther, 57, p. 559-68
- (2001) "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn
- (2012) "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals
pheniramine food
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled 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
- Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
- (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
- (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc
phenyltoloxamine food
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled 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
- Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
- (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
- (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc
phenylpropanolamine food
Applies to: Trihist-D (pheniramine / phenylpropanolamine / phenyltoloxamine / pyrilamine)
MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.
References
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
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.
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
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