Drug Interactions between amphetamine / dextroamphetamine and hydroxypropyl chitosan / terbinafine topical
This report displays the potential drug interactions for the following 2 drugs:
- amphetamine/dextroamphetamine
- hydroxypropyl chitosan/terbinafine topical
Interactions between your drugs
amphetamine terbinafine
Applies to: amphetamine / dextroamphetamine and hydroxypropyl chitosan / terbinafine topical
MONITOR: Coadministration with terbinafine may increase the plasma concentrations of drugs that are substrates of the CYP450 2D6 isoenzyme. The mechanism is decreased clearance due to inhibition of CYP450 2D6 activity by terbinafine, which is expected to occur in patients who are CYP450 2D6 extensive metabolizers (approximately 93% of Caucasians and more than 98% of Asians and individuals of African descent). A case of nortriptyline (a CYP450 2D6 substrate) intoxication corresponding to significantly increased serum drug concentrations was reported in a patient shortly after the addition of terbinafine. Rechallenge in the patient produced similar results.
MANAGEMENT: Caution is advised if terbinafine must be used concurrently with medications that undergo metabolism by CYP450 2D6, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever terbinafine is added to or withdrawn from therapy. Due to the long elimination half-life of terbinafine, especially following prolonged use, such interactions may be observed for several months after discontinuation of terbinafine therapy.
References
- (2001) "Product Information. Lamisil (terbinafine)." Sandoz Pharmaceuticals Corporation
- Van der Kuy PH, Hooymans PM, Verkaaik AJ (1998) "Nortriptyline intoxication induced by terbinafine." BMJ, 316, p. 441
- AbdelRahman SM, Gotschall RR, Kauffman RE, Leeder JS, Kearns GL (1999) "Investigation of terbinafine as a CYP2D6 inhibitor in vivo." Clin Pharmacol Ther, 65, p. 465-72
- Gupta AK, Katz HI, Shear NH (2000) "Terbinafine and potential drug interactions - Reply." J Am Acad Dermatol, 43, p. 883-4
Drug and food interactions
amphetamine food
Applies to: amphetamine / dextroamphetamine
GENERALLY AVOID: Alcohol may potentiate the cardiovascular effects of amphetamines. The exact mechanism of interaction is unknown. 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. The interaction was suspected in a case report of a 20-year-old male who experienced retrosternal chest pain shortly after drinking alcohol and taking a double dose of his amphetamine/dextroamphetamine medication (Adderall 15 mg X 2) to stay alert. The patient had no family history of cardiovascular diseases, and his past medical history was remarkable only for ADHD. Prior to the episode, the patient had not taken his medication for weeks and had been drinking whiskey the previous three nights before going to bed. The patient was diagnosed with myocardial infarction likely secondary to amphetamine-induced coronary vasospasm.
MANAGEMENT: Concomitant use of amphetamines and alcohol should be avoided if possible, especially in patients with a history of heart disease.
References
- Mendelson J, Jones RT, Upton R, Jacob P 3rd (1995) "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther, 57, p. 559-68
- Jiao X, Velez S, Ringstad J, Eyma V, Miller D, Bleiberg M (2009) "Myocardial infarction associated with Adderall XR and alcohol use in a young man." J Am Board Fam Med, 22, p. 197-201
dextroamphetamine food
Applies to: amphetamine / dextroamphetamine
GENERALLY AVOID: Alcohol may potentiate the cardiovascular effects of amphetamines. The exact mechanism of interaction is unknown. 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. The interaction was suspected in a case report of a 20-year-old male who experienced retrosternal chest pain shortly after drinking alcohol and taking a double dose of his amphetamine/dextroamphetamine medication (Adderall 15 mg X 2) to stay alert. The patient had no family history of cardiovascular diseases, and his past medical history was remarkable only for ADHD. Prior to the episode, the patient had not taken his medication for weeks and had been drinking whiskey the previous three nights before going to bed. The patient was diagnosed with myocardial infarction likely secondary to amphetamine-induced coronary vasospasm.
MANAGEMENT: Concomitant use of amphetamines and alcohol should be avoided if possible, especially in patients with a history of heart disease.
References
- Mendelson J, Jones RT, Upton R, Jacob P 3rd (1995) "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther, 57, p. 559-68
- Jiao X, Velez S, Ringstad J, Eyma V, Miller D, Bleiberg M (2009) "Myocardial infarction associated with Adderall XR and alcohol use in a young man." J Am Board Fam Med, 22, p. 197-201
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.
See also
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. |
Further information
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