Drug Interaction Report
5 potential interactions and/or warnings found for the following 2 drugs:
- acetaminophen / caffeine
- deferasirox
Interactions between your drugs
acetaminophen deferasirox
Applies to: acetaminophen / caffeine, deferasirox
MONITOR: Coadministration with deferasirox may increase the plasma concentrations of drugs that are substrates of the CYP450 1A2 isoenzyme. The mechanism is decreased clearance due to inhibition of CYP450 1A2 activity by deferasirox. In a study of healthy volunteers, administration of the CYP450 1A2 substrate theophylline (120 mg single dose) in combination with deferasirox (repeated dosing of 30 mg/kg/day) resulted in an approximate doubling of theophylline systemic exposure (AUC) and elimination half-life.
MANAGEMENT: Caution is advised if deferasirox must be used concurrently with medications that undergo metabolism by CYP450 1A2, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever deferasirox is added to or withdrawn from therapy.
References
- (2005) "Product Information. Exjade (deferasirox)." Novartis Pharmaceuticals
caffeine deferasirox
Applies to: acetaminophen / caffeine, deferasirox
MONITOR: Coadministration with deferasirox may increase the plasma concentrations of drugs that are substrates of the CYP450 1A2 isoenzyme. The mechanism is decreased clearance due to inhibition of CYP450 1A2 activity by deferasirox. In a study of healthy volunteers, administration of the CYP450 1A2 substrate theophylline (120 mg single dose) in combination with deferasirox (repeated dosing of 30 mg/kg/day) resulted in an approximate doubling of theophylline systemic exposure (AUC) and elimination half-life.
MANAGEMENT: Caution is advised if deferasirox must be used concurrently with medications that undergo metabolism by CYP450 1A2, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever deferasirox is added to or withdrawn from therapy.
References
- (2005) "Product Information. Exjade (deferasirox)." Novartis Pharmaceuticals
Drug and food interactions
acetaminophen food
Applies to: acetaminophen / caffeine
GENERALLY AVOID: Chronic, excessive consumption of alcohol may increase the risk of acetaminophen-induced hepatotoxicity, which has included rare cases of fatal hepatitis and frank hepatic failure requiring liver transplantation. The proposed mechanism is induction of hepatic microsomal enzymes during chronic alcohol use, which may result in accelerated metabolism of acetaminophen and increased production of potentially hepatotoxic metabolites.
MANAGEMENT: In general, chronic alcoholics should avoid regular or excessive use of acetaminophen. Alternative analgesic/antipyretic therapy may be appropriate in patients who consume three or more alcoholic drinks per day. However, if acetaminophen is used, these patients should be cautioned not to exceed the recommended dosage (maximum 4 g/day in adults and children 12 years of age or older).
References
- Kaysen GA, Pond SM, Roper MH, Menke DJ, Marrama MA (1985) "Combined hepatic and renal injury in alcoholics during therapeutic use of acetaminophen." Arch Intern Med, 145, p. 2019-23
- O'Dell JR, Zetterman RK, Burnett DA (1986) "Centrilobular hepatic fibrosis following acetaminophen-induced hepatic necrosis in an alcoholic." JAMA, 255, p. 2636-7
- Seeff LB, Cuccherini BA, Zimmerman HJ, Adler E, Benjamin SB (1986) "Acetaminophen hepatotoxicity in alcoholics." Ann Intern Med, 104, p. 399-404
- Thummel KE, Slattery JT, Nelson SD (1988) "Mechanism by which ethanol diminishes the hepatotoxicity of acetaminophen." J Pharmacol Exp Ther, 245, p. 129-36
- McClain CJ, Kromhout JP, Peterson FJ, Holtzman JL (1980) "Potentiation of acetaminophen hepatotoxicity by alcohol." JAMA, 244, p. 251-3
- Kartsonis A, Reddy KR, Schiff ER (1986) "Alcohol, acetaminophen, and hepatic necrosis." Ann Intern Med, 105, p. 138-9
- Prescott LF, Critchley JA (1983) "Drug interactions affecting analgesic toxicity." Am J Med, 75, p. 113-6
- (2002) "Product Information. Tylenol (acetaminophen)." McNeil Pharmaceutical
- Whitcomb DC, Block GD (1994) "Association of acetaminopphen hepatotoxicity with fasting and ethanol use." JAMA, 272, p. 1845-50
- Bonkovsky HL (1995) "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA, 274, p. 301
- Nelson EB, Temple AR (1995) "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA, 274, p. 301
- Zimmerman HJ, Maddrey WC (1995) "Acetaminophen (paracetamol) hepatotoxicity with regular intake of alcohol: analysis of instances of therapeutic misadventure." Hepatology, 22, p. 767-73
deferasirox food
Applies to: deferasirox
ADJUST DOSING INTERVAL: According to product labeling, the bioavailability of deferasirox was variably increased when taken with a meal.
MANAGEMENT: To ensure consistent plasma drug levels, deferasirox should be taken on an empty stomach 30 minutes before eating preferably at the same time everyday.
References
- (2005) "Product Information. Exjade (deferasirox)." Novartis Pharmaceuticals
caffeine food
Applies to: acetaminophen / caffeine
The effect of grapefruit juice on the pharmacologic activity of caffeine is controversial. One report suggests that grapefruit juice increases the effect of caffeine. The proposed mechanism is inhibition of cytochrome P-450 metabolism of caffeine. However, a well-conducted pharmacokinetic/pharmacodynamic study did not demonstrate this effect. The clinical significance of this potential interaction is unknown.
References
- (1995) "Grapefruit juice interactions with drugs." Med Lett Drugs Ther, 37, p. 73-4
- Maish WA, Hampton EM, Whitsett TL, Shepard JD, Lovallo WR (1996) "Influence of grapefruit juice on caffeine pharmacokinetics and pharmacodynamics." Pharmacotherapy, 16, p. 1046-52
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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